Camera module and method for manufacturing the camera module

Abstract

The present invention consists of at least one wiring board (2), at least one image sensor (7), at least one camera housing (4), and a lens module (5). A single support plate (3) is arranged between the wiring board (2) and the camera housing (4). The support plate (3) is fixedly connected to the wiring board (2), and the support plate (3) and the wiring board (2) together form an electronic module, which is a camera module (1). The support plate (3) is connected to the camera housing (4) by a material bonding process in the positioning process of the image sensor (7) and the optical axis (O) and / or the image plane of the lens module (5). A correction gap (6) is provided around the entire circumference between the support plate (3) and the housing (4), and material bonding (8) is formed at the four corners of the camera housing (4). The present invention relates to a camera module characterized by this.

Description

Technical Field

[0001] The present invention relates to a camera module and a method for manufacturing the camera module.

Background Art

[0002] As a conventional technique, for example, a camera having a support means is known from Document WO2016112890A1. The support means is disposed between an image sensor and a printed circuit board, and is at least partially surrounded by an outer wall of a camera housing.

[0003] From Document WO2011120480A1, optical means including an optical module, a wiring board, an image capturing element, and a support plate are known. An optical module and an image capturing element are disposed on one side of the support plate, and a wiring board is disposed on the opposite side. Further, from Document WO2011120481A1, optical means including a lens holder are known. The optical module and the lens holder are provided with connection surfaces for forming an adhesive connection surrounding the optical axis of the optical means in the radial direction.

[0004] In addition, from Document DE102017124550A1, a camera for a motor vehicle including a housing, a wiring board on which an image sensor of the camera is disposed, and at least two support elements connected to the first wiring board and the housing is known. The first wiring board is supported at a distance from the housing by the two support elements and is electrically connected to the housing. The housing has a front housing portion and a rear housing portion. The front housing portion and the rear housing portion are electrically connected to each other, and the front housing portion and the rear housing portion are connected to each other by a welding connection.

[0005] The problems in these conventional techniques are the optical stability and tolerance accuracy of an image sensor (bare die, BGA, CSP structure) with respect to the optical and mechanical axes of an optical module of the camera or a camera housing.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0007] Therefore, an object of the present invention is to provide a camera module and a manufacturing method thereof, the camera module having an improved tolerance system and optical stability.

[0008] The above object is achieved by independent claims 1 and 6.

[0009] Further preferred forms are the subject of the dependent claims.

[0010] First, in a conventional camera module, since the image sensor needs to be appropriately arranged with respect to the optical axis, in many cases, it was considered that it is composed of a plurality of substrates stacked perpendicular to the optical axis. The alignment of the image sensor with respect to the focal position of the lens is performed by a 5-axis or 6-axis alignment process. Due to the variability caused by the tolerance of the focal position, the integration of the camera on the OEM side becomes difficult. As a result, the component costs are high in both the OEM and the sensor manufacturer.

[0011] The front and back of the electronic module have through-holes for the lens (front) and the plug (rear), so they are not useful for direct thermal connection. Therefore, direct heat dissipation from the processor IC, the outer surface of the module, etc. is difficult because the wiring board and the IC are often arranged in parallel with the image sensor. As a result, heat accumulates in the camera housing, the image sensor becomes thicker, and accordingly, noise increases and image quality deteriorates.

[0012] Therefore, in the present invention, there is proposed a camera module comprising at least one wiring board, at least one image sensor, at least one camera housing, and a lens module, wherein a single support plate is arranged between the wiring board and the camera housing, the support plate is fixedly connected to the wiring board, and the support plate forms an electronic module together with the wiring board, provided that here, the support plate is connected to the camera housing by a material bonding process in the positioning process of the image sensor and the optical axis and / or the image plane of the lens module, and a correction gap is provided all around between the support plate and the housing, and material bonding is formed at the four corners of the camera housing.

[0013] The support plate can be connected to the wiring board by a TOX joint or a punched joint at that time. The support plate can have at least two opposite edges for holding the wiring board in a fixed position on the support plate for each support means.

[0014] By adopting the support plate, an electronic module can be configured to open the possibility of introducing a new connection technology in the 5 / 6-axis adjustment process.

[0015] Similarly, the image sensor can also be arranged on the wiring board or the support plate.

[0016] The correction gap corrects irregularities and manufacturing tolerances in the positioning process, enabling more accurate alignment.

[0017] The camera module is preferably used as a satellite monocular camera or, for example, a plurality of them arranged for use in a surround view system inside a vehicle.

[0018] In a preferred embodiment, the positioning process is a five-axis or six-axis alignment between the optical axis of the image sensor and the lens module and / or the image plane.

[0019] In a further preferred embodiment, a laser welding method is used as the material joining process. Since this laser welding method is very precise, this material joining process is advantageous. Subsequently, since the thermal distortion generated here is small, it is also advantageous from the viewpoint of accurately aligning the image sensor with respect to the optical axis and / or the image plane.

[0020] In addition, at least the support plate and the camera housing are preferably made of the same material. By using the same material for the optical module (lens module + camera housing) and the electronic module (support plate + wiring board), it becomes possible to consider the adoption of joining technology here as a material joining process without incurring additional costs during the assembly of the camera (e.g., laser welding, etc.). As a result, improvement in optical stability until the end of the life cycle and improvement in the tolerance between the optical system and the camera housing are also achieved. Furthermore, a cost-optimized joining process can be used for the attachment of the lens module. This optimized electronic module enables the modularization of various image sensor technologies.

[0021] Subsequently, the image sensor is preferably arranged as a bare die, ball grid array, chip scale package or flip chip on the wiring board. By using a bare die, the image sensor provides further advantages. Due to the effect of the inner support plate, the image sensor can be thermally insulated simply by being mounted on the support plate. The support plate is designed to have a hole geometry around the image sensor. By mounting the wiring board from the back side of the support plate, the image sensor can be directly connected to the wiring board using a thin / thick wire / bonding process. Furthermore, the support plate can function as a heat dissipation and heat sink, for example, when made of metal, or as a heat insulator, for example, when made of synthetic resin. In addition, it can be miniaturized without increasing costs. Also, a short signal path has a good effect on EMC interference.

[0022] Subsequently, the present invention also relates to a method for manufacturing a camera module composed of a wiring board, an image sensor, a camera housing and a lens module, wherein a support plate is arranged between the wiring board and the camera housing. Here, however, the following steps are proposed: - Providing a wiring board and a support plate; - Connecting the image sensor to the wiring board or the support plate, and further connecting the wiring board to the support plate to form an electronic module; - Providing a camera housing with a lens module; - Aligning the image sensor with the optical axis and / or the image plane of the lens module in a positioning step; - Connecting the support plate to the four corners of the camera housing by a material joining process, provided that a correction gap (6) is provided all around between the support plate and the camera housing (4).

[0023] In a preferred embodiment of this method, the material joining process is a laser welding method.

[0024] Preferably, the positioning step is a five-axis or six-axis alignment between the optical axis of the image sensor and the lens module and / or the image plane.

[0025] In some other preferred embodiments, the thermal and / or electrical connection between the camera housing and the support plate is generated by a material joining process.

[0026] Further preferred forms and embodiments are the subject of the drawings.

Brief Description of the Drawings

[0027]

Figure 1

Figure 2a

Figure 2b

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0028] FIG. 1 shows a schematic depiction of a camera module according to an embodiment of the present invention. The camera module 1 is composed of a wiring board 2, a support plate 3, a camera housing 4, and a lens module 5. The support plate 3 is disposed between the wiring board 2 and the camera housing 4. The support plate 3 has support elements 3a that hold at least two wiring boards 2 in a fixed position when connecting the support plate 3 to the wiring board 2 on the side facing the wiring board 2. Subsequently, a correction gap 6 is provided all around between the support plate 3 and the camera housing 4.

[0029] Figure 2a shows a cross-sectional view of a camera module according to an embodiment of the present invention. The cross-sectional view A-A of the camera module 1 in FIG. 1 shows a wiring board 2, a support plate 3, a housing 4, a lens module 5, and a material joint 8. The material joint 8 is preferably formed at the corner of the camera housing 4 to the support plate 3 between the support plate 3 and the camera housing 4. Subsequently, an image sensor 7 facing the lens module 5 is shown on the side of the printed circuit board 2. The image sensor 7 is aligned with the optical axis O and / or the image plane of the lens module 5 during the positioning process or the 5 / 6-axis alignment. However, it is also conceivable to arrange the image sensor 7 on the side of the support plate 3 facing the lens module 5 and arrange the wiring board on the side of the support plate 3 opposite to the lens module 5. In this case, the image sensor 7 is connected to the wiring board via wire bonding.

[0030] Figure 2b shows a cross-sectional view of a camera module according to an embodiment of the present invention and an enlarged view of a part thereof. In the partial enlarged view B, in particular, the material joint 8, which is a welding seam of, for example, a laser welding method, and the correction gap 6 can be recognized more clearly. All other elements are essentially the same as in FIG. 2a. The material joint 8 is formed between the support plate 3 and the camera housing 4 as shown in the figure, and covers the correction gap 6 at least at the connection part, preferably at the corner of the housing 4. The material joint 8 is arranged on the outer side of the support plate and the upper side of the camera housing 4 as shown in the figure.

[0031] Figure 3 is a further cross-sectional view of a camera module according to a further embodiment of the present invention and an enlarged view of a part thereof. Also shown in the partial enlarged view C are essentially the same elements as those shown in the partial enlarged view B. In this embodiment, only the support plate 3 holds the wiring board 2 and has a support element 3a that can be used, for example, to connect the wiring board 2 and the support plate 3. Here, a material bond 8 is also formed between the support plate 3 and the camera housing 4. In this case, the material bond 8 is formed between the outer side of the support plate 3 and the outer side of the camera housing 4.

[0032] Figure 4 shows a schematic flowchart of a method according to an embodiment of the present invention. In step S1, the wiring board 2 and the support plate 3 are prepared. In step S2, at least the image sensor 7 is connected to the wiring board 2 or the support plate 3, and subsequently, the wiring board 2 and the support plate 3 are connected to form an electronic module. In step S3, a camera housing 4 provided with a lens module 5 is prepared, and subsequently, in step S4, the image sensor is aligned with the optical axis O and / or the image plane of the lens module 5 in a positioning process. In step 5, the support plate 3 is connected to the four corners of the camera housing 4 by a material bonding process, but a correction gap 6 is provided all around between the support plate 3 and the camera housing 4. Steps S1 and S2 can be carried out in parallel with step S3. Therefore, the electronic module and the optical module can be manufactured in parallel, and then the positioning can be carried out in step S4. Depending on the design of the electronic module, the image sensor can be connected to either the wiring board or the support plate. In the case of connection to the support plate, for example, the image sensor can be connected to the wiring board by wire bonding.

Description of Reference Numerals

[0033] 1 Camera module 2 Wiring board 3 Support plate 3a Support element 4 Camera housing 5 Lens module 6 Correction gap 7 Image sensor 8 Material joint Cross-sectional view A - A Partial enlarged view B Partial enlarged view C O Optical axis S1 - S5 Method steps

Claims

1. A camera module (1) comprising at least one wiring board (2), at least one image sensor (7), at least one camera housing (4), and a lens module (5), wherein a single support plate (3) is disposed between the wiring board (2) and the camera housing (4), the support plate (3) is fixedly connected to the wiring board (2), and the support plate (3) and the wiring board (2) together form an electronic module, wherein the support plate (3) is connected to the camera housing (4) by a material joining process in the process of positioning the image sensor (7) and the optical axis (O) and / or the image plane of the lens module (5), and a correction gap (6) is provided around the entire circumference between the support plate (3) and the housing (4), and material joints (8) are formed at the four corners of the camera housing (4).

2. The camera module (1) according to claim 1, wherein the positioning process is a 5-axis or 6-axis alignment between the image sensor (7) and the optical axis (O) and / or the image plane of the lens module (5).

3. The camera module (1) according to claim 1, wherein a laser welding method is used as the material joining process.

4. The camera module (1) according to claim 1, wherein at least the support plate (3) and the camera housing (4) are made of the same material.

5. The camera module (1) according to claim 1, wherein the image sensor (7) is arranged as a bare die, ball grid array, chip scale package or flip chip on the wiring board (2).

6. A method for manufacturing a camera module (1) comprising a wiring board (2), an image sensor (7), a camera housing (4) and a lens module (5), and having a support plate (3) disposed between the wiring board (2) and the camera housing (4), the method including the following steps: - Providing the wiring board (2), the support plate (3), and the image sensor (7) (step S1); - Connecting the image sensor (7) to the wiring board (2) or the support plate (2), and further connecting the wiring board (2) to the support plate (3) to form an electronic module (step S2); - providing a camera housing (4) with a lens module (5) (step S3); - in the positioning step, aligning the image sensor (7) with the optical axis (O) and / or the image plane of the lens module (5) (step S4); - connecting the support plate (3) to the four corners of the camera housing (4) by a material joining process (step S5), provided that a correction gap (6) is provided all around between the support plate (3) and the camera housing (4).

7. The method according to claim 6, characterized in that the material joining process is a laser welding method.

8. The method according to claim 6, characterized in that the positioning step is a 5-axis or 6-axis alignment between the image sensor (7) and the optical axis (O) and / or the image plane of the lens module (5).

9. The method according to claim 6, characterized in that the thermal and / or electrical connection between the camera housing (4) and the support plate (3) is generated by a material joining process.

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