A soft-hard combined circuit board and its manufacturing method, and camera module

Abstract

A soft-hard combination circuit board is formed by bonding at least one flexible circuit board and at least one rigid circuit board, wherein the flexible circuit board and the rigid circuit board respectively have conductive patterns, and the soft-hard combination circuit board comprises a soft-hard combination area and a soft area, wherein the soft-hard combination area is an area having both the flexible circuit board and the rigid circuit board, and the soft area is an area having only the flexible circuit board, and a covering film for protecting the conductive pattern is attached to the flexible circuit board, wherein the covering film covers the entire soft area in the soft area, and the covering film is partially missing in the soft-hard combination area, thereby forming a covered area and a missing area in the soft-hard combination area.

Description

Technical Field

[0001] The invention relates to a hard-soft combined circuit board capable of improving temperature drift, a method for manufacturing the hard-soft combined circuit board, and a camera module using the hard-soft combined circuit board. Background Art

[0002] In modern industries represented by the automobile industry, camera modules for distance measurement or monitoring have been widely used. In recent years, with the popularization of intelligence, the breadth and depth of application of vehicle-mounted camera modules as the visual system of automobiles have been greatly improved. In addition, in the fields of indoor monitoring, portable communication equipment, etc., higher requirements are also placed on the imaging quality of camera modules.

[0003] For example, in a vehicle-mounted camera module, the lens and the lens holder are assembled by threaded connection or bonding, while the lens holder and the circuit board are assembled by bonding. In this case, especially the assembly between the lens holder and the circuit board, due to the use of a bonding process, the stability of the imaging quality becomes a problem in high temperature / low temperature environments. This is because, due to the thermal expansion and contraction characteristics of the circuit board itself, when the circuit board expands due to heat, it will cause the lens holder and the lens to shift in the Z-axis direction. In addition, in addition to the influence of ambient temperature, the circuit board is also prone to thermal deformation when powered on for a long time. The thermal expansion of the circuit board will cause the imaging focus to shift, and then the imaging quality will deteriorate, which is the so-called imaging temperature drift.

[0004] In camera modules, a combination of hard and soft circuit boards is usually used. A combination of hard and soft circuit boards is a circuit board structure that includes both a flexible circuit board and a rigid circuit board that are interconnected. It has both the flexibility of a flexible circuit board and the hardness of a rigid circuit board. In the production process of a combination of hard and soft circuit boards, a structure in which a rigid circuit board is bonded to the top and bottom of a flexible circuit board is usually adopted, and the flexible circuit board portion and the rigid circuit board portion are connected and conducted through through holes, buried holes, blind holes, etc. As needed, multiple covering films are provided on the flexible circuit board and the rigid circuit board. Usually, a covering film is provided on almost the entire surface of the flexible circuit board and the rigid circuit board. The covering film is used to protect the conductive patterns on the flexible circuit board and the rigid circuit board.

[0005] Although the image temperature drift can be compensated and corrected later by computer algorithms, the compensation of temperature drift is still difficult because the lens mount and the circuit board are in surface contact and the location and degree of expansion and bulge are difficult to predict. Camera modules have entered the era of high pixels and micro-volumes, and effectively suppressing temperature drift and ensuring image quality are becoming increasingly important issues.

[0006] In addition, the conventional rigid-flexible board requires bonding the various layers of materials of the rigid circuit board layer by layer on the upper and / or lower sides of the flexible circuit board, resulting in low manufacturing efficiency. Summary of the invention

[0007] The object of the present invention is to provide a rigid-flexible circuit board that can prevent temperature drift. In order to achieve the above object, one scheme of the present invention is a rigid-flexible circuit board, which is formed by bonding at least one flexible circuit board and at least one rigid circuit board, and is characterized in that:

[0008] The flexible circuit board and the rigid circuit board each have a conductive pattern.

[0009] The hard-soft combined circuit board includes a hard-soft combined area and a soft area, wherein the hard-soft combined area is an area having both the soft circuit board and the hard circuit board, and the soft area is an area having only the soft circuit board.

[0010] A cover film for protecting the conductive pattern is attached to the flexible circuit board and the rigid circuit board.

[0011] On the flexible circuit board, in the flexible area, the cover film covers the entire flexible area, and in the hard-soft bonding area, the cover film is partially missing, so that a covered area and a missing area are formed in the hard-soft bonding area.

[0012] According to the above technical solution, the temperature drift caused by the thermal expansion of the cover film in the rigid-flexible circuit board, especially the cover film of the flexible circuit board, can be effectively avoided.

[0013] In addition, preferably, the rigid-flexible circuit board is formed by bonding the flexible circuit board and the rigid circuit board which are manufactured separately.

[0014] According to the aforementioned technical solution, flexible circuit boards and rigid circuit boards can be manufactured simultaneously, which greatly improves the manufacturing efficiency of the flexible and rigid combined circuit boards.

[0015] In addition, preferably, the flexible circuit board has:

[0016] A first substrate layer having a first surface and a second surface opposite to each other;

[0017] a first conductive pattern disposed on the first surface of the first base layer;

[0018] a second conductive pattern disposed on the second surface of the first base layer;

[0019] a plurality of first connection terminals, which are arranged through the first base layer and are used for electrical connection between the first conductive pattern and the second conductive pattern, and between the flexible circuit board and the rigid circuit board;

[0020] a first covering film disposed on the first surface of the first base layer and covering the first conductive pattern; and

[0021] a second covering film provided on the second surface of the first base layer and covering the second conductive pattern;

[0022] The rigid circuit board has:

[0023] a second base layer having a third surface and a fourth surface opposite to each other;

[0024] a third conductive pattern disposed on the third surface of the second base layer;

[0025] a fourth conductive pattern disposed on the fourth surface of the second base layer;

[0026] a plurality of second connection terminals, which are arranged through the second base layer and are used for electrical connection between the third conductive pattern and the fourth conductive pattern, and between the flexible circuit board and the rigid circuit board; and

[0027] a third covering film disposed on the third surface of the second base layer and covering the third conductive pattern;

[0028] The fourth surface side of the rigid circuit board and the first surface side of the flexible circuit board are bonded together to form a rigid-flexible circuit board.

[0029] The flexible circuit board has a width substantially the same as that of the rigid circuit board and a length longer than that of the flexible circuit board, thereby forming a rigid-flexible combined area having both the flexible circuit board and the rigid circuit board, and at least one flexible area having only the flexible circuit board.

[0030] In the hard-soft bonding region, the first cover film and / or the second cover film is partially missing, so that the cover region and the missing region are formed in the hard-soft bonding region.

[0031] According to the aforementioned technical solution, the missing area can be used to avoid the temperature drift caused by the thermal expansion of the cover film in the rigid-flexible circuit board, especially the cover film of the flexible circuit board, and the manufacturing efficiency of the rigid-flexible circuit board can be greatly improved.

[0032] Furthermore, preferably, the rigid circuit board and the flexible circuit board are bonded together by a film.

[0033] According to the above technical solution, the flexible circuit board and the rigid circuit board can be firmly bonded at low cost.

[0034] Furthermore, it is preferred that the covering region is configured as a ring surrounding the missing region.

[0035] The missing region at least completely includes the first conductive pattern, the second conductive pattern, and the first connecting terminal of the flexible circuit board, and the third conductive pattern, the fourth conductive pattern, and the second connecting terminal of the rigid circuit board.

[0036] According to the aforementioned technical solution, a covering area and a missing area of ​​the covering film can be formed in the soft-hard combination area, and the missing area can be used to avoid temperature drift caused by thermal expansion of the covering film.

[0037] Furthermore, preferably, the covered areas and the missing areas are configured in a stripe shape, a checkerboard shape, or a multiple ring shape that are alternately arranged.

[0038] According to the aforementioned technical solution, by configuring the covered areas and the missing areas to be arranged in alternating stripes, checkerboards, or multiple rings, etc., the rigidity of the rigid-flex circuit board can be improved and the yield rate can be increased.

[0039] In addition, another aspect of the present invention is a method for manufacturing a hard-flexible circuit board, wherein the hard-flexible circuit board is formed by bonding at least one flexible circuit board and at least one rigid circuit board, and includes a hard-flexible region having both the flexible circuit board and the rigid circuit board, and at least one flexible region having only the flexible circuit board. The method for manufacturing the hard-flexible circuit board is characterized in that it comprises the following steps:

[0040] S1: Copper foils are attached to the first surface and the second surface of the first base layer composed of a flexible resin, respectively, and a first conductive pattern and a second conductive pattern and a pattern for forming a first connecting terminal are formed on the first surface and the second surface of the first base layer respectively by selectively etching the copper foils, and a through hole penetrating the first base layer is formed at the pattern for forming the first connecting terminal by a mechanical drilling process, and a conductive material is deposited in the through hole to form the first connecting terminal;

[0041] S2: forming a first covering film covering the first surface of the first base layer, the first conductive pattern and the first connecting terminal, and a second covering film covering the second surface of the first base layer, the second conductive pattern and the first connecting terminal on the first surface side of the first base layer, and the first covering film and / or the second covering film having a partially missing portion corresponding to the rigid circuit board, thereby forming a covering area and a missing area;

[0042] S3: attaching a first reinforcing plate to a side of the second cover film away from the first base layer;

[0043] S4: removing the waste area of ​​the flexible circuit board;

[0044] S5: attaching copper foils to the third surface and the fourth surface of the second base layer composed of a hard resin, respectively, and forming a third conductive pattern and a fourth conductive pattern and a pattern for forming a second connection terminal on the third surface and the fourth surface of the third base layer, respectively, by selectively etching the copper foils;

[0045] Furthermore, a third cover film is attached to the third surface of the second base layer to form the rigid circuit board;

[0046] S6: attaching a film having a shape corresponding to the shape of the first cover film in the hard-soft combination area S1 to the side of the first cover film in the hard-soft combination area of ​​the flexible circuit board away from the first base layer, and then attaching the fourth surface side of the second base layer of the rigid circuit board to the film;

[0047] S7: The rigid-flexible circuit board is compacted and flattened through a pressing process, thereby completing the rigid-flexible circuit board.

[0048] According to the aforementioned technical solution, the missing area can be used to avoid the temperature drift caused by the thermal expansion of the cover film in the rigid-flexible circuit board, especially the cover film of the flexible circuit board, and the manufacturing efficiency of the rigid-flexible circuit board can be greatly improved.

[0049] In addition, another aspect of the present invention is a camera module, characterized in that it has:

[0050] A lens barrel, used to accommodate multiple lens groups;

[0051] A lens base, used for supporting the lens barrel; and

[0052] The rigid-flexible circuit board according to any one of claims 1 to 6,

[0053] The mirror holder is attached to the hard-flexible circuit board by a bonding process and has hard-flexible areas of the soft circuit board and the hard circuit board.

[0054] According to the aforementioned technical solution, a camera module can be provided that can effectively avoid imaging temperature drift and can greatly improve production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 This is a cross-sectional view of a flexible wiring board according to an embodiment of the present invention.

[0056] Figure 2 It is a top view of a first coverlay film for explaining the flexible wiring board according to the embodiment of the present invention.

[0057] Figure 3This is a cross-sectional view of a rigid wiring board according to an embodiment of the present invention.

[0058] Figure 4 It is a schematic diagram of panel assembly in the process of manufacturing a flexible circuit board according to an embodiment of the present invention.

[0059] Figure 5 4 is a cross-sectional view of a rigid-flex circuit board according to an embodiment of the present invention.

[0060] Figure 6 This is a cross-sectional view of the rigid-flex circuit board of comparative example 1.

[0061] Figure 7 This is a cross-sectional view of the rigid-flex circuit board of comparative example 2.

[0062] Figure 8 It is a diagram for explaining the defects of the rigid-flex circuit board of Comparative Example 1.

[0063] Fig. 9 This is a flowchart for explaining a method for producing a hard-flexible board according to an embodiment of the present invention.

[0064] Fig.10 It is a diagram illustrating the assembly of the rigid-flexible circuit board and the camera module of the present invention.

[0065] Caption of the attached figure:

[0066] 1. Rigid-flexible circuit board

[0067] 10 Flexible circuit board

[0068] 101 1st basal layer

[0069] 102 1st conductive pattern

[0070] 103 Second conductive pattern

[0071] 104, 104', 104" 1st covering film

[0072] 105 Second Covering Film

[0073] 106 reinforcement plate

[0074] 107 1st positioning hole

[0075] 1011 Surface 1

[0076] 1012 Surface 2

[0077] 1021 1st connection terminal

[0078] S1 Soft and hard combination area

[0079] S2 Soft Area

[0080] S3 Missing Regions

[0081] S4 Coverage Area

[0082] Bo Soft and Hard Dividing Line

[0083] Sr Waste Area

[0084] 20 Rigid circuit board

[0085] 201 Second basal layer

[0086] 202 3rd conductive pattern

[0087] 203 4th conductive pattern

[0088] 204 Third Covering Film

[0089] 2011 The 3rd Surface

[0090] 2012 Surface 4

[0091] 2021 Second connection terminal

[0092] 301 Film DETAILED DESCRIPTION

[0093] Various exemplary embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is in no way intended to limit the present disclosure and its application or use. The present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the present disclosure thorough and complete and to fully express the scope of the present disclosure to those skilled in the art. It should be noted that unless otherwise stated, the relative arrangement of the components and steps, numerical expressions, and numerical values, etc., described in these embodiments should be interpreted as being merely exemplary and not as limiting.

[0094] The words “include” or “comprising” and the like used in the present disclosure mean that the elements before the words include the elements listed after the words, and do not exclude the possibility of also including other elements.

[0095] All terms (including technical terms or scientific terms) used in the present disclosure have the same meanings as those understood by ordinary technicians in the field to which the present disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be understood to have meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless explicitly defined in this article.

[0096] Components not described in detail in this section, parameters such as specific models of components, relationships between components, and control circuits may be considered as technologies, methods, and equipment known to ordinary technicians in the relevant fields, but in appropriate cases, such technologies, methods, and equipment should be considered as part of the specification.

[0097] (Flexible Printed Circuit Board)

[0098] The following reference Figure 1 and Figure 2 The structure of the flexible wiring board 10 in the rigid-flex wiring board 1 of the present invention will be described. Figure 1 is a schematic cross-sectional view of the flexible circuit board 10, Figure 2 1 is a schematic top view of the flexible circuit board 10 .

[0099] like Figure 1 As shown, the flexible circuit board 10 is a flexible circuit board provided with a conductive pattern, and is composed of a first base layer 101, a first conductive pattern 102, a second conductive pattern 103, a first cover film 104, a second cover film 105, a reinforcing plate 106, and a first positioning hole 107. In a common example, the flexible circuit board 10 is configured in a rectangular shape. The flexible circuit board can be a circuit board with a conductive pattern provided on one side, a circuit board with conductive patterns provided on both sides, or a multilayer circuit board with more than two layers of conductive patterns. That is, the flexible circuit board 10 can have more layers, including multiple base layers and conductive pattern layers arranged alternately. In this embodiment, for the sake of convenience of description, a flexible circuit board with conductive patterns provided on both sides is adopted. That is, in this embodiment, a single-layer structure is adopted in which a first base layer 101 is provided, and a first conductive pattern 102 and a second conductive pattern 103 are provided on both sides of the first base layer 101.

[0100] Among them, the first base layer 101 is a flexible material, and any flexible material such as a resin material can be used as the first base layer 101. For example, the material of the first base layer 101 can be selected from polyimide (PI), polyethylene terephthalate (PET) or polyethylene naphthalate (PEN). The first base layer 101 includes a first surface 1011 and a second surface 1012 located on the opposite side of the first surface 1011. The first surface 1011 is used to set the first conductive pattern 102 described in detail later, and the second surface 1012 is used to set the second conductive pattern 103 described in detail later. In addition, the first surface 1011 side of the first base layer 101 is the bonding side with the rigid circuit board 20 described later.

[0101] The first conductive pattern 102 and the second conductive pattern 103 are formed on the first surface 1011 and the second surface 1012 of the first base layer 101, respectively. The first conductive pattern 102 and the second conductive pattern 103 can be made by attaching a metal material to the first base layer 101 and then selectively etching using a mask. As a typical example, the first conductive pattern 102 and the second conductive pattern 103 are made of copper foil. In addition, there are a plurality of first connecting terminals 1021 that penetrate the first base layer 101 and electrically connect the first conductive pattern 102 and the second conductive pattern 103 on both sides of the first base layer 101. The first connecting terminal 1021 is usually a pad and should generally be understood as a part of the conductive pattern. In addition, the first connecting terminal 1021 also acts as a connecting terminal connected to the conductive pattern (connecting terminal) of the rigid circuit board 20 described later. The through hole on the first base layer 101 for forming the first connecting terminal 1021 can be formed before forming the first conductive pattern 102 and the second conductive pattern 103. For example, a through hole penetrating the first base layer 101 is formed by a mechanical drilling process, and a conductive material is deposited in the through hole, and then a plugging material is filled in the through hole to finally form the first connecting terminal 1021.

[0102] In this embodiment, for simplicity, only two first conductive patterns 102, two second conductive patterns 103, and two first connecting terminals 1021 are schematically shown in the cross-sectional view, and detailed patterns of the first conductive pattern 102, the second conductive pattern 103, and the first connecting terminal 1021 are not drawn. Those skilled in the art can understand that in order to realize the functions of the circuit board, according to actual needs, complex conductive patterns and more connecting terminals are actually provided on the circuit board, and these conductive patterns and more connecting terminals have shapes that are electrically connected to each other when viewed from above.

[0103] In addition, in this embodiment, if Figure 1As shown by the dotted line in , the flexible circuit board 10 is roughly divided into a hard-soft bonding area S1 and a soft area S2. Specifically, the hard-soft bonding area S1 is the area of ​​the flexible circuit board 10 that is bonded to the hard circuit board 20 described later, that is, the hard-soft bonding area S1 is the area of ​​the flexible circuit board 10 that is covered by the hard circuit board 20 described later. In the final hard-soft bonding circuit board 1, this area is an area where the flexible circuit board 10 and the hard circuit board 20 coexist, so it is called the hard-soft bonding area S1. On the other hand, the soft area S2 is the area of ​​the flexible circuit board 10 that is not bonded to the hard circuit board 20 described later, that is, the soft area S2 is the area of ​​the flexible circuit board 10 that is not covered by the hard circuit board 20 described later. In the final hard-soft bonding circuit board 1, this area is composed only of the flexible circuit board 10, so it is called the soft area S2. The hard-soft boundary line Bo is the boundary line that divides the hard-soft bonding area S1 and the soft area S2. In addition, for the convenience of illustration, Figure 1 Only one hard-soft combination region S1 and one soft region S2 are shown, but in practice, more than one hard-soft combination region S1 and / or more than one soft region S2 may be provided as needed.

[0104] The first cover film 104 covers the entire soft region S2 in the first base layer 101 and a partial region of the hard-soft combination region S1 in the first base layer 101 from the first surface 1011 side of the first base layer 101. Specifically, in the soft region S2, the first cover film 104 completely covers the first base layer 101, thereby completely covering the first conductive pattern 102 and the portion of the first connection terminal 1021 exposed from the first conductive pattern side. On the other hand, in the hard-soft combination region S1, the first cover film 104 only covers a partial region of the first base layer 101, and the remaining region is not covered (i.e., the missing region described later).

[0105] More specifically, in one embodiment, in the hard-soft bonding area S1, the first covering film 104 only covers the edge area of ​​the first base layer 101, but does not cover the central area of ​​the first base layer 101. Since the flexible circuit board 10 is configured in a rectangular shape, the first covering film 104 covers the flexible circuit board 10 in the hard-soft bonding area S1 in a rectangular ring shape, that is, it covers the periphery of the flexible circuit board 10. This structure can be achieved by directly forming the first covering film 104 of the desired shape through a mask, or by first forming a whole covering film to cover the entire area of ​​the flexible circuit board, and then removing the portion of the covering film that does not need to cover the flexible circuit board 10 through selective etching or hollowing. In this embodiment, the first covering film 104 is a solder mask layer, which can be made by screen printing solder mask ink or directly bonding a solder mask sheet. In this case, it is preferred to directly cover the first covering film 104 of the desired shape. That is, the first cover film 104 to be formed is directly formed by screen printing a solder resist ink using a mask, or a solder resist sheet to be formed is prepared in advance and bonded to form the first cover film 104 .

[0106] The portion of the hard-soft bonding region S1 of the flexible circuit board 10 that is not covered by the first cover film 104 is referred to as the missing region S3, and the portion of the hard-soft bonding region S1 of the flexible circuit board 10 that is covered by the first cover film 104 is referred to as the covered region S4. Therefore, the missing region S3+covered region S4=hard-soft bonding region S1. When bonding with the hard circuit board 20 described later, the covered region S4 is the region bonded with the hard circuit board 20. On the other hand, in the missing region S3, a cavity having a thickness equal to the thickness of the first cover film 104 is formed between the hard circuit board 20 and the flexible circuit board 10, and the first conductive pattern 102 and the first connection terminal 1021 are exposed in the cavity.

[0107] In addition, on the second surface 1012 of the first base layer 101, that is, on the side of the second conductive pattern 103, a second covering film 105 is formed to cover the entire second surface 1012 of the first base layer 101. The second covering film 105 is made of the same material as the first covering film 104, for example, by screen printing solder resist ink or directly bonding a solder resist film sheet. As a result, the second conductive pattern 103 formed on the second surface 1012 of the first base layer 101 and the portion of the first connecting terminal exposed from the second surface 1012 of the first base layer 101 are completely covered by the second covering film 105. In this embodiment, the second covering film 105 covers the entire area of ​​the first base layer 101. However, the second covering film 105 may also include a covering area and a missing area in the hard-soft combination area S1, as the first covering film 104 does.

[0108] Reference Figure 2In the manufacturing process of the flexible circuit board 10, a first waste area Sr is also provided (in Figure 1 The waste area Sr is omitted in the cross-sectional view. Figure 2 In the figure, the waste area Sr is the portion between the dotted frame and the solid frame. The waste area Sr is used for clamping and fixing the flexible circuit board during the manufacturing process. In the final product, the waste area Sr will be cut off. In the manufacturing process of the flexible circuit board 10, the first covering film 104 is also provided in the waste area Sr, and in the final product, the first covering film 104 in the waste area Sr is also cut off.

[0109] In addition, in order to ensure the rigidity of the flexible circuit board 10 and improve the yield rate during the production process of the flexible circuit board 10, a first reinforcing plate 106 is provided on the side of the second cover film 105 away from the first base layer 101. Figure 1 In the figure, only two first reinforcing plates 106 are shown, but more first reinforcing plates 106 can be provided as needed, or only one first reinforcing plate 106 can be provided. The material of the first reinforcing plate 106 can be PI, glass fiber laminated cloth or metal such as copper. The first reinforcing plate 106 can be attached to the side of the second cover film 105 away from the first base layer 101 by a film or glue. In the case where the rigidity of the flexible circuit board 10 can be ensured, the first reinforcing plate 106 can also be not provided.

[0110] In this embodiment, from the perspective of avoiding breakage of the flexible circuit board 10 during processing, two first reinforcing sheets 106 are provided, namely, they are provided in the parts corresponding to the soft-hard combination area S1 and the soft area S2, respectively, and there is a gap between the two first reinforcing sheets 106, but the first reinforcing sheet 106 can also be provided as a continuous one.

[0111] In addition, a plurality of first positioning holes 107 are also provided in the flexible circuit board 10, and the plurality of first positioning holes 107 are provided through the first base layer 101, the second cover film 105, and the first reinforcing plate 106. The plurality of first positioning holes 107 function as positioning holes and fixing holes in the manufacturing process of the flexible circuit board 10. In the present embodiment, the plurality of first positioning holes 107 of the flexible circuit board 10, and the through holes for accommodating the plurality of first connecting terminals are all circular, and can be manufactured by mechanical drilling or laser drilling. In addition, the plurality of first positioning holes 107 may not be provided, and the flexible circuit board 10 may be processed by corner pressing and positioning.

[0112] (Rigid circuit board)

[0113] Next, refer to Figure 3 A rigid wiring board 20 according to an embodiment of the present invention will be described. Figure 3 It is a cross-sectional view of rigid wiring board 20 according to the present embodiment.

[0114] like Figure 3 As shown, the rigid circuit board 20 is a rigid circuit board provided with a conductive pattern, and is composed of a second base layer 201, a third conductive pattern 202, a fourth conductive pattern 203, a third cover film 204, and a plurality of second connection terminals 2021. In a common example, the rigid circuit board 20 is configured in a rectangular shape. The rigid circuit board can be a circuit board with a conductive pattern provided on one side, a circuit board with conductive patterns provided on both sides, or a multilayer circuit board with more than two layers of conductive patterns. That is, the rigid circuit board 20 can have more layers, including multiple layers of base layers and conductive pattern layers arranged alternately. In this embodiment, for the sake of convenience of explanation, a rigid circuit board with conductive patterns provided on both sides is shown. That is, in this embodiment, a single-layer structure of a second base layer 201 and a third conductive pattern 202 and a fourth conductive pattern 203 respectively arranged on both sides of the second base layer 201 is shown.

[0115] The second base layer 201 is a hard material. Any hard material, such as a resin material, can be used as the second base layer 201. For example, the material of the second base layer 201 can be selected from epoxy resin, fiberglass cloth, etc. The second base layer 201 includes a third surface 2011 and a fourth surface 2012 located on the opposite side of the third surface 2011. The third surface 2011 is used to set the third conductive pattern 202 described later, and the fourth surface 2012 is used to set the fourth conductive pattern 203 described later. In addition, the fourth surface 2012 side of the second base layer 201 is the bonding side with the aforementioned flexible circuit board 10.

[0116] The third conductive pattern 202 and the fourth conductive pattern 203 are formed on the third surface 2011 and the fourth surface 2012 of the second base layer 201, respectively. The third conductive pattern 202 and the fourth conductive pattern 203 can be made by attaching a metal material to the second base layer 201 and then selectively etching using a mask. As a typical example, the third conductive pattern 202 and the fourth conductive pattern 203 are made of copper foil. In addition, there are a plurality of second connecting terminals 2021 that penetrate the second base layer 201 and electrically connect the third conductive pattern 202 and the fourth conductive pattern 203 on both sides of the second base layer 201. The second connecting terminal 2021 is usually a pad and should generally be understood as a part of the conductive pattern. In addition, the second connecting terminal 2021 also acts as a connecting terminal connected to the conductive pattern (connecting terminal) of the aforementioned flexible circuit board 10.

[0117] In this embodiment, for simplicity, Figure 3The cross-sectional view of the rigid circuit board 20 schematically shows only one third conductive pattern 202, one second conductive pattern 203, and two second connection terminals 2021, without drawing the detailed patterns of the third conductive pattern 202, the fourth conductive pattern 203, and the second connection terminals 2021. Those skilled in the art can understand that in order to realize the function of the circuit board, according to actual needs, complex conductive patterns and more connection terminals are actually provided on the circuit board, and these conductive patterns and more connection terminals have a shape of being electrically connected to each other when viewed from above.

[0118] In the rigid circuit board 20, the third conductive pattern 202 and the fourth conductive pattern 203 are electrically connected to each other through a plurality of second connection terminals 2021. As in the case of the flexible circuit board 10, the through holes on the second base layer 201 for forming the second connection terminals 2021 can be formed before forming the third conductive pattern 202 and the fourth conductive pattern 203, for example, by using a mechanical drilling process to form a through hole penetrating the second base layer 201, depositing a conductive material in the through hole, and then filling the through hole with a plugging material, and finally forming the second connection terminal 2021.

[0119] The third cover film 204 is provided on the first surface 2011 side of the second base layer 201, that is, on the side where the third conductive pattern 202 is formed. In this embodiment, the third cover film 204 covers the entire surface of the second base layer, thereby covering the third conductive pattern and the plurality of second connection terminals 2021.

[0120] In addition, although not shown, a waste area is also provided during the manufacturing process of the rigid circuit board 20. The waste area is used for clamping and fixing the rigid circuit board during the manufacturing process. In the final product, the waste area will be cut off.

[0121] In addition, similar to the case of the flexible circuit board 10, a plurality of positioning holes may also be provided in the rigid circuit board, and the plurality of positioning holes function as positioning holes and fixing holes in the manufacturing process of the rigid circuit board. Figure 3 In addition, similar to the case of the flexible circuit board 10, the plurality of positioning holes may not be provided, but the rigid circuit board may be processed by pressing and positioning the edges and corners.

[0122] (Assembly of flexible and rigid circuit boards)

[0123] Next, refer to Figure 4 and Figure 5 The rigid-flexible combined circuit board 1 formed by laminating the flexible circuit board 10 and the rigid circuit board 20 is described. Figure 4It is a top view schematically showing the covered area and the missing area of ​​the first cover film 104 of the flexible circuit board 10 in the rigid-flex circuit board 1 , and is a schematic diagram showing the panel assembly during the manufacturing process of the flexible circuit board 10 . Figure 5 It is a cross-sectional view of the rigid-flexible circuit board 1.

[0124] Figure 4 FIG. 2 shows a top view of a panel assembly during batch production of a flexible circuit board 10. Figure 4 As shown, taking a flexible circuit board 10 in the upper left corner as an example, the flexible circuit board 10 includes a soft area in the upper half and a hard-soft combination area in the lower half. Among them, the first covering film 104 covers the entire soft area (S2) and a part of the hard-soft combination area (S1). In this embodiment, "covering a part of the hard-soft combination area" means covering the edge of the hard-soft combination area and forming a ring (covering area S4). In the center of the hard-soft combination area, the first covering film 104 is missing (missing area S3). That is, the ring-shaped covering area S4 surrounds the missing area S3. However, the missing area S3 is not limited to the case where the central area in the hard-soft combination area is completely missing as shown in the figure, and the covering area S4 surrounds the missing area S3 in a ring shape. The missing area S3 can also be other shapes. For example, the covering area S4 and the missing area S3 can also be arranged alternately in stripes, checkerboards, or multiple circular rings like targets.

[0125] like Figure 5 As shown, the rigid circuit board 20 is bonded to the rigid-flexible bonding area S1 of the flexible circuit board 10. Before bonding, a conductive protrusion 205 is formed in advance on the side (the fourth surface 2012 side) of the plurality of second connection terminals 2021 of the rigid circuit board 20 that is bonded to the flexible circuit board 10. The conductive protrusion 205 can be formed by coating a conductive paste on the second connection terminal 2021 and curing it. Specifically, the conductive paste can be filled onto the surface of the second connection terminal 2021 by screen printing, and the conductive protrusion 205 is formed after the conductive paste is cured.

[0126] In addition, the bonding of the flexible circuit board 10 and the rigid circuit board 20 is performed by the film 301. Specifically, the film 301 is attached to the first cover film 104 (covering area S4) in the rigid-flexible bonding area S1 of the flexible circuit board 10. That is, the film is applied only to the area of ​​the first cover film 104 of the flexible circuit board 10 corresponding to the rigid circuit board 20, and since the first cover film 104 is provided with a hollow area S3, the film is not applied to the hollow area S3. Figure 4 In the figure, the film is shown with pure black shading.

[0127] from Figure 4It can be seen that in this embodiment, a cavity is formed in the hollowed-out area S3 after the flexible circuit board 10 and the rigid circuit board 20 are bonded together. In the cavity, except for the connection between the first connection terminal 1021 of the flexible circuit board 10 and the second connection terminal 2021 of the rigid circuit board 20 (via the conductive protrusion 205), the rest of the cavity is hollowed out, and the fourth surface 2012 of the second base layer 201 of the rigid circuit board 20, the fourth conductive pattern 203, and the first surface 1011 of the first base layer 101 of the flexible circuit board 10, the first conductive pattern 102, etc., are directly exposed in the cavity.

[0128] (Comparison between the present invention and the prior art)

[0129] The following reference Figure 6-Figure 8 The comparison between the present invention and the prior art is described. Figure 6 Comparative Example 1 shows a case where the first covering film is not provided in the hard-soft bonding area S1 of the hard-soft bonding circuit board 1 (that is, there is neither the covering area S4 nor the missing area S3). Figure 7 Comparative Example 2 shows a case where the first covering film is completely provided in the hard-soft bonding area S1 of the hard-soft bonding circuit board 1 (ie, there is no missing area S3). Figure 8 The diagram shows a technical defect when the first cover film is not provided in the rigid-flexible bonding region S1 of the rigid-flexible bonding wiring board 1 .

[0130] like Figure 6 As shown, the first cover film 104' of the flexible circuit board 10 covers the entire flexible area S2, but does not substantially cover the soft-hard combination area S1. Figure 6 As shown by the circle in , at the junction of the soft area S2 and the hard-soft combination area S1 of the flexible circuit board 10, the first cover film 104' partially extends to the hard-soft combination area S1. This is because the cover film plays a role in protecting the conductive patterns on the flexible circuit board 10 and the hard-soft combination area S1. Therefore, if the first cover film 104' is set just at the junction of the soft area S2 and the hard-soft combination area S1, that is, the hard-soft boundary line Bo during manufacturing, a small gap or insufficient coverage may appear at the junction, resulting in an increase in the defective rate of the product. Therefore, the first cover film 104' must be extended to the hard-soft combination area S1 in a small amount to ensure the sealing of the junction of the soft area S2 and the hard-soft combination area S1 and the protection of the conductive patterns.

[0131] Next, a film 301 is attached to the bottom of the rigid circuit board 20, which is the fourth surface 2012 side of the second base layer 201 of the rigid circuit board 20 in this embodiment, and the rigid circuit board 20 and the flexible circuit board 10 are combined by pressing, thereby forming a rigid-flexible combined circuit board 1. Here, the film 301 is semi-fluid before being completely solidified, and becomes solid after solidification.

[0132] However, if Figure 8 As shown, since there is only a portion of the first covering film 104' at the junction of the soft area S2 and the hard-soft combination area S1 of the flexible circuit board 10, and there is no first covering film 104' in other parts of the hard-soft combination area S1, the flexible circuit board 10 and the rigid circuit board 20 will be warped. As a result, there will be a slight deviation between the center line of the camera module installed on the rigid circuit board 20 and the normal direction of the hard-soft combination board 1. The slight deviation between the center line of the camera module and the normal direction of the hard-soft combination board 1 will cause the deviation of the imaging focus and focal length, which will have an adverse effect on the imaging quality. Although the image can be corrected by software algorithms at a later stage, it will bring a lot of software development costs, and the degree of warping of the hard-soft combination circuit boards of each batch and each monomer is difficult to predict, and it is very difficult to correct it by software algorithms.

[0133] Here, we can consider Figure 7 As shown, in order to overcome the warping problem of the rigid-flexible board 1, a first covering film 104" is completely provided in the rigid-flexible bonding area S1 of the flexible circuit board 10 of the rigid-flexible bonding circuit board 1. In other words, the first covering film 104" does not only cover the junction between the flexible area S2 and the rigid-flexible bonding area S1 of the flexible circuit board 10, but completely covers the rigid-flexible bonding area S1 of the flexible circuit board 10.

[0134] In this case, the center line of the camera module mounted on the rigid circuit board 20 and the normal direction of the rigid-flex board 1 can be ensured to be consistent during manufacturing. However, since the flexible board 1 becomes a heating element after being powered on, the first covering film 104" that completely covers the rigid-flex area S1 may expand and deform to a certain extent after being heated. The position and size of the expansion deformation are difficult to predict. The resulting imaging focus deviation and imaging focal length deviation become important causes of product defects as temperature drift, i.e., temperature drift.

[0135] In contrast, in the present invention, since the first cover film 104 is partially missing in the hard-soft bonding area S1 of the flexible circuit board 10, the flexible circuit board 10 and the hard-soft bonding board 20 are substantially at least partially spaced apart, so that the temperature drift caused by the thermal expansion of the first cover film 104 can be avoided. On the other hand, since the first cover film 104 is only partially missing, but the first cover film 104 is provided in most of the hard-soft bonding area S1, especially the periphery of the hard-soft bonding area S1, and the hard-soft bonding area S1 is not almost covered as in Comparative Example 1, the hard-soft bonding circuit board 1 will not be warped during manufacturing, and the center line of the camera module mounted on the hard-soft bonding board 20 and the normal direction of the hard-soft bonding board 1 can be ensured to be consistent.

[0136] In addition, as mentioned above, the missing area S3 is not limited to the case where the central area of ​​the soft-hard combination area is completely missing as shown in the figure, and the covering area S4 surrounds the missing area S3 in a ring shape. The missing area S3 can also be in other shapes. For example, the covering area S4 and the missing area S3 can be arranged alternately in stripes, checkerboards, or multiple circular rings like a target. The more the area of ​​the missing area S3 accounts for the area of ​​the soft-hard combination area S1, the more it can avoid the temperature drift caused by the thermal expansion of the first covering film 104 of the flexible circuit board 10. In contrast, the less the area of ​​the missing area S3 accounts for the area of ​​the soft-hard combination area S1, the more it can improve the rigidity of the soft-hard combination board. Therefore, the shape, area, etc. of the missing area S3 can be selected according to actual conditions. In the technical field of the vehicle-mounted camera module, due to the limited weight of the camera module, the missing area S3 can be configured as a form in which the central area of ​​the soft-hard combination area is completely missing and the covering area S4 surrounds the missing area S3 in a ring shape. Of course, from the perspective of improving durability, the area of ​​the missing region S3 can be appropriately reduced, or the covering region S4 and the missing region S3 can be arranged alternately in stripes, a checkerboard, or multiple circular shapes like a target.

[0137] In addition, in the present invention, the flexible circuit board 10 and the rigid circuit board 20 are manufactured separately (simultaneously), and then the flexible circuit board 10 and the rigid circuit board 20 are bonded together by the film 301 to manufacture the rigid-flexible circuit board 1. Therefore, compared with the conventional method of first manufacturing the flexible circuit board and then bonding the various layers of the rigid circuit board on the flexible circuit board layer by layer, the manufacturing efficiency of the rigid-flexible circuit board can be greatly improved.

[0138] This is because, in the previous method of manufacturing a rigid-flexible circuit board, for example, Figure 7As shown in the comparative example 2, since the film 301 completely covers the entire soft-hard combination area S1 of the flexible circuit board 10, that is, every part of the rigid circuit board 20 is bonded to the flexible circuit board 10. In this case, the flexible circuit board 10 and the rigid circuit board 20 must be completely compacted during bonding. If there are uncompacted parts, it is more likely to cause warping and temperature drift. However, a large force is required during the compaction process, which may cause damage to the soft-hard combination circuit board 1. In order to avoid damage to the soft-hard combination circuit board 1, the only way is to first make the flexible circuit board, and then bond the layers of materials of the rigid circuit board layer by layer on the flexible circuit board, which has low production efficiency.

[0139] However, in the present invention, since the first cover film 104 and / or the second cover film 105 of the flexible circuit board 10 is partially missing in the hard-soft bonding area S1, in particular, when the first cover film 104 is provided only at the periphery of the hard-soft bonding area S1 (see Figure 4 ), there is no need to consider the compaction of the missing area S2, and the conductive patterns of the flexible circuit board 10 and the rigid circuit board 20 in the missing area S2 are in an airtight state, so it is allowed to attach the rigid circuit board 20 and the flexible circuit board 10 with a greater force through the film 301. In this way, the flexible circuit board 10 and the rigid circuit board 20 can be manufactured separately (simultaneously), which greatly improves the manufacturing efficiency of the rigid-flexible circuit board 1.

[0140] (Method for manufacturing a rigid-flexible circuit board)

[0141] Next, refer to Fig. 9 The flowchart of the present invention illustrates the method for manufacturing the rigid-flexible circuit board 1.

[0142] First, in step S1, a conductive pattern of the flexible circuit board 10 is prepared. Copper foils are attached to the first surface 1011 and the second surface 1012 of the first base layer 101 composed of a flexible resin, respectively, and the copper foils are selectively etched to form the first conductive pattern 102 and the second conductive pattern 103, and a pattern for forming the first connection terminal 1021, respectively, on the first surface 1011 and the second surface 1012 of the first base layer 101.

[0143] Next, a through hole penetrating the first base layer 101 is formed at a pattern for forming the first connection terminal 1021 by a mechanical drilling process, and a conductive material is deposited in the through hole by electroplating, thereby forming the first connection terminal 1021 .

[0144] Next, in step S2, a cover film of the flexible circuit board 10 is formed. On the first surface 1011 side of the first base layer 101, a first cover film 104 is formed to cover the first surface 1011 of the first base layer 101, the first conductive pattern 102, and the first connection terminal 1021. The first cover film 104 can be formed into a cover film of a predetermined shape by screen printing solder resist ink through a mask in advance. It is also possible to selectively remove the excess portion through a mask after forming a cover film covering the entire first base layer 101. Thus, the first cover film 104 partially covering the first base layer 101 is formed. In particular, a cover film of a predetermined shape is formed through a mask, or a cover film that covers the entire first base layer 101 is formed and then the excess portion is removed, and finally the first cover film 104 in which the cover film is partially missing in the hard-soft combination area S1 of the flexible circuit board 10 is formed.

[0145] On the other hand, the second cover film 105 is formed on the second surface 1012 side of the first base layer 101. The second cover film 105 covers the second surface 1012 of the first base layer 101, the second conductive pattern 103, and the first connection terminal 1021. In addition, the second cover film 105 may be a cover film that covers the entire second surface 1012 of the first base layer 101, or may be a cover film that is formed into a predetermined shape by masking like the first cover film 104, or may be a cover film that covers the entire first base layer 101 and then removes the excess portion, thereby finally forming the second cover film 105 that is partially missing in the rigid-flexible bonding area S1 of the flexible circuit board 10. In other words, the first cover film 104 may be partially missing in the rigid-flexible bonding area S1, or both the first cover film 104 and the second cover film 105 may be partially missing in the rigid-flexible bonding area S1.

[0146] Next, in step S3 , the first reinforcing plate 106 of the flexible wiring board 10 is formed. The first reinforcing plate is bonded to the side of the second cover film 104 that is away from the first base layer 101 .

[0147] Next, in step S4 , the waste area of ​​the flexible circuit board 10 is removed.

[0148] Next, in step S5, a rigid circuit board 20 is formed. Copper foils are attached to the third surface 2011 and the fourth surface 2012 of the second base layer 201 composed of a rigid resin, respectively, and the third conductive pattern 202 and the fourth conductive pattern 203, as well as a pattern for forming the second connection terminal 2021, are formed on the third surface 2011 and the fourth surface 2012 of the third base layer 201 by selectively etching the copper foils.

[0149] Furthermore, the third cover film 204 is attached to the third surface 2011 of the second base layer 201. Thus, the rigid wiring board 20 is formed.

[0150] Next, in step S6, a film 301 having a shape corresponding to the shape of the first covering film 104 in the hard-soft bonding area S1 is attached to the side of the first covering film 104 in the hard-soft bonding area S1 of the flexible circuit board 10 away from the first base layer 101, and then the fourth surface 2012 side of the second base layer 201 of the rigid circuit board 20 is attached to the film 301.

[0151] Next, in step S7 , the rigid-flexible circuit board 1 is compacted and flattened through a pressing process, thereby completing the rigid-flexible circuit board 1 .

[0152] (Assembly of lens module)

[0153] The following reference Fig.10 The following describes the assembly of the soft-hard circuit board 1 and the lens module. Fig. 9 As shown, the lens holder of the lens module is installed on the hard-soft circuit board 1. The lens holder of the lens module can be assembled on the hard-soft circuit board 1 by bonding. Therefore, through the present invention, the warping deformation of the hard-soft circuit board 1 can be avoided, thereby ensuring the stability of the posture of the lens holder (lens module) and effectively avoiding temperature drift.

[0154] It should be understood that the specific embodiments described above are only used to explain the present invention, and the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make changes, substitutions, and combinations according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A rigid-flexible circuit board for a camera module, which is formed by bonding at least one flexible circuit board and at least one rigid circuit board, characterized in that: The flexible circuit board and the rigid circuit board each have a conductive pattern. The hard-soft combined circuit board includes a hard-soft combined area and a soft area, wherein the hard-soft combined area is an area having both the soft circuit board and the hard circuit board, and the soft area is an area having only the soft circuit board. The boundary between the hard-soft combined area and the soft area is a hard-soft boundary. A cover film for protecting the conductive pattern is attached to the flexible circuit board and the rigid circuit board. On the flexible circuit board, the cover film covers all of the flexible area and the part of the soft-hard combination area close to the soft-hard boundary line, and the cover film is partially missing in the part of the soft-hard combination area except the part close to the soft-hard boundary line, so that a covered area and a missing area are formed in the soft-hard combination area. Thus, in the missing area of ​​the hard-flex combination area, a cavity having a thickness equal to that of the cover film is formed between the hard circuit board and the flexible circuit board.

2. The rigid-flexible circuit board for the camera module according to claim 1, The rigid-flexible circuit board is formed by bonding the flexible circuit board and the rigid circuit board which are manufactured separately.

3. The rigid-flexible circuit board for the camera module according to claim 1 or 2, The flexible circuit board has: A first substrate layer having a first surface and a second surface opposite to each other; a first conductive pattern disposed on the first surface of the first base layer; a second conductive pattern disposed on the second surface of the first base layer; a plurality of first connection terminals, which are arranged through the first base layer and are used for electrical connection between the first conductive pattern and the second conductive pattern, and between the flexible circuit board and the rigid circuit board; a first covering film disposed on the first surface of the first base layer and covering the first conductive pattern; and a second covering film provided on the second surface of the first base layer and covering the second conductive pattern; The rigid circuit board has: a second base layer having a third surface and a fourth surface opposite to each other; a third conductive pattern disposed on the third surface of the second base layer; a fourth conductive pattern disposed on the fourth surface of the second base layer; a plurality of second connection terminals, which are arranged through the second base layer and are used for electrical connection between the third conductive pattern and the fourth conductive pattern, and between the flexible circuit board and the rigid circuit board; as well as a third covering film disposed on the third surface of the second base layer and covering the third conductive pattern; The fourth surface side of the rigid circuit board and the first surface side of the flexible circuit board are bonded together to form a rigid-flexible circuit board. The flexible circuit board has a width substantially the same as that of the rigid circuit board and a length longer than that of the flexible circuit board, thereby forming a rigid-flexible combined area having both the flexible circuit board and the rigid circuit board, and at least one flexible area having only the flexible circuit board. In the hard-soft bonding region, the first cover film and / or the second cover film is partially missing, so that the cover region and the missing region are formed in the hard-soft bonding region.

4. The rigid-flexible circuit board for the camera module according to claim 1 or 2, The rigid circuit board and the flexible circuit board are bonded together by a film.

5. The rigid-flexible circuit board for the camera module according to claim 1 or 2, The coverage area is formed into a ring shape surrounding the missing area, The missing region at least completely includes the first conductive pattern, the second conductive pattern, and the first connecting terminal of the flexible circuit board, and the third conductive pattern, the fourth conductive pattern, and the second connecting terminal of the rigid circuit board.

6. The rigid-flexible circuit board for the camera module according to claim 1 or 2, The covered areas and the missing areas are configured in the form of alternating stripes, a checkerboard, or multiple rings.

7. A method for manufacturing a rigid-flexible circuit board for a camera module, wherein the rigid-flexible circuit board is formed by bonding at least one flexible circuit board and at least one rigid circuit board, and comprises a rigid-flexible region having both the flexible circuit board and the rigid circuit board, and at least one flexible region having only the flexible circuit board, wherein the boundary between the rigid-flexible region and the flexible region is a rigid-flexible boundary, and the method for manufacturing the rigid-flexible circuit board is characterized in that it comprises the following steps: S1: Copper foils are attached to the first surface and the second surface of the first base layer composed of a flexible resin, respectively, and a first conductive pattern and a second conductive pattern and a pattern for forming a first connecting terminal are formed on the first surface and the second surface of the first base layer respectively by selectively etching the copper foils, and a through hole penetrating the first base layer is formed at the pattern for forming the first connecting terminal by a mechanical drilling process, and a conductive material is deposited in the through hole to form the first connecting terminal; S2: On the first surface side of the first base layer, a first covering film covering the first surface of the first base layer, the first conductive pattern and the first connecting terminal, and a second covering film covering the second surface of the first base layer, the second conductive pattern and the first connecting terminal are formed, and the first covering film and / or the second covering film have a partially missing shape corresponding to the portion of the rigid circuit board except the portion close to the hard-soft boundary line, thereby forming a covering area and a missing area, thereby forming a cavity with a thickness equal to the thickness of the covering film between the rigid circuit board and the flexible circuit board in the missing area of ​​the hard-soft combination area; S3: attaching a first reinforcing plate to a side of the second cover film away from the first base layer; S4: removing the waste area of ​​the flexible circuit board; S5: attaching copper foils to the third surface and the fourth surface of the second base layer composed of a hard resin, respectively, and forming a third conductive pattern and a fourth conductive pattern and a pattern for forming a second connection terminal on the third surface and the fourth surface of the second base layer, respectively, by selectively etching the copper foils; Furthermore, a third cover film is attached to the third surface of the second base layer to form the rigid circuit board; S6: attaching a film having a shape corresponding to the shape of the first cover film in the hard-soft combination area S1 to the side of the first cover film in the hard-soft combination area of ​​the flexible circuit board away from the first base layer, and then attaching the fourth surface side of the second base layer of the rigid circuit board to the film; S7: The rigid-flexible circuit board is compacted and flattened through a pressing process, thereby completing the rigid-flexible circuit board.

8. A camera module, characterized in that: have: A lens barrel, used to accommodate multiple lens groups; A lens base, used for supporting the lens barrel; and The rigid-flexible circuit board according to any one of claims 1 to 6, The mirror holder is attached to the hard-flexible circuit board by a bonding process and has hard-flexible areas of the soft circuit board and the hard circuit board.

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