CN103517581B - A kind of multi-layer PCB board manufacture method and multi-layer PCB board - Google Patents

Abstract

The invention discloses a method for manufacturing a multilayer PCB board, which mainly includes: drilling a first through hole on a multilayer PCB board, and metallizing the first through hole to form a first through hole on the wall of the first through hole. Conductive layer; perform first backdrilling on the first backdrilling layer along the metallized first through hole, to remove part of the first conductive layer located on the first backdrilling layer; on the second backdrilling layer A second back-drilling is performed along the metallized first through hole to remove part of the first conductive layer on the second back-drilled layer. The invention also provides a corresponding multi-layer PCB board. The method of the present invention is by making conductive through-hole on multi-layer PCB board, and removes the part conductive layer of conductive through-hole with the mode of back-drilling, so that the conductive through-hole after back-drilling only connects the conductive layer of lamination, and does not connect with back-drilling. The conductive layer of the drilling layer is disconnected, which realizes the connection between the conductive layers of the stacked layers of the multi-layer PCB board, improves the production efficiency, and reduces the difficulty of alignment.

Description

A kind of multilayer PCB board manufacturing method and multilayer PCB board

technical field

The invention relates to the field of electronic devices, in particular to a method for manufacturing a multilayer PCB board and the multilayer PCB board.

Background technique

At present, the connection between inner-layer boards and inner-layer boards of a multilayer printed circuit board (PCB, Printed Circuit Board) is realized by making inner-layer metallized holes in the inner-layer board. Specifically, according to the traditional manufacturing process of buried blind vias, two or more layers of inner layer boards to be connected are usually pressed together first, then through holes are drilled on the inner layer boards, and then electroplated to form inner layer metallized holes to realize inner layer metallization. The connection between the layer board and the inner layer board, and then press the upper and lower outer layer boards and the lower outer layer board on the inner layer board to make a multi-layer PCB board with conductive blind holes. However, this traditional buried blind hole manufacturing process requires secondary lamination, and the production efficiency is low. In addition, the inner layer blind holes are processed before lamination. Since the processing of blind holes requires copper sinking and electroplating processes, it will inevitably lead to expansion and contraction of the inner layer board, which will lead to subsequent lamination and outer circuit processing. Matchup difficulty increased.

Contents of the invention

The invention provides a method for manufacturing a multilayer PCB board and a multilayer PCB board. In the method, conductive through holes are made on the multilayer PCB board, and part of the conductive layer of the conductive through holes is removed by back drilling, so that the back drill The last conductive via only connects the stacked conductive layers between the first back-drilled layer and the second back-drilled layer, and is disconnected from the conductive layer of the first back-drilled layer and the conductive layer of the second back-drilled layer. Therefore, the method of the present invention can realize the connection between the stacked conductive layers in the multilayer PCB board without secondary pressing, thereby improving the production efficiency.

A method for manufacturing a multilayer PCB, comprising:

Drill a first through hole on a multilayer PCB, and metallize the first through hole to form a first conductive layer on the hole wall of the first through hole, wherein the multilayer PCB includes at least the outermost The layer has a first back-drilling layer and a second back-drilling layer of a conductive layer, and a laminate with at least two circuit layers arranged between the first back-drilling layer and the second back-drilling layer, and the first through hole penetrating through the first back-drilling layer, stacked layers and second back-drilling layer;

Perform the first back-drilling on the first back-drilling layer along the metallized first through hole to remove part of the first conductive layer on the first back-drilling layer, so that the first back-drilling after the first back-drilling The conductive layer is disconnected from at least the outermost conductive layer located in the first backdrilling layer;

Carry out a second back-drilling on the second back-drilling layer along the metallized first via hole to remove part of the first conductive layer on the second back-drilling layer, so that the first back-drilling after the second back-drilling The conductive layer is disconnected from at least the outermost conductive layer of the second backdrilling layer.

A multi-layer PCB board, comprising a first back drill layer with at least one outer layer conductive layer, a second back drill layer with at least one outer layer conductive layer and a layer located between the first back drill layer and the A laminate with at least two circuit layers between the second back-drilling layers, the first back-drilling layer is provided with a first back-drilling hole, and the second back-drilling layer is provided with the first back-drilling hole For the second back-drilled hole, the stack is provided with an inner layer conductive hole between the first back-drilled hole and the second back-drilled hole, and the inner wall surface of the inner layer conductive hole is provided with A first conductive layer, the first conductive layer is connected to at least two circuit layers of the stack.

The invention can realize the connection between the stacked conductive layers in the multilayer PCB board without secondary pressing, and improves the production efficiency of the multilayer PCB board. In addition, since the present invention makes conductive holes on the pressed PCB instead of pressing them after making the conductive holes, the present invention can avoid expansion and contraction of the PCB caused by drilling, copper sinking and electroplating. , causing difficulty in pressing alignment.

Description of drawings

Fig. 1 is the schematic flow chart of the manufacturing method of a kind of multilayer PCB board of embodiment 1 of the present invention;

Fig. 2 is a schematic diagram of the state of the manufacturing steps of a manufacturing method of a multilayer PCB board in Embodiment 1 of the present invention;

Fig. 3 is a schematic diagram of the structure of a multi-layer PCB board in Embodiment 2 of the present invention;

Fig. 4 is a schematic structural diagram of a multi-layer PCB board according to Embodiment 3 of the present invention.

detailed description

Embodiments of the present invention provide a method for manufacturing a multilayer PCB board and a corresponding multilayer PCB board. The following examples are given to describe the present invention in detail.

Example 1

As shown in Figure 1, a method for manufacturing a multilayer PCB includes:

101. Drill a first through hole on a multilayer PCB, and metallize the first through hole, so as to form a first conductive layer on a hole wall of the first through hole. Wherein, the multi-layer PCB board includes at least a first back-drilling layer and a second back-drilling layer with a conductive layer on the outermost layer, and at least two back-drilling layers arranged between the first back-drilling layer and the second back-drilling layer A stack of circuit layers, the first through hole runs through the first back-drilling layer, the stack and the second back-drilling layer.

As shown in FIG. 2 , the multi-layer PCB includes a first back-drilling layer 201 , a second back-drilling layer 203 and a laminated layer 202 disposed between the first back-drilling layer 201 and the second back-drilling layer 203 . Wherein, the first backdrilling layer 201 includes a first insulating layer 206 and a first metal layer 205 disposed on the first insulating layer 206; The second metal layer 207 and the third metal layer 209 disposed on the lower surface of the second insulating layer 208; the second backdrilling layer 203 includes a third insulating layer 210 and a fourth metal layer 211 disposed on the lower surface of the third insulating layer 210 . The first through hole 204 is drilled in the multi-layer PCB, and the first through hole 204 is metallized, and the first conductive layer 212 is formed on the surface of the first through hole 204 . The first conductive layer 212 is respectively connected to the first metal layer 205 , the second metal layer 207 , the third metal layer 209 and the fourth metal layer 211 . In this embodiment, the metallization of the first through hole 204 may be performed by using a copper sinking electroplating process.

102. Perform the first back-drilling on the first back-drilling layer along the metallized first through hole, so as to remove part of the first conductive layer on the first back-drilling layer, so that after the first back-drilling The first conductive layer is disconnected from at least the outermost conductive layer of the first backdrilling layer.

As shown in FIG. 2 , after the first back-drilling of the multi-layer PCB board, a first back-drilled hole 214 is formed on the first back-drilled layer 201 . During the formation of the first back-drilled hole 214 , part of the first conductive layer on the first back-drilled layer is removed, so that the first back-drilled first conductive layer is disconnected from the first metal layer 205 .

103. Perform a second back-drilling on the second back-drilling layer along the metallized first through hole, so as to remove part of the first conductive layer on the second back-drilling layer, so that the second back-drilling The first conductive layer is disconnected from at least the outermost conductive layer of the second backdrilling layer.

As shown in FIG. 2 , after the second back-drilling of the multi-layer PCB board, a second back-drilled hole 213 is formed on the second back-drilled layer 203 . During the formation of the second back-drilled hole 213 , part of the first conductive layer on the second back-drilled layer 203 is removed. Therefore, the remaining portion 213 of the first conductive layer formed after the second backdrilling is connected to the second metal layer 207 and the third metal layer 209 , but disconnected from the first metal layer 205 and the fourth metal layer 211 .

As can be seen from the above, the method of this embodiment is to manufacture the multilayer PCB board on the laminated circuit board, and the connection between the laminated metal layers in the multilayer PCB board can be realized without multiple laminations. . In addition, it needs to be explained that when the existing processing technology is processing the inner layer conductive hole of the PCB board, the conductive hole is firstly made on the inner layer board, and then the inner layer board and the outer layer board are pressed together, so that the PCB board Inner layer conductive holes are formed in the board. However, since the conductive holes are generally made by drilling, copper sinking and electroplating, the inner board is prone to expansion and contraction during the processing process, which brings the problem of difficult alignment to the subsequent lamination process. However, in the embodiment of the present invention, conductive holes are made on the laminated PCB board, so the problem of difficult alignment caused by expansion and contraction of the PCB board can be avoided.

Preferably, a second through hole is drilled on the multi-layer PCB, and the second through hole is metallized to form a second conductive layer on the wall of the second through hole.

As shown in FIG. 2 , in this step, the second through hole 216 can be drilled on the multilayer PCB while the first through hole 204 is drilled on the multilayer PCB. While carrying out copper plating on the first through hole 204, carry out copper plating on the second through hole 216 to form a second conductive layer 217 to realize the first metal layer 205, the second metal layer 207, the second metal layer The connection between the third metal layer 209 and the fourth metal layer 211 .

Therefore, the present invention can realize the connection between the metal layers of the back-drilling layer while realizing the connection between the stacked metal layers without adding additional process steps, thereby improving the reliability of the multilayer PCB board. Productivity.

The method of this embodiment may also include:

Resin plug holes are performed in the first through hole after the first back-drilling and the second back-drilling; after the resin plug holes, the multi-layer PCB board is metallized to plug the holes The surface of the resin forms a conductive layer for making circuit patterns.

As shown in FIG. 2 , after resin plugging the first through hole after twice back drilling, a resin plug body 218 is formed in the first through hole. After the multi-layer PCB is fully metallized, a third conductive layer 219 for making circuit patterns is formed on the surface of the resin plug body 218 . Therefore, the surface area of the resin plug body 218 can also be used for making circuit patterns, preventing the surface of the resin plug body 218 from occupying the space for making circuit patterns.

Preferably, the method in this embodiment may also include: drilling a second through hole on the multilayer PCB; performing resin plugging in the first through hole after twice back-drilling; metalizing the multilayer PCB forming a second conductive layer on the wall of the second through hole, and forming a conductive layer for making circuit patterns on the surface of the plug hole resin. That is, the second conductive layer on the wall of the second through hole and the conductive layer on the surface of the plug hole resin can be completed in the same metallization process, which simplifies the process.

Example 2

As shown in Figure 3, a kind of multi-layer PCB board comprises the first back drill layer 301 with at least one outer layer conductive layer, the second back drill layer 303 with at least one outer layer conductive layer and is arranged on said A laminated layer 302 having at least two circuit layers between the first back-drilling layer and the second back-drilling layer. Wherein, the first backdrilling layer 301 includes a first insulating layer 306 and a first metal layer 305 disposed on the first insulating layer 306; The second metal layer 307 and the third metal layer 309 disposed on the lower surface of the second insulating layer 308; the second backdrilling layer 303 includes a third insulating layer 310 and a fourth metal layer 311 disposed on the lower surface of the third insulating layer 310 . The first back-drilled layer 301 is provided with a first back-drilled hole 314 , and the second back-drilled layer 303 is provided with a second back-drilled hole 315 opposite to the first back-drilled hole 314 . The laminated layer 302 is provided with an inner layer conductive hole 312 disposed between the first back-drilled hole and the second back-drilled hole. The inner wall surface of the inner layer conductive hole 312 is provided with a first conductive layer 313. A conductive layer 313 connects at least two circuit layers of the stack. In FIG. 3 , the first conductive layer 313 connects the second metal layer 307 and the third metal layer 309 .

The multi-layer PCB board of this embodiment realizes the connection between the metal layers of the inner board, and the metal layer of the inner board is not connected with the metal layer of the outer board. The preparation of the multi-layer PCB board only needs to be pressed once, and the process is simple.

Example 3

As shown in Figure 4, a kind of multilayer PCB board comprises the first back drilling layer 401 that has at least one outer layer conductive layer, the second back drilling layer 403 that has at least one outer layer conductive layer and is arranged on said A laminated layer 402 having at least two circuit layers between the first back-drilling layer and the second back-drilling layer. Wherein, the first backdrilling layer 401 includes a first insulating layer 406 and a first metal layer 405 disposed on the first insulating layer 406; The second metal layer 407 and the third metal layer 409 disposed on the lower surface of the second insulating layer 408; the second backdrilling layer 403 includes a third insulating layer 410 and a fourth metal layer 411 disposed on the lower surface of the third insulating layer 410 . The first back-drilling layer 401 is provided with a first back-drilling hole 414 , and the second back-drilling layer 403 is provided with a second back-drilling hole 415 opposite to the first back-drilling hole 414 . The laminated layer 402 is provided with an inner layer conductive hole 412 disposed between the first back-drilled hole and the second back-drilled hole. The inner wall surface of the inner layer conductive hole 412 is provided with a first conductive layer 413. A conductive layer 413 connects at least two circuit layers of the stack. In FIG. 3 , the first conductive layer 413 connects the second metal layer 407 and the third metal layer 409 .

The multi-layer PCB board further includes a conductive through hole 420 , which runs through the multi-layer PCB board, and the hole wall of the conductive through hole is provided with a second conductive layer 417 . The second conductive layer 417 is used to connect the first metal layer 405 of the first backdrilling layer 401 and the fourth metal layer 411 of the first backdrilling layer 403 .

The multi-layer PCB further includes a resin plug body 418 for plugging holes in the first back-drilled hole 414 and the second back-drilled hole 415 . The surface of the resin plug body is provided with a conductive layer for making circuit patterns, so that circuit patterns can also be made on the surface area of the plug body, preventing the surface of the plug body from occupying the space for making circuit patterns.

In this embodiment, the multilayer PCB board realizes the connection between the metal layers of the inner layer and the connection between the conductive layers of the outer layer at the same time.

Above, the manufacturing method of a kind of multi-layer PCB board of the present invention and corresponding multi-layer PCB board have been introduced in detail through the embodiment, the description of the above embodiment is only used to help understand the method of the present invention and its core idea; at the same time, for the present invention Those of ordinary skill in the art will have changes in the specific implementation and scope of application according to the idea of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims (8)

1. A multi-layer PCB manufacturing method, characterized in that, comprising: Drill a first through hole on a multilayer PCB, and metallize the first through hole to form a first conductive layer on the hole wall of the first through hole, wherein the multilayer PCB includes at least the outermost The layer has a first back-drilling layer and a second back-drilling layer of a conductive layer, and a laminate with at least two circuit layers arranged between the first back-drilling layer and the second back-drilling layer, and the first through hole penetrating through the first back-drilling layer, stacked layers and second back-drilling layer; Perform the first back-drilling on the first back-drilling layer along the metallized first through hole to remove part of the first conductive layer on the first back-drilling layer, so that the first back-drilling after the first back-drilling The conductive layer is disconnected from at least the outermost conductive layer located in the first backdrilling layer; Carry out a second back-drilling on the second back-drilling layer along the metallized first via hole to remove part of the first conductive layer on the second back-drilling layer, so that the first back-drilling after the second back-drilling The conductive layer is disconnected from at least the outermost conductive layer located in the second backdrilling layer; Wherein, the first backdrilling layer includes a first insulating layer and a first metal layer disposed on the first insulating layer; the laminate includes a second insulating layer, and the second metal layer disposed on the upper surface of the second insulating layer layer and a third metal layer arranged on the lower surface of the second insulating layer; the second backdrilling layer includes a third insulating layer and a fourth metal layer arranged on the lower surface of the third insulating layer. 2. The multilayer PCB manufacturing method according to claim 1, further comprising: Drilling a second through hole on the multi-layer PCB, and metallizing the second through hole, so as to form a second conductive layer on the hole wall of the second through hole. 3. The multilayer PCB manufacturing method according to claim 1 or 2, further comprising: performing resin plugging in the first through-hole after the first back-drilling and the second back-drilling; After the holes are plugged with resin, metallization is carried out on the multi-layer PCB board to form a conductive layer for making circuit patterns on the surface of the plug hole resin. 4. multi-layer PCB manufacturing method according to claim 1, is characterized in that, also comprises: Drill the second through hole on the multi-layer PCB board; performing resin plugging in the first through-hole after the first back-drilling and the second back-drilling; Metallize the multi-layer PCB to form a second conductive layer on the wall of the second through hole, and form a conductive layer for making circuit patterns on the surface of the plug hole resin. 5. A multi-layer PCB board, characterized in that, comprises a first back drill layer with at least one outer layer conductive layer, a second back drill layer with at least one outer layer conductive layer and is located on the first A stack of at least two circuit layers between the back-drilling layer and the second back-drilling layer, the first back-drilling layer is provided with a first back-drilling hole, and the second back-drilling layer is provided with the The second back-drilled hole opposite to the first back-drilled hole, the stack is provided with an inner layer conductive hole arranged between the first back-drilled hole and the second back-drilled hole, and the inner layer is electrically conductive The inner wall surface of the hole is provided with a first conductive layer, and the first conductive layer is connected to at least two circuit layers of the stack; Wherein, the first backdrilling layer includes a first insulating layer and a first metal layer disposed on the first insulating layer; the laminate includes a second insulating layer, and the second metal layer disposed on the upper surface of the second insulating layer layer and a third metal layer arranged on the lower surface of the second insulating layer; the second backdrilling layer includes a third insulating layer and a fourth metal layer arranged on the lower surface of the third insulating layer. 6. The multilayer PCB board according to claim 5, characterized in that, the multilayer PCB board also includes a conductive through hole, the conductive through hole runs through the multilayer PCB board, and the hole wall of the conductive through hole A second conductive layer is provided. 7. The multi-layer PCB board according to claim 5 or 6, wherein the multi-layer PCB board also includes the first back-drilled hole and the second back-drilled hole provided with plug holes. Resin plug body. 8. The multilayer PCB board according to claim 7, characterized in that, the surface of the resin plug body is provided with a conductive layer for making circuit patterns.