Laminated press structure of metal-based circuit board

Abstract

The utility model relates to a kind of laminated board press-bonding structure of metal-based circuit board, it includes upper buffer laminated, lower buffer laminated and the circuit board laminated of being set between upper buffer laminated and lower buffer laminated, upper buffer laminated is in order from top to bottom steel sheet, buffer paper, steel sheet and release film, lower buffer laminated is in order from top to bottom release film, steel sheet, buffer paper and steel sheet, circuit board laminated includes metal substrate and the semi-solidified resin bonding layer and circuit substrate of being sequentially stacked in one side of metal substrate, and metal substrate is equipped with the conductive and / or heat-conducting boss of penetrating circuit substrate.The utility model's laminated board press-bonding structure is set on the upper and lower sides of circuit board laminated and includes the buffer laminated of buffer paper, can improve the stress uniformity of circuit board laminated when pressing, make the gap between boss and circuit substrate can be reliably filled by semi-solidified resin bonding layer.

Description

Technical Field

[0001] This utility model relates to the field of circuit boards; more specifically, it relates to a stacked lamination structure for a metal-based circuit board. Background Technology

[0002] Metal-based circuit boards typically include a circuit board, a resin adhesive layer, and a metal substrate. The circuit board has conductive lines, and the metal substrate is connected to the circuit board through the resin adhesive layer. The metal substrate may have conductive and / or thermally conductive bumps that penetrate the circuit board, allowing for thermal and / or electrical connections between electronic components on the circuit board and the metal substrate.

[0003] The fabrication of metal-based circuit boards involves a lamination step of pressing together a circuit board, a semi-cured resin adhesive layer, and a metal substrate. Ideally, when the metal substrate has bosses, the bosses and the circuit board should have flush surfaces during lamination. However, in actual production, the height difference between the bosses and the circuit board surfaces is often difficult to control precisely, resulting in the bosses protruding from the circuit board surface. The height by which the bosses protrude from the circuit board surface has a significant impact on the lamination effect.

[0004] In the prior art, when laminating a metal-based circuit board with bosses, a buffer layer including a silicone pad is usually placed on one side of the circuit board. This silicone pad is usually thick and too soft, which cannot ensure pressure balance. In particular, if the height of the boss protruding from the circuit board is greater than 0.025mm, the circuit board and the semi-cured resin adhesive layer are more likely to be under insufficient pressure, resulting in weak resin flow in the semi-cured resin adhesive layer. During lamination, the gap between the boss and the circuit board cannot be completely filled by the resin. Utility Model Content

[0005] In view of the shortcomings of the prior art, the main purpose of this utility model is to provide a stacking and lamination structure for metal-based circuit boards, so as to solve the defect that the gap between the boss and the circuit board cannot be completely filled by resin during the lamination of metal-based circuit boards in the prior art.

[0006] To achieve the aforementioned main objectives, this utility model provides a stacked lamination structure for a metal-based circuit board, comprising an upper buffer stack, a lower buffer stack, and a circuit board stack disposed between the upper and lower buffer stacks; the upper buffer stack consists of, from top to bottom, a steel plate, a buffer paper, a steel plate, and a double-sided release film, and the lower buffer stack consists of, from top to bottom, a double-sided release film, a steel plate, a buffer paper, and a steel plate; the circuit board stack includes a metal substrate and a semi-cured resin adhesive layer and a circuit board sequentially stacked on one side of the metal substrate, and the metal substrate is provided with conductive and / or thermally conductive protrusions penetrating the circuit board.

[0007] Furthermore, the number of circuit board stacks is multiple, and an intermediate buffer stack is provided between two adjacent circuit board stacks. The intermediate buffer stack consists of a double-sided release film, a steel plate, a buffer paper, a steel plate, and a double-sided release film from top to bottom.

[0008] Furthermore, the thickness of the steel plate is 1.2mm to 1.6mm.

[0009] Furthermore, the thickness of the cushioning paper is 0.5mm to 1mm.

[0010] Furthermore, the thickness of the double-sided release film is 75μm to 150μm.

[0011] Furthermore, the metal substrate is a copper substrate, and the conductive and / or thermally conductive boss is a copper boss that has an integrally formed structure or is welded to the copper substrate.

[0012] Furthermore, the circuit board includes an insulating core board and a copper foil layer disposed on the insulating core board.

[0013] Furthermore, the circuit board stack is disposed in the stacked plate pressing structure with the circuit board substrate facing upward.

[0014] The technical solution of this utility model has the following beneficial effects:

[0015] In this invention, buffer layers are provided on both the upper and lower sides of the circuit board stack. The buffer layers are made of steel plate, buffer paper and double-sided release film for heat conduction buffering and pressure equalization, so that the circuit board and the semi-cured resin adhesive layer are stably and uniformly heated and pressed. The resin in the semi-cured resin adhesive layer can fully fill the gap between the boss and the circuit board, improving the pressing effect of the circuit board stack.

[0016] To more clearly illustrate the purpose, technical solution, and advantages of this utility model, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the laminated structure in Example 1;

[0018] Figure 2 This is a schematic diagram of the circuit board stack structure in this utility model;

[0019] Figure 3 This is a schematic diagram of the laminated structure in Example 2. Detailed Implementation

[0020] The technical solution of this utility model is described in detail below with reference to specific embodiments. However, this utility model can also be implemented in other variations based on this description. Therefore, the protection scope of this utility model is not limited to the specific embodiments disclosed below.

[0021] Example 1

[0022] The laminated structure disclosed in Example 1 is suitable for laminating a single circuit board stack 2. For example... Figure 1 As shown, the laminated structure includes an upper buffer layer 1a, a lower buffer layer 1b, and a circuit board layer 2 disposed between the upper buffer layer 1a and the lower buffer layer 1b; wherein, the upper buffer layer 1a and the lower buffer layer 1b have a symmetrical structure with respect to the circuit board layer 2, the upper buffer layer 1a consists of a steel plate 11, a buffer paper 12, a steel plate 11, and a double-sided release film 13 from top to bottom, and the lower buffer layer 1b consists of a double-sided release film 13, a steel plate 11, a buffer paper 12, and a steel plate 11 from top to bottom.

[0023] like Figure 2 As shown, in this embodiment, the circuit board stack 2 includes a metal substrate 21 and a semi-cured resin adhesive layer 22 and a circuit board 23 sequentially disposed on one side of the metal substrate 21. The metal substrate 21 has one or more bosses 211 for electrical and / or thermal conductivity. The circuit board 23 has through holes 233 corresponding to the positions of the bosses 211. The bosses 211 pass through the semi-cured resin adhesive layer 22 (e.g., a prepreg) and are located within the through holes 233 of the circuit board 23. Preferably, as shown... Figure 1 As shown, the circuit board stack 2 is arranged in the stacked plate pressing structure with the circuit board 23 facing upward.

[0024] In this embodiment, the metal substrate 21 can be a copper substrate, and the boss 211 can be a copper boss with an integral structure with the copper substrate. For example, the copper boss with an integral structure can be obtained by selectively etching or electroplating the copper substrate, or the fabricated copper boss can be welded to the copper substrate. The boss 211 can also adopt other structures, such as using a ceramic block with copper foil layers on both the top and bottom sides as the boss. This type of boss not only has better thermal conductivity, but also allows conductive lines to be fabricated on the boss.

[0025] In the embodiments, such as Figure 2As shown, the circuit board 23 includes an insulating core board 231 (e.g., an FR-4 core board) and a copper foil layer 232 disposed on the outer side of the insulating core board 231 (the side facing away from the semi-cured resin adhesive layer 22). As a variation of the embodiment, a copper foil layer may also be provided on the inner side of the insulating core board 231; this copper foil layer may not be etched or may have conductive lines etched on it. Alternatively, the circuit board 23 may not include the insulating core board 231, and instead, the copper foil layer 232 may be directly laminated.

[0026] Example 2

[0027] The laminated structure disclosed in Example 2 is suitable for laminating multiple circuit board stacks 2. For example... Figure 3 As shown, the laminated structure includes an upper buffer layer 1a, a lower buffer layer 1b, and multiple circuit board layers 2 disposed between the upper buffer layer 1a and the lower buffer layer 1b. An intermediate buffer layer 1c is provided between two adjacent circuit board layers 2. The intermediate buffer layer 1c consists of, from top to bottom, a release film 13, a steel plate 11, a buffer paper 12, another steel plate 11, and the release film 13. The structures of the upper buffer layer 1a, the lower buffer layer 1b, and the circuit board layers 2 can be referred to the description in Embodiment 1.

[0028] In this invention, the thickness of the steel plate 11 is preferably 1.2mm to 1.6mm. The steel plate 11 has sufficient strength and hardness to withstand high-pressure environments without deformation, thereby improving the flatness and dimensional accuracy of the circuit board lamination. Simultaneously, the steel plate 11 serves as a medium for heat conduction and pressure transfer, possessing excellent thermal conductivity to ensure uniform heat transfer.

[0029] In this invention, the buffer paper 12 can be made of carbon fiber paper. Compared with the silicone pads used in the prior art, the buffer paper 12 can more accurately control heat transfer and balance the pressure on the circuit board surface during the pressing process, thereby playing functions such as pressure equalization, improving board thickness uniformity, and thermal conduction buffering. Preferably, the thickness of the buffer paper 12 is 0.5mm to 1mm.

[0030] In this invention, the thickness of the double-sided release film 13 is preferably 75μm to 150μm. This thickness of release film not only serves as a release agent but also provides auxiliary cushioning. Together with the cushioning paper 12, it can achieve better cushioning and pressure equalization effects.

[0031] In summary, in the stacked lamination structure of this utility model, buffer layers are provided on both the upper and lower sides of the circuit board stack. The buffer layers adopt a specific combination structure in which buffer paper is placed between two steel plates and a double-sided release film is placed between the steel plates and the circuit board stack. This structure can more effectively conduct heat buffering and pressure equalization, enabling the circuit board and the semi-cured resin adhesive layer to be stably and uniformly heated and compressed. The resin in the semi-cured resin adhesive layer can fully fill the gap between the boss and the circuit board. After lamination, the interface between the boss and the circuit board is flat and free of cracks, depressions and bubbles. The final metal-based circuit board exhibits good thermal shock resistance stability.

[0032] Although the present invention has been disclosed above with reference to specific embodiments, these embodiments are not intended to limit the scope of the present invention. Any person skilled in the art may make some modifications or variations without departing from the scope of the present invention; that is, all equivalent changes made in accordance with the present invention should be covered by the protection scope of the present invention.

Claims

1. A laminated structure for a metal-based circuit board, comprising an upper buffer layer, a lower buffer layer, and a circuit board layer disposed between the upper buffer layer and the lower buffer layer, characterized in that: The upper buffer stack consists of a steel plate, a buffer paper, a steel plate, and a double-sided release film from top to bottom. The lower buffer stack consists of a double-sided release film, a steel plate, a buffer paper, and a steel plate from top to bottom. The circuit board stack includes a metal substrate and a semi-cured resin adhesive layer and a circuit board stacked sequentially on one side of the metal substrate. The metal substrate is provided with conductive and / or thermally conductive protrusions that penetrate the circuit board.

2. The stacked lamination structure of the metal-based circuit board according to claim 1, characterized in that: The circuit board has multiple stacks, and an intermediate buffer stack is provided between two adjacent circuit board stacks. The intermediate buffer stack consists of a double-sided release film, a steel plate, a buffer paper, a steel plate, and a double-sided release film from top to bottom.

3. The stacked lamination structure of the metal-based circuit board according to claim 1, characterized in that: The thickness of the steel plate is 1.2mm to 1.6mm.

4. The stacked lamination structure of the metal-based circuit board according to claim 1, characterized in that: The thickness of the cushioning paper is 0.5mm to 1mm.

5. The laminated structure of the metal-based circuit board according to claim 1, characterized in that: The thickness of the double-sided release film is 75μm to 150μm.

6. The laminated structure of the metal-based circuit board according to claim 1, characterized in that: The metal substrate is a copper substrate, and the conductive and / or thermally conductive boss is a copper boss.

7. The laminated structure of the metal-based circuit board according to claim 1, characterized in that: The circuit board includes an insulating core board and a copper foil layer disposed on the insulating core board.

8. The stacked lamination structure of the metal-based circuit board according to claim 1, characterized in that: The circuit board stack is arranged in the stacked plate pressing structure with the circuit board substrate facing upward.

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