Manufacturing method of multi-network embedded copper block board

Abstract

The invention discloses a manufacturing method of a multi-network embedded copper block board, and relates to the technical field of embedded copper block boards, and the method comprises the following steps: S1, cutting: carrying out the positioning cutting of a CCL incoming material, and cutting the CCL incoming material into production sizes with the same size; and S2, preparing an inner layer, namely cleaning the plate surface by using micro-etching liquid medicine, covering photosensitive ink, drying and curing, performing ultraviolet irradiation by using an exposure machine to perform polymerization reaction, and performing expansion and shrinkage compensation on the plate in the polymerization reaction, and the like. According to the invention, the process of replacing the FR4PP + copper substrate containing heat-conducting PP with the whole heat-conducting insulating PP on the secondary outer layer is adopted, so that the original complex process is simplified, the production cycle is shortened, the production efficiency is improved, the connection of the joint of the inner layer and the outer layer is effectively avoided by using the whole PP to press, and the short circuit defect of the network is replaced and avoided, thereby solving the short circuit defect of electroplating and improving the production efficiency. And the product yield is improved.

Description

Technical Field

[0001] The invention relates to the technical field of buried copper block boards, and in particular to a method for manufacturing a multi-network buried copper block board. Background Art

[0002] A buried copper block board is a special circuit board with copper blocks embedded in its internal structure. Since copper blocks have good thermal conductivity, buried copper block boards are widely used in some electronic devices with high heat dissipation requirements.

[0003] Traditional buried copper block boards generally use copper substrates to act as copper blocks for embedding. The outer layer of the buried copper block has different networks and there is a thermal conductivity requirement of 1-10W between the copper block. After production, the connection between the copper substrate and FR4 is filled with PP glue. When the copper is deposited at a high temperature of 80 degrees, the PP glue has a certain shrinkage, resulting in copper deposition at the joints, causing a short circuit between the inner and outer layers at the joints, resulting in a short circuit between different networks on the outer layer, resulting in a high defect rate. Summary of the invention

[0004] The purpose of the present invention is to provide a method for producing a multi-network buried copper block board to solve the problem that the outer layer of the buried copper block has different networks and there is a 1-10W thermal conductivity requirement between the copper block and the copper block. After production, the connection between the copper substrate and FR4 is filled with PP glue. When the copper is deposited at a high temperature of 80 degrees, the PP glue has a certain shrinkage, resulting in copper deposition at the joint, causing a short circuit between the inner and outer layers at the joint, resulting in a short circuit between different networks in the outer layer, resulting in a high defect rate.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for manufacturing a multi-network buried copper block plate, comprising the following steps:

[0006] S1. Cutting: Position and cut the CCL incoming materials into production sizes with the same size;

[0007] S2, inner layer: Use micro-etching solution to clean the board surface, cover it with photosensitive ink and dry it to solidify, use an exposure machine to irradiate it with ultraviolet light to make it polymerize, and compensate for the expansion and contraction of the board during the polymerization reaction. After exposure, use a DES line to develop, etch, and remove the film to achieve the desired graphics and the gong groove positioning hole ring required for the next process on the copper clad board;

[0008] S3, gong groove: use the inner positioning hole ring to identify, use the target machine to locate, and use the CNC molding machine to perform precision gong groove processing;

[0009] S4, pressing: After all the layers of the inner board are browned, fused and riveted, the positioning holes are used to form grooves in the area where the copper block needs to be buried, and then the copper block is placed in the grooves. When pressing and pre-arranging, a whole sheet of thermal conductive glue and copper foil is placed on one side of different networks. After pressing by a press, the copper block is successfully buried;

[0010] S5, drilling: drilling the sheet material according to the drilling requirements;

[0011] S6, copper deposition and electroplating: Use chemical CuCL2 solution to deposit 1-3um copper on the entire board and in the holes, and then electroplate copper on the board surface to increase the copper thickness on the board surface and in the holes;

[0012] S7, Circuit: Use micro-etching solution and brushing process to clean the board surface, apply a layer of photosensitive dry film, use an exposure machine to irradiate with ultraviolet light to make it polymerize, and use a DES line to develop, etch, and remove the film after exposure to achieve the desired pattern on the copper clad board;

[0013] S8, solder mask: Use volcanic ash and brushing process to clean the board surface, print a layer of photosensitive ink on the board surface and dry it for pre-baking, use exposure machine to irradiate with ultraviolet light to make it polymerize, and use developing line after exposure to develop the window required by the customer;

[0014] S9, Text and surface treatment: Use a text printer to print text and perform surface treatment;

[0015] S10: The product is finally formed, tested and inspected for appearance, and packaged after passing the test.

[0016] Preferably, in step S2, the exposure energy is selected to be 5-7 grids, and the expansion and shrinkage compensation is performed according to different board thicknesses and copper thicknesses. Conventional X compensation is 3 / 10000, and Y compensation is 5 / 10000. The expansion and shrinkage method is to shrink the four sides of the board evenly toward the center of the board.

[0017] Preferably, in step S3, the positioning of the CNC molding machine with a target machine for precision gong groove processing includes the following steps:

[0018] S31, placing the positioned plate on the CNC forming machine, presetting the gong groove parameters, and the accuracy of the gong groove is ±0.05mm;

[0019] S32, CNC forming machine performs precision grooving operations on the plate according to the pre-set program;

[0020] S33. After the gong groove is processed, clean the surface.

[0021] Preferably, in step S6, the copper electroplating comprises the following steps:

[0022] S61, the plate is placed in the electroplating tank;

[0023] S62, electroplating with the copper phosphorus ball as an anode and the plate as a cathode;

[0024] S63, copper phosphorus balls lose electrons at the anode and become copper ions. The copper ions move toward the cathode under the action of the electric field and deposit on the surface of the plate;

[0025] S64. Complete the copper thickening on the plate surface and in the holes.

[0026] Preferably, in step S7, the micro-etching solution consists of H2SO4 and H2O2.

[0027] Preferably, in step S7, the developing, etching and film stripping operations using the DES line include the following steps:

[0028] S71, placing the exposed copper-clad laminate into the developing area of ​​the DES line, and chemically reacting the developing solution with the unpolymerized photosensitive material in the exposed area to dissolve the photosensitive material in the developing solution;

[0029] S72, the copper clad laminate after development enters the etching area, and the etching solution chemically reacts with the copper layer on the copper clad laminate that is not protected by the photosensitive material, and the unnecessary copper layer is etched away;

[0030] S73, the copper-clad laminate after etching enters the film stripping area, and the film stripping liquid reacts chemically with the photosensitive material remaining on the copper-clad laminate, causing it to fall off the surface of the copper-clad laminate;

[0031] S74. After the operation is completed, the required pattern will appear on the copper-clad board.

[0032] Preferably, in step S10, the final molding accuracy is ±0.1 mm, and the special control accuracy is ±0.05 mm.

[0033] Preferably, in step S10, the test includes a conduction test and an insulation test; the appearance inspection uses AVI 100% scanning and comparison, and products that do not meet the requirements are selected for repair or scrapping.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. In this method, the original complex process is simplified, the production cycle is shortened, and the production efficiency is improved by using the entire surface of thermally conductive insulating PP in the sub-outer layer to replace the FR4PP+copper substrate containing thermally conductive PP process. The whole PP is pressed to effectively prevent the connection between the inner and outer layer seams, thereby replacing and eliminating network short circuit defects, thereby solving electroplating short circuit defects and improving product yield.

[0036] 2. In this method, the thermal conductivity of the entire circuit board is effectively improved by using thermal conductive glue and copper foil, placing copper blocks reasonably, and using thermal conductive PP for the sub-outer layer. This enables the circuit board to dissipate heat better during operation, improve the stability and service life of the equipment, and reduce failures caused by overheating. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The present invention is a flow chart of a method for manufacturing a multi-network buried copper block plate. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the implementation regulations described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] See also Figure 1 The present invention provides a technical solution: a method for manufacturing a multi-network buried copper block plate, comprising the following steps:

[0040] Step 1: Cutting: Position and cut the CCL materials into production sizes with consistent sizes to ensure the consistency and accuracy of subsequent processing;

[0041] Step 2, inner layer: Use micro-etching solution to clean the board surface, remove impurities and oxide layer, create good conditions for subsequent photosensitive ink coverage and polymerization reaction, cover with photosensitive ink for drying and curing, use exposure machine to irradiate with ultraviolet light to make it polymerize, and compensate for the expansion and contraction of the board in the polymerization reaction. After exposure, use DES line for development, etching, and film removal to realize the required graphics and gong groove positioning hole ring required for the next process on the copper clad board, which is convenient for subsequent equipment identification and prepares for gong groove and other processes;

[0042] Among them, the exposure energy is selected as 5-7 grids, and the expansion and shrinkage compensation is carried out according to different board thickness and copper thickness. The conventional X compensation is 3 / 10000, and the Y compensation is 5 / 10000. The expansion and shrinkage method is to shrink evenly from the four sides of the board to the center of the board;

[0043] Step 3, gong groove: Use the inner layer positioning hole ring to identify, and use the target machine to locate for the CNC molding machine to perform precision gong groove processing. These gong grooves provide accurate positions for the subsequent placement of copper blocks, ensure the matching accuracy of copper blocks and plates, and meet the structural design requirements of various network buried copper block plates; Among them, the precision gong groove processing includes the following steps:

[0044] 31) Place the positioned plate on the CNC forming machine, preset the gong groove parameters, and the accuracy of the gong groove is ±0.05mm;

[0045] 32) The CNC forming machine performs precision grooving operations on the sheet according to a pre-set program;

[0046] 33) After the gong groove is processed, clean the surface;

[0047] Step 4: Pressing: After all layers of inner boards are browned, fused and riveted, use the positioning holes to form grooves in the areas where copper blocks need to be buried, and then place the copper blocks in the grooves. When pre-pressing, place a whole sheet of thermal conductive glue and copper foil on one side of different networks, and then press them with a press to successfully bury the copper blocks.

[0048] Step 5: Drill the sheet material according to the drilling requirements;

[0049] Step 6: Copper deposition and electroplating: Use chemical CuCL2 solution to deposit 1-3um copper on the entire board and in the holes, providing a good foundation for the electroplating process, so that the subsequent electroplated copper can adhere better and improve the conductivity of the product. Then, copper electroplating is performed on the surface of the board to increase the copper thickness on the board surface and in the holes;

[0050] The copper electroplating process is as follows: first, place the plate in the electroplating tank; use the copper phosphorus ball as the anode and the plate as the cathode for electroplating; the copper phosphorus ball loses electrons at the anode and becomes copper ions, which move to the cathode under the action of the electric field and deposit on the surface of the plate; the copper thickening of the plate surface and the inside of the hole is completed;

[0051] Step 7, Circuit: Use micro-etching solution and brushing process to clean the board surface, press a layer of photosensitive dry film, use an exposure machine to irradiate with ultraviolet light to make it polymerize, and use a DES line to develop, etch, and remove the film after exposure to realize the desired pattern on the copper clad board, forming the circuit part of the circuit board, and realizing circuit connection and signal transmission;

[0052] Among them, the micro-etching solution is composed of H2SO4 and H2O2, and the development, etching and film stripping operations using the DES line include the following steps:

[0053] 71) The exposed copper-clad laminate is placed in the developing area of ​​the DES line, and the developer chemically reacts with the unpolymerized photosensitive material in the exposed area to dissolve it in the developer;

[0054] 72) After development, the copper-clad laminate enters the etching area, and the etching solution chemically reacts with the copper layer on the copper-clad laminate that is not protected by the photosensitive material, etching away the unnecessary copper layer;

[0055] 73) After etching, the copper-clad laminate enters the film stripping area, and the film stripping liquid reacts chemically with the remaining photosensitive material on the copper-clad laminate, causing it to fall off the surface of the copper-clad laminate;

[0056] 74) After the operation is completed, the required pattern appears on the copper-clad board;

[0057] Step 8, solder mask: Use volcanic ash and brushing process to clean the board surface, print a layer of photosensitive ink on the board surface, dry and pre-bake it, use an exposure machine to irradiate it with ultraviolet light to make it polymerize, and use a developing line after exposure to develop the window required by the customer;

[0058] Step 9: Text and surface treatment: Use a text printer to print text and treat the surface;

[0059] Step 10: Final molding of the product with molding accuracy of ±0.1mm and special control accuracy of ±0.05mm. Then, testing and appearance inspection are carried out, including continuity test and insulation test. Appearance inspection uses AVI100% scanning and comparison, and products that do not meet the requirements are selected for repair or scrapping to ensure product quality and safety, prevent unqualified products from entering the market, and package the products after they pass the test.

[0060] In the present method, the thermal conductivity of the entire circuit board is effectively improved by using thermally conductive adhesive and copper foil, and by placing copper blocks in a reasonable manner, and by using thermally conductive PP in the sub-outer layer. This enables the circuit board to dissipate heat better during operation, improve the stability and service life of the equipment, and reduce failures caused by overheating. Thermally conductive adhesive and copper foil and other materials are placed on one side of different networks, and precise process control, such as inner layer processing, solder mask and other steps, effectively ensures the insulation performance between different networks, which can prevent circuit short circuits, ensure the normal operation of the circuit, and improve the reliability of the product. The present invention uses the sub-outer layer to use the entire surface of thermally conductive insulating PP to replace the FR4PP+copper substrate containing thermally conductive PP process, which simplifies the original complex process. The use of thermally conductive PP in the entire sub-outer layer can solve the problem of poor electroplating short circuits. The short circuit connectivity problem caused by material shrinkage and other reasons that often occurs in traditional processes is effectively solved, and the product yield is significantly improved.

[0061] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for manufacturing a multi-network buried copper block board, characterized in that: The following steps are involved: S1. Cutting: Position and cut the CCL incoming materials into production sizes with the same size; S2, inner layer: Use micro-etching solution to clean the board surface, cover it with photosensitive ink and dry it to solidify, use an exposure machine to irradiate it with ultraviolet light to make it polymerize, and compensate for the expansion and contraction of the board during the polymerization reaction. After exposure, use a DES line to develop, etch, and remove the film to achieve the desired graphics and the gong groove positioning hole ring required for the next process on the copper clad board; S3, gong groove: use the inner positioning hole ring to identify, use the target machine to locate, and use the CNC molding machine to perform precision gong groove processing; S4, pressing: After all the layers of the inner board are browned, fused and riveted, the positioning holes are used to form grooves in the area where the copper block needs to be buried, and then the copper block is placed in the grooves. When pressing and pre-arranging, a whole sheet of thermal conductive glue and copper foil is placed on one side of different networks. After pressing by a press, the copper block is successfully buried; S5, drilling: drilling the sheet material according to the drilling requirements; S6, copper deposition and electroplating: Use chemical CuCL2 solution to deposit 1-3um copper on the entire board and in the holes, and then electroplate copper on the board surface to increase the copper thickness on the board surface and in the holes; S7, Circuit: Use micro-etching solution and brushing process to clean the board surface, apply a layer of photosensitive dry film, use an exposure machine to irradiate with ultraviolet light to make it polymerize, and use a DES line to develop, etch, and remove the film after exposure to achieve the desired pattern on the copper clad board; S8, solder mask: Use volcanic ash and brushing process to clean the board surface, print a layer of photosensitive ink on the board surface and dry it for pre-baking, use exposure machine to irradiate with ultraviolet light to make it polymerize, and use developing line after exposure to develop the window required by the customer; S9, Text and surface treatment: Use a text printer to print text and perform surface treatment; S10: The product is finally formed, tested and inspected for appearance, and packaged after passing the test.

2. The method for manufacturing a multi-network buried copper block board according to claim 1, characterized in that: In step S2, the exposure energy is selected to be 5-7 grids, and the expansion and shrinkage compensation is performed according to different board thicknesses and copper thicknesses. Conventionally, the X compensation is 3 / 10000, and the Y compensation is 5 / 10000. The expansion and shrinkage method is to shrink the four sides of the board evenly toward the center of the board.

3. The method for manufacturing a multi-network buried copper block board according to claim 1, characterized in that: In step S3, the positioning of the target machine for the CNC molding machine to perform precision gong groove processing includes the following steps: S31, placing the positioned plate on the CNC forming machine, presetting the gong groove parameters, and the accuracy of the gong groove is ±0.05mm; S32, CNC forming machine performs precision grooving operations on the plate according to the pre-set program; S33. After the gong groove is processed, clean the surface.

4. The method for manufacturing a multi-network buried copper block board according to claim 1, characterized in that: In step S6, the copper electroplating comprises the following steps: S61, the plate is placed in the electroplating tank; S62, electroplating with the copper phosphorus ball as an anode and the plate as a cathode; S63, copper phosphorus balls lose electrons at the anode and become copper ions. The copper ions move toward the cathode under the action of the electric field and deposit on the surface of the plate; S64. Complete the copper thickening on the plate surface and in the holes.

5. The method for manufacturing a multi-network buried copper block board according to claim 1, characterized in that: In step S7, the micro-etching solution is composed of H2SO4 and H2O2.

6. The method for manufacturing a multi-network buried copper block board according to claim 1, characterized in that: In step S7, the development, etching and film stripping operations using the DES line include the following steps: S71, placing the exposed copper-clad laminate into the developing area of ​​the DES line, and chemically reacting the developing solution with the unpolymerized photosensitive material in the exposed area to dissolve the unpolymerized photosensitive material in the developing solution; S72, the copper clad laminate after development enters the etching area, and the etching solution chemically reacts with the copper layer on the copper clad laminate that is not protected by the photosensitive material, and the unnecessary copper layer is etched away; S73, the copper-clad laminate after etching enters the film stripping area, and the film stripping liquid reacts chemically with the photosensitive material remaining on the copper-clad laminate, causing it to fall off the surface of the copper-clad laminate; S74. After the operation is completed, the required pattern will appear on the copper-clad board.

7. The method for manufacturing a multi-network buried copper block board according to claim 1, characterized in that: In step S10, the final molding accuracy is ±0.1 mm, and the special control accuracy is ±0.05 mm.

8. The method for manufacturing a multi-network buried copper block board according to claim 1, characterized in that: In step S10, the test includes a conduction test and an insulation test; the appearance inspection uses AVI 100% scanning and comparison to select products that do not meet the requirements for repair or scrapping.

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