Circuit board and its manufacturing method

Abstract

The present application provides a circuit board, which includes a heat conduction component, a heating element and a substrate unit. The heating element is disposed on the substrate unit through the heat conduction component. The substrate unit is provided with a first slot and a second slot. The first slot is disposed on one side of the substrate unit, and the second slot is disposed on the other side of the substrate unit. The first slot is communicated with the second slot. The heat conduction component includes a plurality of heat conduction columns and a heat conduction agent. The plurality of heat conduction columns are spaced apart in the first slot, and there is a liquid storage tank between two adjacent heat conduction columns. The heat conduction agent is filled in the liquid storage tank. The heating element is installed in the second slot, the heating element is connected to the heat conduction columns, and there is a cavity between the heating element and the heat conduction agent. The circuit board provided by the present application can improve the heat dissipation efficiency of the heating element. In addition, the present application also provides a manufacturing method of the circuit board.

Description

Technical Field

[0001] The present application relates to a circuit board and a manufacturing method thereof. Background Art

[0002] A camera module includes a heat-generating component (e.g., an induction chip) and a substrate unit, and the induction chip is disposed on the circuit board substrate. Generally, the heat generated by the induction chip during operation can be conducted through the circuit board itself and dissipated to the outside. However, with the thinning of the circuit board substrate and the continuous increase in functional electronic components, at the same time, the circuit board substrate itself has a large thermal resistance, and the contact area between the circuit board substrate and the photosensitive component is limited. Therefore, the photosensitive chip is prone to temperature rise and difficult heat dissipation after long-term operation, and even the photosensitive component may be burned out. Summary of the Invention

[0003] In view of this, the present application provides a manufacturing method of a circuit board to improve the heat dissipation efficiency of the heat-generating component.

[0004] In addition, it is also necessary to provide a circuit board manufactured by the above manufacturing method.

[0005] A manufacturing method of a circuit board includes the steps of: providing a substrate unit; opening a first slot penetrating through part of the substrate unit in the substrate unit; disposing a pattern at the bottom of the first slot, the pattern having a plurality of discrete through holes; disposing an electroplated copper layer on one side of the substrate unit, and part of the electroplated copper layer fills the through holes to form a plurality of spaced-apart heat-conducting columns; opening a second slot on the other side of the substrate unit, the second slot communicates with the first slot along the thickness direction of the substrate unit, the pattern is exposed at the bottom of the second slot, removing the pattern to obtain a plurality of liquid storage grooves, filling a heat-conducting agent in the liquid storage grooves, and mounting a heat-generating component in the second slot, the heat-generating component connecting the heat-conducting columns.

[0006] Further, there is a gap between the pattern and the inner wall of the first slot, and part of the electroplated copper layer also fills the gap to form an annular heat-conducting wall, and the heat-conducting wall surrounds the heat-conducting columns.

[0007] Further, the heat-conducting wall includes a first end and a second end opposite to the first end, the first end faces the second slot, and the inner wall of the first end extends along a direction perpendicular to the thickness direction of the substrate unit to form a receiving groove, and the periphery of the heat-generating component is received in the receiving groove.

[0008] Further, the substrate unit includes a flexible circuit board, a first outer copper foil layer, and a second outer copper foil layer, and the flexible circuit board is disposed between the first outer copper foil layer and the second outer copper foil layer.

[0009] Further, it further includes steps of: providing a groove on the substrate unit, the groove penetrating through the first outer copper foil layer or the second outer copper foil layer, and the flexible circuit board being exposed at the bottom of the groove; and providing a through hole on the substrate unit, the through hole penetrating through the first outer copper foil layer, the flexible circuit board, and the second outer copper foil layer.

[0010] Further, the step of "providing an electroplated copper layer" includes: providing a first electroplated copper layer on the outer side of the first outer copper foil layer, and part of the first electroplated copper layer is filled into the groove to form a first conduction post, the first conduction post electrically connecting the first outer copper foil layer and the flexible circuit board. Providing a second electroplated copper layer on the outer side of the second outer copper foil layer, and part of the second electroplated copper layer is filled into the groove to form a third conduction post, the third conduction post electrically connecting the second outer copper foil layer and the flexible circuit board, and part of the second electroplated copper layer adheres to the inner wall of the through hole to form a hollow second conduction post, the second conduction post electrically connecting the first outer copper foil layer, the flexible circuit board, and the second outer copper foil layer.

[0011] Further, it further includes steps of: etching the first outer copper foil layer and the first electroplated copper layer to obtain a first outer circuit layer. Etching the second outer copper foil layer and the second electroplated copper layer to obtain a second outer circuit layer.

[0012] A circuit board includes a heat conduction component, a heating element, and a substrate unit, and the heating element is disposed on the substrate unit through the heat conduction component. The substrate unit is provided with a first slot and a second slot, the first slot is disposed on one side of the substrate unit, the second slot is disposed on the other side of the substrate unit, and the first slot communicates with the second slot. The heat conduction component includes a plurality of heat conduction posts and a heat conduction agent, the plurality of heat conduction posts are spaced apart and disposed in the first slot, a liquid storage groove is provided between adjacent two heat conduction posts, and the heat conduction agent is filled into the liquid storage groove. The heating element is installed in the second slot, the heating element is connected to the heat conduction posts, and a cavity exists between the heating element and the heat conduction agent.

[0013] Further, the heat conduction component further includes a plurality of heat conduction colloids, the plurality of heat conduction colloids are spaced apart and disposed between the heat conduction protrusions and the heating element.

[0014] Further, the heat conduction agent is at least one of heat conduction oil, ammonia water, and water.

[0015] The substrate unit provided by the present application can conduct the heat generated by the heating element to the heat conduction agent through the provision of the heat conduction component, and heat convection can be formed by means of the gas-liquid phase change of the heat conduction agent, thereby improving the heat dissipation efficiency. Description of the Drawings

[0016] Figure 1 Schematic diagram of a flexible circuit board provided by an embodiment of the present application.

[0017] Figure 2 is Figure 1 Schematic diagram of the flexible circuit board shown after setting the covering layer.

[0018] Figure 3 Schematic diagram of a flexible circuit board provided by an embodiment of the present application.

[0019] Figure 4 Schematic diagram of the substrate unit before lamination provided by an embodiment of the present application.

[0020] Figure 5 Schematic diagram of a substrate unit provided by an embodiment of the present application.

[0021] Figure 6 is Figure 5 Schematic diagram of the substrate unit shown after setting the first slotted hole.

[0022] Figure 7 is Figure 6 Schematic diagram of the substrate unit shown after setting the pattern.

[0023] Figure 8 is Figure 7 Schematic diagram of the substrate unit shown after setting the electroplated copper layer.

[0024] Figure 9 is Figure 8 Schematic diagram of the substrate unit shown after setting the second slotted hole.

[0025] Figure 10 is Figure 9 Schematic diagram of the substrate unit shown after removing the peelable layer.

[0026] Figure 11 is Figure 10 Schematic diagram of the substrate unit shown after filling with heat conductive agent.

[0027] Figure 12 Schematic diagram of a circuit board provided by an embodiment of the present application.

[0028] Description of main component symbols

[0029] Circuit board 100

[0030] Substrate unit 10

[0031] Insulating layer 101

[0032] Pattern 102

[0033] Through hole 1021

[0034] The third slot 103

[0035] The fourth slot 104

[0036] Flexible circuit board 11

[0037] Flexible printed circuit board 110

[0038] The first circuit layer 111

[0039] The second circuit layer 112

[0040] Base material layer 113

[0041] Conductive body 114

[0042] Cover layer 115

[0043] Adhesive layer 116

[0044] Release layer 117

[0045] The first outer copper foil layer 12

[0046] The first electroplated copper layer 121

[0047] The first outer circuit layer 122

[0048] The second outer copper foil layer 13

[0049] The second electroplated copper layer 131

[0050] The second outer circuit layer 132

[0051] Thermal conductive component 14

[0052] Thermal conductive wall 141

[0053] Liquid storage tank 142

[0054] Thermal conductive column 143

[0055] Receiving groove 146

[0056] Metal layer 148

[0057] Thermal conductive agent 15

[0058] Thermal conductive colloid 16

[0059] The first slot 20

[0060] The first groove 21

[0061] The first conductive post 211

[0062] The second groove 22

[0063] The third conduction post 221

[0064] Through-hole 23

[0065] The second conduction post 231

[0066] The second slotted groove 24

[0067] Solder mask layer 30

[0068] Heating element 40

[0069] Cavity 41

[0070] The first area A

[0071] The second area B

[0072] Connection area C

[0073] Thickness direction F

[0074] The following specific embodiments will further illustrate the present application in conjunction with the above-mentioned drawings. Specific embodiments

[0075] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments.

[0076] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intermediate element at the same time. When an element is considered to be "disposed on" another element, it can be directly disposed on the other element or there may be an intermediate element at the same time.

[0077] Please refer to Figures 1 to 11 , an embodiment of the present application provides a manufacturing method of a circuit board 100, and the manufacturing method includes the steps:

[0078] S1: Please refer to Figure 5 , provide a substrate unit 10, and the substrate unit 10 includes a flexible circuit board 11, a first outer copper foil layer 12, and a second outer copper foil layer 13. The flexible circuit board 11 is disposed between the first outer copper foil layer 12 and the second outer copper foil layer 13.

[0079] In this embodiment, in step S1, please refer to Figures 1 to 5 , the manufacturing method of the substrate unit 10 includes:

[0080] S10: Manufacture the flexible circuit board 11, which specifically includes the steps:

[0081] Please refer to Figure 1 , a flexible printed circuit board 110 is provided. The flexible printed circuit board 110 includes a first circuit layer 111, a second circuit layer 112, a base material layer 113, and a conductor 114. The base material layer 113 is disposed between the first circuit layer 111 and the second circuit layer 112. The flexible printed circuit board 110 is provided with an opening (not shown in the figure). The opening penetrates through the first circuit layer 111 and the base material layer 113. Part of the second circuit layer 112 is exposed at the bottom of the opening. The conductor 114 fills the opening to electrically connect the first circuit layer 111 and the second circuit layer 112.

[0082] Wherein, the flexible printed circuit board 110 is divided into a first area A, a second area B, and a connection area C. The connection area C is located between the first area A and the second area B. The conductor 114 is disposed in the first area A.

[0083] S11: Please refer to Figure 2 , a cover layer 115 is disposed on the connection area C. The cover layer 115 is disposed outside the first circuit layer 111 and the second circuit layer 112. An adhesive layer 116 is disposed between the cover layer 115 and the first circuit layer 111 or the second circuit layer 112.

[0084] S12: Please refer to Figure 3 , a peelable layer 117 is disposed outside the cover layer 115 to obtain the flexible circuit board 11.

[0085] In this embodiment, the material of the base material layer 113 or the cover layer 115 is polyimide (PI). The peelable layer 117 can be a release film. In other embodiments, the material of the base material layer 113 or the cover layer 115 is not limited to polyimide and can also be other flexible base materials.

[0086] S11: Please refer to Figure 4 and Figure 5 , a first outer copper foil layer 12, a second outer copper foil layer 13, and two insulating layers 101 are provided. One of the insulating layers 101 is disposed between the flexible circuit board 11 and the first outer copper foil layer 12, and the other insulating layer 101 is disposed between the flexible circuit board 11 and the second outer copper foil layer 13. The first outer copper foil layer 12, the flexible circuit board 11, and the second outer copper foil layer 13 are pressed together to obtain the substrate unit 10.

[0087] S2: Please refer to Figure 6, a first slotted groove 20 is provided on the substrate unit 10, the first slotted groove 20 penetrates through the first outer copper foil layer 12 and the insulating layer 101, and the flexible circuit board 11 is exposed at the bottom of the first slotted groove 20.

[0088] In this embodiment, please refer to Figure 7 , a first groove 21, a second groove 22 and a through hole 23 may further be provided on the substrate unit 10. The first groove 21 penetrates through the first outer copper foil layer 12 and the adjacent insulating layer 101, and a part of the flexible circuit board 11 is exposed at the bottom of the first groove 21. The second groove 22 penetrates through the second outer copper foil layer 13 and the insulating layer 101, and a part of the flexible circuit board 11 is exposed at the bottom of the second groove 22. The through hole 23 penetrates through the first outer copper foil layer 12, the flexible circuit board 11 and the second outer copper foil layer 13. The first groove 21 or the second groove 22 corresponds to the first area A or the second area B, and the through hole 23 corresponds to the second area B.

[0089] S3: Please refer to Figure 7 , a pattern 102 is provided in the first slotted groove 20, the pattern 102 has a plurality of through holes 1021 which are discretely arranged, and the outer peripheral edge of the pattern 102 is spaced from the inner wall of the first slotted groove 20.

[0090] In this embodiment, step S3 includes the steps of:

[0091] S30: A dry film (not shown in the figure) is provided in the first slotted groove 20.

[0092] S31: The dry film is exposed and developed to form the pattern 102. Along the thickness direction F parallel to the substrate unit 10, the cross section of the pattern 102 is generally square, and the through holes 1021 are generally cylindrical. In other embodiments of the present invention, the through holes 1021 may also be triangular prisms, quadrangular prisms, etc.

[0093] S4: Please refer to Figure 8 , a first electroplated copper layer 121 is provided on the first outer copper foil layer 12, a part of the first electroplated copper layer 121 fills into the through holes 1021 to form a plurality of heat conducting columns 143, the heat conducting columns 143 are generally cylindrical, and it can be understood that the shape of the heat conducting columns 143 can be changed by changing the shape of the through holes 1021. A part of the first electroplated copper layer 121 fills into the gap between the pattern 102 and the first slotted groove 20 to form a heat conducting wall 141, and the heat conducting wall 141 surrounds the outside of the plurality of heat conducting columns 143.

[0094] In this embodiment, a part of the first electroplated copper layer 121 is filled into the first groove 21 to form a first conduction post 211, and the first conduction post 211 is electrically connected to the flexible circuit board 11 and the first outer copper foil layer 12.

[0095] In this embodiment, step S4 further includes steps:

[0096] S40: A second electroplated copper layer 131 is disposed outside the second outer copper foil layer 13, and a part of the second electroplated copper layer 131 adheres to the inner wall of the through hole 23 to form a hollow second conduction post 231, and the second conduction post 231 is electrically connected to the first electroplated copper layer 121.

[0097] In this embodiment, a part of the second electroplated copper layer 131 is filled into the second groove 22 to form a third conduction post 221, and the third conduction post 221 is electrically connected to the flexible circuit board 11 and the second outer copper foil layer 13.

[0098] S41: The first electroplated copper layer 121 and the first outer copper foil layer 12 are etched to form a first outer circuit layer 122. The second electroplated copper layer 131 and the second outer copper foil layer 13 are etched to form a second outer circuit layer 132.

[0099] S42: A solder mask layer 30 is disposed on the first outer circuit layer 122 and the second outer circuit layer 132, and a part of the solder mask layer 30 is filled into the hollow second conduction post 231.

[0100] S5: Please refer to Figure 9 , a second slot 24 is formed on the substrate unit 10, and the second slot 24 penetrates through the second outer circuit layer 132, one of the insulating layers 101 and the flexible circuit board 11, so that one side of the pattern 102 facing away from the first outer circuit layer 122 is exposed at the bottom of the second slot 24. Then, the pattern 102 is removed to form a plurality of liquid storage grooves 142.

[0101] In this embodiment, the heat conducting wall 141 includes a first end (not shown in the figure) and a second end (not shown in the figure) opposite to the first end. The first end faces the second slot 24, and the inner wall of the first end is recessed along the thickness direction F perpendicular to the substrate unit 10 to form a receiving groove 146. The receiving groove 146 is communicated with the second slot 24, and the receiving groove 146 is used for supporting a heating element 40 (shown in Figure 11 ). The heating element 40 can be a photosensitive chip or other heating elements.

[0102] In this embodiment, step S5 further includes:

[0103] S50: Refer to Figure 10 , a metal layer 148 is electroplated on the outer side of the heat conducting column 143, the inner wall of the liquid storage tank 142 and the inner wall of the accommodation groove 146. The material of the metal layer 148 can be nickel-palladium-gold, and the metal layer 148 is used to improve the efficiency of the heating element 40 in conducting heat to the heat conducting column 143.

[0104] S51: Refer to Figure 9 , a third slot 103 and a fourth slot 104 are provided on the substrate unit 10. The third slot 103 penetrates through the second outer circuit layer 132 and a part of the insulating layer 101 adjacent to the second outer circuit layer 132, so that the peelable layer 117 is exposed at the bottom of the third slot 103. The fourth slot 104 penetrates through the first outer circuit layer 122 and a part of the insulating layer 101 adjacent to the first outer circuit layer 122, so that the other peelable layer 117 is exposed at the bottom of the fourth slot 104. Wherein, along the extending direction of the substrate unit 10, the sizes of the third slot 103 and the fourth slot 104 are not less than the size of the peelable layer 117.

[0105] S52: Refer to Figure 10 , the peelable layer 117 is removed, so that the cover layer 115 is exposed at the bottom of the third slot 103 or the fourth slot 104. At this time, the connection area C forms the flexible board part of the circuit board 100.

[0106] S6: Refer to Figure 11 , a heat conducting agent 15 is provided, and the heat conducting agent 15 is injected into the liquid storage tank 142. The depth D of the heat conducting agent 15 can be less than the height H of the heat conducting column 143. The heat conducting agent 15 is a liquid with heat conducting function. For example, the heat conducting agent 15 is at least one of heat conducting oil, ammonia water, water, etc.

[0107] S7: Refer to Figure 12 , a heat conducting colloid 16 and a heating element 40 are provided, the heating element 40 is arranged in the second slot 24, and the heat conducting colloid 16 is arranged between the heating element 40 and the heat conducting column 143 to obtain the circuit board 100.

[0108] Refer to Figure 12 , the present invention provides a circuit board 100, and the circuit board 100 can be used for a camera module. The circuit board 100 includes a substrate unit 10, a heat conducting component 14 and a heating element 40. The heating element 40 is arranged on the substrate unit 10, and the heating element 40 transfers heat through the heat conducting component 14 and radiates it to the external space.

[0109] The substrate unit 10 includes a flexible circuit board 11, a first outer circuit layer 122, and a second outer circuit layer 132. The substrate unit 10 is provided with a first slot 20 and a second slot 24. The first slot 20 penetrates through the first outer circuit layer 122, the insulating layer 101 adjacent to the first outer circuit layer 122, and the flexible circuit board 11. The second slot 24 penetrates through the second outer circuit layer 132 and the insulating layer 101 adjacent to the second outer circuit layer 132. The first slot 20 communicates with the second slot 24.

[0110] The heat conduction component 14 includes a plurality of heat conduction columns 143 and a heat conduction agent 15. The plurality of heat conduction columns 143 are spaced apart in the first slot 20. There is a liquid storage tank 142 between two adjacent heat conduction columns 143. The heat conduction agent 15 is filled into the liquid storage tank 142.

[0111] The heating element 40 is installed in the second slot 24. The heating element 40 is connected to the heat conduction columns 143. The depth D of the heat conduction agent 15 is lower than the height H of the heat conduction columns 143, so that there is a cavity 41 between the heating element 40 and the heat conduction agent 15.

[0112] During specific operation, the heat generated by the operation of the heating element 40 is conducted to the heat conduction agent 15 in direct contact therewith via the heat conduction columns 143 (i.e., heat conduction). The heat conduction agent 15 absorbs heat and undergoes a phase change to be converted into heat conduction steam. The heat conduction steam carries heat into the cavity 41, and then condenses in the cavity 41 to become the heat conduction agent 15 again, and then the heat conduction agent 15 flows back into the liquid storage tank 142 again (i.e., heat convection). The substrate unit 10 provided in this application can conduct the heat generated by the heating element 40 to the heat conduction agent 15 by providing the heat conduction component 14, and can form heat convection by means of the heat conduction agent 15 and the cavity 41, thereby improving the heat dissipation efficiency.

[0113] In this embodiment, the heat conduction component 14 further includes a heat conduction wall 141. The heat conduction wall 141 adheres to the inner wall of the first slot 20. The heat conduction wall 141 includes a first end and a second end opposite to the first end. The first end faces the second slot 24. The inner wall of the first end is recessed along the thickness direction F perpendicular to the substrate unit 10 to form a receiving groove 146. The periphery of the heating element 40 is received in the receiving groove 146. A heat conduction colloid 16 is provided between the heating element 40 and the receiving groove 146. The heat conduction colloid 16 seals the gap between the heating element 40 and the receiving groove 146, thereby preventing the heat conduction steam formed after the phase change of the heat conduction agent 15 from escaping.

[0114] The above description is only a specific implementation of an optimization of this application, but in the actual application process, it cannot be limited to this implementation. For those of ordinary skill in the art, other deformations and changes made according to the technical concept of this application should fall within the protection scope of this application.

Claims

1. A manufacturing method of a circuit board, characterized in that, Including the steps of: Providing a substrate unit; Forming a first slot that penetrates part of the substrate unit in the substrate unit; Providing a pattern at the bottom of the first slot, the pattern having a plurality of discrete through holes, and there is a gap between the pattern and the inner wall of the first slot; Providing an electroplated copper layer on one side of the substrate unit, and part of the electroplated copper layer fills the through holes to form a plurality of spaced heat conducting columns, and part of the electroplated copper layer also fills the gap to form a heat conducting wall, and the heat conducting wall surrounds the heat conducting columns; Forming a second slot on the other side of the substrate unit, and along the thickness direction of the substrate unit, the second slot communicates with the first slot, the pattern is exposed at the bottom of the second slot, and then removing the pattern to obtain a plurality of liquid storage grooves; and filling a heat conducting agent into the liquid storage grooves; and And Mounting a heating element in the second slot, and the heating element is connected to the heat conducting columns.

2. The manufacturing method according to claim 1, wherein The heat conducting wall includes a first end and a second end opposite to the first end, the first end faces the second slot, and the inner wall of the first end extends along a direction perpendicular to the thickness direction of the substrate unit to form a receiving groove, and the periphery of the heating element is received in the receiving groove.

3. The manufacturing method according to claim 1, characterized in that, The substrate unit includes a flexible circuit board, a first outer copper foil layer, and a second outer copper foil layer, and the flexible circuit board is disposed between the first outer copper foil layer and the second outer copper foil layer.

4. The manufacturing method according to claim 3, characterized in that, Further including the steps of: Forming a first groove and a second groove on the substrate unit, the first groove penetrates the first outer copper foil layer, the second groove penetrates the second outer copper foil layer, and the flexible circuit board is exposed at the bottoms of the first groove and the second groove; and Forming a through hole on the substrate unit, and the through hole penetrates the first outer copper foil layer, the flexible circuit board, and the second outer copper foil layer.

5. The manufacturing method according to claim 4, characterized in that, The step of "providing an electroplated copper layer" includes: Providing a first electroplated copper layer on the outer side of the first outer copper foil layer, and part of the first electroplated copper layer fills the first groove to form a first conduction column, and the first conduction column electrically conducts the first outer copper foil layer and the flexible circuit board; Providing a second electroplated copper layer on the outer side of the second outer copper foil layer, and part of the second electroplated copper layer fills the second groove to form a third conduction column, and the third conduction column electrically conducts the second outer copper foil layer and the flexible circuit board, and part of the second electroplated copper layer adheres to the inner wall of the through hole to form a hollow second conduction column, and the second conduction column electrically conducts the first outer copper foil layer, the flexible circuit board, and the second outer copper foil layer.

6. The manufacturing method according to claim 5, characterized in that, Further including the steps of: Etching the first outer copper foil layer and the first electroplated copper layer to obtain a first outer circuit layer; Etching the second outer copper foil layer and the second electroplated copper layer to obtain a second outer circuit layer.

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