Manufacturing method for high-density interconnected printed circuit board heat sink strip

Abstract

The invention provides a manufacturing method of a heat sink strip for a high-density interconnected printed circuit board. S1, heat dissipation strips I are manufactured on the core plate; s2, carrying out electroplating treatment on the manufactured heat dissipation strip I, so that the heat dissipation strip I is completely filled with electroplating copper; s3, manufacturing the core board into a laminated board; s4, manufacturing a heat dissipation strip II on the laminated board; s5, carrying out electroplating treatment on the manufactured heat dissipation strip II, so that the heat dissipation strip II is completely filled with electroplating copper; the size of the heat dissipation strip I can be designed according to the shape and size of the heating element, so that the heat dissipation strip I is in large-area contact with the heating element, and heat generated by the heating element is absorbed more uniformly; the heat dissipation strip II is connected with the heat dissipation strip II after being filled with electroplating copper, the heat dissipation strip II and the copper layer in the laminated board form a continuous copper heat dissipation area penetrating through the whole laminated board, and the copper heat dissipation area is good in heat conduction effect and can also play a role in auxiliary supporting. Therefore, the mechanical stability of the whole printed circuit board and the elements adopting the printed circuit board is better, and the risk of damage caused by external force is also reduced.

Description

Technical Field

[0001] The invention relates to the technical field of circuit board heat dissipation, and in particular to a method for manufacturing a heat dissipation strip for a high-density interconnected printed circuit board. Background Art

[0002] As electronic products develop towards thinness, miniaturization, and multifunctionality, the layout of electronic components on high-density interconnected printed circuit boards becomes tighter, and the circuit lines become finer. This makes heat more concentrated in a limited space, greatly increasing the difficulty of heat dissipation. If the heat cannot be effectively dissipated, excessively high temperatures will cause the performance of electronic components to decline, shorten their lifespan, and may even cause failures, seriously affecting the stability and reliability of electronic equipment;

[0003] In the prior art, most of the heat dissipation methods are thermal vias, that is, through holes are drilled on the PCB board, such as the multi-layer printed PCB board with fast heat dissipation proposed in Publication (Announcement) No. CN215187572U. However, in actual use, there are still the following deficiencies:

[0004] When the heat generated by the heating component is too large or the heat dissipation environment is poor, the heat dissipation capacity of the thermal via will be limited, making it difficult to meet the heat dissipation requirements of the high thermal power component. In addition, drilling holes on the PCB board will weaken the structural strength of the board, especially when there are a large number of thermal vias or the hole diameter is large, which may cause the PCB board to be more easily damaged when subjected to external force. Summary of the invention

[0005] In view of this, the problem to be solved by the present invention is to provide a method for manufacturing a heat dissipation strip for a high-density interconnected printed circuit board.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] A method for manufacturing a heat dissipation strip for a high-density interconnected printed circuit board comprises the following steps

[0008] S1: making heat dissipation strips I on the core board;

[0009] S2: electroplating the heat dissipation bar I so that the electroplated copper completely fills the heat dissipation bar I;

[0010] S3: making the core board into a laminate;

[0011] S4: making heat dissipation strip II on the laminate;

[0012] S5: electroplating the heat dissipation bar II so that the electroplated copper completely fills the heat dissipation bar II.

[0013] The depth of the heat dissipation strip I is based on the copper layer exposed on the bottom surface of the core board.

[0014] The depth of the heat sink II is enough to expose the heat sink I filled with electroplated copper on the core board.

[0015] The size of the heat dissipation strip II corresponds to the size of the heating element.

[0016] Before filling with electroplated copper, the heat dissipation bars I and II are cleaned to remove the residual impurities on the side walls and the bottom.

[0017] The advantages and positive effects of the present invention are:

[0018] (1) The size of the heat dissipation strip I can be designed according to the shape and size of the heating element, so as to form a larger area of ​​contact with the heating element, thereby more evenly absorbing the heat generated by the heating element.

[0019] (2) After being filled with electroplated copper, the heat sink II is connected to the heat sink II and forms a continuous copper heat sink area that runs through the entire laminate with the copper layer in the laminate. The copper heat sink area has excellent thermal conductivity and can also serve as an auxiliary support, thereby improving the mechanical stability of the entire printed circuit board and the components using the printed circuit board and reducing the risk of damage due to external forces. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0021] Figure 1 It is the structural diagram of the core board;

[0022] Figure 2 yes Figure 1 The structural diagram after making the heat dissipation strip I;

[0023] Figure 3 This is a structural diagram of the heat dissipation strip I after being filled with electroplated copper;

[0024] Figure 4 It is a structural diagram of the laminate;

[0025] Figure 5 yes Figure 4 The structural diagram after making the heat dissipation strip II;

[0026] Figure 6 This is the structural diagram of the heat sink II after it is filled with electroplated copper;

[0027] Figure 7 yes Figure 6 The structural diagram after connecting the heating element;

[0028] In the figure: core board 21, heat dissipation bar I22, laminate board 3, heat dissipation bar II31, copper layer 41, support frame 51, thermal conductive silicone pad 52. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may also be a component centered. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may also be a component centered. When a component is considered to be "set on" another component, it may be directly set on the other component or there may also be a component centered. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0032] The present invention provides a method for manufacturing a heat dissipation strip for a high-density interconnected printed circuit board, comprising the following steps:

[0033] like Figures 1 to 3 As shown, S1: making a heat dissipation strip I22 on the core board 21;

[0034] The core board 21 is a double-layer composite board with the top and bottom layers both being copper layers 41. The heat dissipation strip 122 is made by using a laser to ablate the core board 21 in a stacked hole manner in the transverse direction to form a strip-shaped concave area. The depth of the heat dissipation strip 122 is based on the copper layer exposed on the bottom surface of the core board 21.

[0035] S2: electroplating the manufactured heat dissipation bar 122, so that the electroplated copper completely fills the heat dissipation bar 122; thereby making the entire filled heat dissipation bar 122 serve as a heat conductor.

[0036] like Figure 4 As shown, S3: making the core board 21 into a laminated board 3;

[0037] The laminate 3 is manufactured by laminating the prepreg and the copper foil using the conventional lamination process of the printed circuit board to form a composite board having four copper layers 41. This is an existing manufacturing process, so no further description is given.

[0038] like Figure 5 As shown, S4: making a heat dissipation strip II31 on the laminate 3, the size of the heat dissipation strip II31 corresponds to the size of the heating element, and the heat dissipation strip II31 is made by using laser to burn in a stacked hole manner along the lateral direction of the laminate 3 to form a strip-shaped concave area, the depth of the heat dissipation strip II31 above the core board 21 is based on exposing the heat dissipation strip I22 filled with electroplated copper on the core board 21, and the depth of the heat dissipation strip II31 below the core board 21 is based on reaching the copper layer on the bottom surface of the core board 21;

[0039] like Figure 6 As shown, S5: the manufactured heat sink II31 is electroplated to make the electroplated copper completely fill the heat sink II31, thereby connecting the heat sink I22 with the heat sink II31, and forming a continuous copper heat sink area running through the entire laminate 3 with the copper layer 41 in the laminate 3, so when the heating element contacts the heat sink II31, the heat can be directly conducted through the heat sink area for rapid dissipation; when dealing with a larger heat load, since the contact area fits the heating element, the larger contact area makes the heat dissipation advantage more obvious than the thermal via heat dissipation method, and compared with the thermal via heat dissipation method, the heat sink area formed by the heat sink I22 and the heat sink II31 can play an auxiliary support role, so that the mechanical stability of the entire laminate 3 and the components using the laminate 3 is better, and the risk of damage due to external forces is also reduced.

[0040] It should be noted that the size of the heat dissipation strip 122 in the present manufacturing method can be designed according to the shape and size of the heating element, thereby forming a larger area of ​​contact with the heating element, thereby more evenly absorbing the heat generated by the heating element.

[0041] Specifically, before filling the electroplated copper, the prepared heat dissipation bars I22 and II31 need to be cleaned to remove residual impurities on the side walls and bottom to ensure a higher electroplated copper content in the heat dissipation bars I22 and II31, thereby ensuring good thermal conductivity.

[0042] Specifically, after the heat dissipation strip II31 is filled with electroplated copper, the outermost copper wire circuit of the laminate 3 is made by laminating and etching, and then solder resist and surface treatment are performed to form a printed circuit board.

[0043] like Figure 7As shown, further, the heating element is fixed on the printed circuit board through a support frame 51, and a thermal grease pad 52 is installed between the heating element and the heat dissipation strip II31 below, so that the heating element is directly connected to the continuous copper heat dissipation area in the printed circuit board through the thermal grease pad 52, and the good thermal conductivity of copper is used to quickly dissipate heat.

[0044] The working principle and working process of the present invention are as follows:

[0045] S1: Make a heat dissipation strip 122 on the core board 21, and the depth of the heat dissipation strip 122 is based on the copper layer exposed on the bottom surface of the core board 21;

[0046] S2: electroplating the manufactured heat dissipation bar I22, so that the electroplated copper completely fills the heat dissipation bar I22, and the depth of the heat dissipation bar II31 is based on the heat dissipation bar I22 filled with electroplated copper exposed on the core board 21;

[0047] S3: making the core board 21 into a laminated board 3;

[0048] S4: making heat dissipation strip II31 on the laminate 3;

[0049] S5: Perform electroplating on the manufactured heat dissipation bar II31, so that the electroplated copper completely fills the heat dissipation bar II31.

[0050] The embodiments of the present invention are described in detail above, but the contents described are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of this patent.

Claims

1. A method for manufacturing a heat dissipation strip for a high-density interconnected printed circuit board, characterized in that: The following steps are included S1: making a heat dissipation strip I (22) on the core board (21); S2: electroplating the manufactured heat dissipation bar 1 (22) so that the electroplated copper completely fills the heat dissipation bar 1 (22); S3: manufacturing the core board (21) into a laminate board (3); S4: making a heat dissipation strip II (31) on the laminate (3); S5: electroplating the manufactured heat dissipation bar II (31) so that the electroplated copper completely fills the heat dissipation bar II (31).

2. The method for manufacturing a heat dissipation strip for a high-density interconnected printed circuit board according to claim 1, characterized in that: The depth of the heat dissipation strip I (22) is based on the copper layer exposed on the bottom surface of the core board (21).

3. The method for manufacturing a heat dissipation strip for a high-density interconnected printed circuit board according to claim 1, characterized in that: The depth of the heat dissipation strip II (31) above the core board (21) is based on exposing the heat dissipation strip I (22) filled with electroplated copper on the core board (21), and the depth of the heat dissipation strip II (31) below the core board (21) is based on reaching the copper layer on the bottom surface of the core board (21).

4. The method for manufacturing a heat dissipation strip for a high-density interconnected printed circuit board according to claim 1, characterized in that: The size of the heat dissipation strip II (31) corresponds to the size of the heating element.

5. The method for manufacturing a heat dissipation strip for a high-density interconnected printed circuit board according to claim 1, characterized in that: Before filling with electroplated copper, the heat dissipation bar I (22) and heat dissipation bar II (31) are cleaned to remove residual impurities on the side wall and the bottom.

6. The method for manufacturing a heat dissipation strip for a high-density interconnected printed circuit board according to claim 1, characterized in that: The heating element is fixed on the printed circuit board through a support frame (51), and a thermally conductive silicone pad (52) is installed between the heating element and the heat dissipation strip II (31) below.

Images