Method for manufacturing HDI printed circuit board with selective sidewall recess and metallization

Abstract

A method for manufacturing an HDI printed circuit board with selectively recessed and metallized sidewalls comprises the following steps: step 1: opening the board; step 2: reducing copper; step 3: blind groove processing; step 4: blind groove electroplating; step 5: plugging holes; step 6: sealing grooves; step 7: circuit production; step 8: pressing; step 9: cutting; step 10: dissolving glue; step 11: blind hole processing; step 12: film exposure; step 13: sealing holes; step 14: film stripping; step 15: flash etching. The present invention first completes the product's arbitrary interconnection and fills the area that needs metallization with special glue, then uses a mechanical gong plate to expose and dissolve the special glue from the side, and finally produces a shaped metal sidewall. This method can easily meet the needs of selective sidewall metallization and make the circuit design of the processed high-density arbitrary interconnection circuit board more flexible. The present invention is highly practical and has strong promotional significance.

Description

Technical Field

[0001] The present invention relates to the field of printed circuit board manufacturing technology, and in particular to a method for manufacturing a selectively sidewall recessed and metallized HDI printed circuit board. Background Art

[0002] A printed circuit board (PCB) is an important electronic component that supports and connects electronic components. High-density interconnected boards (HDIs) interconnect multiple boards to meet the needs of different devices and are often referred to as HDI boards.

[0003] During the HDI board manufacturing process, holes must be drilled and then metallized to achieve interconnection between the inner and outer layers. However, the existing method for metallizing the sidewalls involves mechanical groove cutting, copper-tin electroplating, and mechanical cutting and etching. This method cannot meet the requirements of selective sidewall metallization. Summary of the Invention

[0004] Based on this, it is necessary to address the deficiencies in the prior art and provide a method for manufacturing a HDI printed circuit board with selective sidewall recessing and metallization.

[0005] A method for manufacturing a selectively sidewall recessed and metallized HDI printed circuit board comprises the following steps:

[0006] Step 1: Open the board, open a copper clad board, and use a two-way build-up method to build up the circuit board to make it a high-density multi-layer circuit board with arbitrary interconnection structure;

[0007] Step 2: Reduce copper by using chemical etching to reduce the thickness of the outer copper layer of the circuit board;

[0008] Step 3: Blind groove processing: use laser drilling equipment to process blind grooves on the surface of the circuit board;

[0009] Step 4: Blind slot electroplating, using chemical copper deposition and electroplating to make metal copper on the side wall of the blind slot;

[0010] Step 5: plugging the hole, using a vacuum plugging machine to plug the special glue into the blind groove, the special glue has the characteristic of being easily soluble in chemical solvents;

[0011] Step 6: Sealing the slot, using sputtering copper and electroplating copper to thicken the surface of the circuit board to ensure that the notch of the blind slot is sealed;

[0012] Step 7: Circuit production, using the printed circuit board negative process to produce the conductor circuit required for the circuit board;

[0013] Step 8: Lamination: Use bidirectional build-up lamination to laminate the dielectric layer and 3-micron-thin copper foil on the upper and lower surfaces of the circuit board respectively;

[0014] Step 9: Cutting: Use a mechanical gong to cut the circuit board along the blind groove position, exposing the special glue in the blind groove from the side;

[0015] Step 10: Sol, use a chemical solvent to dissolve the special glue filled in the blind groove, and use an ultrasonic cleaning device to clean the blind groove cavity;

[0016] Step 11: Blind hole processing: use laser drilling equipment to process blind holes on the surface of the circuit board, and use plasma cleaning equipment to clean the blind holes and blind groove cavities;

[0017] Step 12: Film exposure: apply dry film to the surface of the circuit board and expose it, then use chemicals to remove the unexposed parts;

[0018] Step 13: Sealing the holes: Copper is plated on the surface of the circuit board using chemical copper deposition and electroplating to thicken the holes, ensuring that the openings of the blind holes are sealed and metal copper is formed on the side walls of the circuit board.

[0019] Step 14: Remove the film by using chemicals to remove the exposed dry film on the surface of the circuit board, leaving several pits on the surface of the circuit board;

[0020] Step 15: Flash etching: Use chemicals to flash-etch away the ultra-thin copper foil at the bottom of the pit to form the final circuit board product.

[0021] Furthermore, the outer copper thickness in step 2 is reduced to 10 microns, the metal copper thickness of the blind groove side wall in step 4 is 15 microns, the copper plating thickness in step 6 is 15 microns, and the copper plating thickness in step 13 is 20 microns.

[0022] Furthermore, the laser drilling equipment in step 3 is a UV picosecond laser drilling equipment, which can ablate metal copper, epoxy resin and glass fiber cloth materials.

[0023] Furthermore, in step 5, after the special glue is inserted into the blind groove, the excess special glue at the blind groove opening is ground and leveled until the special glue and the copper surface of the circuit board are in the same plane.

[0024] Furthermore, the chemical dissolving agents in step 5 and step 10 are both alkaline chemical dissolving agents, the chemical agent in step 12 is sodium carbonate solution, and the chemical agent in step 14 is sodium hydroxide solution.

[0025] In summary, the beneficial effect of the method for manufacturing an HDI printed circuit board with selectively recessed and metallized sidewalls of the present invention is that: by first completing the arbitrary interconnection of the product and filling the special glue in the area requiring metallization, then using a mechanical gong plate to expose and dissolve the special glue from the side, and finally manufacturing the formed metal sidewalls, the method can easily meet the requirements of selective sidewall metallization and make the circuit design of the processed high-density arbitrary interconnection circuit board more flexible; the present invention is highly practical and has strong promotion significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of the cross-sectional structure of a circuit board in steps 1 to 3 of a method for manufacturing a selectively sidewall recessed and metallized HDI printed circuit board according to the present invention;

[0027] Figure 2 This is a schematic diagram of the cross-sectional structure of a circuit board in the process of steps 4 to 6 in a method for manufacturing a selectively sidewall recessed and metallized HDI printed circuit board according to the present invention;

[0028] Figure 3 A schematic diagram of the cross-sectional structure of a circuit board in steps 7 to 9 of a method for manufacturing a selectively sidewall recessed and metallized HDI printed circuit board according to the present invention;

[0029] Figure 4 A schematic diagram of the cross-sectional structure of a circuit board in the process from step 10 to step 12 in a method for manufacturing a selectively sidewall recessed and metallized HDI printed circuit board according to the present invention;

[0030] Figure 5 This is a schematic diagram of the cross-sectional structure of a circuit board during steps 13 to 15 of a method for manufacturing a selectively sidewall recessed and metallized HDI printed circuit board according to the present invention. DETAILED DESCRIPTION

[0031] In order to further understand the features, technical means, specific objectives and functions achieved by the present invention, and to analyze the advantages and spirit of the present invention, a further understanding is obtained through the following detailed description of the present invention in conjunction with the accompanying drawings and specific embodiments.

[0032] like Figures 1 to 5 As shown, the present invention provides a method for manufacturing an HDI printed circuit board with selective sidewall recess and metallization, comprising the following steps:

[0033] Step 1: Open the board, open a copper clad board, and use a two-way build-up method to build up the circuit board to make it a high-density multi-layer circuit board with arbitrary interconnection structure;

[0034] Step 2: Reduce copper by using chemical etching to reduce the outer copper thickness of the circuit board to 10 microns;

[0035] Step 3: Processing the blind groove 10: using a UV picosecond laser drilling device that can ablate metal copper, epoxy resin and fiberglass cloth to process the blind groove 10 on the surface of the circuit board;

[0036] Step 4: electroplating the blind groove 10, using chemical copper deposition and electroplating methods to produce a 15 micron thick metal copper on the side wall of the blind groove 10;

[0037] Step 5: Plug the hole. Use a vacuum plugging machine to plug the special glue 20 into the blind groove 10, and grind and level the excess special glue 20 at the mouth of the blind groove 10 until the special glue 20 and the copper surface of the circuit board are in the same plane. The special glue 20 is easily soluble in alkaline chemical solvents.

[0038] Step 6: Sealing the groove, using sputtering copper and electroplating copper to plate copper on the surface of the circuit board with a thickness of 15 microns to ensure that the notch of the blind groove 10 is sealed;

[0039] Step 7: Circuit production, using the printed circuit board negative process to produce the conductor circuit required for the circuit board;

[0040] Step 8: Lamination: Use bidirectional build-up lamination to laminate the dielectric layer and 3-micron-thin copper foil on the upper and lower surfaces of the circuit board respectively;

[0041] Step 9: Cutting: Use a mechanical gong plate method to cut the circuit board along the position of the blind groove 10 to expose the special glue 20 in the blind groove 10 from the side;

[0042] Step 10: Sol, using an alkaline chemical solvent to dissolve the special glue 20 filled in the blind groove 10, and using an ultrasonic cleaning device to clean the cavity of the blind groove 10;

[0043] Step 11: Processing the blind hole 30: Use a laser drilling device to process the blind hole 30 on the surface of the circuit board, and use a plasma cleaning device to clean the blind hole 30 and the blind groove 10 cavity;

[0044] Step 12: Film exposure: apply dry film 40 to the surface of the circuit board and expose it, then use sodium carbonate solution to remove the unexposed part;

[0045] Step 13: Sealing the holes: Copper is plated on the surface of the circuit board to a thickness of 20 microns using a method of chemical copper deposition and electroplating to ensure that the openings of the blind holes 30 are sealed, and metal copper is formed on the side walls of the circuit board.

[0046] Step 14: De-filming: using sodium hydroxide solution to remove the exposed dry film 40 on the circuit board surface, forming a plurality of pits 50 on the circuit board surface;

[0047] Step 15: Flash etching: using chemical agents to flash-etch away the ultra-thin copper foil at the bottom of the pit 50 to form the final circuit board product.

[0048] In summary, the beneficial effect of the method for manufacturing a HDI printed circuit board with selective sidewall recess and metallization of the present invention is that: by first completing the arbitrary interconnection of the product and filling the special glue 20 in the area requiring metallization, then using a mechanical gong plate to expose and dissolve the special glue 20 from the side, and finally manufacturing the formed metal sidewall, the method can easily meet the requirements of selective sidewall metallization and make the circuit design of the processed high-density arbitrary interconnection circuit board more flexible; the present invention is highly practical and has strong promotion significance.

[0049] The above-described embodiment merely represents one embodiment of the invention, and while the description is relatively specific and detailed, it should not be construed as limiting the scope of the patent. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the inventive concept, and these modifications and improvements fall within the scope of the invention. Therefore, the scope of patent protection for an invention shall be determined by the appended claims.

Claims

1. A method for manufacturing a selectively sidewall recessed and metallized HDI printed circuit board, characterized in that: The steps include: Step 1: Open the board, open a copper clad board, and use a two-way build-up method to build up the circuit board to make it a high-density multi-layer circuit board with arbitrary interconnection structure; Step 2: Reduce copper by using chemical etching to reduce the thickness of the outer copper layer of the circuit board; Step 3: Blind groove processing: use laser drilling equipment to process blind grooves on the surface of the circuit board; Step 4: Blind slot electroplating, using chemical copper deposition and electroplating to make metal copper on the side wall of the blind slot; Step 5: plugging the hole, using a vacuum plugging machine to plug the special glue into the blind groove, the special glue has the characteristic of being easily soluble in chemical solvents; Step 6: Sealing the slot, using sputtering copper and electroplating copper to thicken the surface of the circuit board to ensure that the notch of the blind slot is sealed; Step 7: Circuit production, using the printed circuit board negative process to produce the conductor circuit required for the circuit board; Step 8: Lamination: Use bidirectional build-up lamination to laminate the dielectric layer and 3-micron-thin copper foil on the upper and lower surfaces of the circuit board respectively; Step 9: Cutting: Use a mechanical gong to cut the circuit board along the blind groove position, exposing the special glue in the blind groove from the side; Step 10: Sol, use a chemical solvent to dissolve the special glue filled in the blind groove, and use an ultrasonic cleaning device to clean the blind groove cavity; Step 11: Blind hole processing: use laser drilling equipment to process blind holes on the surface of the circuit board, and use plasma cleaning equipment to clean the blind holes and blind groove cavities; Step 12: Film exposure: apply dry film to the surface of the circuit board and expose it, then use chemicals to remove the unexposed parts; Step 13: Sealing the holes: Copper is plated on the surface of the circuit board using chemical copper deposition and electroplating to thicken the holes, ensuring that the openings of the blind holes are sealed and metal copper is formed on the side walls of the circuit board. Step 14: Remove the film by using chemicals to remove the exposed dry film on the surface of the circuit board, leaving several pits on the surface of the circuit board; Step 15: Flash etching: Use chemicals to flash-etch away the ultra-thin copper foil at the bottom of the pit to form the final circuit board product.

2. The method for manufacturing a selectively sidewall recessed and metallized HDI printed circuit board according to claim 1, wherein: The outer copper thickness in step 2 is reduced to 10 microns, the metal copper thickness of the blind groove side wall in step 4 is 15 microns, the copper plating thickness in step 6 is 15 microns, and the copper plating thickness in step 13 is 20 microns.

3. The method for manufacturing a selectively recessed and metallized HDI printed circuit board according to claim 1, wherein: The laser drilling equipment in step 3 is a UV picosecond laser drilling equipment, which can ablate metal copper, epoxy resin and glass fiber cloth.

4. The method for manufacturing a selectively recessed and metallized HDI printed circuit board according to claim 1, wherein: In step 5, after the special glue is inserted into the blind groove, the excess special glue at the blind groove is ground and leveled until the special glue and the copper surface of the circuit board are in the same plane.

5. The method for manufacturing a selectively recessed and metallized HDI printed circuit board according to claim 1, wherein: The chemical dissolving agents in step 5 and step 10 are both alkaline chemical dissolving agents, the chemical agent in step 12 is sodium carbonate solution, and the chemical agent in step 14 is sodium hydroxide solution.

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