KR102674022B1 - Chip Package and Apparatus of MEMS Gas Sensor to provide Variable Output Voltage - Google Patents

Abstract

The present invention is a MEMS gas sensor device capable of supplying a variable output voltage, comprising: a MEMS gas detection unit provided on a printed circuit board; A signal processing unit spaced apart from the MEMS gas detection unit and electrically connected to the printed circuit board; and a chip cover having a gas injection hole formed on one side and provided on a printed circuit board to surround the MEMS gas detection unit and the signal processing unit in a spaced apart state, wherein the signal processing unit applies a variable voltage to the MEMS gas detection unit. It has a variable output voltage charge pump unit that supplies, and the MEMS gas detection unit includes a compensation element having a micro heater; and a micro heater, including a detection element with a sensing material formed on the micro heater, and in a semi-finished product state before the chip package is combined with the finished gas sensor product, the operation and performance of the detection element according to the preset reaction gas can be checked. It can be provided so that

Description

MEMS gas sensor chip package and MEMS gas sensor device capable of supplying variable output voltage {Chip Package and Apparatus of MEMS Gas Sensor to provide Variable Output Voltage}

The present invention relates to a MEMS gas sensor chip package and a MEMS gas sensor device. Specifically, it relates to a MEMS gas sensor chip package and MEMS gas sensor device capable of supplying variable output voltage.

A gas sensor is a sensor that measures the concentration of a specific gas. The method of measuring the concentration of a specific gas is an electrochemical method that measures the change in the electrical conductivity of a thin film due to an electrochemical reaction, and an optical method (NDIR, Non-Non-Dirty Method) that measures the gas concentration by examining the characteristic absorption line and measuring the amount of absorbed light. -dispersive Infra-Red).

Here, the electrochemical method is low-cost and can be miniaturized, but has the disadvantage of low reliability as it changes significantly depending on temperature and humidity. The optical method consists of an infrared irradiation unit, a sensor unit, and a waveguide unit, and is large in size. It takes a long time to measure and consumes a lot of power, making it difficult to implement a gas sensor that is inexpensive and can implement rapid measurement.

The present invention is a chemical (gas) sensor related to electrochemical method.

Uniform temperature distribution is very important in chemical sensor operation. Thermal uniformity is a factor that increases the sensitivity and selectivity of the sensor. Additionally, a micro heater is required for reproducibility.

Heater structural design is important to obtain uniform temperature distribution, and research has been conducted on various heater structural designs. Even if the heater design is excellent, supplying a constant voltage corresponding to the design is very important.

Conventional chemical sensors have been developed in the form of a microheater, a MEMS gas detection chip consisting of a compensation element formed of electrodes and a detection element, and a PCB circuit board including a signal processing chip, and housing.

It cannot be packaged with other semiconductor chips, is sensitive to moisture, shock, and heat dissipation from the PCB board, and must be protected with filtering and a housing that acts as an unstable chamber to collect gas.

In addition, there were problems with the relatively high price and difficulty in mass production, such as the need for manual calibration or expensive automated equipment for each housing product. In addition, there is a difficulty in that it involves a lot of defective costs.

On the other hand, MEMS chemical (gas) sensor devices using semiconductor packaging technology are advantageous for miniaturization, can be mass-produced through a semiconductor process with uniform quality, and can be produced by adding a housing, so they can be applied to a variety of application products. there is.

Because semiconductor packaging is possible, active biasing can be provided to the sensing unit and micro heater. To provide this active biasing, a charge pump circuit may be used.

Since existing micro heaters for chemical (gas) sensors were designed to be limited to specific specifications, in order to apply them to MEMS sensors of various specifications, circuits that fit each specification had to be individually designed.

In addition, there was a problem that the circuit had to be redesigned when the design specifications, such as the structure of the micro heater and the size of the electrode and detection unit, were changed.

However, redesigning the voltage supply circuit (charge pump) for each MEMS sensor specification has the problem of increasing development and manufacturing costs and causing inefficiencies, such as changing the process and layout accordingly.

If the supply voltage of the MEMS micro heater can be supplied variably, the micro heater design and process development period can be shortened. In addition, effects such as reducing process costs, making mass production easier, and reducing defect costs will occur.

(Document 1) Korean Patent Publication No. 10-1773954 (2017.08.28)

The MEMS gas sensor chip package and MEMS gas sensor device capable of supplying variable output voltage according to the present invention have the following problems to solve.

First, we want to variably supply the supply voltage of the MEMS micro heater.

Second, we want to variably control the heating temperature of the micro heater.

Third, we want to manufacture the gas detection unit in the form of a semi-finished product.

The problems to be solved by the present invention are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

The present invention is a MEMS gas sensor chip package capable of supplying a variable output voltage, comprising: a MEMS gas detection unit provided on a printed circuit board; A signal processing unit spaced apart from the MEMS gas detection unit and electrically connected to the printed circuit board; and a chip cover having a gas injection hole formed on one side and provided on a printed circuit board to surround the MEMS gas detection unit and the signal processing unit in a spaced apart state, wherein the signal processing unit applies a variable voltage to the MEMS gas detection unit. It has a variable output voltage charge pump unit that supplies, and the MEMS gas detection unit includes a compensation element having a micro heater; and a micro heater, including a detection element with a sensing material formed on the micro heater, and in a semi-finished product state before the chip package is combined with the finished gas sensor product, the operation and performance of the detection element according to the preset reaction gas can be checked. It can be provided so that

The present invention is a MEMS gas sensor chip package capable of supplying a variable output voltage, comprising: a MEMS gas detection unit provided on a printed circuit board; A signal processing unit spaced apart from the MEMS gas detection unit and electrically connected to the printed circuit board; and a chip cover having a gas injection hole formed on one side and provided on a printed circuit board to surround the MEMS gas detection unit in a spaced state, wherein the signal processing unit provides a variable output for supplying a variable voltage to the MEMS gas detection unit. It has a voltage charge pump unit, and the MEMS gas detection unit includes a compensation element having a micro heater; and a micro heater, including a detection element with a sensing material formed on the micro heater, and in a semi-finished product state before the chip package is combined with the finished gas sensor product, the operation and performance of the detection element according to the preset reaction gas can be checked. It can be provided so that

In the present invention, the signal processing unit includes the variable output voltage charge pump unit; a detection signal detection unit that detects a potential difference value from a detection circuit and outputs a detection signal; and an output signal amplifier that amplifies the detection signal (Vs) and outputs it to the outside as a gas sensor output signal.

In the present invention, the variable output voltage charge pump unit can boost the power supply voltage according to a voltage selection signal and a reference voltage according to the characteristics of the compensation element and detection element of the MEMS gas detection unit and output the variable output voltage.

In the present invention, the variable output voltage charge pump unit is obtained by multiplying the variable output voltage of the charge pump by the distribution ratio n/N according to a voltage selection signal that specifies the distribution ratio n/N (a natural number of 1≤=n≤=N). A voltage level control unit that generates an oscillator control signal to be activated or deactivated according to the result of comparing the distribution voltage with the reference voltage; an oscillator that outputs a clock signal of a preset frequency when the oscillator control signal is activated; and a charge pump that outputs the variable output voltage by boosting the power supply voltage while the clock signal is applied from the oscillator.

In the present invention, the voltage level control unit includes a voltage divider that receives feedback from the variable output voltage of the charge pump and generates N distribution voltages distributed at preset voltage intervals; a voltage selector that selects an nth distribution voltage corresponding to a division ratio n/N among the N distribution voltages by the voltage selection signal and outputs the selected nth distribution voltage; and comparing the nth distribution voltage with the reference voltage, activating the operation of the oscillator when the nth distribution voltage is lower than the reference voltage, and deactivating the operation of the oscillator when the nth distribution voltage is higher than or equal to the reference voltage. It may include a comparator that generates a control signal.

In the present invention, the voltage selector selects the nth division voltage corresponding to the division ratio n/N of the voltage divider among the N division voltages output from each node of the N series-connected resistive elements or diodes. It can be selected by a voltage selection signal and operate to output the selected nth distribution voltage.

In the present invention, the charge pump may further include a low-pass filter for removing ripple components of the variable output voltage due to repeated activation and deactivation of the charge pump.

The present invention is a MEMS gas sensor device capable of supplying a variable output voltage, comprising: a first chip package according to the present invention; And a gas injection hole is formed on one side, and may include a housing cover provided on the printed circuit board to surround the first chip package in a spaced apart state.

The present invention is a MEMS gas sensor device capable of supplying a variable output voltage, comprising: a second chip package according to the present invention; And a gas injection hole is formed on one side, and may include a housing cover provided on the printed circuit board to surround the second chip package in a spaced apart state.

In the present invention, each gas injection hole may be provided with a thin film-type filter unit.

The present invention is a charge pump circuit capable of supplying a variable output voltage, and multiplies the variable output voltage of the charge pump by the distribution ratio n/N according to a voltage selection signal that specifies the distribution ratio n/N (a natural number with 1≤=n≤=N). a voltage level control unit that generates an oscillator control signal to activate or deactivate the distribution voltage obtained by comparing it with the reference voltage; an oscillator that outputs a clock signal of a preset frequency when the oscillator control signal is activated; and a charge pump that outputs the variable output voltage by boosting the power supply voltage while the clock signal is applied from the oscillator.

In the present invention, the voltage level control unit includes a voltage divider that receives feedback from the variable output voltage of the charge pump and generates N distribution voltages distributed at preset voltage intervals; a voltage selector that selects an nth distribution voltage corresponding to a division ratio n/N among the N distribution voltages by the voltage selection signal and outputs the selected nth distribution voltage; and comparing the nth distribution voltage with the reference voltage, activating the operation of the oscillator when the nth distribution voltage is lower than the reference voltage, and deactivating the operation of the oscillator when the nth distribution voltage is higher than or equal to the reference voltage. It may include a comparator that generates a control signal.

In the present invention, the voltage selector selects the nth division voltage corresponding to the division ratio n/N of the voltage divider among the N division voltages output from each node of the N series-connected resistive elements or diodes. It can be selected by a voltage selection signal and operate to output the selected nth distribution voltage.

In the present invention, the charge pump may further include a low-pass filter for removing ripple components of the variable output voltage due to repeated activation and deactivation of the charge pump.

The present invention is a method of driving a variable output voltage charge pump device including a voltage level control unit, an oscillator, and a charge pump, wherein the voltage level control unit selects a voltage that specifies the distribution ratio n/N (a natural number with 1≤=n≤=N). S100 step of generating an oscillator control signal to be activated or deactivated according to the result of comparing the distribution voltage obtained by multiplying the variable output voltage of the charge pump by the distribution ratio n/N according to the signal with the reference voltage; Step S200 in which the oscillator outputs a clock signal of a preset frequency when the oscillator control signal is activated; And it may include a step S300 in which the charge pump outputs the variable output voltage by boosting the power supply voltage while the clock signal is applied from the oscillator.

In the present invention, step S100 includes step S110 in which a voltage divider receives feedback from the variable output voltage of the charge pump and generates N distribution voltages distributed at preset voltage intervals; Step S120 in which a voltage selector selects an nth distribution voltage corresponding to a division ratio n/N among the N distribution voltages by the voltage selection signal, and outputs the selected nth distribution voltage; And a comparator compares the nth division voltage and the reference voltage, so that if the nth division voltage is lower than the reference voltage, the operation of the oscillator is activated, and if the nth division voltage is higher than or equal to the reference voltage, the operation of the oscillator is deactivated, It may include step S130 of generating the oscillator control signal.

In the present invention, in step S110, the voltage divider divides the nth distribution corresponding to the division ratio n/N of the voltage divider among the N distribution voltages output from each node of the N series-connected resistive elements or diodes. The voltage may be selected using the voltage selection signal, and the selected nth distribution voltage may be output.

In the present invention, in step S300, the charge pump may further include a low-pass filter to remove a ripple component of the variable output voltage due to repeated activation and deactivation of the charge pump.

The MEMS gas sensor chip package and MEMS gas sensor device capable of supplying variable output voltage according to the present invention have the following effects.

First, there is an effect of variably supplying the supply voltage of the MEMS micro heater by using a variable output voltage charge pump.

Second, since variable voltage can be supplied to the micro heater, the heating temperature can be variably controlled.

Third, through a structure in which the MEMS gas detection unit 100 and the signal processing unit 200 are packaged together in a chip cover, or in a structure in which the MEMS gas detection unit 100 is packaged in a chip cover, performance evaluation can be performed by manufacturing in the form of a semi-finished product. There is a possible effect.

Fourth, even if the application changes, it can be applied to a new application by simply changing the output voltage setting without the need to redesign the charge pump, which has the effect of providing versatility and expandability.

The effects of the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

Figure 1 is a first embodiment of a MEMS gas sensor device capable of supplying a variable output voltage according to the present invention.
Figure 2 is a second embodiment of a MEMS gas sensor device capable of supplying a variable output voltage according to the present invention.
Figure 3 is an embodiment of a block diagram of a MEMS gas sensor device capable of supplying a variable output voltage according to the present invention.
Figure 4 is an embodiment of a block diagram of a variable output voltage charge pump according to the present invention.
Figure 5 is an embodiment of a circuit diagram of a voltage divider of a variable output voltage charge pump according to the present invention.
Figure 6 is an embodiment of a circuit diagram relating to the voltage selection unit of the variable output voltage charge pump according to the present invention.
Figure 7 is an example of a graph showing the output voltages of the variable output voltage charge pump according to the present invention.
Figure 8 is a flowchart of a method of driving a variable output voltage charge pump device according to the present invention.
Figure 9 is a detailed flowchart of step S100 according to the present invention.
FIG. 10A is a schematic diagram of the first chip package shown in FIG. 1, and FIG. 10B is a schematic diagram of the second chip package shown in FIG. 2.

Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described so that those skilled in the art can easily implement the present invention. As can be easily understood by those skilled in the art to which the present invention pertains, the embodiments described below may be modified into various forms without departing from the concept and scope of the present invention. As much as possible, identical or similar parts are indicated using the same reference numerals in the drawings.

The terminology used herein is only intended to refer to specific embodiments and is not intended to limit the invention. As used herein, singular forms include plural forms unless phrases clearly indicate the contrary.

As used herein, the meaning of "comprising" is to specify a specific characteristic, area, integer, step, operation, element, and/or component, and to specify other specific characteristic, area, integer, step, operation, element, component, and/or This does not exclude the presence or addition of the military.

All terms, including technical and scientific terms, used in this specification have the same meaning as those generally understood by those skilled in the art in the technical field to which the present invention pertains. Terms defined in the dictionary are further interpreted as having a meaning consistent with the related technical literature and currently disclosed content, and are not interpreted in an ideal or very formal sense unless defined.

Expressions related to direction used in this specification, for example, front/back/left/right, top/bottom, and vertical/lateral directions, can be interpreted with reference to the directions shown in the drawings.

Hereinafter, the present invention will be described with reference to the drawings. For reference, the drawings may be somewhat exaggerated in order to explain the features of the present invention. In this case, it is preferable to interpret in light of the entire purpose of this specification.

Uniform temperature distribution is very important in the operation of gas sensors. Thermal uniformity is a factor that increases the sensitivity and selectivity of gas sensors. For this purpose, the design and development of micro heaters within the MEMS gas detection unit (detection element and compensation element) are very important.

In addition, uniform temperature distribution must be achieved at a level corresponding to the characteristics (application amount or thin film thickness) of the sensing material formed on top of the micro heater by methods such as dispensing, screen printing, and thin film deposition.

The sensing material can be a compound or synthetic compound that reacts with gas (e.g., hydrogen), and is a complex compound synthesized with a catalyst that can lower the activation energy, and is manufactured as a semi-finished sensor (micro heater/detection unit and signal processing unit). It can be formed later (without chip case or housing case) and perform performance evaluation.

If voltage can be variably supplied to the micro heater, the heating temperature can be variably adjusted and a uniform temperature distribution corresponding to the characteristics of the sensing material can be maintained, thereby greatly improving performance such as loss prevention and durability of the sensing material. .

In addition, semiconductor packaging becomes possible, and sensor semi-finished products (chip packages) or finished products (housing) can be tuned, making it possible to produce a variety of products that can be used in hydrogen automobiles and other fields.

The present invention can be implemented by an invention of a MEMS gas sensor chip package capable of supplying a variable output voltage, an invention of a MEMS gas sensor device, an invention of a charge pump circuit, and an invention of a driving method of the charge pump device.

Below, each invention will be described sequentially. In addition, each invention will be explained with a focus on key, differentiated content rather than overlapping content.

First, we will explain the invention of a MEMS gas sensor chip package capable of supplying variable output voltage. The chip package invention can have two embodiments.

The first embodiment of the chip package invention according to the present invention is as follows (see Figure 1).

The present invention is a MEMS gas sensor chip package capable of supplying a variable output voltage, comprising: a MEMS gas detection unit 100 provided on a printed circuit board 10; A signal processing unit 200 spaced apart from the MEMS gas detection unit 100 and electrically connected to the printed circuit board 10; and a chip cover 20 having a gas injection hole 21 formed on one side and provided on the printed circuit board 10 to surround the MEMS gas detection unit 100 and the signal processing unit 200 in a spaced apart state. Includes, the signal processing unit 200 is provided with a variable output voltage charge pump unit 210 that supplies a variable voltage to the MEMS gas detection unit 100, and is in a semi-finished product state before the chip package is combined with the finished gas sensor product. It may be provided to check whether the detection element is operating and its performance according to the preset reaction gas.

The second embodiment of the chip package invention according to the present invention is as follows (see Figure 2).

The present invention includes a MEMS gas detection unit 100 provided on a printed circuit board 10; A signal processing unit 200 spaced apart from the MEMS gas detection unit 100 and electrically connected to the printed circuit board 10; And a gas injection hole 21 is formed on one side, and a chip cover 20 is provided on the printed circuit board 10 to surround the MEMS gas detection unit 100 in a spaced state, and the signal processing unit. (200) is provided with a variable output voltage charge pump unit 210 that supplies a variable voltage to the MEMS gas detection unit 100, and is supplied to a preset reaction gas in a semi-finished product state before the chip package is combined with the finished gas sensor product. It can be provided to check whether the detection element is operating and its performance.

Due to the manufacturing characteristics of an electrochemical gas sensor such as the present invention, the operation and performance of the sensor's detection element (sensing material) and reaction gas must be confirmed.

However, the conventional chemical sensor was manufactured after manufacturing the finished gas sensor product, and in the case of poor performance later, most of the finished products had to be discarded.

Accordingly, the present invention can be manufactured as a semi-finished sensor, like the first and second embodiments of the chip package described above.

The present invention has the feature of being able to perform performance evaluation in the state of semi-finished products of the first and second embodiments.

In the MEMS gas sensor chip package according to the first and second embodiments of the present invention, the MEMS gas detection unit 100 includes a compensation element 110 having a micro heater 111; And it has a micro heater 121, and includes a detection element 120 on which a sensing material 122 is formed on the micro heater 121.

The MEMS gas detection unit 100 according to the present invention includes a compensation element 110 on which a micro heater 111 is formed, and a detection element 120 on which a sensing material 122 is formed on the micro heater 121 with the same specifications as the compensation element. It consists of

The MEMS gas detection unit 100 and signal processing unit 200 may be formed on separate chips in separate processes and then packaged together, or may be formed during the same process on one wafer. For convenience of explanation, it is illustrated in FIG. 3 that the two chips 100 and 200 are formed separately and then packaged.

A MEMS compensation element 110 and a detection element 120 are formed on the MEMS gas detection unit 100.

Voltage is supplied to the compensation element 110 and the detection element 120 by a variable output voltage (Vcpo) applied through the voltage input terminal 130. The resistance of the detection element 120 changes according to the heat change due to the heat of reaction with the target gas (e.g., hydrogen), and in FIG. 3, reference resistance-1 and reference resistance-2, the compensation element 110 and the detection element 120 are shown in FIG. The voltage (V1-V2) output value of the resistance change value is input to the detection signal detector 220 according to the Wheatstone bridge detection method.

The signal processing unit 200 according to the present invention includes a variable output voltage charge pump unit 210; A detection signal detector 220 that detects a potential difference value from a detection circuit and outputs a detection signal; and an output signal amplifier 230 that amplifies the detection signal Vs and outputs it to the outside as a gas sensor output signal.

The variable output voltage charge pump unit 210 according to the present invention provides a power supply voltage according to the voltage selection signal (Vref) and the reference voltage according to the characteristics of the compensation element 110 and the detection element 120 of the MEMS gas detection unit 100. (Vcc) can be stepped up and output as a variable output voltage (Vcpo).

The variable output voltage charge pump unit 210 according to the present invention multiplies the variable output voltage of the charge pump by the distribution ratio n/N according to a voltage selection signal that specifies the distribution ratio n/N (1≤=n≤=N factor number). a voltage level control unit 211 that generates an oscillator control signal to activate or deactivate the distribution voltage obtained by comparing it with the reference voltage; An oscillator 212 that outputs a clock signal of a preset frequency when the oscillator control signal is activated; and a charge pump 213 that boosts the power supply voltage while the clock signal is applied from the oscillator 212 and outputs the variable output voltage.

The detection signal detection unit 220 detects the value of the potential difference (V1-V2) from the Wheatstone Bridge detection circuit and outputs the detection signal (Vs).

The output signal amplifier 230 amplifies the detection signal (Vs) and outputs it to the outside as a chemical sensor output signal (Vout).

The operation and configuration of the variable output voltage charge pump unit 210 according to the present invention will be described in more detail.

Figure 4 is an embodiment of a block diagram of a variable output voltage charge pump according to the present invention.

Referring to FIG. 3 together, it may appear that the variable output voltage charge pump unit 210 of FIG. 4 can only be used in a MEMS chemical gas sensor device, but the variable output voltage charge pump according to the present invention is a MEMS chemical gas sensor device. It is not a circuit that is limited to application fields. It is intended to clarify that the present invention can be applied to any application field when designing a device that typically requires a charge pump, as long as it is desirable for the charge pump to provide different output direct current voltages depending on the purpose or specifications.

In FIG. 4 , the variable output voltage charge pump unit 210 includes a voltage level control unit 211, an oscillator 212, and a charge pump 213.

The voltage level control unit 211 according to the present invention includes a voltage divider 2111 that receives feedback from the variable output voltage of the charge pump 213 and generates N distribution voltages distributed at preset voltage intervals; A voltage selector 2112 that selects an nth distribution voltage corresponding to a division ratio n/N among N distribution voltages by the voltage selection signal and outputs the selected nth distribution voltage; And by comparing the nth distribution voltage and the reference voltage, if the nth distribution voltage is lower than the reference voltage, the operation of the oscillator 212 is activated, and if the nth distribution voltage is higher than or equal to the reference voltage, the operation of the oscillator 212 is activated. It includes a comparator 2113 that generates the oscillator control signal to deactivate it.

The voltage level control unit 211 according to the present invention has a distribution ratio n/N (a natural number of 1≤=n≤=N) determined according to the specifications of the compensation element 110 and the detection element 120 in the MEMS gas detection unit 100. The oscillator according to the result of comparing the distribution voltage (V_n) obtained by multiplying the variable output voltage (Vcpo) of the charge pump 213 by the division ratio n/N according to the voltage selection signal (Vsel) that specifies the reference voltage (Vref). Generates an oscillator control signal (ENb) that is activated or deactivated to control the operation of (212).

The voltage value corresponding to the specifications of the compensation element 110 and the detection element 120 in the MEMS gas detection unit 100 is. For example, it can be selected within the range from the minimum output possible voltage to the maximum output possible voltage of the charge pump 213.

In addition, for the variable output voltage (Vcpo) to reach and maintain the desired voltage value, the distribution voltage (V_n) obtained by multiplying the variable output voltage (Vcpo) by the division ratio n/N must be equal to the reference voltage (Vref).

Accordingly, the distribution ratio n/N can be said to be the ratio of the reference voltage (Vref) divided by the desired voltage value, that is, the target variable output voltage (Vcpo).

Therefore, the variable output voltage charge pump unit 210 of the present invention has a variable output voltage level fixed at a higher voltage level as the distribution ratio n/N is lowered within the range from the minimum output possible voltage to the maximum output possible voltage of the charge pump 213. The output voltage (Vcpo) can be obtained, and by increasing the distribution ratio n/N, a variable output voltage (Vcpo) that is fixed at a low voltage level can be obtained.

Meanwhile, in FIG. 4, the oscillator control signal ENb is illustrated as a signal activated when logic is low, but this is not necessarily the case and may be generated as a signal activated when logic is high.

Specifically, the voltage level control unit 211 may include a voltage divider 2111, a voltage selector 2112, and a comparator 2113.

The voltage divider 2111 according to the present invention has an nth division voltage corresponding to the division ratio n/N of the voltage divider 2111 among the N division voltages output from each node of the N series-connected resistive elements or diodes. The distribution voltage may be selected using the voltage selection signal and may be operated to output the selected nth distribution voltage.

The voltage divider 2111 receives the variable output voltage (Vcpo) of the charge pump 213 as feedback and divides N distribution voltages (V_1...*V_N) at preset voltage intervals, preferably at equal voltage intervals. create

For example, the voltage divider 2111 can be implemented with N series-connected resistive elements or N series-connected diodes (D_1, D_2, D_3, ...*, D_n, ...*D_N), as shown in FIG. 5. there is. The divided voltages (V_1, V_2, V_3, …*, Vn, …*V_N) can be output from the contact nodes of the two resistive elements or the two diodes.

The voltage selector 2112 selects the voltage divider 2111 corresponding to the distribution ratio n/N among the N distribution voltages (V_1, ...*, V_N) output from each node of the N series-connected resistive elements or diodes. The nth distribution voltage (V_n) is selected by the voltage selection signal (Vsel), and the selected distribution voltage (V_n) is output.

Preferably, the voltage selector 2112 is the nth node corresponding to the division ratio n/N of the voltage divider 2111 among the N distribution voltages (V_1, ...*, V_N), that is, the nth resistive element or diode from below. The nth distribution voltage (V_n) output from the node between and the n+1th resistive element or diode is selected by the voltage selection signal (Vsel), and the selected distribution voltage (V_n) is output.

At this time, the voltage selector 2112 selects the Nth distribution voltage (V_N) when the distribution ratio n/N is the maximum (n=N), and the 1st distribution voltage when the distribution ratio n/N is the minimum (n=1). Note that we choose the voltage (V_1).

For example, as shown in FIG. 6, the voltage selector 2112 has N switches (SW_1 to SW_N) connected in parallel on one side of each side to a distribution voltage (one of V_1 to V_N) and the other side connected to the comparator 2113. and by selectively energizing only one (SW_n) of the switches (SW_1 to SW_N) by the voltage selection signal (Vsel), the nth of the N distribution voltages (V_1 to V_N) provided from the voltage divider 2111. The distribution voltage (V_n) can be selectively output to the comparator (2113).

The comparator 2113 compares the nth distribution voltage (V_n) corresponding to the distribution ratio n/N and the reference voltage (Vref), so that the nth distribution voltage (V_n) corresponding to the distribution ratio n/N is higher than the reference voltage (Vref). An oscillator control signal ENb is generated to activate the operation of the oscillator 212 when it is low, and to deactivate the operation of the oscillator 212 otherwise (if it is high or equal to the same value).

Meanwhile, in FIG. 4, the comparator 2113 is illustrated as receiving the nth division voltage (V_n) corresponding to the division ratio n/N from the (+) terminal and the reference voltage (Vref) from the (-) terminal. . While the nth division voltage (V_n) corresponding to the division ratio n/N is lower than the reference voltage (Vref), that is, while logic Low is output from the comparator 2113, the oscillator 212 is used to increase the variable output voltage (Vcpo). ), the comparator 2113 exemplarily outputs the oscillator control signal (ENb) as a signal (ENb) that is activated when the logic is low.

Depending on the embodiment, the comparator 2113 may be implemented by receiving the nth division voltage (V_n) corresponding to the division ratio n/N from the (-) terminal and receiving the reference voltage (Vref) from the (+) terminal. there is. In this case, while the nth division voltage (V_n) corresponding to the division ratio n/N is higher than the reference voltage (Vref), that is, while logic High is output from the comparator 2113, the variable output voltage (Vcpo) is increased. Since the oscillator 212 must be operated for this purpose, the comparator 2113 may exemplarily output an oscillator control signal as a signal activated when the logic is high.

Subsequently, the oscillator 212 may output clock signals (CLK, CLKb) of a preset frequency to the charge pump 213 depending on whether the oscillator control signal (ENb) is activated. When the oscillator control signal ENb is deactivated (that is, when the distribution voltage V_n of the distribution ratio n/N in the comparator 2113 in FIG. 4 is higher than the reference voltage Vref), the clock signal of the oscillator 212 ( The production of CLK, CLKb) itself may be interrupted.

The charge pump 213 boosts the power supply voltage (Vcc) while the clock signal (CLK) is applied from the oscillator 212 and outputs a variable output voltage (Vcpo).

Since the output of the clock signal (CLK) from the oscillator 212 is activated by the oscillator control signal (Enb) of the voltage level control unit 211 until the variable output voltage (Vcpo) of the charge pump 213 reaches the desired voltage level. The variable output voltage (Vcpo) continues to rise.

When the variable output voltage (Vcpo) reaches a certain voltage level, the output of the clock signal (CLK) from the oscillator 212 is deactivated by the oscillator control signal (Enb) of the voltage level control unit 211, so that the charge pump 213 Actions are also disabled. Accordingly, the variable output voltage (Vcpo) no longer increases but decreases according to the equivalent time constant inside the compensation element 110 and the detection element 120, but the decrease in the variable output voltage (Vcpo) is reduced by the voltage level control unit 211. When the level detected by the internal comparator 2113 is exceeded, the output of the clock signal CLK of the oscillator 212 is activated again and the variable output voltage Vcpo becomes high again. In this way, the charge pump 213 repeats activation/deactivation while maintaining the size of the variable output voltage (Vcpo) constant.

The charge pump 213 according to the present invention may further include a low-pass filter to remove the ripple component of the variable output voltage due to repeated activation and deactivation of the charge pump.

Depending on the embodiment, the ripple component of the variable output voltage (Vcpo) according to activation/deactivation of the charge pump 213 may be removed using a low-pass filter 214 including a capacitor at the output terminal of the charge pump 213. It may be possible.

Hereinafter, the MEMS gas sensor device capable of supplying a variable output voltage according to the present invention will be described. The technical features of the above-described MEMS gas sensor chip package invention are substantially the same. Accordingly, we will omit redundant content and focus on differentiation.

Figure 1 is a first embodiment of a MEMS gas sensor device capable of supplying a variable output voltage according to the present invention. Figure 2 is a second embodiment of a MEMS gas sensor device capable of supplying a variable output voltage according to the present invention.

The first embodiment of the MEMS gas sensor device according to the present invention is as follows.

The present invention is a MEMS gas sensor device, comprising: a first chip package (20a) according to the present invention; And a gas injection hole 31 is formed on one side, and a housing cover 30 is provided on the printed circuit board 10 to surround the first chip package 20a in a spaced apart state.

The second embodiment of the MEMS gas sensor device according to the present invention is as follows.

The present invention is a MEMS gas sensor device, comprising: a second chip package (20b) according to the present invention; And a gas injection hole 31 is formed on one side, and a housing cover 30 is provided on the printed circuit board 10 to surround the second chip package 20b and the signal processing unit 200 in a spaced apart state. Includes.

The first embodiment of the MEMS gas sensor device shown in FIG. 1 includes a first embodiment (related to the first chip package) of the MEMS gas sensor chip package according to the present invention.

The second embodiment of the MEMS gas sensor device shown in FIG. 2 includes a second embodiment (related to the second chip package) of the MEMS gas sensor chip package according to the present invention.

As shown in Figures 1 and 2, the MEMS gas sensor device according to the present invention may be provided with a gas injection hole 21 formed in the chip cover 20 and a gas injection hole 22 formed in the housing cover 30. can

Each gas injection hole (21) (31) according to the present invention may be provided with a thin film-shaped filter unit (40). The filter unit 40 may be provided differently depending on the type and purpose of the gas.

The two filter units provided in the gas injection holes 21 and 31 can play a role in minimizing poisoning (moisture or carbon monoxide, etc.). The material used in the filter part is a thin film or film that can filter a specific gas and can be attached to the case (housing, chip cover) containing the gas injection hole.

As an example, moisture/humidity poisoning is carried out step by step, in the order of the filter unit provided in the gas injection hole 31 of the housing cover 30 and the filter unit provided in the gas injection hole 210 of the chip package 20. Step-by-step filtering is possible.

By passing through the filter part of the chip cover, the amount of moisture poisoning is minimized, and depending on the size of the chamber (gas collection amount), recovery time and reaction time can be affected.

As another example, the filter part of the housing cover may prevent moisture, and the filter part of the chip cover may prevent other gases, thereby preventing poisoning.

The MEMS gas sensor device according to the present invention can be divided into a housing chamber and a chip cover chamber. The volume of the chamber can determine the amount of gas capture. In other words, the size of the chamber refers to the amount of gas collected. Depending on the amount of gas, the recovery and response time performance of the gas sensor can be affected.

The conventional chamber size is equal to the volume of the housing case and is therefore larger than the embodiments of Figures 1 and 2 according to the present invention.

In the case of the embodiment of FIG. 1, it is larger than the embodiment of FIG. 2, but is reduced by about 70% from the conventional size, and the smallest size is the one in which only the MEMS portion is cased, as shown in FIG. 2.

Among the performance of gas sensors, recovery time and response time after reacting to a specific gas are very important measures. As described above, through the configuration shown in FIGS. 1 and 2 and the microheater technology according to the present invention, very fast recovery time and reaction time can be reduced. Additionally, reproducibility and accuracy can be improved.

Hereinafter, the charge pump circuit invention capable of supplying a variable output voltage according to the present invention will be described. The technical features of the above-described MEMS gas sensor chip package invention are substantially the same. Accordingly, we will omit redundant content and focus on differentiation.

The present invention is a charge pump circuit capable of supplying a variable output voltage, and multiplies the variable output voltage of the charge pump by the distribution ratio n/N according to a voltage selection signal that specifies the distribution ratio n/N (1≤=n≤=N factor number). a voltage level control unit 211 that generates an oscillator control signal to activate or deactivate the distribution voltage obtained by comparing it with the reference voltage; An oscillator 212 that outputs a clock signal of a preset frequency when the oscillator control signal is activated; and a charge pump 213 that boosts the power supply voltage while the clock signal is applied from the oscillator 212 and outputs the variable output voltage.

Figure 5 is an embodiment of a circuit diagram of a voltage divider of a variable output voltage charge pump according to the present invention. Figure 6 is an embodiment of a circuit diagram relating to the voltage selection unit of the variable output voltage charge pump according to the present invention. Figure 7 is an example of a graph showing the output voltages of the variable output voltage charge pump according to the present invention.

Referring to FIG. 7, the variable output voltage charge pump of the MEMS gas sensor device according to the present invention has a distribution ratio n/N depending on the size of the distribution ratio n/N as the voltage between the compensation element 110 and the detection element 120. When the distribution ratio n/N is large (close to 1), it is close to the minimum level, and when the distribution ratio n/N is small (close to 0), one of the output voltages that varies close to the maximum level can be output as a bias voltage signal.

Hereinafter, the invention of a driving method of a charge pump device capable of supplying a variable output voltage according to the present invention will be described. The technical features of the above-described MEMS gas sensor chip package invention are substantially the same. Accordingly, we will omit redundant content and focus on differentiation.

Figure 8 is a flowchart of a method of driving a variable output voltage charge pump device according to the present invention. Figure 9 is a detailed flowchart of step S100 according to the present invention.

The present invention is a method of driving a variable output voltage charge pump device including a voltage level control unit 211, an oscillator 212, and a charge pump 213, wherein the voltage level control unit 211 has a distribution ratio n/N (1≤= An oscillator control signal that is activated or deactivated according to the result of comparing the distribution voltage obtained by multiplying the variable output voltage of the charge pump by the division ratio n/N according to the voltage selection signal that specifies (n≤=N, a natural number) with the reference voltage. S100 step of generating; Step S200 in which the oscillator 212 outputs a clock signal of a preset frequency when the oscillator control signal is activated; And a step S300 in which the charge pump 213 boosts the power supply voltage while the clock signal is applied from the oscillator 212 and outputs the variable output voltage.

Step S100 according to the present invention includes a step S110 in which the voltage divider 2111 receives feedback from the variable output voltage of the charge pump 213 and generates N distribution voltages distributed at preset voltage intervals; Step S120 in which the voltage selector 2112 selects an nth distribution voltage corresponding to a division ratio n/N among the N distribution voltages using the voltage selection signal, and outputs the selected nth distribution voltage; And a comparator 2113 compares the nth division voltage and the reference voltage, activating the operation of the oscillator 212 if the nth division voltage is lower than the reference voltage, and activating the oscillator 212 if the nth division voltage is higher than or equal to the reference voltage. and step S130 of generating the oscillator control signal to disable the operation of 212.

The embodiments described in this specification and the accompanying drawings merely illustratively illustrate some of the technical ideas included in the present invention. Accordingly, the embodiments disclosed in this specification are not intended to limit the technical idea of the present invention, but rather to explain it, and therefore, it is obvious that the scope of the technical idea of the present invention is not limited by these embodiments. All modifications and specific embodiments that can be easily inferred by a person skilled in the art within the scope of the technical idea included in the specification and drawings of the present invention should be construed as being included in the scope of the present invention.

10: substrate 20: chip cover
21: gas injection hole 30: housing cover
31: gas injection hole 40: filter unit
100: MEMS gas detection unit 110: Compensation element
111: micro heater 120: detection element
121: Micro heater 122: Sensing material
130: voltage input terminal
200: signal processing unit 210: variable output voltage charge pump unit
211: voltage level control unit 2111: voltage divider
2112: voltage selector 2113: comparator
212: Oscillator 213: Charge pump
220: detection signal detection unit 230: output signal amplification unit

Claims (20)

MEMS gas detection unit provided on a printed circuit board; A signal processing unit spaced apart from the MEMS gas detection unit and electrically connected to the printed circuit board; And a chip cover having a gas injection hole formed on one side and provided on a printed circuit board to surround the MEMS gas detection unit and the signal processing unit in a spaced apart state,
The signal processing unit includes a variable output voltage charge pump unit that supplies a variable voltage to the MEMS gas detection unit,
The MEMS gas detection unit includes a compensation element having a micro heater; And it has a micro heater, and includes a detection element on which a sensing material is formed on the micro heater,
A MEMS gas sensor chip package capable of supplying a variable output voltage, characterized in that it is equipped to check the operation and performance of the detection element according to a preset reaction gas in a semi-finished product state before the chip package is combined with the finished gas sensor product. MEMS gas detection unit provided on a printed circuit board; A signal processing unit spaced apart from the MEMS gas detection unit and electrically connected to the printed circuit board; and a chip cover having a gas injection hole formed on one side and provided on a printed circuit board to surround the MEMS gas sensing unit in a spaced apart state,
The signal processing unit includes a variable output voltage charge pump unit that supplies a variable voltage to the MEMS gas detection unit, and the MEMS gas detection unit includes a compensation element having a micro heater; And it has a micro heater, and includes a detection element on which a sensing material is formed on the micro heater,
A MEMS gas sensor chip package capable of supplying a variable output voltage, characterized in that it is equipped to check the operation and performance of the detection element according to a preset reaction gas in a semi-finished product state before the chip package is combined with the finished gas sensor product. delete In claim 1 or claim 2,
The signal processing unit
The variable output voltage charge pump unit;
a detection signal detection unit that detects a potential difference value from a detection circuit and outputs a detection signal; and
A MEMS gas sensor chip package capable of supplying a variable output voltage, comprising an output signal amplifier that amplifies the detection signal (Vs) and outputs it to the outside as a gas sensor output signal. In claim 4,
The variable output voltage charge pump unit
A MEMS gas sensor chip package capable of supplying a variable output voltage, characterized in that the power supply voltage is boosted according to the voltage selection signal and reference voltage according to the characteristics of the compensation element and detection element of the MEMS gas detection unit and output as a variable output voltage. In claim 5,
The variable output voltage charge pump unit
Activated according to the result of comparing the distribution voltage obtained by multiplying the variable output voltage of the charge pump by the distribution ratio n/N with the reference voltage according to a voltage selection signal that specifies the distribution ratio n/N (a natural number with 1≤=n≤=N). or a voltage level control unit that generates an oscillator control signal to be deactivated;
an oscillator that outputs a clock signal of a preset frequency when the oscillator control signal is activated; and
A MEMS gas sensor chip package capable of supplying a variable output voltage, comprising a charge pump that outputs the variable output voltage by boosting the power supply voltage while the clock signal is applied from the oscillator. In claim 6,
The voltage level control unit
a voltage divider that receives feedback from the variable output voltage of the charge pump and generates N distribution voltages distributed at preset voltage intervals;
a voltage selector that selects an nth distribution voltage corresponding to a division ratio n/N among the N distribution voltages by the voltage selection signal and outputs the selected nth distribution voltage; and
The oscillator is controlled to compare the nth distribution voltage and the reference voltage, to activate the operation of the oscillator if the nth distribution voltage is lower than the reference voltage, and to deactivate the operation of the oscillator if the nth distribution voltage is higher than or equal to the reference voltage. A MEMS gas sensor chip package capable of supplying a variable output voltage, characterized by including a comparator that generates a signal. In claim 7,
The voltage selector is
Among the N distribution voltages output from each of the nodes of the N series-connected resistive elements or diodes, the nth distribution voltage corresponding to the division ratio n/N of the voltage divider is selected by the voltage selection signal, and the selected A MEMS gas sensor chip package capable of supplying a variable output voltage, characterized in that it operates to output the nth distribution voltage. In claim 6,
The charge pump is
A MEMS gas sensor chip package capable of supplying a variable output voltage, further comprising a low-pass filter for removing ripple components of the variable output voltage due to repeated activation and deactivation of the charge pump. A first chip package according to claim 1; and
A MEMS gas sensor device capable of supplying a variable output voltage, comprising a gas injection hole formed on one side and a housing cover provided on a printed circuit board to surround the first chip package in a spaced apart state. A second chip package according to claim 2; and
A MEMS gas sensor device capable of supplying a variable output voltage, comprising a gas injection hole formed on one side and a housing cover provided on a printed circuit board to surround the second chip package in a spaced apart state. In claim 10 or claim 11,
A MEMS gas sensor device capable of supplying a variable output voltage, characterized in that each gas injection hole is provided with a thin film-shaped filter unit. delete delete delete delete delete delete delete delete