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CN-122002716-A - PCB manufacturing method for matching local thick copper with fine circuit and product thereof

CN122002716ACN 122002716 ACN122002716 ACN 122002716ACN-122002716-A

Abstract

The application discloses a PCB manufacturing method of local thick copper matched with fine circuits and a product thereof, belongs to the field of multilayer circuit boards, and aims to simplify the structure of the PCB and further reduce the whole volume. The method comprises the steps of S1, cutting a copper-clad plate, preparing an inner layer circuit, taking two layers of copper foils for standby, S2, pressing the two layers of copper foils after being respectively arranged on two sides of the inner layer circuit to obtain a first intermediate, S3, sequentially drilling and depositing copper on the first intermediate, then carrying out full-plate electroplating to obtain a second intermediate, S4, carrying out thick copper plating treatment by taking the uppermost treatment layer and the lowermost treatment layer of the second intermediate as treatment objects, forming a thin copper circuit and a thick copper circuit on the treatment objects, and obtaining a third intermediate, and S5, carrying out subsequent treatment on the third intermediate. The application can replace two traditional PCBs by using one PCB, effectively reduces the manufacturing cost of the PCBs and PCBA, and improves the corresponding production efficiency.

Inventors

  • LI YONG
  • CAO XIAOMING
  • LIU FAQIANG
  • CHEN XUDONG
  • WU ZURONG

Assignees

  • 广东依顿电子科技股份有限公司

Dates

Publication Date
20260508
Application Date
20260327

Claims (10)

  1. 1. A PCB manufacturing method of local thick copper matching fine circuit is characterized by comprising the following steps: s1, cutting a copper-clad plate, preparing an inner layer circuit, and taking two layers of copper foils for standby; s2, respectively placing two layers of copper foils on two sides of the inner layer circuit, and then pressing to obtain a first intermediate, wherein the two layers of copper foils are respectively positioned on the uppermost layer and the lowermost layer of the first intermediate and are marked as the uppermost treatment layer and the lowermost treatment layer; s3, drilling and copper deposition are sequentially carried out on the first intermediate, and then full-plate electroplating is carried out to obtain a second intermediate; s4, carrying out thick and thin copper plating treatment by taking the uppermost treatment layer and the lowermost treatment layer of the second intermediate as treatment objects, forming a thin copper circuit and a thick copper circuit on the treatment objects, and obtaining a third intermediate; S5, carrying out subsequent treatment on the third intermediate.
  2. 2. The method of manufacturing a PCB according to claim 1, wherein in the step S3, the hole copper is plated at a thickness of 15-20um and the surface copper is plated at a thickness of 30-35um when the full-plate plating is performed.
  3. 3. The method according to claim 1, wherein in the step S4, the uppermost and lowermost treatment layers of the second intermediate are treated, and the uppermost and lowermost treatment layers are subjected to the thick and thin copper plating treatment at the same time.
  4. 4. The method for fabricating a PCB according to any one of claims 1 to 3, wherein in the step S4, the copper thickness of the thick copper line is 106-125um, and the copper thickness of the thin copper line is 35-40um; in the step S4, the thick and thin copper plating process is performed as follows: dividing the surface to be treated of the treatment object into a thin copper area and a thick copper area; s401, only exposing a thick copper area through a window, covering a dry film for protection on a thin copper area, and completing preparation of a first outer layer circuit; S402, after the step S401 is completed, making a design pattern in the thin copper area, windowing the thick copper area to expose the thick copper area, adding a lead wire to connect the windowed thick copper area with a copper sheet of a processing object to complete the preparation of a second outer layer circuit, and after the preparation of the second outer layer circuit is completed, performing second pattern electroplating copper plating and tinning; After alkaline etching is finished, protecting a circuit of the thin copper area, wherein the thick copper area adopts a windowing design; S403, covering a dry film protection on the thin copper area after the step S402 is completed, and windowing and exposing the thick copper area in the thick copper area, completing the preparation of a third outer layer circuit after the thin copper area and the thick copper area are processed, performing third pattern electroplating after the preparation of the third outer layer circuit is completed, performing copper plating only for the third pattern electroplating, and performing acid etching after the third pattern electroplating is completed; after the acid etching is finished, protecting a circuit of the thin copper area, wherein the thick copper area adopts a windowing design; S404, covering a dry film protection on the thin copper area after the step S403 is completed, exposing a designed circuit on the thick copper area, completing the preparation of a fourth outer layer circuit after the treatment of the thin copper area and the thick copper area is completed, and performing acid etching after the preparation of the fourth outer layer circuit is completed; and after the acid etching is finished, performing surface third green oil protection to obtain a third intermediate.
  5. 5. The method of manufacturing a PCB according to claim 4, wherein in the step S401, after the first outer layer circuit is manufactured, the first pattern plating is performed, wherein the hole copper plating thickness is 35-40um, and the surface copper plating thickness is 55-60um.
  6. 6. The method of manufacturing a PCB according to claim 4, wherein in the step S402, after the second pattern plating is completed, alkaline etching is performed, and the thin copper area circuit and the thick copper area circuit are respectively manufactured by alkaline etching, wherein the thick copper area circuit is a large copper sheet plus lead structure.
  7. 7. The method of manufacturing a PCB according to claim 4, wherein in the step S402, after the alkaline etching is completed, a printed wet film or a gold plating resistant ink is used to protect the circuit of the thin copper area.
  8. 8. The method of manufacturing a PCB as recited in claim 4, wherein in the step S403, the thickness of the hole copper in the thick copper region is at least 80um and the thickness of the surface copper is at least 106um when the third pattern plating is performed.
  9. 9. The method of manufacturing a PCB as defined in claim 4, wherein in the step S404, after the step S403 is completed, the pre-treatment is performed to close the brush, the dry film protection is covered on the thin copper area, and the circuit pattern is normally exposed on the thick copper area, and the circuit compensation on the thick copper area is performed according to the normal position of 4.3mil, the dense position of 3.8mil, the isolated position of 4.8mil, the SMD compensation of 4.8mil, and the BGA compensation of 5.3 mil.
  10. 10. A product prepared by the PCB manufacturing method of any one of claims 1 to 9.

Description

PCB manufacturing method for matching local thick copper with fine circuit and product thereof Technical Field The application relates to the field of multilayer circuit boards, in particular to a PCB manufacturing method of local thick copper matched with fine circuits and a product thereof. More specifically, the application provides a PCB manufacturing method and a product thereof, which are a PCB manufacturing method and a product of matching local thick copper with fine lines, can be used for driving new energy automobiles, industrial high-power supplies, high-end server power supply modules and high-power LEDs, and have higher application value and better application prospect. Background The Chinese patent application CN106852003A discloses a manufacturing method of a fine circuit board without a corrosion-resistant layer, which comprises copper deposition pre-plating and pattern plating, wherein the pattern plating is used for thickening copper thickness of an area without a plating-resistant layer on a plate, wherein the copper thickness range of an isolated line area on the plate is controlled to be +/-6 mu m, and the range of the isolated line area and a dense line area is controlled to be +/-7 mu m. Wherein, the copper thickness after thinning in the step (2) is controlled to be 5 mu m when the plate structure is provided with the through holes, and 7 mu m when the plate is provided with the blind holes and the through holes. The product manufactured by the structure is only a fine circuit, no local thick copper exists, the thickness of the whole copper is extremely poor at +/-7 um, and the circuit pattern is obtained by one-time etching. The Chinese patent application CN106341939A discloses a multilayer circuit board structure and a manufacturing method thereof, and comprises (4) manufacturing an outer layer circuit, namely performing plating through hole operation on the multilayer circuit board, including numerical control drilling, removing drilling glue residues and burrs, then electroplating the whole board, performing pattern electroplating, removing dry films and performing outer layer alkaline etching after outer layer image transfer to form the outer layer circuit. In the step (4), etching compensation is carried out, the line width of the dense line is pre-compensated by 15 mu m, the minimum distance of the line is ensured to be 60 mu m, the outermost line is used as the isolated line compensation, the external pre-compensation is carried out by 30 mu m, the minimum distance of the line is ensured to be 60 mu m, the space at the BGA bonding pad clamping line is less than the compensation by 10 mu m for segment compensation, and the normal compensation is carried out at other places by 20-30 mu m. The product manufactured by the structure is only one copper thickness gradient, the copper thickness is more than or equal to 30um and the extremely poor copper thickness is 5um, namely, the copper thickness interval is 30-35um, and the circuit pattern is also obtained by one-time etching. In a PCB board, large current routing requires a wider linewidth to reduce resistance and temperature rise. In the existing PCB products, if a fine circuit is needed to be matched on the PCB, only the hole copper adopts a local thick copper design, only heat can be dissipated, and the fine circuit cannot bear large current. When the PCB needs to be matched with fine circuits and high current, the sub-mother boards need to be designed, namely two PCBs are needed, one PCB is used as a power module, and the other PCB is used as a fine circuit layout. In some cases, it is desirable to reduce the volume of the device. How to further reduce the whole volume or realize the modularized design on the premise of meeting the functions of the existing PCB becomes a urgent problem to be solved. Disclosure of Invention The application aims to provide a PCB manufacturing method of matching local thick copper with fine circuits and a product thereof, so as to simplify the structure of a PCB and further reduce the whole volume. Different from the existing PCB manufacturing process, the application adopts the structural design of matching local thick copper with the fine circuit PCB, and can replace two PCBs in the past by using one PCB, thereby effectively reducing the manufacturing cost of the PCB and the PCBA and improving the corresponding production efficiency. In order to achieve the above purpose, the present application adopts the following technical scheme: A PCB manufacturing method of local thick copper matched fine circuit includes the following steps: s1, cutting a copper-clad plate, preparing an inner layer circuit, and taking two layers of copper foils for standby; s2, respectively placing two layers of copper foils on two sides of the inner layer circuit, and then pressing to obtain a first intermediate, wherein the two layers of copper foils are respectively positioned on the uppermost layer and the lowermos