A method for designing and manufacturing a thick copper plate tin spraying process

Abstract

The application discloses a thick copper plate tin spraying process design and manufacturing method, relates to the thick copper plate tin spraying field, and comprises the following steps: firstly, raw material preparation and cutting are performed; after the raw material preparation and cutting are completed, pretreatment and inner layer manufacturing are performed; after the pretreatment and the inner layer manufacturing are completed, brown oxidation and lamination are performed; after the brown oxidation and the lamination are completed, drilling and slot milling are performed; after the drilling and the slot milling are completed, circuit manufacturing and electroplating are performed; and after the circuit manufacturing and the electroplating are completed, etching and outer layer detection are performed. According to the thick copper plate tin spraying process design and manufacturing method, when CAM data is manufactured, a non-copper area is set in a 5mm edge rail area of a pnl distance set area, glue defects and cavities will appear in the non-copper area after lamination, in order to prevent the glue defects in the board, the 5mm edge rail area of the pnl distance set area is set as a copper laying area, a "edge milling" process is added before tin spraying, 5mm frames are milled off the outer edges of the PNL, the cavities can be leaked, and channels are provided for stress release and water vapor discharge, so that the problems of board explosion and hole explosion of the circuit board are prevented.

Description

TECHNICAL FIELD

[0001] The application relates to a thick copper plate tin spraying technology field, in particular to a thick copper plate tin spraying process design and manufacturing method. BACKGROUND

[0002] The thick copper plate tin spraying process is mainly used for improving the performance of the copper plate, and the tin spraying process is widely applied in the fields of electronics, communication, automobile manufacturing and other fields requiring electrical connection and reliability.

[0003] In the prior art, the baking process is added, and the heat spraying aging time after baking is only 10 minutes, the aging time is too short, it is difficult to control, and personnel are difficult to operate; after baking, the pre-treatment temperature is reduced, and the heat spraying requirement cannot be met; after pre-treatment, baking is performed again, and heat spraying is performed after baking, thereby increasing human operation and being difficult to implement.

[0004] In order to overcome the above-mentioned defects, the prior art (publication number CN114206018A) discloses a kind of high efficiency thick copper plate solder mask printing method, and the ink used in the high efficiency thick copper plate solder mask printing method is mainly composed of the following quality raw materials: epoxy cyclohexyl methyl methacrylate, amido resin, titanium dioxide, methacryloyloxypropyl trimethoxysilane, propylene glycol methyl ether acetate, trimethyl benzoyl phenyl ethyl phosphonate, the interaction between each substance makes the ink have good curing performance, adhesion, also has excellent heat resistance, weather resistance, and fast curing speed.

[0005] In order to overcome the above-mentioned defects, the prior art (publication number CN112153820A) discloses a kind of method for improving thick copper plate tin spraying explosion plate, which comprises the following steps: before tin spraying, the PCB plate is subjected to plate ringing, and the copper block on the side of the PCB plate is removed in the plate ringing. The copper block on the side of the PCB plate is removed before baking, so as to expose the base material of the PCB plate. After the side of the PCB plate is less shielded by the copper block, heat can be better released during tin spraying, thereby effectively preventing the PCB plate from exploding during tin spraying.

[0006] Although the prior art can overcome the above-mentioned defects, there are still other problems in the running process. At present, the industry is not mature in the thick copper plate tin spraying process technology of 8 / 9oz, and there are often quality risks such as plate explosion and hole explosion. In order to prevent hole explosion and plate explosion, the general method in the industry is to perform baking before tin spraying, the baking temperature is 120-150 DEG C, the baking time is 20-40 minutes, and hot spraying is performed, but it only solves individual thick copper plates (6 / 7OZ copper thick plates), and the problem of plate explosion and hole explosion still frequently occurs for 8 / 9oz thick copper plates. SUMMARY

[0007] The purpose of the present invention is to provide a design and production method for the tin spraying process of thick copper plates, so as to solve the problem raised in the above background technology that the tin spraying process technology for 8 / 9oz thick copper plates is immature in the industry and often has quality risks of bursting and hole explosion. In order to prevent hole explosion and bursting of plates, the common method in the industry is to bake before tin spraying, with a baking temperature of 120-150°C and a baking time of 20-40 minutes for hot spraying. However, it only solves the problem of individual thick copper plates (6 / 7OZ copper thick plates). For 8 / 9oz thick copper plates, the problem of bursting and hole explosion still frequently occurs.

[0008] To achieve the above-mentioned object, the present invention provides the following technical solution: a method for designing and manufacturing a tin-spraying process for a thick copper plate, comprising S1, raw material preparation and cutting; S2, pretreatment and inner layer production; S3, browning and lamination; S4, drilling and slot milling; S5, circuit production and electroplating; S6, etching and outer layer inspection; S7, solder mask and character printing; S8, outer shape processing and tin-spraying treatment; S9, testing, inspection and packaging;

[0009] The specific steps include:

[0010] S1. Raw material preparation and cutting

[0011] Cutting: Cut the required 8 / 9OZ thick copper plate from the raw material;

[0012] S2. Pretreatment and inner layer production

[0013] Baking plate: Baking the cut thick copper plate to remove moisture and volatiles in the plate;

[0014] Inner layer circuit: Make circuit patterns on the inner layer of thick copper plate;

[0015] Inner layer etching: Etch away the unnecessary copper parts of the inner layer to form circuit lines;

[0016] Inner layer AOI: Use automatic optical inspection equipment to perform quality inspection on inner layer circuits;

[0017] S3, Browning and Lamination

[0018] Browning: Browning the copper plate surface to enhance the bonding strength between copper and resin;

[0019] Lamination: Laminating multiple layers of circuit boards together to form a multi-layer structure;

[0020] S4, drilling and milling holes

[0021] Drilling and milling slots: Drilling the required through holes and slots on the circuit board;

[0022] S5. Circuit production and electroplating

[0023] Copper plating and board plating: depositing a copper layer on the inner wall of the drill hole and slot hole, and plating the board surface with copper;

[0024] Outer layer circuit: making a circuit pattern on the outer layer of the circuit board;

[0025] False positive electroplating: electroplating on the outer layer circuit to enhance the conductivity and corrosion resistance of the circuit;

[0026] S6, etching and outer layer detection

[0027] Alkaline etching: etching the unwanted copper part of the outer layer to form the final circuit line;

[0028] Outer layer AOI: using automatic optical detection equipment to detect the quality of the outer layer circuit;

[0029] S7, solder mask and character printing

[0030] Solder mask printing: printing a solder mask on the circuit board to protect the circuit from corrosion;

[0031] Character and post-baking: printing character identification on the circuit board and performing post-baking treatment;

[0032] S8, profile processing and tin spraying treatment

[0033] Milling edge: milling off 5mm frame from the outer edge of PNL, controlling the milling edge accuracy and depth to ensure the hole is leaked, providing a channel for stress release and water vapor discharge;

[0034] Lead-free tin spraying: lead-free tin spraying treatment on the circuit board to enhance the conductivity and solderability of the circuit board;

[0035] Electrical milling: electrical milling treatment on the circuit board after tin spraying to remove excess tin layer;

[0036] S9, test inspection and packaging

[0037] Test: comprehensive electrical performance test and functional test on the circuit board;

[0038] FQC and packaging: final quality inspection and packaging of the circuit board.

[0039] Further, the step S1, check the quality of raw materials, use accurate cutting equipment to cut 8 / 9OZ thick copper plate of required size and weight from raw materials, ensure the cutting surface is flat, without burr, and monitor the cutting accuracy and speed in real time.

[0040] Further, the step S2, the cut copper plate is baked, then the inner layer is drawn with a circuit pattern, and etching and AOI detection are performed, and the baking is completed. Natural cooling is required, and the accuracy and integrity of the pattern and circuit during drawing and etching process must be ensured.

[0041] Further, after the step S3 of carrying out the brown film treatment on the copper plate, the multi-layer circuit board is laminated according to the design requirements, and the parameters in the brown liquid and the lamination process are controlled to ensure the quality of the brown film and the close combination of the laminated plate.

[0042] Further, in the step S4, the numerical control drilling machine or the laser drilling machine is used to drill the required through holes and slot holes on the circuit board, the drilling speed and the feeding amount are controlled to ensure that the hole diameter, the hole depth and the hole position accuracy meet the design requirements.

[0043] Further, in the step S5, the inner wall of the drilled holes and the slot holes is activated, the copper layer is deposited, then the copper on the plate surface is plated, and then the circuit pattern is drawn on the outer layer and the electroplating treatment is carried out, so as to ensure the uniformity and compactness of the copper layer and the electroplating layer, and the alignment accuracy of the outer layer circuit and the inner layer circuit.

[0044] Further, in the step S6, the copper part not required on the outer layer is etched and removed, and then the AOI detection is carried out to ensure that the etching is uniform and meets the design requirements, and the detected defects are recorded and classified.

[0045] Further, in the step S7, the solder resist layer and the character mark are printed on the circuit board, and the baking and curing are carried out to ensure that the uniformity, adhesion and accuracy of the solder resist layer and the character meet the design requirements.

[0046] Further, in the step S8, the outer edge of the circuit board is milled to remove the frame, and then the lead-free tin spraying treatment is carried out to ensure that the quality of the milled surface and the tin spraying layer meets the design requirements, and the waste liquid and waste gas are properly treated.

[0047] Further, in the step S9, the circuit board is subjected to comprehensive electrical performance test and function test, and the final quality inspection is carried out, and the qualified circuit board is packaged to ensure the accuracy and reliability of the test equipment, the test results are analyzed and recorded, and the appropriate packaging materials and tools are used for packaging.

[0048] Compared with the prior art, the beneficial effects of the present application are:

[0049] 1. When the CAM data is made, the edge rail area 5mm away from the pnl distance set area is set as a non-copper area. The non-copper area will have glue defects and cavities after lamination. In order to prevent the glue defects in the board, the pnl distance set area 5mm is set as a copper area, and a "milling edge" process is added before tin spraying to mill off the 5mm frame on the outer edge of the PNL. The cavities will leak out, providing a channel for stress release and water vapor discharge, preventing the problem of board and hole explosion of the circuit board.

[0050] 2. The process of tin spraying and hot spray baking has been eliminated, which simplifies the process steps and optimizes the complexity of the work. The automated step reminders reduce manual operations for the staff, which can reduce the complexity of the staff's work and save physical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a schematic diagram of the overall process of the present invention;

[0052] Figure 2 This is a schematic flow chart of the pretreatment steps of the present invention;

[0053] Figure 3 A schematic flow chart of the steps of making the present invention;

[0054] Figure 4 This is a schematic diagram of the subsequent processing flow of the present invention. DETAILED DESCRIPTION

[0055] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0056] Example 1: Figures 1-4 The technical solution shown is a design and production method for a tin-spraying process for thick copper plates. To solve the problem of easy board explosion after the product is manufactured, the following steps are disclosed: S1, raw material preparation and cutting; S2, pretreatment and inner layer production; S3, browning and lamination; S4, drilling and slot milling;

[0057] S5, circuit production and electroplating; S6, etching and outer layer inspection; S7, solder mask and character printing; S8, appearance processing and tin spraying; S9, testing, inspection and packaging;

[0058] The specific steps include:

[0059] S1. Raw material preparation and cutting

[0060] Cutting: Cut the required 8 / 9OZ thick copper plate from the raw material;

[0061] S2. Pretreatment and inner layer production

[0062] Baking plate: Baking the cut thick copper plate to remove moisture and volatiles in the plate;

[0063] Inner layer circuit: Make circuit patterns on the inner layer of thick copper plate;

[0064] Inner layer etching: etching away unwanted copper parts on the inner layer to form circuit traces;

[0065] Inner layer AOI: using automatic optical inspection equipment to detect the quality of the inner layer circuit;

[0066] S3, brown and laminate

[0067] Brown: brown treatment on the surface of the copper plate to enhance the bonding force between copper and resin;

[0068] Lamination: laminating multiple layers of circuit board together to form a multi-layer structure;

[0069] S4, drilling and milling slot hole

[0070] Drilling and milling slot hole: drilling the required through hole and slot hole on the circuit board;

[0071] S5, line making and plating

[0072] Copper deposition and plate plating: copper deposition on the inner wall of the drilled and slotted hole, and plate plating;

[0073] Outer layer circuit: making circuit patterns on the outer layer of the circuit board;

[0074] False positive plating: plating on the outer layer circuit to enhance the conductivity and corrosion resistance of the circuit;

[0075] S6, etching and outer layer detection

[0076] Alkaline etching: etching away unwanted copper parts on the outer layer to form the final circuit traces;

[0077] Outer layer AOI: using automatic optical inspection equipment to detect the quality of the outer layer circuit;

[0078] S7, solder mask and character printing

[0079] Solder mask printing: printing solder mask on the circuit board to protect the circuit traces from corrosion;

[0080] Character and post-baking: printing character identification on the circuit board and performing post-baking treatment;

[0081] S8, profile processing and tin spraying treatment

[0082] Milling edge: milling off 5mm frame on the outer edge of PNL to control the milling edge precision and depth, ensuring the hollow leakage, providing a channel for stress release and water vapor discharge;

[0083] Lead-free tin spraying: lead-free tin spraying treatment on the circuit board to enhance the conductivity and solderability of the circuit board;

[0084] Electrical milling: After the tin spraying of the circuit board, the excess tin layer is removed by electrical milling;

[0085] S9, test inspection and packaging

[0086] Test: The circuit board is subjected to comprehensive electrical performance test and function test;

[0087] FQC and packaging: The circuit board is subjected to final quality inspection and packaging.

[0088] Step S1, check the quality of raw materials, use accurate cutting equipment to cut 8 / 9OZ thick copper plates of the required size and weight from the raw materials, ensure that the cutting surface is flat and has no burrs, and monitor the cutting accuracy and speed in real time, step S2, bake the cut copper plate, then draw the circuit pattern on the inner layer, and perform etching and AOI detection, the baked copper plate needs to be naturally cooled, and the accuracy and integrity of the pattern and circuit during the drawing and etching process need to be ensured, step S3, the copper plate is subjected to brown oxidation treatment, after the formation of the brown oxidation film, the multilayer circuit board is laminated according to the design requirements, the parameters of the brown oxidation liquid and the lamination process are controlled to ensure the quality of the brown oxidation film and the tight combination of the laminated plate, step S4, use a numerical control drilling machine or a laser drilling machine to drill the required through holes and slot holes on the circuit board, control the drilling speed and feed amount to ensure that the hole diameter, hole depth and hole position accuracy meet the design requirements, step S5, activate the inner wall of the drilled holes and slot holes, deposit a copper layer, then plate the copper on the surface of the plate, then draw the circuit pattern on the outer layer and perform electroplating treatment, ensure the uniformity and density of the copper layer and the electroplated layer, and the alignment accuracy of the outer layer circuit and the inner layer circuit, step S6, etch and remove the unnecessary copper part on the outer layer, then perform AOI detection, ensure that the etching is uniform and meets the design requirements, record and classify the detected defects, step S7, print the resist layer and character identification on the circuit board and perform baking and curing, ensure that the uniformity, adhesion and accuracy of the resist layer and characters meet the design requirements, step S8, mill the outer edge of the circuit board, remove the frame and perform lead-free tin spraying treatment, ensure that the quality of the milled surface and the tin spraying layer meets the design requirements, and properly handle the waste liquid and waste gas, step S9, the circuit board is subjected to comprehensive electrical performance test and function test, final quality inspection, and packaging treatment for qualified circuit boards, ensure the accuracy and reliability of the test equipment, analyze and record the test results, and use appropriate packaging materials and tools for packaging;

[0089] When making CAM data, set the edge rail area 5mm away from the pnl distance set area as a non-copper area. The non-copper area will have glue deficiency and cavities after lamination. To prevent glue deficiency in the board, set the pnl distance set area 5mm away as a copper area. Increase the "milling edge" process before tin spraying to mill off the 5mm frame on the outer edge of the PNL. The cavities will leak out, providing a channel for stress release and water vapor discharge to prevent board and hole explosion problems.

[0090] While embodiments of the application have been shown and described, it is to be understood that the application is not limited to the details of the embodiments described, since numerous changes, modifications, substitutions and variations can be made thereto without departing from the spirit and scope of the application as defined by the appended claims and their equivalents.

Claims

1. A method for designing and manufacturing a tin-spraying process for thick copper plates, including S1, raw material preparation and cutting; S2, pretreatment and inner layer fabrication; S3, browning and lamination; S4, drilling and slot milling; S5, circuit fabrication and electroplating; S6, etching and outer layer inspection; S7, solder mask and character printing; S8, outer shape processing and tin-spraying; S9, testing, inspection, and packaging. It is characterized by: The specific steps include: S1. Raw material preparation and cutting Cutting: Cut the required 8 / 9OZ thick copper plate from the raw material; S2. Pretreatment and inner layer production Baking plate: Baking the cut thick copper plate to remove moisture and volatiles in the plate; Inner layer circuit: Make circuit patterns on the inner layer of thick copper plate; Inner layer etching: Etch away the unnecessary copper parts of the inner layer to form circuit lines; Inner layer AOI: Use automatic optical inspection equipment to perform quality inspection on inner layer circuits; S3, Browning and Lamination Browning: Browning the copper plate surface to enhance the bonding strength between copper and resin; Lamination: Laminating multiple layers of circuit boards together to form a multi-layer structure; S4, drilling and milling holes Drilling and milling slots: Drilling the required through holes and slots on the circuit board; S5. Circuit production and electroplating Copper deposition and board plating: depositing copper layers on the inner walls of drilled holes and slots, and copper plating the board surface; Outer layer circuit: Make circuit patterns on the outer layer of the circuit board; False positive plating: electroplating is performed on the outer circuit to enhance the circuit's conductivity and corrosion resistance; S6, Etching and outer layer inspection Alkaline etching: Etches away the unnecessary copper parts of the outer layer to form the final circuit line; Outer layer AOI: Use automatic optical inspection equipment to perform quality inspection on the outer layer circuit; S7, solder mask and character printing Solder mask printing: Printing a solder mask layer on the circuit board to protect the circuit lines from corrosion; Characters and post-baking: Print character logos on the circuit board and perform post-baking; S8, shape processing and tin spraying Add milling edge: mill off 5mm of the outer edge of the PNL, control the milling accuracy and depth, ensure that the cavity leaks out, and provide a channel for stress release and water vapor discharge; Lead-free tin spraying: Lead-free tin spraying is performed on the circuit board to enhance the conductivity and solderability of the circuit board; Electric milling: Electric milling is performed on the circuit board after tin spraying to remove the excess tin layer; S9. Testing, inspection and packaging Testing: Conduct comprehensive electrical performance and functional testing on the circuit board; FQC and Packing: Final quality inspection and packaging of the circuit boards.

2. The method for designing and manufacturing a tin-spraying process for a thick copper plate according to claim 1, characterized in that: In step S1, the quality of the raw materials is checked, and 8 / 9OZ thick copper plates of the required size and weight are cut from the raw materials using precise cutting equipment, ensuring that the cut surface is flat and burr-free, and the cutting accuracy and speed are monitored in real time.

3. The method for designing and manufacturing a tin-spraying process for a thick copper plate according to claim 1, characterized in that: In step S2, the cut copper plate is baked, and then a circuit pattern is drawn on the inner layer, and etching and AOI inspection are performed. After baking, it is required to cool naturally. The accuracy and integrity of the pattern and circuit must be ensured during the drawing and etching process.

4. The method for designing and manufacturing a tin-spraying process for a thick copper plate according to claim 1, characterized in that: In step S3, the copper plate is subjected to a browning treatment to form a browning film, and then a multi-layer circuit board is laminated according to design requirements. The browning liquid and parameters during the lamination process are controlled to ensure the quality of the browning film and the close connection between the laminated board and the browning film.

5. The method for designing and manufacturing a tin-spraying process for a thick copper plate according to claim 1, characterized in that: In step S4, a CNC drilling machine or a laser drilling machine is used to drill the required through holes and slots on the circuit board, and the drilling speed and feed rate are controlled to ensure that the hole diameter, hole depth and hole position accuracy meet the design requirements.

6. The method for designing and manufacturing a tin-spraying process for a thick copper plate according to claim 1, characterized in that: In step S5, the inner walls of the drilled holes and slots are activated, the copper layer is deposited, and the board surface is copper plated. Then, a circuit pattern is drawn on the outer layer and electroplated to ensure the uniformity and density of the copper layer and the electroplated layer, as well as the alignment accuracy of the outer layer circuit and the inner layer circuit.

7. The method for designing and manufacturing a tin-spraying process for a thick copper plate according to claim 1, characterized in that: In step S6, the unnecessary copper portion of the outer layer is etched away, and then an AOI inspection is performed to ensure that the etching is uniform and meets the design requirements, and the detected defects are recorded and classified.

8. The method for designing and manufacturing a tin-spraying process for a thick copper plate according to claim 1, characterized in that: In step S7, a solder mask layer and character logos are printed on the circuit board, and then baked and cured to ensure that the uniformity, adhesion and accuracy of the solder mask layer and the characters meet the design requirements.

9. The method for designing and manufacturing a tin-spraying process for a thick copper plate according to claim 1, characterized in that: In step S8, the outer edge of the circuit board is milled, and a lead-free tin spraying process is performed after the frame is removed to ensure that the quality of the milled surface and the tin spraying layer meets the design requirements, and the waste liquid and waste gas are properly handled.

10. The method for designing and manufacturing a tin-spraying process for a thick copper plate according to claim 1, characterized in that: In step S9, the circuit boards are subjected to comprehensive electrical performance and functional tests, final quality checks, and qualified circuit boards are packaged to ensure the accuracy and reliability of the test equipment, analyze and record the test results, and use appropriate packaging materials and tools for packaging.

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