Method for manufacturing camera module, camera module

Abstract

The present invention relates to a method for producing a camera module (1), wherein an objective lens (2) is oriented with respect to an image sensor (3) and is subsequently fixed in position by engaging with a carrier (4) receiving the image sensor (3), a housing (5) surrounding the image sensor (3) or a connecting structure (6) between the carrier and the housing as a mating part. According to the present invention, the objective lens (2) is supported on a spacing element (7) which is initially still movable and is oriented with respect to the image sensor (3) by the movement of the spacing element (7). After the orientation of the objective lens (2), the spacing element (7) is welded to the objective lens (2) and the mating part (4, 5, 6). The present invention also relates to a camera module (1).

Description

Technical Field

[0001] The invention relates to a method for producing a camera module having the features of the preamble of claim 1. The invention also relates to a camera module having the features of the preamble of claim 6. The camera module is preferably produced according to the method according to the invention. Background Art

[0002] Camera modules of the type mentioned at the outset are used in a variety of different applications. For example, they can be used for monitoring the environment in stationary or moving safety systems, for example in video-based driver assistance systems in vehicles. In addition, such camera modules can be used in various consumer products, for example in mobile end devices such as smartphones or tablet computers. In this context, the trend is towards modules that are as simple as possible in design and small in size.

[0003] The main components of the camera module of the type described at the beginning are an image sensor and an objective lens having at least one lens. The image sensor is usually arranged on a carrier and surrounded by a housing to protect it from external influences. Before the lens can be connected to the carrier or the housing, the lens must be actively oriented with respect to the image sensor. In order to subsequently connect the objective lens to the carrier or the housing, a bonding or welding method is usually used, because the required sealing can be produced at the same time by the bonding or welding method. However, the adhesive connection has a number of disadvantages. This includes that conventional adhesives change their material properties due to moisture swelling and / or aging, so that (depending on the environmental conditions) a stable focusing position of the objective lens can hardly be achieved during the entire service life. In addition, the usually high thermal expansion coefficient of the adhesive has proven to be disadvantageous. Therefore, a welding connection is usually better than an adhesive connection.

[0004] For example, US 2019 / 005278 A2 discloses a camera module having an objective lens, a lens holder, an image sensor and a printed circuit board. When assembling the camera module, the objective lens and the lens holder are oriented relative to each other and then permanently fixed by means of welding points. The welding points are implemented by means of a laser. In addition, it is proposed that a sealing element is arranged between the objective lens and the lens holder.

[0005] The production of a soldered connection requires no or only very small gap dimensions between the joining partners. However, a multi-axial orientation of the objective lens with respect to the image sensor can lead to relatively large gap dimensions that no longer permit a soldered connection. Summary of the invention

[0006] The present invention provides a remedy for this. In particular, after the multi-axial orientation of the objective lens with respect to the image sensor, it should be possible to fix the position by means of a welded connection, that is, independently of the gap size between the corresponding joint partners. In this way, a stable connection and a stable focus position should be achieved.

[0007] In order to achieve this object, a method is proposed having the features of claim 1 and a camera module having the features of claim 6. Advantageous embodiments of the invention are derived from the respective dependent claims.

[0008] In the proposed method for manufacturing a camera module, the objective lens is oriented with respect to the image sensor and is subsequently fixed in position by engaging with a carrier that receives the image sensor, a housing that surrounds the image sensor, or a connecting structure located therebetween as a mating partner. According to the invention, the objective lens is supported on a spacing element that is still movable at first and is oriented with respect to the image sensor by the movement of the spacing element. After the orientation of the objective lens, the spacing element is welded to the objective lens and the mating partner.

[0009] Since the spacer element is welded to the objective lens on the one hand and to the corresponding joining partner of the objective lens on the other hand, a fixed position of the spacer element and the objective lens is achieved. That is to say, the spacer element cannot move further after welding and the set focal position of the objective lens is maintained. Since the welded connection is largely insensitive to temperature and humidity, it is particularly stable, especially compared to an adhesive connection, and at the same time a particularly stable focal position of the objective lens is achieved.

[0010] Before welding, the still movable spacing element first enables a multi-axis orientation of the objective lens, preferably about three translation axes and two rotation axes, so that precise focusing of the objective lens is possible. The advantage here is that the objective lens can be moved freely to a large extent, because there is no direct contact between the objective lens and the joint partner, but only indirectly via the movable spacing element.

[0011] Preferably, when manufacturing the camera module, a spacer element having at least one abutment contour that is spherical, partially spherical, cylindrical or partially cylindrical is used. For example, a ball or a roller can be used as a spacer element. In addition, a rod that has a partially spherical or partially cylindrical contact contour only on the end side can be used as a spacer element. Through the contact contour shaped in this way, a point-shaped or line-shaped contact between the spacer element and the abutment surface constructed on the objective lens or on the corresponding engagement partner is achieved. The point-shaped or line-shaped contact enables the spacer element to roll on the abutment surface, thereby further simplifying the orientation of the objective lens with respect to the image sensor.

[0012] In addition, preferably, the spacing elements are arranged around the preferably cylindrical or conical outer contour of the objective lens with the same angular spacing from each other. Advantageously, the number of spacing elements is three, which enables maximum freedom while reliably supporting the objective lens. By rolling in the point-shaped or line-shaped contact area, the spacing element can participate in all the movements required for the orientation of the objective lens. Here, the rod-shaped spacing element changes its adjustment angle. If the outer contour of the objective lens is conically shaped, the diameter at which the point-shaped or line-shaped contact area of ​​the spacing element is located changes.

[0013] Advantageously, the spacing element is guided by a guiding geometry constituted by a carrier or by a housing. This guidance limits the motion space of the spacing element in the corresponding contact area with the carrier or housing, so that the spacing element implements controlled motion. The guiding geometry can be constructed so as to realize the lateral guidance of the spacing element in particular. For this reason, the guiding geometry preferably has two guiding surfaces extending in parallel for each spacing element, and the guiding surfaces are arranged radially substantially with respect to the objective lens. If the spacing element is abutted on the guiding surface, additional point-shaped or line-shaped contact areas are provided. Alternatively or in addition, the guiding geometry can constitute a kind of support. In this case, the guiding geometry predetermines a maximum diameter, and the point-shaped and / or line-shaped contact areas of the spacing element and the carrier or housing are located on this maximum diameter. In order to constitute a support for the spacing element, for example, the guiding geometry can have a guiding surface oriented substantially tangentially with respect to the objective lens, and the spacing element is supported on this guiding surface. In this case, the point-shaped or line-shaped contact of the spacing element with the guiding surface constituting the support is also produced.

[0014] Alternatively to the guiding geometry consisting of carrier or housing, the spacing element can also be guided by the connecting structure already mentioned, if this connecting structure is provided. The connecting structure can for example be a metal part of a carrier, or, as long as a circuit board is used as a carrier, the connecting structure is a metallization of a circuit board. The connecting structure can also be a metal frame arranged on a carrier or housing. The advantage of using a metal connecting structure is that the weldability of the connecting structure is guaranteed. In order to guide the spacing element, the connecting structure can have a parallel extension, substantially about the radially oriented sidewall of the object lens and / or substantially about the tangentially oriented wall of the object lens, which constitutes the support for the spacing element respectively.

[0015] It is further proposed that the spacing elements are guided by a common holder. Instead of or in addition to the guiding geometry or the guiding by the connecting structure, a guiding by a common holder can be provided. The guiding by a common holder has the advantage that the spacing elements are connected to each other. In order to allow the required movement of the spacing elements for the orientation of the objective lens, the holder can be made of a flexible or elastically deformable material at least partially. In addition, the holder can have at least one hinged portion in order to allow the adjustment angle of the rod-shaped placement element to be changed.

[0016] Furthermore, the camera module proposed to achieve the task mentioned at the outset comprises an objective lens and an image sensor, which is arranged on a carrier and surrounded by a housing. According to the invention, the objective lens is supported on a spacing element, which is materially connected to the objective lens on the one hand and to the carrier, the housing or a connecting structure located therebetween on the other hand.

[0017] In the proposed camera module, the objective lens is therefore not connected directly to the corresponding joining partner, but indirectly via a spacing element. The spacing element bridges the gap between the objective lens and the respective joining partner, so that a stable solder connection can be established independently of the gap size. Before the solder connection is established, the spacing element also enables the objective lens to be oriented relative to the image sensor, i.e. preferably according to the method according to the invention as described above.

[0018] Furthermore, the spacer element preferably has at least one spherical, partially spherical, cylindrical or partially cylindrical contact contour, respectively. Such a contact contour enables rolling on the contact surface, so that the spacer element can participate in all movements required for the orientation of the objective lens before welding with the objective lens and the corresponding joint partner.

[0019] According to a preferred embodiment of the invention, the spacer elements are arranged around the preferably cylindrical or conical outer contour of the objective lens at the same angular spacing from one another. The objective lens is thus supported uniformly on the periphery, which supports a stable focus position of the objective lens. The number of spacer elements is preferably three, since three spacer elements enable reliable support and the greatest possible freedom when orienting the objective lens during the manufacture of the camera module.

[0020] It is further proposed that the spacer element is received at least in sections in a guide geometry and / or in a common holder. The guidance of the spacer element should in particular simplify the orientation of the objective during the production of the camera module. In the finished camera module, additional support of the spacer element can be achieved by the guide geometry and / or the holder, thereby further increasing the stability of the focus position. The guidance thus has advantages that are not only apparent during the production of the camera module.

[0021] In an improved solution of the present invention, a sealing element is arranged between the objective lens and the carrier, between the objective lens and the housing, or between the objective lens and the connecting structure. The sealing element is mainly used to isolate the optically relevant area to prevent dirt from entering. In particular, the image sensor should be protected from contamination. Therefore, the sealing element is ideally a sealing ring that can achieve surrounding isolation or sealing.

[0022] The proposed camera module according to the invention is preferably produced according to the above-described method according to the invention, since this method enables multi-axis orientation of the objective and ensures a stable focus position by subsequent welding of the spacing element to the objective and the corresponding joining partner.

[0023] The proposed camera module may also be an imager module. In this respect, no distinction is made between camera modules and imager modules.

[0024] The carrier on which the image sensor is arranged is preferably fixedly connected to the housing or the lens holder, for example screwed, glued, soldered or welded. The carrier can be a printed circuit board in particular. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. These drawings show:

[0026] 1 shows a perspective view of different spacing elements for a camera module according to the invention: a) a rod with a circular cross section and partly spherical ends, b) a rod with a rectangular cross section and partly cylindrical ends, c) a sphere and d) a roller,

[0027] Figure 1a )-d) show perspective views of a rod-shaped spacing element for a camera module according to the present invention in different positions,

[0028] Figure 2a ) to d) show perspective views of different spacing elements for a camera module according to the invention,

[0029] Figure 3a ) shows a perspective view of a first preferred embodiment of a camera module according to the present invention and b) shows a cross-sectional view thereof,

[0030] Figure 4a ) shows a perspective view of a second preferred embodiment of a camera module according to the present invention and b) shows a cross-sectional view thereof,

[0031] Figure 5a ) shows a perspective view of a third preferred embodiment of a camera module according to the present invention and b) shows a cross-sectional view thereof,

[0032] Figure 6a ) shows a perspective view of a fourth preferred embodiment of a camera module according to the present invention and b) shows a cross-sectional view thereof, and

[0033] Figure 7a ) shows a perspective view of a fifth preferred embodiment of a camera module according to the present invention and b) shows a sectional view thereof. DETAILED DESCRIPTION

[0034] The camera module 1 according to the invention has spacer elements 7 which enable a multi-axial alignment of the objective 2 relative to the image sensor 3. The mode of operation of these spacer elements 7 will first be explained with reference to FIG. 1 .

[0035] exist Figure 1a , three rod-shaped spacer elements 7 are shown, which have a circular cross section and partially spherical ends, wherein the ends form a contact contour 8. The three spacer elements 7 are placed along a circumferential line with a diameter D1 and are each tilted inwards so that the upper contact contour 8 is located on a common circumferential line with a diameter D2. These circumferential lines mark the contact areas of the spacer elements 7 with the outer contour 9 of the objective lens 2.

[0036] Since the contact contours 8 are each partially spherical, the spacer elements 7 each make point contact with the outer contour 9 of the objective lens 2 on the one hand and with the placement surface on the other hand. The partially spherical ends thus form the contact contours 8, through which the spacer elements 7 can roll on the corresponding contact surface. This makes it possible to vary the adjustment angle of the spacer elements 7 in order to orient the objective lens 2 multiaxially.

[0037] like Figure 1b , it is shown by way of example that the adjustment angle of the spacing element 7 can be reduced in order to reduce the distance between the objective 2 and the image sensor 3. Since the diameter D1 is limited at its outer limit in this case, essentially only the diameter D2 is changed.

[0038] In order to bring the objective lens 2 to a slightly tilted position, such as Figure 1c and Figure 1d As shown by way of example in FIG. 1 , the spacer element 7 can also be tilted to different degrees. In this case, the spacer element 7 follows the movement of the objective lens 2 during alignment.

[0039] exist Figure 1c and 1d In FIG. 1 , the diameter D2 on the objective lens 2 is not an exact circle but an ellipse, but this is ignored in the present case.

[0040] FIG. 2 shows an alternative spacing element 7 . Figure 2a The rod-shaped spacer element 7 already known from FIG. 1 is shown, which has a circular cross section and a part-spherical contact contour 8 . Figure 2b A rod-shaped spacing element 7 is likewise shown, but has a rectangular cross section and a partially cylindrical contact contour 8 . Figure 2c A spherical spacing element 7 is shown, and Figure 2d Roller-shaped spacing elements 7 are shown. The various possible uses of spacing elements 7 are explained in more detail below with reference to specific exemplary embodiments.

[0041] Depend on Figure 3a and 3bA first camera module 1 according to the invention can be seen, with an objective lens 2 and an image sensor 3. The image sensor 3 is arranged on a carrier 4, which is a circuit board in this case, via which the necessary electrical contacts of the image sensor 3 are established. The objective lens 2 is placed above the image sensor 3 at a certain distance and is connected to the image sensor 3 by means of a circuit board according to the invention. Figure 1a The three rod-shaped spacer elements 7 are supported. Figure 1a In contrast, the spacer element 7 rests on the objective lens 2 at the periphery rather than at the end via its contact contour 8. This has the effect that the diameter D2 is not variable, but the diameter D1 is variable. If the adjustment angle of the spacer element 7 is changed when the objective lens 2 is oriented, the diameter D1 changes at the same time.

[0042] exist Figure 3a and 3b In the embodiment, the spacer element 7 is not directly supported on the carrier 4, but indirectly supported by a connecting structure 6 arranged on the carrier 4. The connecting structure is made of a metal material, so that the spacer element 7, which is also made of a metal material, can be welded to the connecting structure 6 after the objective lens 2 is oriented. In this way, the position of the objective lens 2 is fixed. Because the welded connection is particularly stable, a stable focus position of the objective lens 2 is achieved at the same time.

[0043] exist Figure 3a and 3b In the exemplary embodiment shown, the metallic connecting structure 6 simultaneously serves as a guide geometry 10, by which the spacing element 7 is guided during the alignment of the objective 2. For this purpose, the guide geometry 10 has vertical side walls 13, which extend parallel to radial lines and parallel to tangents with respect to the objective 2. The side walls 13 extending parallel to the tangents each form a seat for the spacing element 7, thereby predetermining a maximum diameter D1.

[0044] exist Figure 3a and Figure 3b In the embodiment shown, an annular sealing element 12 is additionally arranged between the objective 2 and the carrier 4. Since the sealing element is made of an elastically deformable material, it can participate in the movement of the objective 2 during alignment. In the present case, the sealing element 12 surrounds the end of the objective 2 with a reduced outer diameter, thereby forming an annular recess 14, to which the sealing element 12 is connected in a sealing manner.

[0045] exist Figure 4a and 4b 2 shows a second preferred embodiment of the camera module 1 according to the present invention. Here, the objective lens 2 is not supported on the carrier 4, but on the housing 5 via the spacing element 7. The carrier 4 is fixedly connected to the housing 5. The structure of the objective lens 2 and the structure of the spacing element 7 basically correspond to Figure 3a and 3bA sealing element 12 is also provided between the objective lens 2 and the housing 5 , wherein the sealing element 12 is arranged on a hollow cylindrical projection 15 of the housing 5 .

[0046] The sections 16 of the guide geometry 10 extend radially outward from the hollow cylindrical projection 15. The guide geometry 10 is thus integrated into the housing 5. The number of sections 16 corresponds to the number of spacing elements 7. Each section 16 has two side walls 13 extending parallel to the radial line and one side wall 13 extending parallel to the tangent line. The latter forms a support, so that the diameter D1 is limited outwardly. The diameter D2 is predetermined by the objective lens 2, because here the spacing element 7 also rests on the cylindrical outer contour 9 of the objective lens 2 on the outer circumference.

[0047] This is Figure 5a and 5b This is different in the camera module 1 shown. Here, the objective 2 has a conical outer contour 9 in the area of ​​the setback 14, against which the spacer element 7 rests. In other words, the diameter D2 can be changed depending on the position of the spacer element 7 on the conical outer contour 9 of the objective 2. Since the spacer element 7 is not guided by the guide geometry 10 at the other end, the diameter D1 can also be changed. At the same time, the guidance of the spacer element 7 is achieved by a holder 11, in which the spacer element 7 is movably supported. For this purpose, the holder 11 has a sleeve-shaped receiving part 17, which is connected by a ring 18 and is respectively supported so that it can rotate and move, so that the holder 11 allows the adjustment angle of the spacer element 7 to be changed.

[0048] The spacing element 7 is supported at its base point indirectly on the carrier 5 via a metallic connecting structure 6. In order to fix the position of the objective lens 2, the spacing element 7 is welded to the connecting structure 6 on the one hand and to the outer contour 9 of the objective lens 2 on the other hand. The sealing element 12 is arranged between the objective lens 2 and the connecting structure 6.

[0049] exist Figure 6a and 6b 1 shows another preferred embodiment of the camera module 1 according to the invention. The spacer element 7 is spherical here and bears against the conically shaped outer contour 9 of the objective 2. The conically shaped outer contour 9 is formed on the annular flange section 19 of the objective 2 in the present case. The spherical spacer element 7 rolls on the metallic connecting structure 6, which is arranged on the carrier 4 and enables welding of the spacer element 7 after orientation of the objective 2. The sealing element 12 is arranged between the objective 2 and the connecting structure 6.

[0050] Instead of spherical spacing elements 7, roller-shaped spacing elements 7 can also be used. Figure 7a and 7b The objective lens 2 is similar to Figure 6aand 6b The objective lens 2 is embodied so that the roller rests on the conically shaped outer contour 9 of the objective lens 2. Opposite the outer contour 9 of the objective lens 2 is a metallic connecting structure 6, which is arranged on the carrier 4. The connecting structure 6 is embodied as a ring on which the roller-shaped spacing element 7 rolls when the objective lens 2 is oriented. After orientation, the spacing element 7 is welded to the connecting structure 6. A sealing element 12 is arranged between the objective lens 2 and the carrier 4.

[0051] In addition to the exemplary embodiments shown, numerous further embodiments are possible which reflect the basic inventive concept. Figure 6a , 6b The spherical or roller-shaped spacing elements 7 of 7a, 7b require a conical contact surface in order to be able to follow the movement of the objective lens 2 during orientation. The conical contact surface can be selectively formed by the outer contour 9 of the objective lens 2 or the conical contact surface of the housing 5, the carrier 4 or the connecting structure 6. In the case of rod-shaped spacing elements 7, the outer contour 9 of the objective lens 2 can also be cylindrically configured, because if at least one diameter D1 and / or D2 is variable, the rod-shaped spacing element 7 can change its adjustment angle.

Claims

1. A method for manufacturing a camera module (1), wherein: The objective lens (2) is oriented relative to the image sensor (3) and is subsequently fixed in position by engaging with a carrier (4) receiving the image sensor (3), a housing (5) surrounding the image sensor (3), or a connecting structure (6) between the carrier and the housing as an engaging counterpart. It is characterized in that the objective lens (2) is supported on a spacing element (7) which is still movable at first, and is oriented relative to the image sensor (3) by the movement of the spacing element (7), wherein the ends of the spacing element (7) form a contact contour (8), and the spacing elements (7) are placed along a circular line and are respectively inclined inwardly so that the upper contact contour (8) is located on a common circular line, wherein the circular line marks the contact area of ​​the spacing element (7) with the outer contour (9) of the objective lens (2), and after the orientation of the objective lens (2), the spacing element (7) is welded to the objective lens (2) and the joint partner.

2. The method according to claim 1, It is characterized in that Spacer elements (7) are used which each have at least one contact contour (8) which is spherical, partially spherical, cylindrical or partially cylindrical.

3. The method according to claim 1 or 2, It is characterized in that The spacing elements (7) are arranged around the outer contour (9) of the objective (2) at equal angular distances from one another.

4. The method according to claim 1 or 2, It is characterized in that The spacer element (7) is guided via a guide geometry (10) formed by the carrier (4) or by the housing (5) or via the connecting structure (6).

5. The method according to claim 1 or 2, It is characterized in that The spacer elements (7) are guided via a common cage (11).

6. The method according to claim 3, It is characterized in that The outer contour (9) of the objective (2) is designed as a cylindrical or conical outer contour.

7. A camera module (1), comprising an objective lens (2) and an image sensor (3), wherein the image sensor is arranged on a carrier (4) and surrounded by a housing (5), in, The objective lens (2) is supported on a spacing element (7), which is welded to the objective lens (2) on the one hand and to the carrier (4), the housing (5) or a connecting structure (6) between the carrier and the housing on the other hand. It is characterized in that the camera module (1) is manufactured according to the method according to any one of claims 1 to 6.

8. The camera module (1) according to claim 7, It is characterized in that The spacer elements (7) each have at least one spherical, partially spherical, cylindrical or partially cylindrical contact contour (8).

9. The camera module (1) according to claim 7 or 8, It is characterized in that The spacing elements (7) are arranged around the outer contour (9) of the objective (2) at equal angular distances from one another.

10. The camera module (1) according to claim 9, It is characterized in that The outer contour (9) of the objective (2) is designed as a cylindrical or conical outer contour.

11. The camera module (1) according to any one of claims 7, 8 and 10, It is characterized in that The spacer element (7) is received at least in sections in a guide geometry (10) and / or in a common cage (11).

12. The camera module (1) according to any one of claims 7, 8 and 10, It is characterized in that A sealing element (12) is arranged between the objective lens (2) and the carrier (4), between the objective lens (2) and the housing (5), or between the objective lens (2) and the connecting structure (6).

13. The camera module (1) according to claim 10, It is characterized in that The spacing element (7) is designed in a roller-like manner and bears against a conically shaped outer contour (9) of the objective (2).

14. The camera module (1) according to claim 12, It is characterized in that The sealing element (12) is designed as a sealing ring.

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