Circuit board with heat dissipation structure and manufacturing method thereof

Abstract

A circuit board with a heat dissipation structure and a manufacturing method thereof, the manufacturing method comprising: providing an inner layer circuit substrate; providing a first metal foil provided with at least one first metal block; providing a second metal foil; sequentially stacking and pressing the first metal foil provided with the first metal block, a first dielectric layer, an inner layer circuit substrate, a second dielectric layer, and the second metal foil to obtain an intermediate structure; opening a blind hole inwardly from the second metal foil in the intermediate structure corresponding to each first metal block along the stacking direction to expose the first metal block; filling the blind hole with semi-cured heat dissipation material, wherein the heat dissipation material does not fill the blind hole and forms a gap with the inner wall of the blind hole; continuously filling the blind hole with adhesive to fill the gap between the heat dissipation material and the inner wall of the blind hole, and then curing the adhesive after covering the heat dissipation material; removing part of the cured adhesive to expose part of the heat dissipation material; forming a metal heat conductive block in the blind hole to contact the part of the heat dissipation material exposed from the adhesive.

Description

Technical Field

[0001] The present invention relates to the field of circuit boards, and in particular to a circuit board with a heat dissipation structure and a manufacturing method thereof. Background Art

[0002] With the development of 5G technology, electronic products are moving towards high integration and miniaturization, resulting in increasingly dense assembly of electronic components and increasing power consumption. Consequently, the heat dissipation requirements for circuit boards in electronic products are also increasing. However, the heat dissipation performance of current circuit boards cannot meet these requirements. Summary of the Invention

[0003] In view of this, the present invention provides a circuit board with a heat dissipation structure, which has good heat dissipation effect and simple structure.

[0004] Also provided is a method for manufacturing a circuit board with a heat dissipation structure, which has good heat dissipation effect and simple process.

[0005] A method for manufacturing a circuit board with a heat dissipation structure comprises the following steps:

[0006] Providing an inner circuit substrate;

[0007] Providing a first metal foil, and disposing at least one first metal block and at least one second metal block on one side of the first metal foil, wherein the first metal block is spaced apart from the second metal block;

[0008] Providing a second metal foil, and disposing at least one third metal block on one side of the second metal foil;

[0009] A first metal foil having the first metal block and the second metal block, a first dielectric layer, the inner circuit substrate, a second dielectric layer, and a second metal foil having the third metal block are sequentially stacked and pressed together to obtain an intermediate structure, wherein the first metal block and the second metal block respectively pierce the first dielectric layer, the second metal block is electrically connected to the inner circuit substrate, and the third metal block pierces the second dielectric layer and is electrically connected to the inner circuit substrate;

[0010] A blind hole is formed along the stacking direction from the second metal foil in the intermediate structure inwardly corresponding to each first metal block to expose the first metal block;

[0011] Filling each of the blind holes with semi-cured heat dissipation material, wherein the heat dissipation material does not completely fill the blind hole and forms a gap with the inner wall of the blind hole;

[0012] Continue filling adhesive into the blind hole filled with the heat dissipation material to fill the gap between the heat dissipation material and the inner wall of the blind hole and cover the heat dissipation material, and then solidify;

[0013] removing the partially cured adhesive to expose a portion of the heat dissipation material; and

[0014] A metal heat-conducting block is formed in the blind hole after a portion of the cured adhesive is removed, wherein the metal heat-conducting block is in contact with a portion of the heat-dissipating material exposed from the adhesive.

[0015] A circuit board with a heat dissipation structure is manufactured by the above-mentioned method for manufacturing a circuit board with a heat dissipation structure.

[0016] The circuit board with a heat dissipation structure produced by the above-mentioned manufacturing method of the present application first forms an intermediate structure through lamination and lamination, and then the blind holes are opened corresponding to the first metal blocks. The first metal blocks are used to support the heat dissipation material set in the blind holes, and can also effectively diffuse the heat absorbed by the heat dissipation material to the outside, thereby improving the heat dissipation efficiency. Secondly, the semi-cured heat dissipation material facilitates the adjustment of the shape of the heat dissipation material according to the shape of the actual blind holes, making it easier to accommodate the heat dissipation material in the blind holes, thereby reducing the precision requirements when opening the blind holes. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figures 1-9 This is a schematic diagram of manufacturing a circuit board with a heat dissipation structure according to one embodiment of the present application.

[0018] Description of main component symbols

[0019] Inner circuit substrate 10

[0020] First inner circuit layer 11

[0021] Insulation layer 13

[0022] Second inner circuit layer 15

[0023] First metal foil 30

[0024] First metal block 33

[0025] Second metal block 35

[0026] Second metal foil 40

[0027] The third metal block 43

[0028] First dielectric layer 51

[0029] Second dielectric layer 53

[0030] Intermediate structure 60

[0031] Blind hole 62

[0032] Heat dissipation material 70

[0033] Gap 63

[0034] Adhesive 73

[0035] Through hole 64

[0036] Metal thermal block 75

[0037] Conductive hole 66

[0038] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0041] The following describes some embodiments of the present application in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features of the embodiments may be combined with each other.

[0042] See also Figures 1 to 9 One embodiment of the present application provides a method for manufacturing a circuit board with a heat dissipation structure, which includes the following steps:

[0043] Step S1, see Figure 1 , providing an inner circuit substrate 10.

[0044] The inner circuit substrate 10 can be a single-layer circuit substrate, a double-layer circuit substrate, or a multi-layer circuit substrate. In this embodiment, the circuit substrate 10 is a double-layer circuit substrate, which includes a first inner circuit layer 11, an insulating layer 13, and a second inner circuit layer 15 stacked in sequence.

[0045] The material of the insulating layer 13 can be selected from, but not limited to, epoxy resin, polypropylene (PP), BT resin, polyphenylene oxide (PPO), polyimide (PI), polyethylene terephthalate (PET), and polyethylene naphthalate (PEN).

[0046] Step S2, see Figure 2 A first metal foil 30 is provided, and at least one first metal block 33 and at least one second metal block 35 are disposed on one side of the first metal foil 30. The first metal block 33 and the second metal block 35 are spaced apart.

[0047] Preferably, the width of each first metal block 33 gradually decreases from the end connected to the first metal foil 30 toward the end away from the first metal foil 30, and the width of each second metal block 35 gradually decreases from the end connected to the first metal foil 30 toward the end away from the first metal foil 30.

[0048] Preferably, the first metal block 33 is made of a material with high thermal conductivity.

[0049] Step S3, see Figure 3 , providing a second metal foil 40 , and disposing at least one third metal block 43 on one side of the second metal foil 40 .

[0050] Preferably, the width of each of the third metal blocks 43 gradually decreases from the end connected to the second metal foil 40 toward the end away from the second metal foil 40 .

[0051] In some embodiments, at least one fourth metal block (not shown) may be further provided on the side of the second metal foil 40 where the third metal block 43 is provided, wherein the fourth metal block is spaced apart from the third metal block 43 .

[0052] Preferably, the width of each of the fourth metal blocks gradually decreases from the end connected to the second metal foil 40 toward the end away from the second metal foil 40 .

[0053] Step S4, see Figure 4A first metal foil 30 having the first metal block 33 and the second metal block 35, a first dielectric layer 51, the inner circuit substrate 10, a second dielectric layer 53, and a second metal foil 40 having the third metal block 43 are sequentially stacked and pressed together to obtain an intermediate structure 60. The first metal block 33 and the second metal block 35 each pierce the first dielectric layer 51, the second metal block 35 is electrically connected to the inner circuit substrate 10, and the third metal block 43 pierces the second dielectric layer 53 and is electrically connected to the inner circuit substrate 10.

[0054] Specifically, the first metal foil 30 is bonded to the first circuit layer 11 via the first dielectric layer 51, and the second metal block 35 is electrically connected to the first circuit layer 11. The second metal foil 40 is bonded to the second circuit layer 15 via the second dielectric layer 53, and the third metal block 43 is electrically connected to the second circuit layer 15.

[0055] Step S5, see Figure 5 A blind hole 62 is opened inwardly from the second metal foil 40 in the intermediate structure 60 along the stacking direction to correspond to each first metal block 33 to expose the first metal block 33 .

[0056] The blind hole 62 can be formed by, but is not limited to, laser cutting.

[0057] Specifically, each of the blind vias 62 passes through the second metal foil 40 , the second dielectric layer 53 , and the inner circuit substrate 10 in sequence, and one end of each of the blind vias 62 is sealed by the corresponding first metal block 33 .

[0058] When a fourth metal block is further provided on the second metal foil 40, the above step S5 may be: a blind hole 62 is opened inward from the second metal foil 40 in the intermediate structure 60 along the stacking direction corresponding to each first metal block 33 and each fourth metal block to expose the first metal block 33 and the fourth metal block.

[0059] Step S6, see Figure 6 , a semi-cured heat dissipation material 70 is filled into each of the blind holes 62 , and the heat dissipation material 70 does not completely fill the blind hole 62 , and a gap 63 is formed between the heat dissipation material 70 and the inner wall of the blind hole 62 .

[0060] In this embodiment, along the stacking direction, the thickness of the heat dissipation material 70 may be substantially the same as the thickness of the inner circuit substrate 10, so as to fully absorb the heat generated by the inner circuit substrate 10. In some embodiments, along the stacking direction, the thickness of the heat dissipation material 70 may be greater than or less than the thickness of the inner circuit substrate 10.

[0061] In this embodiment, along a width direction perpendicular to the stacking direction, the width of the gap 63 between the heat dissipation material 70 and the inner wall of the blind hole 62 is greater than 0 and less than 50 micrometers.

[0062] Step S7, see Figure 7 , the adhesive 73 is continuously filled into the blind hole 62 filled with the heat dissipation material 70 to fill the gap 63 between the heat dissipation material 70 and the inner wall of the blind hole 62 and cover the heat dissipation material 70 and then solidify.

[0063] Preferably, the adhesive 73 is an adhesive material with good thermal conductivity.

[0064] Specifically, the adhesive 73 fills the gap 63 between the heat dissipation material 70 and the inner wall of the blind hole 62, securing the heat dissipation material 70 within the blind hole 62 while also facilitating heat transfer and accelerating heat dissipation. Covering the heat dissipation material 70 with the adhesive 73 further enhances the bond strength between the heat dissipation material 70 and the intermediate structure 60.

[0065] Step S8, see Figure 8 , after partially curing the adhesive 73 , a portion of the heat dissipation material 70 is exposed.

[0066] In this embodiment, the cured adhesive 73 can be removed by, but not limited to, laser ablation, mechanical cutting, and the like.

[0067] In some embodiments, the step S8 may further include: opening a through hole 64 penetrating the intermediate structure 60 along the stacking direction, wherein the through hole 64 and the blind hole 62 are spaced apart.

[0068] Step S9, please refer to Figure 9 After removing the partially cured adhesive 73 , a metal heat conducting block 75 is formed in the blind hole 62 . The metal heat conducting block 75 is in direct contact with the portion of the heat dissipation material 70 exposed from the adhesive 73 .

[0069] In this embodiment, the metal heat conductive block 75 can be formed by, but is not limited to, electroplating.

[0070] In some embodiments, the step S9 may further include: forming a conductive structure in the through hole 64 so that the through hole 64 forms a conductive hole 66 corresponding to the through hole 64 .

[0071] In some embodiments, after step S9 , the method for manufacturing a circuit board with a heat dissipation structure may further include: performing circuit manufacturing on the first metal foil 30 and the second metal foil 40 .

[0072] In some embodiments, for the circuits in the large line width area of ​​the inner circuit substrate 10 , the blind vias 62 and the heat dissipation material 70 may be arranged with the same routing as the circuits, thereby improving heat dissipation efficiency.

[0073] The circuit board with a heat dissipation structure produced by the above-mentioned manufacturing method of this application first forms an intermediate structure 60 through lamination and lamination, and then the blind hole 62 is opened corresponding to the first metal block 33. The first metal block 33 is used to support the heat dissipation material 70 set in the blind hole 62, and can also effectively diffuse the heat absorbed by the heat dissipation material 70 to the outside, thereby improving heat dissipation efficiency. Secondly, the semi-cured heat dissipation material 70 facilitates the adjustment of the shape of the heat dissipation material 70 according to the actual shape of the blind hole 62, facilitating the placement of the heat dissipation material 70 in the blind hole 62, thereby reducing the precision requirements when opening the blind hole 62.

[0074] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of the technical content disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for manufacturing a circuit board with a heat dissipation structure, characterized in that: The following steps are involved: Providing an inner circuit substrate; Providing a first metal foil, and disposing at least one first metal block and at least one second metal block on one side of the first metal foil, wherein the first metal block is spaced apart from the second metal block; Providing a second metal foil, and disposing at least one third metal block on one side of the second metal foil; A first metal foil having the first metal block and the second metal block, a first dielectric layer, the inner circuit substrate, a second dielectric layer, and a second metal foil having the third metal block are sequentially stacked and pressed together to obtain an intermediate structure, wherein the first metal block and the second metal block respectively pierce the first dielectric layer, the second metal block is electrically connected to the inner circuit substrate, and the third metal block pierces the second dielectric layer and is electrically connected to the inner circuit substrate; A blind hole is formed along the stacking direction from the second metal foil in the intermediate structure inwardly corresponding to each first metal block to expose the first metal block; Filling each of the blind holes with semi-cured heat dissipation material, wherein the heat dissipation material does not completely fill the blind hole and forms a gap with the inner wall of the blind hole; Continue filling adhesive into the blind hole filled with the heat dissipation material to fill the gap between the heat dissipation material and the inner wall of the blind hole and cover the heat dissipation material, and then solidify; removing the partially cured adhesive to expose a portion of the heat dissipation material; and A metal heat-conducting block is formed in the blind hole after a portion of the cured adhesive is removed, wherein the metal heat-conducting block is in contact with a portion of the heat-dissipating material exposed from the adhesive.

2. The method for manufacturing a circuit board with a heat dissipation structure according to claim 1, wherein: The width of each first metal block gradually decreases from the end connected to the first metal foil toward the end away from the first metal foil, and the width of each second metal block gradually decreases from the end connected to the first metal foil toward the end away from the first metal foil.

3. The method for manufacturing a circuit board with a heat dissipation structure according to claim 1, wherein: The width of each of the third metal blocks gradually decreases from an end connected to the second metal foil toward an end away from the second metal foil.

4. The method for manufacturing a circuit board with a heat dissipation structure according to claim 1, wherein: Along the stacking direction, the thickness of the heat dissipation material is consistent with the thickness of the inner circuit substrate.

5. The method for manufacturing a circuit board with a heat dissipation structure according to claim 1, wherein: The width of the gap between the heat dissipation material and the inner wall of the blind hole is greater than 0 and less than 50 micrometers.

6. The method for manufacturing a circuit board with a heat dissipation structure according to claim 1, wherein: Before the step of "forming a metal heat-conducting block in the blind hole after removing a portion of the cured adhesive, wherein the metal heat-conducting block contacts the portion of the heat dissipation material exposed from the adhesive", the method may further include: A through hole is provided along the stacking direction and passes through the intermediate structure, wherein the through hole is spaced apart from the blind hole; The step of "forming a metal heat-conducting block in the blind hole after removing a portion of the cured adhesive, wherein the metal heat-conducting block contacts the portion of the heat dissipation material exposed from the adhesive" further includes: A conductive structure is formed in the through hole so that the through hole forms a conductive hole corresponding to the through hole.

7. The method for manufacturing a circuit board with a heat dissipation structure according to claim 1, wherein: After the step of "forming a metal heat-conducting block in the blind hole after removing a portion of the cured adhesive, wherein the metal heat-conducting block contacts the portion of the heat dissipation material exposed from the adhesive", the method further includes: Circuits are fabricated on the first metal foil and the second metal foil.

8. A circuit board with a heat dissipation structure, characterized in that: The circuit board is manufactured by the method for manufacturing a circuit board with a heat dissipation structure according to any one of claims 1 to 7.

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