A production method of a copper-embedded heat sink PCB board and a copper-embedded heat sink PCB board

Abstract

The present invention relates to a production method of a PCB board with embedded copper heat sink blocks and a PCB board with embedded copper heat sink blocks. The production method of the PCB board with embedded copper heat sink blocks comprises: processing a bottom core board; welding a copper heat sink block at a preset position on the first surface of the bottom core board; stacking a release film on the first surface of the bottom core board; stacking an inner core board and a prepreg on the release film; pressing the bottom core board, the release film, the inner core board and the prepreg welded with the copper heat sink block; milling grooves on the second surface of the bottom core board corresponding to the welding position of the copper heat sink block to separate the bottom core board, the release film and the production board, the production board includes the inner core board, the prepreg and the copper heat sink after pressing; grinding the welding position of the copper heat sink on the production board, and performing post-production processes. The production method of the PCB board with embedded copper heat sink blocks of the present invention can automatically produce PCB boards with embedded copper heat sink blocks, reduce the influence of human factors, and improve the production yield of PCB boards with embedded copper heat sink blocks.

Description

Technical Field

[0001] The invention relates to the technical field of PCB production, and in particular to a production method of a PCB board with an embedded copper heat sink block and a PCB board with an embedded copper heat sink block. Background Art

[0002] As electronic products develop towards miniaturization, multi-function and portability, the size of PCB boards is getting smaller and smaller. For the safe use of products, the heat dissipation requirements are also increased accordingly. Copper heat sinks have excellent thermal conductivity, so they naturally become the preferred material for improving the heat dissipation capacity of PCB boards, and PCB boards with embedded copper heat sinks came into being.

[0003] In the past, PCB boards embedded with copper heat sinks were mostly used in automotive power products, mainly because the embedding of copper heat sinks during the production process was mainly done manually, and the copper heat sinks used in automotive power products were large in size and convenient for manual operation. However, the demand for miniaturized products has made the copper heat sinks smaller in size. During the manual operation, the inner core board and prepreg are drilled, positioned, milled, and riveted, and the copper blocks are manually placed in the through slots. When the copper blocks are small in size and in large quantities, the process is time-consuming and there are risks of missing, tilting, and shifting, which leads to product quality problems, increases the risk of process scrapping, and directly causes cost increases.

[0004] For example, when a large number of small-sized copper heat sinks are used (>100 pieces / PNL) and are placed manually, due to the small size of the copper heat sink (taking 0201 specifications as an example: 0.8mm long, 0.4mm wide, 0.2mm high), when the entire board needs to be placed, manual operation can easily cause copper blocks to be missed, resulting in missing copper blocks and scrap.

[0005] Similarly, when using a small-sized copper heat sink, the size of the semi-cured sheet milling groove is also very small. Since the minimum diameter of the milling cutter is 0.8mm, it cannot be operated and can only be cut by laser cutting or mechanical drilling. Laser cutting has two disadvantages: first, the cutting depth is limited. A semi-cured sheet with a thickness of 0.1mm can only be produced in single sheets, which is inefficient; second, the high temperature during cutting will burn the semi-cured sheet, and the periphery of the groove will be carbonized and blackened. Similarly, mechanical drilling also has shortcomings: first, the size of the semi-cured sheet drilling hole is not a regular rectangle, and there is a risk of offset during alignment; second, there will be glass fiber fibers of the semi-cured sheet in the middle of the connecting hole, which will affect the alignment of the copper block during lamination. Due to the irregularity of the semi-cured sheet drilling groove, the glue flow around the copper block is uneven, resulting in uneven force and displacement of the copper block during lamination.

[0006] Even if the core board and prepreg are ready, and the copper heat sink is placed without omission, the prepreg and core board are prone to slight tilt during the stacking process, and the copper heat sink will follow the tilt. During the pressing process, the copper heat sink will tilt sideways relative to the outer plane of the entire board, causing glue flow and overflow, resulting in half of the surface of the copper heat sink being exposed and half being covered by glue, which makes the copper heat sink and the outer copper surface poorly conductive. Summary of the invention

[0007] Based on this, it is necessary to provide a production method and a copper embedded heat sink PCB board to address the problem that deviation, omission, lateral tilt and the like are prone to occur during manual operation, which may lead to product quality problems, increase the risk of process scrapping, and directly cause cost increases.

[0008] A method for producing a PCB board with an embedded copper heat sink, the method comprising:

[0009] Bottom core board processing;

[0010] Welding a copper heat sink block at a preset position on the first surface of the bottom supporting core plate;

[0011] A release film is stacked on the first surface of the bottom core plate, and a first slot is formed on the release film at a position corresponding to the copper heat sink;

[0012] An inner core plate and a prepreg are stacked on the release film, and a second slot hole and a third slot hole are respectively opened on the inner core plate and the prepreg at positions corresponding to the copper heat sink;

[0013] Pressing the bottom core plate welded with the copper heat sink, the release film, the inner core plate and the prepreg;

[0014] Milling grooves on the second surface of the bottom core plate corresponding to the welding position of the copper heat sink block to separate the bottom core plate, the release film and the production plate, wherein the production plate includes the pressed inner core plate, the prepreg and the copper heat sink block;

[0015] The welding position of the copper heat sink block on the production board is ground and the post-production process is carried out.

[0016] The production method of the above-mentioned PCB board with embedded copper heat sink includes: processing a bottom core board; welding a copper heat sink at a preset position on the first side of the bottom core board; stacking a release film on the first side of the bottom core board, a first slot hole is provided on the release film at a position corresponding to the copper heat sink; stacking an inner core board and a semi-cured sheet on the release film, a second slot hole and a third slot hole are provided on the inner core board and the semi-cured sheet at positions corresponding to the copper heat sink, respectively; pressing the bottom core board, the release film, the inner core board and the semi-cured sheet to which the copper heat sink is welded; milling grooves on the second side of the bottom core board corresponding to the welding position of the copper heat sink to separate the bottom core board, the release film and the production board, the production board includes the pressed inner core board, the semi-cured sheet and the copper heat sink; grinding the welding position of the copper heat sink on the production board, and performing post-production processes. It can be seen that through the above-mentioned production method, the copper heat sink is pre-welded to the first surface of the bottom core board, and then the release film is stacked on the first surface of the bottom core board, and then the inner core board and the semi-cured sheet are stacked on the release film. After the pressing, milling and grinding processes, the production board with the inner core board, the semi-cured sheet and the copper heat sink can be pressed for post-production processes. The whole process avoids the manual placement of the copper heat sink, and also avoids the possible offset, missing, and lateral tilt of the copper heat sink. The production yield of the PCB board embedded with the copper heat sink can be increased by more than 20%, and the production efficiency can be increased by more than 30%.

[0017] In one embodiment, welding a copper heat sink block at a preset position on the first surface of the bottom core plate comprises:

[0018] Determine the soldering surface of the copper heat sink block to be soldered;

[0019] The copper heat dissipation block is welded at a preset position on the first surface of the bottom supporting core plate, so that the copper heat dissipation block is fixedly connected to the bottom supporting core plate through the welding surface.

[0020] In one embodiment, the post-production process includes:

[0021] drilling;

[0022] Copper plating;

[0023] Outer circuit production;

[0024] Solder mask area production;

[0025] Surface treatment;

[0026] test;

[0027] forming;

[0028] Finished product inspection.

[0029] In one embodiment, the processing method of the bottom supporting core plate includes:

[0030] Cutting materials;

[0031] Baking sheet;

[0032] Drilling positioning holes;

[0033] Solder mask;

[0034] Browning.

[0035] In one embodiment, the processing method of the inner core plate includes:

[0036] Cutting materials;

[0037] bake;

[0038] Inner circuit production;

[0039] Inner layer etching;

[0040] Inner circuit inspection;

[0041] Slot milling;

[0042] Browning.

[0043] In one embodiment, the processing method of the prepreg comprises:

[0044] Cutting materials;

[0045] Drilling positioning holes;

[0046] Milling a groove at a position corresponding to the copper heat sink;

[0047] test.

[0048] In one embodiment, the processing method of the copper heat sink block includes:

[0049] Cutting materials;

[0050] Gong copper block;

[0051] Browning;

[0052] clean;

[0053] bake.

[0054] In one embodiment, the copper heat sink has a length no greater than 10 mm, a width no greater than 10 mm, and a thickness no greater than 3 mm.

[0055] In one embodiment, the copper heat sink has a shape of a cube or a cylinder.

[0056] A copper embedded heat sink block PCB board is produced according to the production method of the copper embedded heat sink block PCB board. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 It is a schematic diagram of the process of producing a PCB board with embedded copper heat sink of the present invention;

[0058] Figure 2 It is a schematic diagram of the production structure after pressing in the production method of the copper-embedded heat sink PCB board of the present invention;

[0059] Figure 3 It is a schematic diagram of the production structure after the groove is milled in the production method of the copper-embedded heat sink PCB board of the present invention;

[0060] Figure 4 It is a schematic diagram of the production structure after grinding in the production method of the copper embedded heat sink PCB board of the present invention. DETAILED DESCRIPTION

[0061] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0062] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may also be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. In contrast, when an element is referred to as being "directly on" another element, there is no intermediate element. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only."

[0063] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0064] The invention discloses a production method of a PCB board embedded with a copper heat dissipation block.

[0065] like Figures 1 to 4 As shown, the method includes:

[0066] Step S01: Processing the bottom core board.

[0067] Among them, the processing methods of the bottom core board include cutting; baking the board; drilling positioning holes; solder resist; and browning.

[0068] When cutting the bottom core board, the cutting operation is carried out according to the laminated structure and the engineering MI size and quantity requirements; when baking the bottom core board, the conventional baking parameters are followed, for example, baking at 150℃ for 2-4 hours; when drilling positioning holes for the bottom core board, the positioning holes required for subsequent production are drilled according to the engineering data; when solder masking the bottom core board, the solder mask is silk-screened at the welding position of the copper heat sink to prevent the diffusion of solder paste and cause the copper heat sink welding to be offset; when browning the bottom core board, the surface of the bottom core board is cleaned by browning to prepare for the welding of the copper heat sink.

[0069] Furthermore, when processing the bottom core board, engineering data design is also required. A welding pad of the same size as the welding surface of the copper heat sink block is designed in a mirror-symmetrical manner at the preset position of the copper heat sink block, and a positioning welding pad is set around the welding position for subsequent processes.

[0070] Step S02: welding a copper heat sink block at a preset position on the first surface of the bottom core plate.

[0071] The copper heat sink block can be pre-processed. The processing method of the copper heat sink block includes: cutting; gong copper block; browning; cleaning; baking. It can be understood that the processing method of the copper heat sink block is a prior art and will not be repeated here.

[0072] The copper heat sink is a small-sized copper block. The size of the copper heat sink is usually limited by the design and manufacturing capabilities of the PCB board. Generally speaking, the length and width of the small-sized copper block are between a few millimeters and tens of millimeters, and the thickness of the small-sized copper block will also vary depending on the specific application. The common thickness range of small-sized copper blocks is between 0.5mm-3mm. The shape of the copper heat sink can be a cube, a cylinder, or other specific shapes, depending on the layout of the PCB board and the heat dissipation requirements.

[0073] In the manual placement mode, the size range that a person can comfortably operate is affected by factors such as the shape of the copper block, surface friction, and personal hand flexibility. The size range that a person can comfortably operate is usually greater than 10 mm. In the embodiment of the present invention, the length of the copper heat sink is not greater than 10 mm, the width is not greater than 10 mm, and the thickness is not greater than 3 mm. Therefore, the copper heat sink in the embodiment of the present invention cannot be placed manually, and the copper heat sink can be automatically welded by welding equipment at a preset position on the first side of the bottom core plate, which improves production efficiency.

[0074] Since the copper heat sink may be an irregular shape, it is necessary to determine the most suitable side of the copper heat sink as the welding side to improve the welding quality. Furthermore, when welding the copper heat sink at the preset position of the first side of the bottom core plate, first determine the welding side of the copper heat sink to be welded; then weld the copper heat sink at the preset position of the first side of the bottom core plate, so that the copper heat sink is fixedly connected to the bottom core plate through the welding side.

[0075] Step S03: stacking a release film on the first surface of the bottom core board, wherein a first slot is formed on the release film at a position corresponding to the copper heat dissipation block.

[0076] The release film can be pre-processed, and the size of the first slot on the release film matches the size of the copper heat sink.

[0077] Step S04: stacking an inner core board and a prepreg on the release film, wherein a second slot hole and a third slot hole are respectively formed on the inner core board and the prepreg at positions corresponding to the copper heat sink.

[0078] The inner core plate and the prepreg are pre-processed. The size of the second slot on the inner core plate matches the size of the copper heat sink, and the size of the third slot on the prepreg matches the size of the copper heat sink.

[0079] Furthermore, the processing method of the inner core board includes: cutting; baking; inner layer circuit production; inner layer etching; inner layer circuit inspection; milling grooves; and browning.

[0080] Furthermore, the processing method of the prepreg includes: cutting; drilling positioning holes; milling grooves at positions corresponding to the copper heat sinks; and testing. It is understandable that the processing methods of the inner core board and the prepreg are both prior arts and will not be described in detail here.

[0081] Step S05: Pressing the bottom core board welded with the copper heat sink, the release film, the inner core board and the prepreg.

[0082] Among them, the bottom core board welded with the copper heat sink block, the release film, the inner core board and the prepreg can be pressed together by a press machine. Since the copper heat sink block is welded with the bottom core board, the risk of loosening and dislocation of the copper heat sink block during the pressing process is reduced, and the risk of displacement of the copper heat sink block during the pressing process is reduced.

[0083] Step S06: Milling grooves on the second surface of the bottom core board corresponding to the welding positions of the copper heat sink block to separate the bottom core board, the release film and the production board, wherein the production board includes the pressed inner core board, the semi-cured sheet and the copper heat sink block.

[0084] Among them, since the release film isolates the bonding between the bottom core board and the production board after lamination, the bottom core board and the production board are connected only through the welding position of the copper heat sink after lamination. By milling grooves on the second surface of the bottom core board corresponding to the welding position of the copper heat sink, the connection between the bottom core board and the production board can be disconnected, so as to separate the bottom core board, the release film and the production board.

[0085] Furthermore, the target hole positioning can be pre-performed on the second surface of the bottom core board corresponding to the welding position of the copper heat sink. When milling the groove, the second surface of the bottom core board is turned upward according to the target hole positioning, and the depth of the milling groove is controlled at the target hole position to separate the bottom core board, the release film and the production board.

[0086] Step S07: grinding the welding position of the copper heat sink block on the production board and performing post-production process.

[0087] Among them, when grinding the welding position of the copper heat sink on the production board, the tin and surface PP powder glue flow at the welding position of the copper heat sink on the production board can be ground and cleaned by sanding belt to facilitate the subsequent production process. After actual inspection, the production board is relatively flat after pressing, the glue flow around the copper heat sink is uniform, the pressure around the copper heat sink is balanced during the process, and there are no quality problems such as glue overflow and glue shortage.

[0088] The production method of the embodiment of the present invention has higher precision and tolerance than the prior art. For some high-precision applications, stricter dimensional precision and tolerance control may be required to ensure the matching and performance of the copper block and the PCB board. Generally, the precision tolerance of the prior art press fit is greater than 0.1mm, but in some high-precision applications, stricter tolerance control may be required. The embodiment of the present invention can increase the precision tolerance to ±0.05mm.

[0089] Furthermore, the post-production process includes: drilling; copper plating; outer layer circuit production; solder mask area production; surface treatment; testing; molding; and finished product inspection.

[0090] The production method of the above-mentioned PCB board with embedded copper heat sink includes: processing a bottom core board; welding a copper heat sink at a preset position on the first side of the bottom core board; stacking a release film on the first side of the bottom core board, a first slot hole is provided on the release film at a position corresponding to the copper heat sink; stacking an inner core board and a semi-cured sheet on the release film, a second slot hole and a third slot hole are provided on the inner core board and the semi-cured sheet at positions corresponding to the copper heat sink, respectively; pressing the bottom core board, the release film, the inner core board and the semi-cured sheet to which the copper heat sink is welded; milling grooves on the second side of the bottom core board corresponding to the welding position of the copper heat sink to separate the bottom core board, the release film and the production board, the production board includes the pressed inner core board, the semi-cured sheet and the copper heat sink; grinding the welding position of the copper heat sink on the production board, and performing post-production processes. It can be seen that through the above-mentioned production method, the copper heat sink is pre-welded to the first surface of the bottom core board, and then the release film is stacked on the first surface of the bottom core board, and then the inner core board and the semi-cured sheet are stacked on the release film. After the pressing, milling and grinding processes, the production board with the inner core board, the semi-cured sheet and the copper heat sink can be pressed for post-production processes. The whole process avoids the manual placement of the copper heat sink, and also avoids the possible offset, missing, and lateral tilt of the copper heat sink. The production yield of the PCB board embedded with the copper heat sink can be increased by more than 20%, and the production efficiency can be increased by more than 30%.

[0091] The present invention also discloses a copper-embedded heat sink block PCB board. The copper-embedded heat sink block PCB board is produced according to the above-mentioned copper-embedded heat sink block PCB board production method. Since the execution steps of the above-mentioned copper-embedded heat sink block PCB board production method can be normally scheduled by production equipment without manual operation, the product quantity problem caused by human omissions and irregular operations in the process is avoided, and the production yield of the copper-embedded heat sink block PCB board can be increased by more than 20%, and the production efficiency can be increased by more than 30%.

[0092] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0093] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for producing a PCB board with an embedded copper heat sink, characterized in that: The method comprises: Bottom core board processing; Welding a copper heat sink block at a preset position on the first surface of the bottom supporting core plate; A release film is stacked on the first surface of the bottom core plate, and a first slot is formed on the release film at a position corresponding to the copper heat sink; An inner core plate and a prepreg are stacked on the release film, and a second slot hole and a third slot hole are respectively opened on the inner core plate and the prepreg at positions corresponding to the copper heat sink; Pressing the bottom core plate welded with the copper heat sink, the release film, the inner core plate and the prepreg; Milling grooves on the second surface of the bottom core plate corresponding to the welding position of the copper heat sink block to separate the bottom core plate, the release film and the production plate, wherein the production plate includes the pressed inner core plate, the prepreg and the copper heat sink block; Grinding the welding position of the copper heat sink block on the production board and performing post-production process; The step of welding a copper heat sink block at a preset position on the first surface of the bottom core plate comprises: Determine the soldering surface of the copper heat sink block to be soldered; The copper heat dissipation block is welded at a preset position on the first surface of the bottom supporting core plate, so that the copper heat dissipation block is fixedly connected to the bottom supporting core plate through the welding surface.

2. The method for producing a PCB board with an embedded copper heat sink according to claim 1, characterized in that: The post-production process includes: drilling; Copper plating; Outer circuit production; Solder mask area production; Surface treatment; test; forming; Finished product inspection.

3. The method for producing a PCB board with an embedded copper heat sink according to claim 1, characterized in that: The processing method of the bottom supporting core plate comprises: Cutting materials; Baking sheet; Drilling positioning holes; Solder mask; Browning.

4. The method for producing a PCB board with an embedded copper heat sink according to claim 1, characterized in that: The inner core plate is pre-processed, and the processing method of the inner core plate includes: Cutting materials; bake; Inner circuit production; Inner layer etching; Inner circuit inspection; Slot milling; Browning.

5. The method for producing a PCB board with an embedded copper heat sink according to claim 1, characterized in that: The prepreg is pre-processed, and the processing method of the prepreg includes: Cutting materials; Drilling positioning holes; Milling a groove at a position corresponding to the copper heat sink; test.

6. The method for producing a PCB board with an embedded copper heat sink according to claim 1, characterized in that: The copper heat sink block is pre-processed, and the processing method of the copper heat sink block includes: Cutting materials; Gong copper block; Browning; clean; bake.

7. The method for producing a PCB board with an embedded copper heat sink according to claim 1, characterized in that: The copper heat sink has a length of no more than 10 mm, a width of no more than 10 mm and a thickness of no more than 3 mm.

8. The method for producing a PCB board with an embedded copper heat sink according to claim 7, characterized in that: The copper heat sink block has a cubic or cylindrical shape.

9. A PCB board with embedded copper heat sink, characterized in that: The copper embedded heat sink block PCB board is produced according to the production method of the copper embedded heat sink block PCB board according to any one of claims 1 to 8.

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