Method for producing an imager module, imager module

Abstract

The invention relates to a method for producing an imager module (1), comprising the steps - arranging an image sensor (2) on a circuit board (3), - Connecting the circuit board (3) to a carrier element (4), - Inserting the carrier element (4) including the circuit board (3) and the image sensor (2) into a first housing part (5.1) of a multi-part housing (5), - connecting the first housing part (5.1) at one end to a lens assembly (6), and at the other end to a cover-like second housing part (5.2) which has a central opening (7) for receiving a connecting section (8) of the carrier element (4) and at least three spring tabs (9) projecting into the opening (7), the spring tabs (8) coming to bear against the connecting section (8), - optical alignment of the image sensor (2) with respect to the lens assembly (6) by a relative movement of the carrier element (4) with respect to the housing (5), - Fix the support element to the housing (5). The invention further relates to an imager module (1) which can be produced or has been produced according to the method.

Description

The invention relates to a method for producing an imager module and to an imager module which can be produced in particular by a method according to the invention.Preferred application areas of the invention are driver assistance systems for vehicles, industrial or safety camera applications and end user devices, such as smartphones and tablets.Prior ArtAn imager module generally comprises a multipart housing made of plastic or metal, an objective connected to the housing, and a printed circuit board accommodated in the housing and having an image sensor arranged thereon. The parts must be joined and the objective and the image sensor must be aligned with one another during the joining. This is usually carried out in a process which is also called "active alignment". During active alignment, the objective is generally aligned toward a reference point, so that the image projected on the image sensor is sharply set. The position of the objective is then fixed in order to keep the setting made permanently. An adhesive is often used for fixing. However, this has the disadvantage that it cannot ensure a stable focus position via temperature and moisture.The present invention is concerned with the object of simplifying the optical alignment of the objective and image sensor with respect to one another during the production of an imager module and subsequently fixing the parts aligned with respect to one another as permanently as possible. In this way, an imager module is to be created which has a stable focus position over temperature and moisture.To achieve the object, the method having the features of claim 1 and the imager module having the features of claim 5 are proposed. Advantageous further developments of the invention can be found in the respective dependent claims.Disclosure of the InventionThe proposed method for producing an imager module comprises the steps:arranging an image sensor on a printed circuit board,connecting the printed circuit board to a carrier element,inserting the carrier element including the circuit board and the image sensor into a first housing part of a multi-part housing,connecting the first housing part at one end to an objective assembly, at the other end to a cover-like second housing part which has a central opening for receiving a connecting section of the carrier element and at least three spring tabs projecting into the opening, the spring tabs coming to bear against the connecting section,optically aligning the image sensor with respect to the objective assembly by a relative movement of the carrier element with respect to the housing,fixing the carrier element to the housing.According to the proposed method, during the optical alignment, the image sensor is moved relative to the objective assembly. This requires a certain mobility of the image sensor relative to the objective assembly. This is ensured in the present case in that the image sensor and the printed circuit board are connected to a carrier element which engages in the central opening of the cover-like second housing part and is held in a clamping manner between the spring tabs of the cover-like second housing part. The clamping mounting is effected in the present case in that, during the mounting of the cover-like second housing part, the spring tabs come to bear against the connecting section of the carrier element. This presupposes that the connecting section of the carrier element, which engages in the central opening during assembly, deflects the spring tabs which project into the opening.The clamping seat allows both an axial displacement and tilting movements of the carrier element, namely in all spatial directions. As a result, the image sensor can be aligned optimally with respect to the objective assembly. Subsequently, the position of the carrier element only needs to be fixed.According to a preferred embodiment of the invention, the carrier element is fixed to the cover-like second housing part of the housing, preferably in the region of the spring tabs, by means of at least one welded connection, for example a laser welded connection. Since the spring tabs abut on the connecting section of the carrier element, a welded connection can be produced in a simple manner in the contact region of a spring tab with the connecting section. The welded connection contributes to a robust connection which-unlike the bonded connection-ensures a stable focal position via temperature and moisture.When carrying out the proposed method, the printed circuit board is preferably connected to the carrier element via bolt-like spacer elements. A fixed connection between the printed circuit board and the carrier element can be produced via the bolt-like spacer elements, so that relative movements of the printed circuit board and thus also of the image sensor arranged on the printed circuit board with respect to the carrier element are prevented. This is necessary in order subsequently to optically align the image sensor via the carrier element relative to the objective assembly. On the other hand, the axial position of the image sensor in the housing and thus with respect to the objective assembly can be preset by means of the bolt-like spacer elements.Furthermore, the printed circuit board preferably has a plug part which is guided through a central opening of the carrier element when the printed circuit board is connected to the carrier element. The necessary electrical contacting of the printed circuit board and of the image sensor and, if appropriate, of further electronic components which are arranged on the printed circuit board can then be produced in a simple manner via the plug part.In addition, an imager module for driver assistance systems is proposed. The imager module comprises:an image sensor,a printed circuit board receiving the image sensor,a carrier element receiving the printed circuit board with the image sensor,a multi-part housing having a first housing part in which the carrier element including the printed circuit board and the image sensor is accommodated, and a cover-like second housing part which has a central opening and at least three spring tabs projecting into the opening.The spring tabs bear under a prestress against a connecting section of the carrier element which is guided through the opening of the cover-like second housing part.In the case of the proposed imager module, the carrier element which accommodates the printed circuit board and the image sensor is held in the housing in a clamping manner via the spring tabs. The clamping connection permits a relative movement of the carrier element with respect to the housing, so that the image sensor can be optically aligned with respect to the housing-in particular with respect to an objective assembly connected to the housing. The imager module can thus be produced in particular according to the method according to the invention described above.In a development of the invention, it is proposed that the carrier element is fixed to the housing via at least one welded connection, in particular a laser welded connection. The fixing presupposes that the image sensor has been previously optically aligned. Only then is the fixing effected in order to permanently hold the position of the image sensor set during the alignment. The welded connection represents a particularly robust connection, in particular compared to an adhesive connection, since the adhesive connection is not able to ensure a stable focal position over temperature and moisture.The carrier element is preferably fixed to the cover-like second housing part, further preferably in the region of the spring tabs. This region lends itself to producing the connection, since the spring tabs bear under a prestress against the connecting section of the carrier element and thus already have a common contact region with the carrier element.Ideally, the contact of the carrier element with the housing is limited to the region of the spring tabs. This is because it is ensured that the carrier element is both axially displaceable and tiltable in all spatial directions with respect to the housing before fixing via the at least one welded connection in order to optically align the image sensor.Furthermore, it is proposed that the printed circuit board is connected to the carrier element via bolt-like spacer elements. The bolt-like spacer elements enable a fixed connection of the printed circuit board and thus of the image sensor to the carrier element, so that the image sensor can be exactly optically aligned via movements of the carrier element. In addition, the axial position of the image sensor with respect to the housing can be preset via the bolt-like spacer elements. The support element can then be readjusted if necessary, which then, however, only requires a slight axial displacement of the support element with respect to the housing.The printed circuit board preferably has a plug part which is guided through a central opening of the carrier element. The plug part is thus accessible from the outside and enables in a simple manner the electrical contacting of the printed circuit board and of the image sensor and, if appropriate, of further electronic components arranged on the printed circuit board. The electrical contacting can also be produced via a simple plug connection.Furthermore, the first housing part of the housing is preferably connected to an objective assembly. The connection can be such that it does not allow any relative movement of the objective assembly with respect to the housing, since the focal position can be adjusted by means of a relative movement of the carrier element and thus of the image sensor with respect to the housing, as long as the carrier element is held merely in a clamping manner by means of the spring tabs of the cover-like second housing part.A preferred embodiment of an imager module according to the invention is explained in more detail below with reference to the attached drawings. These show: FIG. 1 shows a partially cut-away perspective illustration of the imager module, FIG. 2 shows a longitudinal section through the imager module,Fug. FIG. 3 shows a further perspective illustration of the imager module, and FIG. 4 shows a further longitudinal section through the imager module.DETAILED DESCRIPTION OF THE DRAWINGSThe imager module 1 according to the invention shown in FIGS. 1 to 4 has a housing 5 with a pot-shaped first housing part 5.1 and a cover-like second housing part 5.2. The pot-shaped first housing part 5.1 is connected at one end to an objective assembly 6 having a lens package 14 and at the other end to the cover-like second housing part 5.2.The cover-like second housing part 5.1 has a central opening 7, through which a connecting section 8 of a carrier element 4 accommodated in the housing 5 is guided. A printed circuit board 3 and an image sensor 2 arranged on the printed circuit board 3 are held in the housing 5 via the carrier element 4. This is because, as can be seen in particular from FIG. 3, spring tabs 9 of the cover-like housing part 5.2 lie against the connecting section 8 of the carrier element 4, which spring tabs project into the central opening 7 and are bent outwards by the connecting section 8. The spring tabs 9 thus bear under a radial prestress against the connecting section 8. This means that the carrier element 4 is held in a clamping manner via the spring tabs 9. The clamping connection enables relative movements of the carrier element 4 with respect to the housing 5, so that the image sensor 2 can be optically aligned with respect to the objective assembly 6 thereby. The clamping connection permits both an axial displacement (see FIG. 4, arrow 15) and a radial displacement (see FIG. 4, arrow 16) of the carrier element 4 with respect to the housing 5. In addition, the carrier element 4 can be tilted in all spatial directions with respect to the housing 5. After the image sensor 2 has been optically aligned, its position is fixed via welded connections 10 which are arranged in the region of the spring tabs 9 (see in particular FIG. 4 ).In the imager module 1 shown in FIGS. 1 to 4, the two housing parts 5.1, 5.2 are likewise connected to one another via a welded connection 10. This is formed circumferentially and at the same time serves for sealing the housing 5 (see FIG. 4 ). For further sealing, as shown by way of example in FIGS. 1 and 2, a cap 17 can be placed over the connecting section 8 of the carrier element 4 and the spring tabs 9.In the illustrated exemplary embodiment of an imager module 1 according to the invention, the printed circuit board 3 is connected to a plug part 12 via which the printed circuit board 3 or the image sensor 2 arranged thereon can be electrically connected. For this purpose, the plug part 12 is guided outwards through an opening 13 of the connecting section 8 of the carrier element 4 and through the cap 17.

Claims

Method for producing an imager module (1), comprising the steps of - arranging an image sensor (2) on a printed circuit board (3), - connecting the printed circuit board (3) to a carrier element (4), - inserting the carrier element (4) including the printed circuit board (3) and the image sensor (2) into a first housing part (5.1) of a multipart housing (5), - connecting the first housing part (5.1) at one end to an objective assembly (6), at the other end to a cover-like second housing part (5.2) which has a central opening (7) for receiving a connecting section (8) of the carrier element (4) and at least three spring tabs (9) projecting into the opening (7), wherein the spring tabs (9) come to bear against the connecting section (8), optically aligning the image sensor (2) with respect to the objective assembly (6) by a relative movement of the carrier element (4) with respect to the housing (5), fixing the carrier element to the housing (5).Method according to claim 1, characterised in that the carrier element (4) is fixed to the cover-like second housing part (5.2) of the housing (5), preferably in the region of the spring tabs (9), by means of at least one welded connection (10), for example a laser welded connection.Method according to Claim 1 or 2, characterized in that the printed circuit board (3) is connected to the carrier element (4) via bolt-like spacer elements (11).Method according to one of the preceding claims, characterized in that the printed circuit board (3) has a plug part (12) which, when the printed circuit board (3) is connected to the carrier element (4), is guided through a central opening (13) of the carrier element (4).Imager module (1) for driver assistance systems, comprising - an image sensor (2), - a printed circuit board (3) receiving the image sensor (2), - a carrier element (4) receiving the printed circuit board (3) with the image sensor (2), - a multipart housing (5) having a first housing part (5.1), in which the carrier element (4) including the printed circuit board (3) and the image sensor (2) is received, and a cover-like second housing part (5.2), which has a central opening (7) and at least three spring tabs (9) projecting into the opening (7), wherein the spring tabs (9) bear under a prestress against a connecting section (8) of the carrier element (4) which is guided through the opening (7) of the cover-like second housing part (5.2).Imager module (1) according to claim 5, characterised in that the carrier element (4) is fixed to the housing (5) via at least one welded connection, in particular a laser welded connection, preferably to the cover-like second housing part (5.2), further preferably in the region of the spring tabs (9).Imager module (1) according to Claim 5 or 6, characterized in that the printed circuit board (3) is connected to the carrier element (4) via bolt-like spacer elements (11).Imager module (1) according to one of Claims 5 to 7, characterized in that the printed circuit board (3) has a plug part (12) which is guided through a central opening (13) of the carrier element (4).Imager module (1) according to one of Claims 5 to 8, characterized in that the first housing part (5.1) is connected to an objective assembly (6).

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