CN106783792A - There is a kind of plastic-sealed body lateral leads side to climb the encapsulating structure of tin performance - Google Patents

Abstract

The invention relates to a package structure with side pins of a plastic package having side tin creeping performance, which includes a pin (1) and a base island (2), the pin (1) is arranged around the base island (2), and the The front of the base island (2) is provided with a chip (4) through an adhesive substance or solder (3), and the chip (4) is electrically connected to the pin (1) through a metal bonding wire (5), and the lead A hypotenuse (7) is provided on the outside of the back of the foot (1), and a tin layer (8) is provided on the surface of the pin (1), the base island (2) and the hypotenuse (7), and the pin (1), The base island (2) and the peripheral area of the chip (4) are encapsulated with a plastic encapsulant (6). The invention discloses a packaging structure with side pins of a plastic package having side tin-climbing performance, which can effectively increase the side tinning area, and improve the welding performance and welding reliability of products.

Description

A packaging structure with side pins on the side of the plastic package with side tin creep performance

technical field

The invention relates to a packaging structure in which the side pins of a plastic package have side tin creeping performance, and the pins of the packaging structure have side tin creeping performance, belonging to the technical field of semiconductor packaging.

Background technique

With the development of modern technology, semiconductor packaging has been widely used. Its extensive applications in radar, remote control telemetry, aerospace, etc. put forward higher and higher requirements for its reliability. The failure caused by poor chip welding has attracted more and more people's attention, because this failure is often fatal and irreversible. Therefore, it is very important to get a good soldering reliability in the semiconductor industry. The tin layer on the soldering surface of the semiconductor can make the soldering stronger, especially for automotive electronics.

As we all know, QFN (Quad Flat No-lead Package, four-sided leadless flat package) and DFN (DuadFlat No-lead Package, double-sided leadless flat package) are leadless packages with a large area exposed in the center The pad has a thermal conductivity, and there is a conductive pad for electrical connection on the periphery of the package of the large pad. Usually the heat dissipation pad is mounted on the circuit board together with the conductive pad. However, in the prior art, after the plastic package is cut, the sides of the metal pins cannot be coated with electro-tinned layers, which directly causes the solder paste on the PCB to not climb up to the metal area on the side of the plastic package, resulting in virtual soldering on the side of the metal pins. Or the problem of cold sweat, especially the safety of integrated circuit chips used in automotive electronics is very strict, so the tin climbing of the metal pins on the side of the plastic package is particularly critical.

In order to solve this problem, the conventional practice in the industry is to etch or cut the outer end of the back of the lead frame pin to form a drop-shaped or stepped step, then perform electroplating, and then perform cutting operations, so that the steps on the side of the lead can be obtained. The package structure is electroplated with solder (see Figure 1A), thereby improving its reliability when soldering to a PCB.

However, when the exposed pad and electrode contacts at the bottom of the package structure with such pins have steps are soldered to the thermal pads on the PCB, as shown at A in Figure 1B, air is likely to remain at the steps of the pins and cannot be discharged. Causes poor solder bonding. Especially when the product is working, the air remaining inside the steps will expand due to the heating of the product, which will form cracks in the tin layer between the PCB pad and the pins of the plastic package, resulting in poor electrical function of the integrated circuit. It will also directly cause the electrical function to stop working.

Contents of the invention

The technical problem to be solved by the present invention is to provide a packaging structure in which the side pins of the plastic package have side tin creeping performance in view of the above-mentioned prior art, which can effectively increase the side tin plating area, improve the welding performance of the product and the reliability of welding sex.

The technical solution adopted by the present invention to solve the above-mentioned problems is: a packaging structure with side pins of a plastic package having side tin-climbing performance, which includes pins and a base island, the pins are arranged around the base island, and the base island The front side is provided with a chip through an adhesive substance or solder, and the chip is electrically connected to the pin through a metal bonding wire. The back side of the pin is provided with a hypotenuse, and the pin, the base island and the surface of the hypotenuse are provided with The tin layer, the pins, the base island and the peripheral area of the chip are encapsulated with a plastic encapsulant.

A packaging structure in which the side pins of a plastic package have the ability to climb tin on the side. It includes pins, a chip is arranged on the pins, and a metal post is provided on the chip, and the metal post forms an electrical connection with the pins through solder. There is a beveled edge on the outside of the back of the pin, a tin layer is set on the surface of the pin and the beveled edge, and the pin and the peripheral area of the chip are encapsulated with a plastic encapsulant.

Compared with the prior art, the present invention has the advantages of:

1. The side pins of a plastic package of the present invention have a packaging structure with side tin-climbing performance, which forms a beveled edge on the outside of the back of the pins by cutting, which can make it easier to carry out tin-climbing when soldering PCBs, and at the same time, its solder-climbing state is directly It can be clearly seen from the appearance;

2. The packaging structure of the side pins of the plastic package of the present invention has the ability to climb tin on the side, which forms a beveled edge on the outside of the back of the pin by cutting, so that the air at the pin can be discharged along the beveled edge to avoid residues in the solder There are air bubbles to strengthen the combination of the pin and the PCB to improve the soldering performance and reliability of the product.

Description of drawings

FIG. 1A is a schematic diagram of a conventional packaging structure with sidewall tin creeping performance.

FIG. 1B is a schematic diagram of the combination of the existing packaging structure with sidewall tin-climbing performance and the PCB board.

FIG. 2 is a schematic diagram of a packaging structure in which the side pins of the plastic package have side solder creeping performance according to the present invention.

FIG. 3 is a three-dimensional schematic diagram of a packaging structure with side pins of the plastic package having side solder creeping performance according to the present invention.

Fig. 4 is a schematic diagram of the combination of a package structure with side pins of a plastic package with side tin creeping performance and a PCB board according to the present invention.

FIG. 5 is a schematic diagram of another embodiment of a package structure of the present invention with side pins of a plastic package having side solder creeping performance.

FIG. 6 is a schematic perspective view of another embodiment of a package structure with side pins of the plastic package having side solder creeping performance according to the present invention.

in:

pin 1

Key Island 2

Bonding substance or solder3

chip 4

Metal wire 5

Plastic compound 6

hypotenuse 7

Tin layer 8

Metal Post 9

Solder10.

detailed description

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

Example 1: chip is installed

As shown in Fig. 2 and Fig. 3, a package structure in which the side pins of the plastic package in this embodiment have side solder creeping performance includes a pin 1 and a base island 2, and the pin 1 is arranged on the base island 2 Around, the front of the base island 2 is provided with a chip 4 through an adhesive substance or solder 3, and the chip 4 is electrically connected to the pin 1 through a metal bonding wire 5, and the outer side of the back of the pin 1 is provided with a bevel 7 The surface of the pin 1 , the base island 2 and the bevel 7 is provided with a tin layer 8 , and the peripheral area of the pin 1 , the base island 2 and the chip 4 is encapsulated with a plastic encapsulant 6 .

Referring to Fig. 4, a package structure of the present invention has a side pin of the plastic package with side tin-climbing performance, and a beveled edge is formed on the outside of the back of the pin, which makes it easier to carry out tin-climbing when soldering the PCB, and at the same time can make the air at the pin Discharge along the bevel to avoid residual air bubbles in the solder to improve the soldering performance and reliability of the product.

Example 2: Flip chip

Referring to Fig. 5 and Fig. 6, a package structure with side pins of a plastic package in this embodiment having side tin-climbing performance includes a pin 1, a chip 4 is arranged on the pin 1, and a chip 4 is arranged on the chip 4. A metal column 9 is provided, and the metal column 9 is electrically connected to the pin 1 through the solder 10, and the outer side of the back of the pin 1 is provided with a bevel 7, and the surface of the pin 1 and the bevel 7 is provided with a tin layer 8. The peripheral areas of the pins 1 and the chip 4 are encapsulated with a plastic encapsulant 6 .

The difference between embodiment 2 and embodiment 1 lies in that the chip 4 is connected to the pin 1 through the metal pillar 9, and there is no exposed base island in the middle of the product.

In addition to the above-mentioned embodiments, the present invention also includes other implementations, and any technical solution formed by equivalent transformation or equivalent replacement shall fall within the protection scope of the claims of the present invention.

Claims (2)

1. A packaging structure in which the side pins of the plastic package have side solder climbing performance, characterized in that it includes pins (1) and a base island (2), and the pins (1) are arranged on the base island (2) Around, the front of the base island (2) is provided with a chip (4) through an adhesive substance or solder (3), and the chip (4) is electrically connected to the pin (1) through a metal bonding wire (5), A hypotenuse (7) is provided on the outside of the back of the pin (1), a tin layer (8) is provided on the surface of the pin (1), the base island (2) and the hypotenuse (7), and the pin ( 1), the base island (2) and the peripheral area of the chip (4) are encapsulated with a plastic encapsulant (6). 2. A packaging structure in which the side pins of the plastic package have side tin climbing performance, characterized in that it includes a pin (1), a chip (4) is arranged on the pin (1), and the chip (4 ) is provided with a metal column (9), the metal column (9) is electrically connected to the pin (1) through the solder (10), and the outer side of the back of the pin (1) is provided with a hypotenuse (7), The surface of the pin (1) and the bevel (7) is provided with a tin layer (8), and the peripheral area of the pin (1) and the chip (4) is encapsulated with a plastic encapsulant (6).