Asymmetric pressing structure

Abstract

The utility model discloses an asymmetric pressing structure which comprises an upper plate unit, an outer layer core plate, a mother plate, a lower steel plate, a lower buffer unit and a base plate. The upper plate unit, the outer-layer core plate, the mother plate, the lower steel plate, the lower buffer unit and the chassis are sequentially arranged from top to bottom; a lower composite board is arranged between the mother board and the lower steel board, and the heat conductivity coefficient of the mother board is consistent with that of the outer-layer core board; the outer-layer core plate comprises a core plate main body; the upper plate unit comprises an upper buffer unit, an upper steel plate and an upper composite plate; the upper buffer unit, the upper steel plate and the upper composite plate are sequentially arranged from top to bottom; and the upper composite plate is arranged between the upper steel plate and the outer-layer core plate. According to the utility model, non-uniform expansion and shrinkage caused by non-uniform heat transfer between the outer layer core plate and the mother plate can be reduced, so that the problem of layer deviation caused by non-uniform expansion and shrinkage between the outer layer core plate and the mother plate can be reduced.

Description

Technical Field

[0001] This utility model relates to an asymmetric pressing structure. Background Technology

[0002] In the manufacturing of high-end PCBs (such as HDI and high-frequency / high-speed boards), lamination is a core step in the production of multilayer PCBs. It directly determines the structural strength, electrical performance, signal integrity, and long-term reliability of the PCB, thus affecting the performance, yield, and cost of the multilayer board. A reasonable stack-up design can optimize material stress distribution and reduce defect rates, while improper design can lead to problems such as delamination, warping, and impedance runaway. Therefore, it is necessary to minimize the negative impact of lamination on drilling through material science optimization, stack-up symmetry design, and dynamic process control. Existing lamination structures are often designed to be symmetrical, but some lamination structures are designed to be asymmetrical due to process and product requirements. However, for asymmetrical lamination structures that require multiple laminations, the outer core board and the mother board are prone to severe layer misalignment during the second lamination due to the mismatch of expansion and contraction coefficients, resulting in serious scrap and a product pass rate that falls far short of the high requirements of enterprises. Utility Model Content

[0003] In order to overcome the shortcomings of the prior art, the purpose of this utility model is to provide an asymmetric pressing structure, which can reduce the problem of layer misalignment caused by the different expansion and contraction of the outer core board and the mother board.

[0004] The objective of this utility model is achieved through the following technical solution:

[0005] An asymmetric pressing structure includes an upper plate unit, an outer core plate, a mother plate, a lower steel plate, a lower buffer unit, and a chassis; the upper plate unit, outer core plate, mother plate, lower steel plate, lower buffer unit, and chassis are arranged sequentially from top to bottom; a lower composite plate is disposed between the mother plate and the lower steel plate, and the thermal conductivity of the mother plate is the same as that of the outer core plate; the outer core plate includes a core plate body, and the ratio of the thickness of the core plate body to the thickness of the mother plate is 0.05-0.09; the upper plate unit includes an upper buffer unit, an upper steel plate, and an upper composite plate; the upper buffer unit, upper steel plate, and upper composite plate are arranged sequentially from top to bottom; the upper composite plate is disposed between the upper steel plate and the outer core plate; the lower composite plate has the same thickness as the upper composite plate.

[0006] The upper plate unit also includes a top cover; the upper buffer unit is disposed between the upper steel plate and the top cover.

[0007] The projection of the outer core board onto the upper composite board is located within the area of ​​the upper composite board; the projection of the mother board onto the lower composite board is located within the area of ​​the lower composite board.

[0008] The upper composite board includes a first upper copper foil layer, a first adhesive layer, and a first lower copper foil layer; the first upper copper foil layer is located above the first lower copper foil layer, and the first upper copper foil layer is connected to the first lower copper foil layer through the first adhesive layer.

[0009] The lower composite board includes a second upper copper foil layer, a second adhesive layer, and a second lower copper foil layer; the second upper copper foil layer is located above the second lower copper foil layer, and the second upper copper foil layer is connected to the second lower copper foil layer through the second adhesive layer.

[0010] The first lower copper foil layer is provided with a first glossy surface for contacting the upper surface of the outer core board; the second upper copper foil layer is provided with a second glossy surface for contacting the lower surface of the motherboard.

[0011] The thickness of the first upper copper foil layer, the first lower copper foil layer, the second upper copper foil layer, and the second lower copper foil layer is 0.5oz-1oz.

[0012] The thickness of both the first adhesive layer and the second adhesive layer is 50-120 μm.

[0013] The motherboard comprises several layers of central core boards, and a third adhesive layer is provided between any two adjacent central core boards.

[0014] The cross-sectional area of ​​the lower composite plate is the same as that of the lower steel plate.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0016] This utility model provides an asymmetric pressing structure, which avoids direct contact between the mother plate and the lower steel plate, and between the upper composite plate and the outer core plate by placing a lower composite plate between the mother plate and the lower steel plate, and between the outer core plate and the upper steel plate. The lower composite plate and the upper composite plate have the same thickness. The ratio of the thickness of the outer core plate to the thickness of the mother plate is set to 0.05-0.09. The thermal conductivity of the mother plate is also set to the ratio of the thermal conductivity of the outer core plate to the thermal conductivity of the outer core plate. Setting the thermal conductivity to be consistent can reduce the difference in expansion and contraction between the outer core board and the mother board due to different heat transfer, thereby reducing the layer misalignment problem caused by the difference in expansion and contraction between the outer core board and the mother board. Moreover, by using a combination of a first upper copper foil layer, a first adhesive layer and a first lower copper foil layer for the upper composite board, and a combination of a second upper copper foil layer, a second adhesive layer and a second lower copper foil layer for the lower composite board, the layer misalignment problem caused by the difference in expansion and contraction between the outer core board and the mother board can be further improved. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model;

[0018] Figure 2 This is an exploded view of the present invention;

[0019] Figure 3 This is a cross-sectional view of the present invention;

[0020] Figure 4 This is a schematic diagram of the motherboard structure;

[0021] Figure 5 This is a schematic diagram of the lower composite panel structure;

[0022] Figure 6 This is a schematic diagram of the structure of the top-mounted composite panel;

[0023] Among them, 10 is the chassis; 20 is the lower buffer unit; 30 is the lower steel plate; 40 is the lower composite plate; 41 is the second upper copper foil layer; 42 is the second adhesive layer; 43 is the second lower copper foil layer; 50 is the mother board; 51 is the middle core board; 52 is the third adhesive layer; 60 is the lower sheet; 70 is the outer core board; 80 is the upper composite plate; 81 is the first upper copper foil layer; 82 is the first adhesive layer; 83 is the first lower copper foil layer; 90 is the upper steel plate; 91 is the upper buffer unit; and 92 is the top cover. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0025] As shown in Figures 1-6, an asymmetric pressing structure includes an upper plate unit, an outer core plate 70, a mother plate 50, a lower steel plate 30, a lower buffer unit 20, and a chassis 10; the upper plate unit, outer core plate 70, mother plate 50, lower steel plate 30, lower buffer unit 20, and chassis 10 are arranged sequentially from top to bottom; a lower composite plate 40 is disposed between the mother plate 50 and the lower steel plate 30, and the thermal conductivity of the mother plate 50 is the same as that of the outer core plate 70; the outer core plate 70 includes a core plate body, and the ratio of the thickness of the core plate body to the thickness of the mother plate 50 is 0.05 - 0.09; The upper plate unit includes an upper buffer unit 91, an upper steel plate 90, and an upper composite plate 80; the upper buffer unit 91, the upper steel plate 90, and the upper composite plate 80 are arranged sequentially from top to bottom; the upper composite plate 80 is disposed between the upper steel plate 90 and the outer core plate 70; the lower composite plate 40 has the same thickness as the upper composite plate 80.

[0026] This utility model provides an asymmetric pressing structure, which avoids direct contact between the mother plate 50 and the lower steel plate 30 by setting a lower composite plate 40 between the mother plate 50 and the lower steel plate 30, and an upper composite plate 80 between the upper steel plate 90 and the outer core plate 70. The thicknesses of the lower composite plate 40 and the upper composite plate 80 are set to be the same, and the ratio of the thickness of the core plate body to the thickness of the mother plate 50 is 0.05-0.09. The thermal conductivity of the mother plate 50 is the same as that of the outer core plate 70. This ensures that the heat transferred during hot pressing is consistent across all areas of the mother plate 50 and the outer core plate 70, reducing uneven expansion and contraction between the outer core plate 70 and the mother plate 50 due to uneven heat transfer, thus minimizing layer misalignment caused by uneven expansion and contraction.

[0027] The upper plate unit also includes a top cover 92; the upper buffer unit 91 is disposed between the upper steel plate 90 and the top cover 92. By using a top cover 92 for the upper plate unit, the pressing effect can be improved.

[0028] The projection of the outer core plate 70 onto the upper composite plate 80 is located within the area where the upper composite plate 80 is located; the projection of the mother plate 50 onto the lower composite plate 40 is located within the area where the lower composite plate 40 is located. By adopting the above structure, the pressing effect and the heat transfer effect can be improved.

[0029] The upper composite board 80 includes a first upper copper foil layer 81, a first adhesive layer 82, and a first lower copper foil layer 83; the first upper copper foil layer 81 is located above the first lower copper foil layer 83, and the first upper copper foil layer 81 is connected to the first lower copper foil layer 83 through the first adhesive layer 82. The lower composite board 40 includes a second upper copper foil layer 41, a second adhesive layer 42, and a second lower copper foil layer 43; the second upper copper foil layer 41 is located above the second lower copper foil layer 43, and the second upper copper foil layer 41 is connected to the second lower copper foil layer 43 through the second adhesive layer 42. The motherboard 50 includes several layers of central core boards 51, and a third adhesive layer 52 is provided between any two adjacent central core boards 51. By combining the upper composite plate 80 with a first upper copper foil layer 81, a first adhesive layer 82, and a first lower copper foil layer 83, and combining the lower composite plate 40 with a second upper copper foil layer 41, a second adhesive layer 42, and a second lower copper foil layer 43, the structural composition of the lower composite plate 40 and the upper composite plate 80 is similar to that of the mother plate 50. The thermal conductivity of the lower composite plate 40 and the upper composite plate 80 is the same as that of the mother plate 50. During hot pressing, the lower composite plate 40, the upper composite plate 80, the outer core plate 70, and the mother plate 50 expand and contract in unison, avoiding uneven expansion and contraction of the outer core plate 70 and the mother plate 50 due to heat transfer and expansion and contraction of adjacent materials. This further improves the problem of layer misalignment caused by uneven expansion and contraction between the outer core plate 70 and the mother plate 50.

[0030] The first lower copper foil layer 83 is provided with a first glossy surface for contacting the upper surface of the outer core board 70; the second upper copper foil layer 41 is provided with a second glossy surface for contacting the lower surface of the mother board 50.

[0031] The thickness of the upper composite plate 80 and the lower composite plate 40 is 0.1-0.3mm.

[0032] Of course, in addition, the thickness of the upper composite plate 80 and the lower composite plate 40 can be set according to actual needs, but setting the thickness of the upper composite plate 80 and the lower composite plate 40 to 0.1-0.3mm is the preferred embodiment of this utility model, which can ensure the pressing and heat conduction effect and reduce costs.

[0033] Specifically, the thicknesses of the first upper copper foil layer 81, the first lower copper foil layer 83, the second upper copper foil layer 41, and the second lower copper foil layer 43 are all 0.5 oz - 1 oz. The thicknesses of the first adhesive layer 82 and the second adhesive layer 42 are both 50-120 μm, which ensures the bonding effect and reduces costs.

[0034] Preferably, rivets may also be attached to the upper plate unit, outer core plate 70, mother plate 50, lower steel plate 30, lower buffer unit 20 and chassis 10.

[0035] A lower sheet 60 is provided on the side of the core board body near the mother board 50. The first adhesive layer 82, the second adhesive layer 42, the third adhesive layer 52, and the lower sheet 60 are all PP sheets.

[0036] The core board body has the same structural composition as the central core board 51. The thickness of the core board body is 0.09-0.15mm. The thickness of the mother board 50 is 1.0-3.0mm. The outer core board 70 is a core board that has undergone browning and baking, and the mother board 50 is a board body that has undergone browning and baking.

[0037] The cross-sectional area of ​​the lower composite plate 40 is the same as that of the lower steel plate 30.

[0038] Both the upper and lower buffer units are made of kraft paper to provide good cushioning.

[0039] The above embodiments are merely preferred embodiments of this utility model and should not be construed as limiting the scope of protection of this utility model. Any non-substantial changes and substitutions made by those skilled in the art based on this utility model shall fall within the scope of protection claimed by this utility model.

Claims

1. An asymmetric pressing structure, characterized in that: The system includes an upper plate unit, an outer core plate, a mother plate, a lower steel plate, a lower buffer unit, and a chassis; these components are arranged sequentially from top to bottom; a lower composite plate is disposed between the mother plate and the lower steel plate, and the thermal conductivity of the mother plate is the same as that of the outer core plate; the outer core plate includes a core plate body, and the ratio of the thickness of the core plate body to the thickness of the mother plate is 0.05-0.09; the upper plate unit includes an upper buffer unit, an upper steel plate, and an upper composite plate; these components are arranged sequentially from top to bottom; the upper composite plate is disposed between the upper steel plate and the outer core plate; the lower composite plate has the same thickness as the upper composite plate.

2. The asymmetric pressing structure as described in claim 1, characterized in that: The upper plate unit also includes a top cover; the upper buffer unit is disposed between the upper steel plate and the top cover.

3. The asymmetric pressing structure as described in claim 1, characterized in that: The projection of the outer core board onto the upper composite board is located within the area of ​​the upper composite board; the projection of the mother board onto the lower composite board is located within the area of ​​the lower composite board.

4. The asymmetric pressing structure as described in claim 3, characterized in that: The upper composite board includes a first upper copper foil layer, a first adhesive layer, and a first lower copper foil layer; the first upper copper foil layer is located above the first lower copper foil layer, and the first upper copper foil layer is connected to the first lower copper foil layer through the first adhesive layer.

5. The asymmetric pressing structure as described in claim 4, characterized in that: The lower composite board includes a second upper copper foil layer, a second adhesive layer, and a second lower copper foil layer; the second upper copper foil layer is located above the second lower copper foil layer, and the second upper copper foil layer is connected to the second lower copper foil layer through the second adhesive layer.

6. The asymmetric pressing structure as described in claim 5, characterized in that: The first lower copper foil layer is provided with a first glossy surface for contacting the upper surface of the outer core board; the second upper copper foil layer is provided with a second glossy surface for contacting the lower surface of the motherboard.

7. The asymmetric pressing structure as described in claim 6, characterized in that: The thickness of the first upper copper foil layer, the first lower copper foil layer, the second upper copper foil layer, and the second lower copper foil layer is 0.5oz-1oz.

8. The asymmetric pressing structure as described in claim 7, characterized in that: The thickness of both the first adhesive layer and the second adhesive layer is 50-120 μm.

9. The asymmetric pressing structure as described in claim 1, characterized in that: The motherboard comprises several layers of central core boards, and a third adhesive layer is provided between any two adjacent central core boards.

10. The asymmetric pressing structure as described in claim 1, characterized in that: The cross-sectional area of ​​the lower composite plate is the same as that of the lower steel plate.

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