Flexible circuit board for lens module and manufacturing method thereof

Abstract

The application provides a manufacturing method of a flexible circuit board for a lens module, comprising the following steps: providing a flexible circuit substrate, wherein a containing groove is arranged in the flexible circuit substrate; arranging a first blind groove and a second blind groove in the flexible circuit substrate; filling a heat-conducting material in the first blind groove and the second blind groove to form a first heat-conducting column and a second heat-conducting column respectively; forming a reinforcing plate on the flexible circuit substrate, wherein a first opening and a second opening are arranged in the reinforcing plate, and the first heat-conducting part and the second heat-conducting part are arranged in the first opening and the second opening respectively; and mounting an image sensor in the containing groove, and making the image sensor in thermal conduction with the first heat-conducting column and the second heat-conducting column, so as to obtain the flexible circuit board. The flexible circuit board manufactured by the manufacturing method has high heat dissipation effect. The application further provides a flexible circuit board for a lens module.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of circuit board, in particular to a flexible circuit board for lens module and a manufacturing method thereof. BACKGROUND

[0002] The lens module is an image or video input device, which is widely used in industrial and consumer electronics. The circuit board, as a carrier of image sensor and other components, is one of the key components in the lens module. The flexible circuit board (FPC) is a printed circuit board with high reliability and good flexibility. With the increasing demand of users for the picture quality of the lens module, the pixel of the lens module is getting higher and higher, which in turn increases the power of the image sensor.

[0003] The image sensor generates a large amount of heat during long-time work, which leads to the temperature rise of the entire lens module, and further affects the user experience. The heat generated by the image sensor is dissipated through the conventional design of the flexible circuit board. However, the heat dissipation effect often cannot meet the needs of the product. At present, the flexible circuit board is usually attached with a heat sink on one side to dissipate heat, but the heat dissipation effect is not good. SUMMARY

[0004] Therefore, the present application provides a manufacturing method of a circuit board with good heat dissipation effect.

[0005] In addition, it is necessary to provide a circuit board manufactured by the above method.

[0006] An embodiment of the present application provides a manufacturing method of a flexible circuit board for lens module, comprising:

[0007] A flexible circuit board is provided, and a receiving groove is formed in the flexible circuit board;

[0008] A first blind groove and a second blind groove are formed in the flexible circuit board, and the first blind groove and the second blind groove correspond to the receiving groove, and the first blind groove and the second blind groove and the receiving groove are located on opposite surfaces of the flexible circuit board, respectively;

[0009] Thermally conductive materials are filled in the first blind groove and the second blind groove to form a first thermally conductive column and a second thermally conductive column, respectively. The first thermally conductive column comprises a first thermally conductive part and a first heat dissipation part connected with the first thermally conductive part, the first thermally conductive part is located in the first blind groove, and the first heat dissipation part protrudes out of the surface of the flexible circuit board. The second thermally conductive column comprises a second thermally conductive part and a second heat dissipation part connected with the second thermally conductive part, the second thermally conductive part is located in the second blind groove, and the second heat dissipation part protrudes out of the surface of the flexible circuit board.

[0010] a reinforcing plate is formed on the flexible circuit substrate, the reinforcing plate has a first opening and a second opening, and the first heat dissipation part and the second heat dissipation part are located in the first opening and the second opening respectively; and

[0011] an image sensor is installed in the accommodating groove, the image sensor is electrically connected with the flexible circuit substrate, and the image sensor is in thermal conduction with the first heat conduction column and the second heat conduction column, thereby obtaining the flexible circuit board.

[0012] An embodiment of the present application further provides a flexible circuit board for a lens module, which comprises:

[0013] a flexible circuit substrate, the flexible circuit substrate has an accommodating groove, a first blind groove and a second blind groove, the first blind groove and the second blind groove correspond to the accommodating groove, the first blind groove and the second blind groove are located on opposite surfaces of the flexible circuit substrate respectively, the first blind groove and the second blind groove form a first heat conduction column and a second heat conduction column respectively, the first heat conduction column comprises a first heat conduction part and a first heat dissipation part connected with the first heat conduction part, the first heat conduction part is located in the first blind groove, and the first heat dissipation part protrudes out of the surface of the flexible circuit substrate, the second heat conduction column comprises a second heat conduction part and a second heat dissipation part connected with the second heat conduction part, the second heat conduction part is located in the second blind groove, and the second heat dissipation part protrudes out of the surface of the flexible circuit substrate;

[0014] a reinforcing plate is formed on the flexible circuit substrate, the reinforcing plate has a first opening and a second opening, and the first heat dissipation part and the second heat dissipation part are located in the first opening and the second opening respectively; and

[0015] an image sensor is installed in the accommodating groove, the image sensor is electrically connected with the flexible circuit substrate, and the image sensor is in thermal conduction with the first heat conduction column and the second heat conduction column.

[0016] The heat generated by the image sensor in the present application is transmitted to the first heat conduction part and the second heat conduction part, and is dissipated to the outside through the first heat dissipation part and the second heat dissipation part respectively. Since the first heat dissipation part and the second heat dissipation part protrude out of the surface of the flexible circuit substrate, the heat dissipation area of the first heat conduction column and the second heat conduction column is increased, so that the heat dissipation effect of the image sensor is improved. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a structural schematic diagram of the flexible circuit substrate provided by an embodiment of the present application.

[0018] Figure 2 is Figure 1 the structure schematic diagram after the peelable film is attached on the third cover film shown in

[0019] Figure 3 is Figure 2 the structure schematic diagram after the first blind groove and the second blind groove are opened in the flexible circuit substrate and the peelable film shown in

[0020] Figure 4 is Figure 3 the structure schematic diagram after the thermally conductive material is filled in the first blind groove and the second blind groove shown in

[0021] Figure 5 is Figure 4 the structure schematic diagram after the peelable film shown in

[0022] Figure 6 is Figure 5 the structure schematic diagram after the reinforcing plate is formed on the third cover film shown in

[0023] Figure 7 is Figure 6 the structure schematic diagram of the flexible circuit board for the lens module after the image sensor is installed in the accommodating groove shown in

[0024] Main component symbol explanation

[0025] Flexible circuit board 100

[0026] Flexible circuit substrate 10

[0027] First cover film 11

[0028] First adhesive layer 12

[0029] First conductive circuit layer 13

[0030] First base copper layer 131

[0031] First electroplated copper layer 132

[0032] Second cover film 14

[0033] Second conductive circuit layer 15

[0034] Second base copper layer 151

[0035] Second electroplated copper layer 152

[0036] Second adhesive layer 16

[0037] Third cover film 17

[0038] Protective layer 18

[0039] receiving groove 20

[0040] solder pad 21

[0041] conductive portion 22

[0042] peelable film 30

[0043] first blind groove 40

[0044] second blind groove 41

[0045] first heat-conductive column 42

[0046] first heat-conductive portion 421

[0047] first heat-dissipating portion 422

[0048] second heat-conductive column 43

[0049] second heat-conductive portion 431

[0050] second heat-dissipating portion 432

[0051] reinforcing plate 50

[0052] first opening 51

[0053] second opening 52

[0054] third adhesive layer 60

[0055] image sensor 70

[0056] The following detailed description will further describe the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0057] The technical solutions in the embodiments of the present application will be described clearly and completely in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments.

[0058] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for describing the specific embodiments only and is not intended to be limiting of the application.

[0059] In order to further clarify the technical means and effects taken by the present application to achieve the predetermined purpose, the following will be described in detail in conjunction with the drawings and the preferred embodiments.

[0060] An embodiment of the present application provides a manufacturing method of a flexible circuit board for a lens module, comprising the following steps:

[0061] Step S11, please refer to Figure 1 , provide flexible circuit board 10.

[0062] In an embodiment, the flexible circuit board 10 includes a first cover film 11, a first adhesive layer 12, a first conductive circuit layer 13, a second cover film 14, a second conductive circuit layer 15, a second adhesive layer 16 and a third cover film 17 arranged in sequence.

[0063] The material of the first cover film 11, the second cover film 14 and the third cover film 17 can be selected from one of the resins such as epoxy resin, polypropylene (PP), BT resin, polyphenylene oxide (PPO), polyimide (PI), polyethylene terephthalate (PET) and polyethylene naphthalate (PEN). In this embodiment, the material of the first cover film 11, the second cover film 14 and the third cover film 17 is polyimide.

[0064] In an embodiment, the first conductive circuit layer 13 includes a first base copper layer 131 disposed on the second cover film 14 and a first electroplated copper layer 132 disposed on the first base copper layer 131. The first conductive circuit layer 13 is provided with a first gap (not shown). The first adhesive layer 12 also fills in the first gap.

[0065] In an embodiment, the second conductive circuit layer 15 includes a second base copper layer 151 disposed on the second cover film 14 and a second electroplated copper layer 152 disposed on the second base copper layer 151. The second conductive circuit layer 15 is provided with a second gap (not shown). The second adhesive layer 16 also fills in the second gap.

[0066] The flexible circuit board 10 is provided with a receiving groove 20. The receiving groove 20 penetrates the first cover film 11 and the first adhesive layer 12 in sequence, and the bottom of the receiving groove 20 corresponds to the first electroplated copper layer 132. Part of the first conductive circuit layer 13 is exposed to the receiving groove 20 to form a solder pad 21.

[0067] In an embodiment, the flexible circuit board 10 further includes a protective layer 18. The protective layer 18 is located in the first gap, and the protective layer 18 is exposed to the receiving groove 20.

[0068] The material of the protective layer 18 can be a solder resist ink, such as green oil. The protective layer 18 is used to prevent the solder pads 21 from shorting with each other during subsequent soldering.

[0069] The flexible circuit substrate 10 is provided with a conductive portion 22. In an embodiment, the cross section of the conductive portion 22 is substantially trapezoidal along the thickness direction of the flexible circuit substrate 10. The conductive portion 22 is used to electrically connect the first conductive circuit layer 13 and the second conductive circuit layer 15.

[0070] Step S12, please refer to Figure 2 A peelable film 30 is attached to the third cover film 17.

[0071] Step S13, please refer to Figure 3 First and second blind slots 40 and 41 are formed in the flexible circuit substrate 10 and the peelable film 30.

[0072] The first and second blind slots 40 and 41 both sequentially pass through the peelable film 30, the third cover film 17, the second adhesive layer 16, the second conductive circuit layer 15, and the second cover film 14. The bottoms of the first and second blind slots 40 and 41 both correspond to the first base copper layer 131, and the first and second blind slots 40 and 41 both correspond to the accommodation slot 20.

[0073] In an embodiment, the first and second blind slots 40 and 41 can be formed by laser drilling or depth cutting. The shapes of the first and second blind slots 40 and 41 are not limited in the present application, and the shapes of the first and second blind slots 40 and 41 can be rectangular, circular, or any other regular or irregular shape.

[0074] The inner diameter D1 of the first blind slot 40 is greater than or equal to 100 μm, and the inner diameter D2 of the second blind slot 41 is greater than or equal to 100 μm. The inner diameter of the first blind slot 40 can be equal to or different from the inner diameter of the second blind slot 41.

[0075] The distance L1 between the first and second blind slots 40 and 41 is greater than or equal to 150 μm.

[0076] The number of the first and second blind slots 40 and 41 is not limited in the present application.

[0077] Step S14, please refer to Figure 4 Thermally conductive material is filled into the first and second blind slots 40 and 41 to form first and second thermally conductive columns 42 and 43, respectively.

[0078] In an embodiment, the first heat-conductive column 42 comprises a first heat-conductive part 421 and a first heat-dissipating part 422 connected with the first heat-conductive part 421. The first heat-conductive part 421 is located in the first blind groove 40 in the flexible circuit substrate 10, and the first heat-dissipating part 422 is located in the first blind groove 40 in the strippable film 30.

[0079] In an embodiment, the second heat-conductive column 43 comprises a second heat-conductive part 431 and a second heat-dissipating part 432 connected with the second heat-conductive part 431. The second heat-conductive part 431 is located in the second blind groove 41 in the flexible circuit substrate 10, and the second heat-dissipating part 432 is located in the second blind groove 41 in the strippable film 30.

[0080] In an embodiment, the first heat-dissipating part 422 and the second heat-dissipating part 432 are both substantially flush with the surface of the strippable film 30 away from the third cover film 17.

[0081] In an embodiment, the heat-conductive material comprises at least one of heat-conductive copper paste, heat-conductive silver paste and ceramic powder. That is, the material of the first heat-conductive column 42 and the second heat-conductive column 43 can comprise at least one of heat-conductive copper paste, heat-conductive silver paste and ceramic powder.

[0082] In an embodiment, the first conductive circuit layer 13 is in thermal conduction with the first heat-conductive column 42 and the second heat-conductive column 43.

[0083] It can be understood that the diameters of the first heat-conductive column 42 and the second heat-conductive column 43 are equal to the inner diameters of the first blind groove 40 and the second blind groove 41, respectively.

[0084] Step S15, please refer to Figure 5 , removing the strippable film 30.

[0085] After removing the strippable film 30, the first heat-dissipating part 422 and the second heat-dissipating part 432 both protrude out of the surface of the third cover film 17 away from the second adhesive layer 16.

[0086] Step S16, please refer to Figure 6 , forming a reinforcing plate 50 on the third cover film 17.

[0087] Specifically, a third adhesive layer 60 is formed on the third cover film 17, and the reinforcing plate 50 is formed on the third adhesive layer 60.

[0088] In an embodiment, the reinforcing plate 50 is provided with a first opening 51 and a second opening 52. The first opening 51 and the second opening 52 both penetrate the third adhesive layer 60.

[0089] The first heat dissipation part 422 and the second heat dissipation part 432 are respectively located in the first opening 51 and the second opening 52.

[0090] The inner diameter D3 of the first opening 51 is greater than or equal to (D1+100) μm, and the inner diameter D4 of the second opening 52 is greater than or equal to (D2+100) μm. In this way, a gap is left between the first heat dissipation part 422 and the reinforcing plate 50 and between the second heat dissipation part 432 and the reinforcing plate 50.

[0091] The first opening 51 has a first inner wall (not shown in the figure), and the distance L2 between the first heat dissipation part 422 and the first inner wall is greater than or equal to 50 μm. The second opening 52 has a second inner wall (not shown in the figure), and the distance L3 between the second heat dissipation part 432 and the second inner wall is greater than or equal to 50 μm.

[0092] The total thickness H1 of the third adhesive layer 60 and the reinforcing plate 50 is 15-500 μm, the height H2 of the first heat dissipation part 422 is (H1-10) μm, and the height H3 of the second heat dissipation part 432 is (H1-10) μm. That is, the height of the first heat dissipation part 422 and the height of the second heat dissipation part 432 are both less than the total thickness of the third adhesive layer 60 and the reinforcing plate 50, so as to ensure that the thickness of the subsequent flexible circuit board (not shown in the figure) is not increased, and the flatness of the flexible circuit board is ensured. Figure 7

[0093] Step S17, please refer to Figure 7 The image sensor 70 is installed in the accommodating groove 20 and electrically connected with the solder pad 21, so as to obtain the flexible circuit board 100.

[0094] The image sensor 70 is electrically connected with the solder pad 21, so as to electrically connect the image sensor 70 with the first conductive circuit layer 13, and further electrically connect the image sensor 70 with the second conductive circuit layer 15.

[0095] In actual application, a filter (not shown in the figure) and a lens (not shown in the figure) can be installed on one side of the image sensor 70 of the flexible circuit board 100, so that the image sensor 70 is opposite to the filter, and the filter is opposite to the lens, that is, a lens module is obtained.

[0096] Please refer to​Figure 7 An embodiment of the present application further provides a flexible circuit board 100 for a lens module, comprising a flexible circuit substrate 10, a reinforcing plate 50, a third adhesive layer 60, and an image sensor 70.

[0097] In an embodiment, the flexible circuit substrate 10 comprises a first cover film 11, a first adhesive layer 12, a first conductive circuit layer 13, a second cover film 14, a second conductive circuit layer 15, a second adhesive layer 16, and a third cover film 17 which are sequentially stacked.

[0098] The material of the first cover film 11, the second cover film 14, and the third cover film 17 can be selected from one of epoxy resin, polypropylene (PP), BT resin, polyphenylene oxide (PPO), polyimide (PI), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and the like. In this embodiment, the material of the first cover film 11, the second cover film 14, and the third cover film 17 is polyimide.

[0099] In an embodiment, the first conductive circuit layer 13 comprises a first base copper layer 131 disposed on the second cover film 14 and a first electroplated copper layer 132 disposed on the first base copper layer 131. The first conductive circuit layer 13 is provided with a first gap (not shown in the figure). The first adhesive layer 12 also fills in the first gap.

[0100] In an embodiment, the second conductive circuit layer 15 comprises a second base copper layer 151 disposed on the second cover film 14 and a second electroplated copper layer 152 disposed on the second base copper layer 151. The second conductive circuit layer 15 is provided with a second gap (not shown in the figure). The second adhesive layer 16 also fills in the second gap.

[0101] The flexible circuit substrate 10 is provided with a receiving groove 20. The receiving groove 20 sequentially penetrates the first cover film 11 and the first adhesive layer 12, and the bottom of the receiving groove 20 corresponds to the first electroplated copper layer 132. Part of the first conductive circuit layer 13 is exposed to the receiving groove 20 to form a solder pad 21.

[0102] In an embodiment, the flexible circuit substrate 10 further comprises a protective layer 18. The protective layer 18 is located in the first gap, and the protective layer 18 is exposed to the receiving groove 20.

[0103] The material of the protective layer 18 can be a solder resist ink, such as green oil. The protective layer 18 is used to prevent the solder pads 21 from shorting with each other.

[0104] The flexible circuit substrate 10 is provided with a conductive portion 22. In an embodiment, the cross section of the conductive portion 22 is substantially trapezoidal along the thickness direction of the flexible circuit substrate 10. The conductive portion 22 is used to electrically connect the first conductive circuit layer 13 and the second conductive circuit layer 15.

[0105] The flexible circuit substrate 10 is provided with a first blind slot 40 and a second blind slot 41. The first blind slot 40 and the second blind slot 41 both sequentially pass through the peelable film 30, the third cover film 17, the second adhesive layer 16, the second conductive circuit layer 15, and the second cover film 14. The bottom of the first blind slot 40 and the second blind slot 41 corresponds to the first base material copper layer 131, and the first blind slot 40 and the second blind slot 41 correspond to the accommodating groove 20.

[0106] The shape of the first blind slot 40 and the second blind slot 41 is not limited in the present application, and the shape of the first blind slot 40 and the second blind slot 41 can be rectangular, circular, or any other regular or irregular shape.

[0107] The inner diameter D1 of the first blind slot 40 is greater than or equal to 100 μm, and the inner diameter D2 of the second blind slot 41 is greater than or equal to 100 μm. The inner diameter of the first blind slot 40 and the inner diameter of the second blind slot 41 can be equal or not equal.

[0108] The distance L1 between the first blind slot 40 and the second blind slot 41 is greater than or equal to 150 μm.

[0109] The number of the first blind slot 40 and the second blind slot 41 is not limited in the present application.

[0110] The first blind slot 40 and the second blind slot 41 are filled with a heat-conducting material to form a first heat-conducting column 42 and a second heat-conducting column 43, respectively.

[0111] In an embodiment, the first heat-conducting column 42 includes a first heat-conducting portion 421 and a first heat-dissipating portion 422 connected to the first heat-conducting portion 421. The first heat-conducting portion 421 is located in the first blind slot 40, and the first heat-dissipating portion 422 protrudes out of the surface of the third cover film 17 away from the second adhesive layer 16.

[0112] In an embodiment, the second heat-conductive column 43 comprises a second heat-conductive part 431 and a second heat-dissipating part 432 connected with the second heat-conductive part 431. The second heat-conductive part 431 is located in the second blind groove 41, and the second heat-dissipating part 432 protrudes out of the surface of the third cover film 17 away from the second adhesive layer 16.

[0113] In an embodiment, the heat-conductive material comprises at least one of heat-conductive copper paste, heat-conductive silver paste and ceramic powder. That is, the material of the first heat-conductive column 42 and the second heat-conductive column 43 can comprise at least one of heat-conductive copper paste, heat-conductive silver paste and ceramic powder.

[0114] The first conductive circuit layer 13 is in thermal conduction with the first heat-conductive column 42 and the second heat-conductive column 43.

[0115] It can be understood that the diameters of the first heat-conductive column 42 and the second heat-conductive column 43 are equal to the inner diameters of the first blind groove 40 and the second blind groove 41, respectively.

[0116] The reinforcing plate 50 is arranged on the third cover film 17 through the third adhesive layer 60.

[0117] In an embodiment, the reinforcing plate 50 is provided with a first opening 51 and a second opening 52. The first opening 51 and the second opening 52 both penetrate through the third adhesive layer 60.

[0118] The first heat-dissipating part 422 and the second heat-dissipating part 432 are located in the first opening 51 and the second opening 52, respectively.

[0119] The inner diameter D3 of the first opening 51 is greater than or equal to (D1+100) μm, and the inner diameter D4 of the second opening 52 is greater than or equal to (D2+100) μm. In this way, gaps are left between the first heat-dissipating part 422 and the reinforcing plate 50 and between the second heat-dissipating part 432 and the reinforcing plate 50.

[0120] The first opening 51 has a first inner wall (not shown in the figure), and the distance L2 between the first heat-dissipating part 422 and the first inner wall is greater than or equal to 50 μm. The second opening 52 has a second inner wall (not shown in the figure), and the distance L3 between the second heat-dissipating part 432 and the second inner wall is greater than or equal to 50 μm.

[0121] The total thickness H1 of the third adhesive layer 60 and the reinforcing plate 50 is 15-500 μm, the height H2 of the first heat dissipation part 422 is (H1-10) μm, and the height H3 of the second heat dissipation part 432 is (H1-10) μm. That is, the height of the first heat dissipation part 422 and the height of the second heat dissipation part 432 are both less than the total thickness of the third adhesive layer 60 and the reinforcing plate 50, so as to ensure that the thickness of the flexible circuit board 100 is not increased and the flatness of the flexible circuit board 100 is ensured.

[0122] The image sensor 70 is mounted in the accommodating groove 20. The image sensor 70 is electrically connected to the solder pad 21, so that the image sensor 70 is electrically connected to the first conductive circuit layer 13, and further electrically connected to the second conductive circuit layer 15.

[0123] In actual application, a filter (not shown) and a lens (not shown) can be mounted on one side of the image sensor 70 of the flexible circuit board 100, so that the image sensor 70 is opposite to the filter, and the filter is opposite to the lens, that is, a lens module is obtained.

[0124] The heat generated by the image sensor 70 in the application is transmitted to the first heat conduction part 421 and the second heat conduction part 431 through the first conductive circuit layer 13, and is dissipated to the outside through the first heat dissipation part 422 and the second heat dissipation part 432 respectively. Since the first heat dissipation part 422 and the second heat dissipation part 432 both protrude out of the third cover film 17 away from the surface of the second adhesive layer 16, the heat dissipation area of the first heat conduction column 42 and the second heat conduction column 43 is increased, and the heat dissipation effect of the image sensor 70 is improved. At the same time, since there is a gap between the first heat dissipation part 422 and the first inner wall, and between the second heat dissipation part 432 and the second inner wall, the convection of air is facilitated, the limitation of the reinforcing plate 50 on the heat dissipation of the first heat dissipation part 422 and the second heat dissipation part 432 is reduced, and the heat dissipation effect of the image sensor 70 is improved.

[0125] Compared with only one first heat conduction column 42 or only one second heat conduction column 43, at least one first heat conduction column 42 and at least one second heat conduction column 43 are provided in the application. Since the first heat conduction column 42 and the second heat conduction column 43 correspond to different positions of the image sensor 70 respectively, the uniform heat dissipation of the image sensor 70 is facilitated. At the same time, since the reinforcing plate 50 is arranged between the first heat conduction column 42 and the second heat conduction column 43, the reinforcing plate 50 is beneficial to support the flexible circuit substrate 10 and the image sensor 70.

[0126] In addition, compared with the heat dissipation by attaching a heat sink on one side of the flexible circuit board, the height of the first heat dissipation part 422 and the height of the second heat dissipation part 432 are both set to be less than the total thickness of the third adhesive layer 60 and the reinforcing plate 50, so as to ensure that the thickness of the flexible circuit board 100 is not increased, which is conducive to the thinning of the flexible circuit board 100 and ensures the flatness of the flexible circuit board 100. At the same time, since the first heat conduction column 42 and the second heat conduction column 43 are closer to the image sensor 70, the heat conduction and heat dissipation of the image sensor 70 are facilitated. Since the heat sink is omitted, the production cost is also reduced.

[0127] The above description is only one of the specific embodiments of the present application, but in the actual application process, it cannot be limited to this embodiment. Other modifications and changes made by those skilled in the art according to the technical concept of the present application should be within the scope of protection of the present application.

Claims

1. A method for manufacturing a flexible circuit board for a lens module, characterized by, The application relates to a flexible circuit board manufacturing method. The method comprises the following steps: a receiving groove is formed in a flexible circuit board; a first blind groove and a second blind groove are formed in the flexible circuit board, and the first blind groove and the second blind groove correspond to the receiving groove, and the first blind groove and the second blind groove are located on opposite surfaces of the flexible circuit board respectively; a heat-conducting material is filled in the first blind groove and the second blind groove to form a first heat-conducting column and a second heat-conducting column respectively, the first heat-conducting column comprises a first heat-conducting part and a first heat-dissipating part connected with the first heat-conducting part, the first heat-conducting part is located in the first blind groove, and the first heat-dissipating part protrudes out of the surface of the flexible circuit board, the second heat-conducting column comprises a second heat-conducting part and a second heat-dissipating part connected with the second heat-conducting part, the second heat-conducting part is located in the second blind groove, and the second heat-dissipating part protrudes out of the surface of the flexible circuit board; a reinforcing plate is formed on the flexible circuit board, the reinforcing plate comprises a first opening and a second opening, the first heat-dissipating part and the second heat-dissipating part are located in the first opening and the second opening respectively, the first opening has a first inner wall, the second opening has a second inner wall, the distance between the first heat-dissipating part and the first inner wall is greater than or equal to 50 microns, and the distance between the second heat-dissipating part and the second inner wall is greater than or equal to 50 microns; and an image sensor is installed in the receiving groove, the image sensor is electrically connected with the flexible circuit board, and the image sensor is in thermal conduction with the first heat-conducting column and the second heat-conducting column, so that the flexible circuit board is obtained.

2. The method of claim 1, wherein the flexible circuit board is formed by a process comprising: The flexible circuit board comprises a first cover film, a first adhesive layer, a first conductive circuit layer, a second cover film, a second conductive circuit layer, a second adhesive layer and a third cover film which are sequentially stacked, the receiving groove penetrates through the first cover film and the first adhesive layer sequentially, and the bottom of the receiving groove corresponds to the first conductive circuit layer, the first blind groove and the second blind groove penetrate through the third cover film, the second adhesive layer, the second conductive circuit layer and the second cover film sequentially, and the bottoms of the first blind groove and the second blind groove correspond to the first conductive circuit layer, the first heat-dissipating part and the second heat-dissipating part protrude out of the surface of the third cover film away from the second adhesive layer, and the image sensor is in thermal conduction with the first heat-conducting column and the second heat-conducting column through the first conductive circuit layer.

3. The method of claim 2, wherein the flexible circuit board is formed by a process comprising: Before the first blind groove and the second blind groove are formed in the flexible circuit board, the manufacturing method further comprises the following steps: an exfoliation film is attached to the third cover film; the first blind groove and the second blind groove further penetrate through the exfoliation film, and the end surface of the first heat-dissipating part away from the first heat-conducting part and the end surface of the second heat-dissipating part away from the second heat-conducting part are flush with the surface of the exfoliation film away from the third cover film; after the first heat-conducting column and the second heat-conducting column are formed, the manufacturing method further comprises the following step: the exfoliation film is removed.

4. The method of claim 2, wherein the flexible circuit board is formed by a process comprising: The step of forming the reinforcing plate on the flexible circuit substrate comprises: forming a third adhesive layer on the third cover film, wherein the first opening and the second opening both further penetrate the third adhesive layer; and forming the reinforcing plate on the third adhesive layer; wherein the total thickness H1 of the third adhesive layer and the reinforcing plate is 15-500 μm, the height H2 of the first heat dissipation part is (H1-10) μm, and the height H3 of the second heat dissipation part is (H1-10) μm.

5. A flexible circuit board for a lens module, characterized by, comprises: a flexible circuit substrate, the flexible circuit substrate having a receiving groove, a first blind groove and a second blind groove, the first blind groove and the second blind groove corresponding to the receiving groove, the first blind groove and the second blind groove and the receiving groove being located on opposite surfaces of the flexible circuit substrate, the first blind groove and the second blind groove forming a first heat conduction column and a second heat conduction column respectively, the first heat conduction column comprising a first heat conduction part and a first heat dissipation part connected to the first heat conduction part, the first heat conduction part being located in the first blind groove, the first heat dissipation part protruding out of the surface of the flexible circuit substrate, the second heat conduction column comprising a second heat conduction part and a second heat dissipation part connected to the second heat conduction part, the second heat conduction part being located in the second blind groove, the second heat dissipation part protruding out of the surface of the flexible circuit substrate; a reinforcing plate arranged on the flexible circuit substrate, the reinforcing plate having a first opening and a second opening, and the first heat dissipation part and the second heat dissipation part being located in the first opening and the second opening respectively, the first opening having a first inner wall, the second opening having a second inner wall, the distance between the first heat dissipation part and the first inner wall being greater than or equal to 50 μm, and the distance between the second heat dissipation part and the second inner wall being greater than or equal to 50 μm; and a image sensor located in the receiving groove, the image sensor being electrically connected to the flexible circuit substrate, and the image sensor being in thermal conduction with the first heat conduction column and the second heat conduction column. The flexible circuit substrate comprises a first cover film, a first adhesive layer, a first conductive circuit layer, a second cover film, a second conductive circuit layer, a second adhesive layer and a third cover film arranged in sequence, the receiving groove penetrates the first cover film and the first adhesive layer in sequence, and the bottom of the receiving groove corresponds to the first conductive circuit layer, the first blind groove and the second blind groove both penetrate the third cover film, the second adhesive layer, the second conductive circuit layer and the second cover film in sequence, and the bottoms of the first blind groove and the second blind groove both correspond to the first conductive circuit layer, the first heat dissipation part and the second heat dissipation part both protrude out of the surface of the third cover film away from the second adhesive layer, and the image sensor is in thermal conduction with the first heat conduction column and the second heat conduction column through the first conductive circuit layer.

6. The flexible circuit board of claim 5, wherein, Further comprising:

7. The flexible circuit board of claim 6, wherein, a third adhesive layer arranged on the third cover film, and the reinforcing plate being arranged on the third adhesive layer; ​ The total thickness H1 of the third adhesive layer and the reinforcing plate is 15-500 microns, the height H2 of the first heat dissipation part is (H1-10) microns, and the height H3 of the second heat dissipation part is (H1-10) microns.

8. The flexible circuit board of claim 6, wherein, The first conductive circuit layer comprises a first base material copper layer disposed on the second cover film and a first electroplated copper layer disposed on the first base material copper layer, and the second conductive circuit layer comprises a second base material copper layer disposed on the second cover film and a second electroplated copper layer disposed on the second base material copper layer.

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