Thermocompression bonding typesetting structure of high-precision circuit board

Abstract

The utility model provides a thermocompression bonding typesetting structure of a high-precision circuit board. The thermocompression bonding typesetting structure comprises two surface copper layers, a plurality of core plates, a bonding heat release type copper layer, a first release type layer, a second release type layer and a covering type layer, a plurality of core plates are arranged on the inner side between the two surface copper layers, an adhesive heat release copper layer is arranged between every two adjacent core plates, and a first release layer, a coating layer and a second release layer are sequentially arranged on the outer side of each surface copper layer; according to the bonding heat release type copper layer, a pyrolysis adhesive layer is arranged between two copper layers, the bonding heat release type copper layer of the copper layer, the pyrolysis adhesive layer and the copper layer is adopted, a typesetting structure is changed into a stacking structure of the surface copper layer, the core plate layer and the bonding heat release type copper layer, equivalently, two release films are reduced before adjacent core plates, the thickness of the stacking structure is reduced, and the thickness of the stacking structure is reduced. According to the invention, more sub-boards can be added for typesetting, the heat conduction efficiency is improved, and the beneficial effects of improving the processing efficiency and the product percent of pass are achieved.

Description

Technical Field

[0001] This utility model relates to the field of circuit board processing, and in particular to a hot-pressing and layout structure for high-precision circuit boards. Background Technology

[0002] In some electronic product fields, the high-precision circuit boards used are relatively thin. Therefore, during the hot pressing process, multiple circuit boards with the same pressing conditions can be stacked at once to improve processing efficiency.

[0003] The existing layer stacking method involves setting up an interlayer auxiliary pressing structure of "release layer + cover layer + release layer" between each circuit board, and then laying out and pressing the remaining layers.

[0004] However, the above processing method has the following disadvantages: on the one hand, the interlayer auxiliary pressing structure is relatively complex and the auxiliary layer itself has a high cost, which will increase the processing cost. On the other hand, the thickness of the interlayer auxiliary pressing structure itself will form thermal isolation between the layers, which will reduce the thermal conductivity of hot pressing, increase the hot pressing time, reduce the pressing efficiency, and easily cause the problem of weak stacking and pressing in the central area.

[0005] Based on this, and in response to the aforementioned background and problems, there is a need to provide a novel hot-pressing and layout structure for high-precision circuit boards. Utility Model Content

[0006] This utility model aims to solve the problems of high processing cost and low pressing efficiency in the current hot-pressing layout of high-precision circuit boards. It proposes a hot-pressing layout structure for high-precision circuit boards, including two surface copper layers, several core boards, a thermal release copper layer, a first release layer, a second release layer, and a cover layer. Several core boards are arranged on the inner side between the two surface copper layers, and the thermal release copper layer is arranged between adjacent core boards. The first release layer, the cover layer, and the second release layer are arranged sequentially on the outer side of each surface copper layer. The thermal release copper layer is a thermal adhesive layer arranged between the two copper layers.

[0007] Furthermore, the pyrolytic adhesive layer is a polypropylene pyrolytic adhesive, an acrylic pyrolytic adhesive, or an epoxy resin pyrolytic adhesive.

[0008] Furthermore, the thickness of the pyrolytic adhesive layer is 10 micrometers to 35 micrometers.

[0009] Furthermore, the thickness of the copper layer is 10 micrometers to 70 micrometers.

[0010] Furthermore, the core plate thickness is between 70 micrometers and 500 micrometers.

[0011] Furthermore, the surface copper layer is larger on one side than the core board.

[0012] Furthermore, the coating layer is larger on one side than the surface copper layer.

[0013] Furthermore, one side of the adhesive thermal release copper layer is equal to that of the core board.

[0014] Furthermore, both the first release layer and the second release layer are larger on one side than the cover layer.

[0015] Furthermore, the first release layer and the second release layer are made of polytetrafluoroethylene, TPX or ETFE.

[0016] The high-precision circuit board hot-pressing layout structure proposed in this utility model adopts a bonding and heat-release copper layer consisting of a copper layer, a pyrolytic adhesive layer, and a copper layer. This transforms the layout structure into a stacked structure of a surface copper layer, a core board layer, and a bonding and heat-release copper layer, replacing the previous structure of a release layer, a cover layer, and a release layer between sub-boards. This is equivalent to reducing two release films between adjacent core boards, significantly reducing the thickness of the stacked structure. This allows for the addition of more sub-boards in each layout, effectively reducing layout complexity and processing costs. Furthermore, the reduced layout thickness improves thermal conductivity, resulting in improved processing efficiency and product qualification rate. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 This is a cross-sectional schematic diagram of the hot-pressing and layout structure of the high-precision circuit board of this utility model.

[0019] Explanation of icon numbers:

[0020]

[0021] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0024] To better understand the above technical solution, the following detailed explanation is provided in conjunction with the accompanying drawings.

[0025] Please see Figure 1 , Figure 1 This is a cross-sectional schematic diagram of the hot-pressing and layout structure of the high-precision circuit board of this utility model.

[0026] The high-precision circuit board hot-pressing layout structure 10 of this embodiment includes two surface copper layers 100, a plurality of core boards 200, an adhesive thermal release copper layer 300, a first release layer 400, a second release layer 500, and a cover layer 600. A plurality of core boards 200 are disposed on the inner side between the two surface copper layers 100, and an adhesive thermal release copper layer 300 is disposed between adjacent core boards 200. The first release layer 400, the cover layer 600, and the second release layer 500 are disposed sequentially on the outer side of the surface copper layers 100. The adhesive thermal release copper layer 300 is two ordinary copper layers 3020 with a thermal adhesive layer 3010 disposed between them.

[0027] This embodiment uses a thermal release copper layer 300 consisting of "copper layer 3020 + thermal adhesive layer 3010 + copper layer 3020" to replace the existing structure of "release layer + cover layer + release layer" between adjacent core boards 200. This transforms the stacked structure into a structure of "surface copper layer 100 + core board 200 + thermal release copper layer 300". Due to its simplicity, this structure can be pre-processed and then cut to the required size for hot-pressing and layout applications. During layout, there is no need to arrange the layers one by one as with the "release layer + cover layer + release layer" structure. It is equivalent to using a single layer for layout. The use of release film and cover film between adjacent core boards 200 is reduced, which greatly reduces the thickness of the stacked structure. This allows for the addition of more core boards 200 in each layout, effectively reducing the complexity of layout and processing costs. Furthermore, it improves thermal conductivity and has the beneficial effects of improving processing efficiency and product qualification rate.

[0028] It is worth noting that the pyrolytic adhesive layer 3010 is usually a compound colloid. By adding components with pyrolytic adhesive properties (such as pregelatinized starch, foamed microspheres, etc.) to ordinary colloids, it forms a colloid that is tacky at room temperature and detacky at high temperature. Therefore, the pyrolytic adhesive layer 3010 in this embodiment is a polypropylene pyrolytic adhesive, an acrylic pyrolytic adhesive, or an epoxy resin pyrolytic adhesive. The main components of these three types of colloids have similar properties to the main components of the insulating dielectric layer in the circuit board. Therefore, the similar properties during the hot pressing process facilitate better bonding between the two and effectively avoid problems such as poor hot pressing and uneven filling.

[0029] Furthermore, in this embodiment, the thickness of the adhesive thermal release copper layer 300 is designed to be relatively thin, ranging from 10 micrometers to 35 micrometers. On the one hand, this ensures the adhesion of the thermal adhesive layer 3010, allowing the two copper layers 200 of the adhesive thermal release copper layer 300 to adhere together through the colloid and to separate after being heated. On the other hand, it prevents the thermal adhesive layer 3010 from being too thick, which could lead to problems such as difficulty in debonding after heating or significant thermal conductivity obstruction.

[0030] It is worth noting that the copper layer 200 is designed to be relatively thin, ranging from 10 micrometers to 70 micrometers, to meet the processing requirements of thin, high-precision circuit boards. At the same time, it avoids the problem that the "copper layer 200 + pyrolytic adhesive layer 3010 + copper layer 200" structure design of the thermal release copper layer 300 would have too much binding force on the copper layer 200, resulting in problems such as poor bonding due to limited lateral expansion and contraction, or the problem that the thermal release adhesive layer 3010 would be hindered due to the copper layer 200 being too thick.

[0031] In particular, the core board 200 thickness should not be too thick, and can be selected from 70 micrometers to 500 micrometers to meet the processing requirements of thin and high-precision circuit boards. Furthermore, if the core board 200 thickness is larger, the number of multiple circuit board structures stacked at one time will be reduced, and the stacking and pressing processing will be more difficult. In addition, a larger thickness will increase the hot pressing time, resulting in a decrease in the thermal conductivity of hot pressing, which leads to a decrease in pressing efficiency and makes it easy for the stacking and pressing in the central area to be not firm.

[0032] In this embodiment, the coating layer 600 is larger than the surface copper layer 100 on one side, and the adhesive heat release copper layer 300 is equal to the core board 200 on one side. Since the core board 200 contains an insulating dielectric layer, colloid will flow during the hot pressing process. Therefore, both the surface copper layer 100 and the adhesive heat release copper layer 400 are larger than the core board 200 on one side, forming a full coverage of the core board 200. This ensures that the copper layer 200 and the adhesive heat release copper layer 400 can completely wrap the core board 200 after pressing, preventing the colloid of the insulating dielectric layer of the core board 200 from flowing to the outside of the board and causing problems such as mutual adhesion.

[0033] Furthermore, the surface copper layer 100 is larger than the core board 200 on one side, so that the core board 200 can completely cover the surface copper layer 100. This ensures that the surface copper layer 100 and the core board 200 are within the coverage area of ​​the coating layer 600, and avoids the core board 200 being larger than the surface copper layer 100. This would cause uneven stress on the surface of the core board 200 during the lamination process, which could easily lead to quality problems such as insufficient adhesive during lamination and copper foil wrinkles.

[0034] It is worth noting that both the first release layer 400 and the second release layer 500 are larger than the cover layer 600 on one side, which can provide better protection and ensure that the cover layer 600 does not flow onto the surface copper layer 100 or steel plate 700 during the pressing process, thus preventing contamination.

[0035] In this embodiment, the first release layer 400 and the second release layer 500 are made of polytetrafluoroethylene, TPX or ETFE. All three materials have good release properties after hot pressing. During the hot pressing process, the first release layer 400 and the second release layer 500 can prevent the steel plate 700 from bonding with the cover layer 600 and the cover layer 600 from bonding with the surface copper layer 100.

[0036] In this embodiment, the overlay layer 600 is made of polyolefin, PP, PE, or epoxy resin. These four materials have good formability and excellent high-temperature stability, maintaining good performance during hot pressing. This effectively solves the problem of "board surface expansion and contraction," reduces deformation caused by heat and pressure, and thus ensures the bonding quality of the circuit board.

[0037] In summary, the specific manufacturing method of this embodiment is as follows: The plates are arranged according to the above structure and then pressed together on two steel plates 700. The adhesive layer 3010 is pyrolyzed and debonded by heat. After pressing, the sub-plates are separated, and then surface cleaning, micro-grinding, and other processing are performed to form the pressed sub-plates.

[0038] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model and based on the description and drawings of the present utility model, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A high-precision circuit board hot-pressing and layout structure, characterized in that, It includes two surface copper layers, several core boards, adhesive-dissolvable release copper layers, a first release layer, a second release layer, and a cover layer; A plurality of core plates are disposed on the inner side between the two surface copper layers, and a heat release copper layer is disposed between adjacent core plates. A first release layer, a cover layer and a second release layer are disposed sequentially on the outer side of each surface copper layer. The adhesive thermal release copper layer consists of two copper layers with a thermal adhesive layer between them.

2. The high-precision circuit board hot-pressing and layout structure as described in claim 1, characterized in that, The pyrolytic adhesive layer is made of polypropylene pyrolytic adhesive, acrylic pyrolytic adhesive, or epoxy resin pyrolytic adhesive.

3. The hot-pressing and layout structure of a high-precision circuit board as described in claim 1 or 2, characterized in that, The thickness of the pyrolytic adhesive layer is 10 micrometers to 35 micrometers.

4. The high-precision circuit board hot-pressing and layout structure as described in claim 1, characterized in that, The thickness of the copper layer is 10 micrometers to 70 micrometers.

5. The hot-pressing and layout structure of a high-precision circuit board as described in claim 1, characterized in that, The core plate thickness is 70 micrometers to 500 micrometers.

6. The hot-pressing and layout structure of a high-precision circuit board as described in claim 1, characterized in that, The surface copper layer is larger on one side than the core board.

7. The high-precision circuit board hot-pressing and layout structure as described in claim 1, characterized in that, The coating layer is larger on one side than the surface copper layer.

8. The hot-pressing and layout structure of a high-precision circuit board as described in claim 1, characterized in that, The adhesive-dissolution thermal release copper layer has one side equal to the core board.

9. The hot-pressing and layout structure of a high-precision circuit board as described in claim 1, characterized in that, Both the first release layer and the second release layer are larger on one side than the cover layer.

10. A high-precision circuit board hot-pressing and layout structure as described in claim 1 or 9, characterized in that, The first release layer and the second release layer are made of polytetrafluoroethylene, TPX or ETFE.

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