High-order AI circuit board production method

Abstract

The invention discloses a high-order AI circuit board production method, and relates to the field of circuit board production. According to the circuit processing precision, a copper surface is treated before ultra-roughening, the concentration of an ultra-roughening liquid medicine is controlled to be 15-35 g, the concentration of hydrochloric acid is controlled to be 1.0-1.5 Mol / L, the micro-etching amount is controlled to be 0.6-1.2 um / pass, and the roughness of the copper surface is controlled to be RA 0.3-0.5 um when the micro-etching amount is low, so that a high-strength dry film is attached; the width of the circuit is processed to be 30-80 microns through a laser imaging technology, the precision is controlled to be 3 microns or below, and then the rough and dense circuit is etched and processed into a finished product through a vacuum etching mode. According to the production method of the high-order AI circuit board, a laser imaging technology, a vacuum etching technology, an OPE automatic punching technology and a Pin-lam lamination alignment system are adopted in an inner layer, solder mask is upgraded from solder resist ink to a technical design of using epoxy resin as a solder resist layer, and the application problem of the high-order AI circuit board in an extreme or special environment is solved by utilizing a new process design of the high-order AI circuit board in line precision, alignment precision and solder resist.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit board production, and in particular to a method for producing a high-order AI circuit board. Background Art

[0002] Circuit boards are important electronic components, supporting electronic components and providing electrical connections for electronic components. At the current stage, high-end AI circuit board production technology uses film production for the inner layer, target shooting machine production technology, Mass-Lam alignment system, and ordinary solder mask ink production.

[0003] Prior art 1 (application number CN201410587419.1, Chinese patent published on June 30, 2017) A high-step copper circuit board and its manufacturing method, belonging to the technical field of circuit board manufacturing, the method includes deep grooving, copper deposition, full-board electroplating, embedded copper, grinding, pattern transfer, etching process, the method first grooving thick copper circuit grooves at the thick copper circuit position on the circuit board, and then embedding the grooved thick copper circuit grooves into the copper layer, and then grinding and pattern transfer processes are performed to produce surface step copper circuits, that is, through deep grooving and simultaneous plating of thick copper and thin copper to achieve staggered perfect routing, the uneven surface of the step copper is embedded in the circuit board sheet, the circuit board manufactured by this method, because the high current copper plating is directly embedded in the resin, there is no problem of surface unevenness, on the one hand, it improves the availability of the layout space of the circuit board, on the other hand, it also avoids the problem of film bubbles during pattern transfer caused by surface unevenness, thereby improving the product yield. ; Prior art 2 (application number CN201210445604.8, Chinese patent published on August 3, 2016) A circuit board production method, comprising the following steps: using a resin system in a specific form; using a mold that matches the shape of the circuit board and the wiring pattern on the circuit board; placing the above-mentioned resin system in the above-mentioned mold; directly casting the shape of the circuit board and the wiring pattern on the circuit board through the mold; filling the conductive material on the wiring pattern to form a conductive pattern of the circuit board; wherein, reinforcing materials are pre-suspended in the mold in an orderly manner, and then cast, and during casting, the resin system solution passes through the reinforcing material, and after cooling, the reinforcing material is solidified in the resin system; the mold is made of ceramic material, and the reinforcing material is orderly glass fiber. By using the mold to directly shape the circuit board, the entire circuit board manufacturing process is simplified, the production cost is reduced, and the production accuracy and efficiency are improved.

[0004] At present, after the circuit board processing is completed, when the product environment temperature and humidity are too high and affected by acid and alkali gases, it is easy to reduce its interference performance and insulation performance, thereby causing product performance to decline and affecting the overall effect. The existing processing methods are prone to low circuit processing accuracy and low positioning accuracy, affecting the performance shielding effect and the solder mask ink cannot cope with special environmental scenarios. Summary of the invention

[0005] The purpose of the present invention is to provide a method for producing a high-order AI circuit board to solve the problem that after the circuit board processing is completed, when the product environment temperature and humidity are too high and affected by acid and alkaline gases, the interference performance and insulation performance are easily reduced, thereby causing the product performance to decline and affecting the overall effect.

[0006] To achieve the above object, the present invention provides the following technical solution: a method for producing a high-order AI circuit board, the method comprising the following steps:

[0007] Step 1: Cutting: Set the size of the work plate according to the equipment process capability and plate utilization rate, and then cut the plate into the corresponding size for cutting;

[0008] Step 2: Inner layer circuit processing, the wet film resist is exposed to ultraviolet light, the photoinitiator decomposes into free radicals, stimulates the monomer to produce a polymerization reaction to form a polymer compound to transfer the pattern to the copper surface, and then develops and uses acidic etching solution to etch out the required pattern;

[0009] Step 3: Inner layer AOI, use automatic optical inspection to compare the etched pattern with the set pattern, and display the inconsistent parts for judgment;

[0010] Step 3: OPE punching, using OPE punching die to process the holes for all layers to prepare for lamination accuracy;

[0011] Step 4: Lamination, using semi-cured sheets, the flatness of the press lamination equipment is less than 0.1mm, using PIN-LAM alignment below the drawing positioning design, the alignment tolerance is controlled within 0.025mm, through the Pin-Lam system alignment, the alignment accuracy is controlled within 0.025mm, after layer by layer superposition, and then using high-precision temperature performance less than 1.5℃ customized equipment, using the principle of high temperature and high pressure, the resin is fully filled and cured after high pressure and high temperature to complete the combination;

[0012] Step 5: Drilling: Drill through holes on the board surface through drilling equipment, and then chemically plate copper in the later process to achieve electrical conductivity between the upper and lower layers of copper;

[0013] Step 6: Plasma treatment, using O2, N2, H2 gas at a certain temperature and time to improve the adhesion of PCB resin copper plating and remove dirt and residual glue;

[0014] Step 7: Horizontal copper deposition: a 0.3-0.6um thin copper layer is plated in the drilled hole to achieve electrical conductivity between the upper and lower layers of the board;

[0015] Step 8: Full board electroplating, copper plating is done in the drilled holes to plate a thin layer of copper, so that the upper and lower layers of the board are electrically conductive, and electroplating thickens the copper in the holes and on the surface;

[0016] Step 9: Graphic transfer: according to the design data, transfer the graphics from the film to the work board in the pre-processing, film lamination and development process;

[0017] Step 10: Electroplating copper tin, electroplating thickens the copper in the through hole and the copper on the surface to meet the design requirements to ensure that the electrical performance requirements of the end user are met;

[0018] Step 11: Etching of the outer layer, after film stripping, etching, and tin stripping processes, according to the design data, the circuit pattern is completed on the working board, and all the patterns required by the design are etched out using a vacuum etcher and alkaline etching solution;

[0019] Step 12: External layer etching inspection: the etched pattern is compared with the designed pattern by automatic optical inspection, and the inconsistent parts are displayed for judgment;

[0020] Step 13: High reliability solder mask, laminated with epoxy resin, and cured at high temperature using a vacuum press;

[0021] Step 14: Laser ablation: Using laser focusing reaction, use five-element gas to directly ablate and remove the copper surface and resin to be welded, revealing the surface to be welded;

[0022] Step 15: Gold deposition: According to the chemical principle, the nickel-gold surface is completed on the surface of the pad, and the nickel thickness reaches 3-8um and the gold thickness reaches 0.05-0.11um to meet the use requirements;

[0023] Step 16: Forming, using a gong machine and a gong cutter to gong out the size required by the design;

[0024] Step 17: Test: Perform open and short circuit test on the working board;

[0025] Step 18: FQC, inspect the products according to customer standards, and the panels that meet the requirements are put into the warehouse.

[0026] To further optimize the technical solution, the acidic corrosive solution in step 2 is sodium hypochlorite, hydrochloric acid and additives.

[0027] To further optimize the technical solution, the alkaline etching solution in step eleven includes plate etching salt, ammonia water, a complexing agent and oxygen.

[0028] To further optimize the technical solution, the pressing and curing conditions in step thirteen are: temperature 180° C., time more than 45 minutes, vacuum degree reaching more than 730 mmHg, and pressure more than 320 PSI.

[0029] To further optimize the technical solution, after step fourteen, characters are added to the plate, and identification letters, graphics and company logos are printed on them for easy identification.

[0030] To further optimize the technical solution, the product is packaged after the step eighteen is completed, and the high-speed material is vacuum-packaged with aluminum foil.

[0031] To further optimize the technical solution, the circuit processing accuracy adopts ultra-roughening pre-treatment of the copper surface, the ultra-roughening solution concentration controls Cu2+: 15-35g, the hydrochloric acid concentration controls: 1.0-1.5Mol / L, the micro-etching amount controls: 0.6-1.2um / pass, and the copper surface roughness is controlled at: RA0.3-0.5um at low micro-etching amount to achieve high-strength adhesion of the dry film; through laser imaging technology, the circuit width is processed to 30-80um, the accuracy is controlled below 3um, and then the coarse and dense circuits are etched and processed into finished products through vacuum etching.

[0032] Compared with the prior art, the invention has the following beneficial effects: the inner layer adopts laser imaging technology, vacuum etching technology, OPE automatic punching technology, Pin-lam pressing and alignment system, the solder mask is upgraded from solder mask ink to epoxy resin as solder mask layer technology design, and the high-end AI circuit board is used in line accuracy, alignment accuracy and new solder mask process design to solve the application in extreme or special environments;

[0033] This product has been tested in all aspects and meets the requirements. The high-end AI circuit board produced by the above method has good signal transmission performance, high precision, and stable output process in special or extreme environments, meeting customer requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the process flow of the present invention. DETAILED DESCRIPTION

[0035] 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 described embodiments 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.

[0036] See also Figure 1 The present invention provides the following technical solutions: a method for producing a high-level AI circuit board. This technology belongs to the production technology of a 12-30-layer high-level AI circuit board. The inner layer adopts laser imaging technology, vacuum etching technology, OPE automatic punching technology, Pin-lam pressing and alignment system, and the solder mask is upgraded from solder mask ink to epoxy resin as the solder mask layer technology design.

[0037] Embodiment 1: The present invention provides the following technical solution, which discloses that the method comprises the following steps:

[0038] Step 1: Cutting: Set the size of the work plate according to the equipment process capability and plate utilization rate, and then cut the plate into the corresponding size for cutting;

[0039] Step 2: Inner layer circuit processing, the wet film resist is exposed to ultraviolet light, the photoinitiator decomposes into free radicals, stimulates the monomer to produce a polymerization reaction to form a polymer compound to transfer the pattern to the copper surface, and then develops and uses acidic etching solution to etch out the required pattern;

[0040] Step 3: Inner layer AOI, use automatic optical inspection to compare the etched pattern with the set pattern, and display the inconsistent parts for judgment;

[0041] Step 3: OPE punching, using OPE punching die to process the holes for all layers to prepare for lamination accuracy;

[0042] Step 4: Lamination, using semi-cured sheets, the flatness of the press lamination equipment is less than 0.1mm, using PIN-LAM alignment below the drawing positioning design, the alignment tolerance is controlled within 0.025mm, through the Pin-Lam system alignment, the alignment accuracy is controlled within 0.025mm, after layer by layer superposition, and then using high-precision temperature performance less than 1.5℃ customized equipment, using the principle of high temperature and high pressure, the resin is fully filled and cured after high pressure and high temperature to complete the combination;

[0043] Step 5: Drilling: Drill through holes on the board surface through drilling equipment, and then chemically plate copper in the later process to achieve electrical conductivity between the upper and lower layers of copper;

[0044] Step 6: Plasma treatment, using O2, N2, H2 gas at a certain temperature and time to improve the adhesion of PCB resin copper plating and remove dirt and residual glue;

[0045] Step 7: Horizontal copper deposition: a 0.3-0.6um thin copper layer is plated in the drilled hole to achieve electrical conductivity between the upper and lower layers of the board;

[0046] Step 8: Full board electroplating, copper plating is done in the drilled holes to plate a thin layer of copper, so that the upper and lower layers of the board are electrically conductive, and electroplating thickens the copper in the holes and on the surface;

[0047] Step 9: Graphic transfer: according to the design data, transfer the graphics from the film to the work board in the pre-processing, film lamination and development process;

[0048] Step 10: Electroplating copper tin, electroplating thickens the copper in the through hole and the copper on the surface to meet the design requirements to ensure that the electrical performance requirements of the end user are met;

[0049] Step 11: Etching of the outer layer, after film stripping, etching, and tin stripping processes, according to the design data, the circuit pattern is completed on the working board, and all the patterns required by the design are etched out using a vacuum etcher and alkaline etching solution;

[0050] Step 12: External layer etching inspection: the etched pattern is compared with the designed pattern by automatic optical inspection, and the inconsistent parts are displayed for judgment;

[0051] Step 13: High reliability solder mask, laminated with epoxy resin, and cured at high temperature using a vacuum press;

[0052] Step 14: Laser ablation: Using laser focusing reaction, use five-element gas to directly ablate and remove the copper surface and resin to be welded, revealing the surface to be welded;

[0053] Step 15: Gold deposition: According to the chemical principle, the nickel-gold surface is completed on the surface of the pad, and the nickel thickness reaches 3-8um and the gold thickness reaches 0.05-0.11um to meet the use requirements;

[0054] Step 16: Forming, using a gong machine and a gong cutter to gong out the size required by the design;

[0055] Step 17: Test: Perform open and short circuit test on the working board;

[0056] Step 18: FQC, inspect the products according to customer standards, and the panels that meet the requirements are put into the warehouse.

[0057] Key technical points: circuit processing accuracy technology, lamination alignment accuracy technology, and new solder mask processing method.

[0058] Circuit processing precision technology:

[0059] The circuit processing precision adopts ultra-roughening pre-treatment of copper surface, the ultra-roughening solution concentration is controlled Cu2+: 15-35g, the hydrochloric acid concentration is controlled: 1.0-1.5Mol / L, the micro-etching amount is controlled: 0.6-1.2um / pass, and the copper surface roughness should be uniformly controlled at low micro-etching amount: RA0.3-0.5um to achieve high-strength adhesion of dry film; through laser imaging technology, the circuit width is processed to 30-80um, and the accuracy is controlled below 3um; and then the coarse and dense circuits are etched and processed into finished products by vacuum etching.

[0060] Lamination Technology:

[0061] OPE die punching is adopted, and the alignment accuracy of all layers is controlled within 0.02mm. All layers are punched by OPE die, and the alignment tolerance between all layers is controlled within 0.02mm; the flatness of press lamination equipment is less than 0.1mm (all layers), and PIN-LAM alignment design is adopted, and the alignment tolerance is controlled within 0.025mm. When all hot plates are at 200℃, the temperature difference should be controlled within + / -1.5℃;

[0062] New solder mask processing method:

[0063] Conventional solder resist is made of silk screen ink, silk screen printing, pre-curing, exposure, development, and post-curing. The new solder resist is laminated with epoxy resin and cured at high temperature with a vacuum press (pressing and curing conditions: 180℃, more than 45min, vacuum degree must reach more than 730mmHg, pressure needs to be more than 320PSI, and 100% can be free of any bubbles). Finally, the surface of the pad to be welded is removed of resin with a laser. The solder resist layer made by this method can meet the 288℃*10S*6 times thermal shock reliability test without any bubbles or cracks, completely subverting the capabilities of traditional solder resist inks.

[0064] Embodiment 2: Based on Embodiment 1, the acidic etching solution in step 2 is sodium hypochlorite, hydrochloric acid and additives, the alkaline etching solution in step 11 includes etching salt, ammonia, complexing agent and oxygen, the pressing and curing conditions in step 13 are: temperature 180°C, time above 45 minutes, vacuum degree above 730 mmHg, pressure above 320 PSI, after step 14, characters are added to the board body, and identification letters, graphics and company logos are printed on them for easy identification, and after step 18, the product is packaged, and high-speed material procurement is carried out. It is vacuum packed with aluminum foil, and the circuit processing accuracy uses ultra-roughening pre-treatment of the copper surface. The ultra-roughening solution concentration controls Cu2+: 15-35g, the hydrochloric acid concentration controls: 1.0-1.5Mol / L, the micro-etching amount controls: 0.6-1.2um / pass, and the copper surface roughness is controlled at low micro-etching amount: RA0.3-0.5um to achieve high-strength adhesion of the dry film; through laser imaging technology, the circuit width is processed to 30-80um, and the accuracy is controlled below 3um, and then the coarse and dense circuits are etched and processed into finished products through vacuum etching.

[0065] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

[0066] 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 producing a high-order AI circuit board, characterized in that: The method comprises the following steps: Step 1: Cutting: Set the size of the work plate according to the equipment process capability and plate utilization rate, and then cut the plate into the corresponding size for cutting; Step 2: Inner layer circuit processing, the wet film resist is exposed to ultraviolet light, the photoinitiator decomposes into free radicals, stimulates the monomer to produce a polymerization reaction to form a polymer compound to transfer the pattern to the copper surface, and then develops and uses acidic etching solution to etch out the required pattern; Step 3: Inner layer AOI, use automatic optical inspection to compare the etched pattern with the set pattern, and display the inconsistent parts for judgment; Step 3: OPE punching, using OPE punching die to process the holes for all layers to prepare for lamination accuracy; Step 4: Lamination, using semi-cured sheets, the flatness of the press lamination equipment is less than 0.1mm, using PIN-LAM alignment below the drawing positioning design, the alignment tolerance is controlled within 0.025mm, through the Pin-Lam system alignment, the alignment accuracy is controlled within 0.025mm, after layer by layer superposition, and then using high-precision temperature performance less than 1.5℃ customized equipment, using the principle of high temperature and high pressure, the resin is fully filled and cured after high pressure and high temperature to complete the combination; Step 5: Drilling: Drill through holes on the board surface through drilling equipment, and then chemically plate copper in the later process to achieve electrical conductivity between the upper and lower layers of copper; Step 6: Plasma treatment, using O2, N2, H2 gas at a certain temperature and time to improve the adhesion of PCB resin copper plating and remove dirt and residual glue; Step 7: Horizontal copper deposition: a 0.3-0.6um thin copper layer is plated in the drilled hole to achieve electrical conductivity between the upper and lower layers of the board; Step 8: Full board electroplating, copper plating is done in the drilled holes to plate a thin layer of copper, so that the upper and lower layers of the board are electrically conductive, and electroplating thickens the copper in the holes and on the surface; Step 9: Graphic transfer: according to the design data, transfer the graphics from the film to the work board in the pre-processing, film lamination and development process; Step 10: Electroplating copper tin, electroplating thickens the copper in the through hole and the copper on the surface to meet the design requirements to ensure that the electrical performance requirements of the end user are met; Step 11: Etching of the outer layer, after film stripping, etching, and tin stripping processes, according to the design data, the circuit pattern is completed on the working board, and all the patterns required by the design are etched out using a vacuum etcher and alkaline etching solution; Step 12: External layer etching inspection: the etched pattern is compared with the designed pattern by automatic optical inspection, and the inconsistent parts are displayed for judgment; Step 13: High reliability solder mask, laminated with epoxy resin, and cured at high temperature using a vacuum press; Step 14: Laser ablation: Using laser focusing reaction, use five-element gas to directly ablate and remove the copper surface and resin to be welded, revealing the surface to be welded; Step 15: Gold deposition: According to the chemical principle, the nickel-gold surface is completed on the surface of the pad, and the nickel thickness reaches 3-8um and the gold thickness reaches 0.05-0.11um to meet the use requirements; Step 16: Forming, using a gong machine and a gong cutter to gong out the size required by the design; Step 17: Test: Perform open and short circuit test on the working board; Step 18: FQC, inspect the products according to customer standards, and the panels that meet the requirements are put into the warehouse.

2. A method for producing a high-order AI circuit board according to claim 1, characterized in that: The acidic corrosive solution in step 2 is sodium hypochlorite, hydrochloric acid and additives.

3. The method for producing a high-order AI circuit board according to claim 1, characterized in that: The alkaline etching solution in step 11 includes etching salt, ammonia water, a complexing agent and oxygen.

4. The method for producing a high-order AI circuit board according to claim 1, characterized in that: The pressing and curing conditions in step thirteen are: temperature 180° C., time more than 45 minutes, vacuum degree reaching more than 730 mmHg, and pressure more than 320 PSI.

5. The method for producing a high-order AI circuit board according to claim 1, characterized in that: After step 14, characters are added to the plate, and identification letters, graphics and company logos are printed on the plate for easy identification.

6. The method for producing a high-order AI circuit board according to claim 1, characterized in that: After the step 18 is completed, the product is packaged, and the high-speed material is vacuum-packed with aluminum foil.

7. The method for producing a high-order AI circuit board according to claim 1, characterized in that: The circuit processing precision adopts ultra-roughening pre-treatment of the copper surface, the ultra-roughening solution concentration is controlled to Cu2+: 15-35g, the hydrochloric acid concentration is controlled to: 1.0-1.5Mol / L, the micro-etching amount is controlled to: 0.6-1.2um / pass, and the copper surface roughness is controlled at: RA0.3-0.5um at low micro-etching amount to achieve high-strength adhesion of the dry film; through laser imaging technology, the circuit width is processed to 30-80um, the accuracy is controlled to be below 3um, and then the coarse and dense circuits are etched and processed into finished products through vacuum etching.

Images