CN-121985482-A - Manufacturing method of copper-embedded double-sided printed circuit board

Abstract

The invention discloses a manufacturing method of a double-sided printed circuit board with a buried copper block, which comprises the following steps of grooving a core board, controlling the precision of a groove hole to be within +/-50 mu m, placing the core board on a marble platform, placing the copper block in the groove hole, ensuring the flatness of the copper block to be within +/-12.7 mu m, plugging holes by vacuum resin, attaching a high-temperature adhesive tape to fix the copper block after plugging holes, fixing a baking board by adopting a vertical placement or special jig, drilling, using a UC type coating drilling tool, adopting a sectional drilling mode to cope with hardness difference of different materials, dynamically setting and strictly controlling the service life of a drill bit according to the diameter of the drilling tool, the thickness of the copper block and a laminated board structure, carrying out hole metallization, carrying out full-board electroplating, ensuring the thickness of the copper in the hole to be 25-30 mu m, adopting a high-precision pattern transfer process to manufacture an outer layer circuit, carrying out surface treatment, and then carrying out molding and electric testing. According to the manufacturing method of the copper block-embedded double-sided printed circuit board, the displacement risk of the copper block in the double-sided board structure is reduced by 15% through measures such as leveling control of a marble platform, erection of a baking board and the like, and the problems of copper block fixation, precise drilling and interface reliability are systematically solved.

Inventors

• Lu Xiangchui
• Jiang Zhangqiang
• Lai Changyin
• LIU BING
• SHI XIAOFENG
• Liu Zukai
• Tian Hehuan

Assignees

• 江西旭昇电子股份有限公司

Dates

Publication Date

20260505

Application Date

20260202

Claims (8)

1. 1. The manufacturing method of the copper-embedded double-sided printed circuit board is characterized by comprising the following steps of: S1, grooving the core plate, and controlling the precision of the groove hole within +/-50 mu m; S2, placing the core plate on a marble platform, and placing the copper block in the slotted hole to ensure that the flatness of the copper block is within +/-12.7 mu m; S3, plugging holes by vacuum resin, and attaching a high-temperature adhesive tape to fix the copper block after plugging holes; S4, baking the plate, wherein the plate is vertically placed or fixed by a special jig, so that the copper block is prevented from shifting due to gravity or stress before the resin is solidified; Step S5, drilling, namely, using a UC type coating drilling tool, adopting a sectional drilling mode to cope with hardness differences of different materials, dynamically setting and strictly controlling the service life of a drill bit through trial drilling and hole wall quality monitoring according to the diameter of the drilling tool, the thickness of a copper block and a laminated plate structure; s6, hole metallization, full-plate electroplating, and ensuring that the thickness of hole copper is 25-30 mu m; S7, manufacturing an outer layer circuit by adopting a high-precision pattern transfer process; And S8, surface treatment, molding and electric testing are carried out.
2. 2. The method for manufacturing a double-sided printed wiring board with embedded copper blocks according to claim 1, wherein in step S3, a double-sided plugging method is adopted for the vacuum resin plug holes.
3. 3. The method for manufacturing a double-sided printed circuit board with embedded copper blocks according to claim 1, wherein in step S5, a sectional drilling process adopts a slow-first-fast-second mode, specifically: The first stage of copper block drilling adopts a low-rotation-speed slow feeding mode; And the second stage drills the base material in a high-rotation-speed and fast-feeding mode.
4. 4. The method of manufacturing a double-sided printed wiring board with embedded copper block as claimed in claim 1, wherein in step S7, the tolerance to the radio frequency circuit is controlled to +25.4μm.
5. 5. The method for manufacturing a double-sided printed wiring board with copper buried blocks according to claim 1, further comprising a step of detecting the reliability of the product, in particular, a thermal stress test, a reflow soldering test and a conventional reliability test.
6. 6. The method for manufacturing a double-sided printed wiring board with embedded copper blocks according to claim 5, wherein the thermal stress test method is that the finished board is immersed in a tin furnace at 288 ℃ for 10 seconds, and after repeating for 3-5 times, the copper blocks and resin bonding interface are subjected to slicing inspection, and delamination or cracking are not allowed to occur.
7. 7. The method for manufacturing the double-sided printed wiring board with the embedded copper block according to claim 5, wherein the reflow soldering test method is characterized in that the actual assembly process is simulated, the finished board is subjected to 3 times of reflow soldering, the peak furnace temperature is required to reach 250-265 ℃, and the copper block position and the interface are confirmed to be delamination-free, crack-free and displacement-free by slicing again after the test.
8. 8. The method of manufacturing a double-sided printed wiring board with embedded copper block according to claim 5, wherein the conventional reliability test includes a high and low temperature cycle test, a salt spray test, an ion contamination degree test, and a solder resist layer adhesion test.

Description

Manufacturing method of copper-embedded double-sided printed circuit board Technical Field The invention relates to the technical field of circuit board manufacturing, in particular to a manufacturing method of a copper-embedded double-sided printed circuit board. Background In the fields of high-power applications such as communication power supplies and automotive electronics, double-sided PCBs are widely used due to their simple structure and low cost. However, an effective heat dissipation path is needed for a large amount of heat generated when the power device is operated. Embedding copper blocks into the double-sided board is an effective way to increase its heat dissipation capability. However, the technology faces serious challenges that firstly, a thick copper block is added into a simple double-sided structure, plate warpage, copper block displacement or resin filling unsaturation are easily caused by uneven stress in the lamination process, and secondly, when the copper block is drilled later, the problems of hole deviation, rapid drilling tool abrasion, poor hole wall quality and the like are easily caused due to abrupt change of the hardness of the material, and the reliability of a metallized hole is seriously affected. The prior art lacks a complete set of process solutions for a double-sided structure that can systematically address the fixation from buried blocks to high reliability interconnects. In view of the above, the present invention aims to provide a method for manufacturing a copper-embedded double-sided printed wiring board, which solves the above technical problems. Disclosure of Invention The invention aims to solve the technical problem of providing a manufacturing method of a buried copper block double-sided printed circuit board, which systematically solves the problems of copper block fixation, precise drilling and interface reliability by optimizing the technological process and technological parameters. The technical scheme of the invention is as follows: a manufacturing method of a copper-embedded double-sided printed circuit board comprises the following steps: S1, grooving the core plate, and controlling the precision of the groove hole within +/-50 mu m; S2, placing the core plate on a marble platform, and placing the copper block in the slotted hole to ensure that the flatness of the copper block is within +/-12.7 mu m; S3, plugging holes by vacuum resin, and attaching a high-temperature adhesive tape to fix the copper block after plugging holes; S4, baking the plate, wherein the plate is vertically placed or fixed by a special jig, so that the copper block is prevented from shifting due to gravity or stress before the resin is solidified; S5, drilling, namely, when drilling holes on the copper block, using a UC type coating drilling tool, adopting a sectional drilling mode to cope with hardness differences of different materials, dynamically setting and strictly controlling the service life of the drill bit through trial drilling and hole wall quality monitoring according to the diameter of the drilling tool, the thickness of the copper block and a laminated plate structure; s6, hole metallization, full-plate electroplating, and ensuring that the thickness of hole copper is 25-30 mu m; S7, manufacturing an outer layer circuit by adopting a high-precision pattern transfer process; And S8, surface treatment, molding and electric testing are carried out. Further, in step S3, the vacuum resin plug hole adopts a double-faced plug manner. Further, in step S5, the sectional drilling process adopts a slow-first-then-fast mode, specifically: The first stage of copper block drilling adopts a low-rotation-speed slow feeding mode; And the second stage drills the base material in a high-rotation-speed and fast-feeding mode. Further, in step S7, the tolerance of the rf circuit is controlled to +25.4μm. Further, the method also comprises the step of detecting the reliability of the product, and specifically comprises a thermal stress test, a reflow soldering test and a conventional reliability test. Further, the thermal stress test method is that the finished plate is immersed in a tin furnace at 288 ℃ for 10 seconds, and after 3-5 times of repetition, the copper block and resin bonding interface are checked by slicing, and delamination or cracking is not allowed to occur. Further, the reflow soldering test method is that the actual assembly process is simulated, the finished board is subjected to 3 times of reflow soldering, the peak furnace temperature is required to reach 250-265 ℃, and after the test, the copper block is sliced again to confirm that the copper block position and the interface are not layered, cracked or displaced. Further, the conventional reliability test includes a high and low temperature cycle test, a salt spray test, an ion contamination degree test, and a solder mask adhesion test. Compared with the prior art, the manufacturing method of the copper-embed