Optical detection unit having a specifically fastened circuit board, and method

Abstract

One aspect of the invention relates to an optical detection unit (1) comprising a housing (2) having an accommodating space (5) in which at least one circuit board (6) is located, wherein the housing (2) has at least one bearing journal (7) and the circuit board (6) has a journal socket (8) in which the bearing journal (7) engages, wherein the housing (2) has at least one hold-down pin (13) which holds the circuit board (6) in place, and wherein a positioning compensation element (14) is positioned between the circuit board (6) and the hold-down pin (13).

Description

[0001] Optical detection unit with specifically attached circuit board and method

[0002] One aspect of the invention relates to an optical detection unit. The optical detection unit has a housing, which can also be referred to as an outer housing. A receiving chamber is formed within the housing, in which at least one circuit board or circuit carrier is arranged. The housing has at least one bearing pin. The circuit board has a pin receptacle into which the bearing pin engages. Another aspect relates to a method.

[0003] From CN 212434087 U a detection unit is known in which a circuit board is appropriately stored in a housing.

[0004] In optical detection units, such as LiDAR sensors or laser scanners, it is essential that the components are fixed in position. This is particularly important for the reliable and precise transmission and reception of optical signals. Conventional detection units typically fix the circuit board in place by screwing it down. However, this requires additional fasteners in the form of screws and increases assembly effort. Furthermore, it usually increases the weight, and the fixed position is not always guaranteed.

[0005] Mounting on bearing journals simplifies assembly in this context. However, securing the position, especially long-term positioning, is difficult.

[0006] The object of the present invention is to create an optical detection unit in which a circuit board can be mounted with minimal effort and is permanently fixed in position within the housing.

[0007] This task is solved by an optical detection unit and a method according to the independent claims.

[0008] One aspect of the invention relates to an optical detection unit. The optical detection unit can also be referred to as a laser-based detection unit. It is particularly sensitive in the infrared range. The optical detection unit has a housing. This can also be referred to as an outer housing. A receiving space is formed in the housing, in which at least one circuit board or circuit carrier is arranged. The housing has at least one bearing pin. The circuit board has a pin receptacle into which the bearing pin engages.

[0009] The housing features at least one retaining dome. This dome is designed to hold the circuit board in place. A particularly advantageous feature is the separate positioning compensation element located between the circuit board and the retaining dome. This allows for a particularly convenient and simple way to mount the circuit board within the housing, minimizing assembly effort and ensuring its secure position over the long term. On the one hand, the mechanical coupling between the bearing journal and the journal receptacle facilitates a straightforward assembly process. On the other hand, the additional and separate retaining dome, which differs from the bearing journal, provides further mechanical fixation by acting upon the circuit board and securing it in place.This additional positioning compensation element counteracts even minor deviations caused by assembly and manufacturing tolerances. It allows for the compensation of such tolerances, ensuring a particularly secure arrangement of the circuit board within the housing, even with a wide range of possible tolerances. This is especially true when tolerances between the retaining dome and the circuit board, or between the bearing journal and the circuit board, result in an insufficient or no direct mechanical fit. This additional element and its precise positioning facilitate quick and easy assembly and ensure a particularly durable, fixed mounting of the circuit board within the housing.

[0010] In particular, the bearing journal enables the circuit board to be held in the spatial directions in which the plane of the circuit board extends. Specifically, the hold-down dome then fixes the position in the third spatial direction, i.e., perpendicular to the plane of the circuit board. This is especially true because the hold-down dome, with its positioning compensation element, acts on the circuit board in this perpendicular direction. Specifically, the bearing journal and the hold-down dome are arranged with their longitudinal axes parallel, and in particular coaxially. Preferably, the positioning compensation element is designed as an elastic and / or flexible element, so that tolerances can be compensated for by deformation of the positioning compensation element and the circuit board can be held under preload.

[0011] In one embodiment, the positioning compensation element is a paste. This is a further advantageous concept, as it allows the paste, designed as an elastic material, to be applied with particular precision and thus form-fitting security between the hold-down dome and the circuit board during the assembly process. This enables particularly direct mechanical contact even with varying tolerances, since the paste adapts to these individual conditions and can be shaped accordingly.

[0012] It is particularly advantageous if this paste is a thermally conductive paste. This not only allows for highly customized deformation during specific manufacturing processes, but also enables a highly specific curing of this positioning compensation element. This allows the positioning compensation element to be individually cured once it is in its final position and has established direct mechanical contact between the hold-down dome and the circuit board. This also ensures that the positioning compensation element remains dimensionally rigid and stable after assembly, so that the fixed final position of the circuit board achieved during manufacturing is maintained with exceptional reliability. Furthermore, a thermally conductive paste also facilitates heat dissipation, particularly from the circuit board, when it heats up during operation of the optical detection unit.

[0013] In one embodiment, the retaining dome has a receptacle on the side facing the circuit board into which the bearing journal projects with a journal portion that extends through the journal receptacle, which is designed as a through-hole. This embodiment is highly individual in many respects. Specifically, the bearing journal extends from one side of the circuit board through the through-hole, so that a journal portion protrudes through this hole and is thus freely cantilevered on the opposite side of the circuit board. Since the retaining dome has a designated receptacle for this purpose, this journal portion can project into this receptacle. This further improves and strengthens the mechanical coupling.In both vertical and horizontal directions, unwanted movement between the hold-down dome and the bearing journal can thus be significantly reduced, and in particular prevented. This also positively influences the positional accuracy of the positioning compensation element.

[0014] Preferably, the bearing journal is arranged on a base. The base can be designed as a pin. The bearing journal is formed at a front end of the base, in particular integrally with it. The bearing journal is, in particular, smaller at its end connected to the base than the surface of this front end. This also forms a seat for the circuit board, and the bearing journal engages securely in the receptacle.

[0015] In one embodiment, the receptacle can be designed as a blind hole in the hold-down dome. This means that the entire hold-down dome does not need to be designed as a hollow body, but only a small section at the end needs to be. This results in high rigidity for the hold-down dome.

[0016] In one embodiment, the hold-down dome can be pin-shaped. This design saves both space and weight. It also allows for a particularly customized local coupling with the circuit board, especially the positioning compensation element. Consequently, the positioning compensation element can be relatively small and delicate, as it is only required where the pin-shaped hold-down dome is located in close proximity to a top surface of the circuit board.

[0017] Furthermore, a pin-like design of the retaining dome enables a particularly targeted and mechanically stable coupling with the bearing journal. This is especially true when the bearing journal extends axially into the retaining dome, particularly its receptacle, overlapping it.

[0018] In one embodiment, the bearing journal is conical. This means, in particular, that its dimensions decrease in the axial direction when viewed perpendicular to the longitudinal axis. Specifically, it has its smallest radial dimensions at the end facing the hold-down boss. This facilitates the easy placement of the circuit board onto the bearing journal, as this tapered front end can then be inserted into the journal receptacle more easily, particularly through a through-hole. Furthermore, the conical shape of the bearing journal is preferably such that, in the final position of the circuit board, the clear opening or area of ​​the through-hole is completely filled by the bearing journal. This prevents horizontal movement of the circuit board relative to the bearing journal.In an advantageous embodiment, the conical shape also improves the penetration of the bearing pin into the receptacle of the retaining dome. This design also allows for smoother insertion into the receptacle until a precise clamping fit is achieved.

[0019] In one embodiment, the bearing journal is arranged on a first housing part of the housing. In particular, the bearing journal is formed integrally with the housing part. This can be the case if the housing part is made of plastic, for example, if it is an injection-molded component.

[0020] In one embodiment, the retaining dome is arranged on a second housing part of the housing, which is separate from the first housing part. In particular, it can be formed integrally with it. Here too, the second housing part can be made of plastic. It can also be an injection-molded component. The two housing parts can be separate from each other.

[0021] Such designs allow for the individual customization of housing components in terms of material, shape, and / or manufacturing process. Furthermore, they simplify the assembly of individual components onto a housing part.

[0022] In one embodiment, the two housing parts are connected by a detachable connection. This detachable connection can be a mechanical connection, and it is particularly non-destructive. This means that the connection can be reversibly disconnected and reconnected without losing functionality. In another embodiment, the detachable connection can be a screw connection, in which case the two housing parts are screwed together.

[0023] In one embodiment, the circuit board is held in the housing without screws. This means that it is mounted in the housing without screws. Specifically, it is secured solely by attaching the circuit board to several bearing pins and holding it in place with one or more retaining bosses. Additionally, the circuit board can also be inserted laterally, section by section, into recesses, such as grooves, formed in a housing component. In another embodiment, the optical detection unit is a LiDAR sensor. Specifically, the optical detection unit is a vehicle detection unit. This means that it is intended for use and / or installation on a vehicle, such as a motor vehicle. With such optical detection units, for example, the surroundings of a vehicle can be detected. Object detection is particularly advantageous with this technology.

[0024] The optical detection unit comprises, in particular, a laser unit and a receiver unit. The laser unit emits electromagnetic beams in a wavelength range between 800 nm and 1600 nm, specifically 850 nm, 905 nm, or 1550 nm.

[0025] Another aspect of the invention relates to a method for mounting an optical detection unit. The optical detection unit can be configured in particular according to the aspect mentioned above or in an advantageous embodiment thereof. The method comprises, in particular, the following steps:

[0026] Providing a first housing part of a housing of the optical detection unit, wherein the first housing part has at least one bearing pin;

[0027] Providing a second housing part of the housing of the optical detection unit, wherein the second housing part has at least one retaining dome;

[0028] Inserting a circuit board into the first housing part in such a way that the bearing pin engages in a pin receptacle of the circuit board;

[0029] Applying a positioning compensation element to a top side of the circuit board and / or to the hold-down dome;

[0030] Applying one housing part to the other housing part, so that the housing is formed and the circuit board is held in its position in the first housing part and the positioning compensation element is arranged between the circuit board, in particular directly resting on it, and the holding dome, in particular a front end of the holding dome facing the circuit board.

[0031] This method enables highly targeted, and in particular screwless, mounting of the circuit board in the housing, while still allowing for a particularly secure arrangement of the circuit board. It can be provided that, when the second housing part is applied to the first, these housing parts, or one housing part, are brought closer to the other by a linear assembly movement. This is particularly useful when the retaining dome is moved linearly towards the associated bearing journal. This is advantageous when, in one embodiment, the bearing journal is also to be inserted into a receptacle of the retaining dome. The position compensation element, which is still elastically deformable in this state, in particular the paste, preferably thermal paste, enables a highly situation-dependent, form-fitting, and adapted, and thus preferably also void- and bubble-free, filling of the area between the retaining dome and the circuit board.This means that the positioning compensation element also functions in a very specific way as a filling element or a spacer compensation adapter element. Once the desired final position is reached, this positioning compensation element can be cured in the next step of the process. This can be done, for example, by thermal, optical, and / or electrical processes.

[0032] Furthermore, the thermal paste also advantageously creates a heat dissipation element. For example, the thermal paste also dissipates heat generated during operation of the optical detection unit, such as that produced by electronic components on the circuit board.

[0033] Advantageous embodiments of the optical detection unit, such as the positions of elements and / or of elements relative to each other, are also to be considered advantageous embodiments of the method, and vice versa. The assembly process steps are carried out in such a way that these positions are achieved.

[0034] Exemplary embodiments of the invention are explained in more detail below with reference to schematic drawings. These show:

[0035] Fig. 1 . an exploded view of an embodiment of an optical detection unit according to the invention;

[0036] Fig. 2 shows a cross-sectional view through an embodiment of a specific intermediate assembly state during the manufacture of the optical detection unit; Fig. 3 shows a cross-sectional view according to Fig. 2 in the assembled final state of the optical detection unit; and

[0037] Fig. 4. an enlarged view of a sub-area in Fig. 3, showing the stored state of a circuit board of the optical detection unit.

[0038] In the figures, identical or functionally equivalent elements are given the same reference symbols.

[0039] Figure 1 shows an exploded view of an embodiment of an optical detection unit 1. This is a vehicle detection unit, specifically a LiDAR sensor. The optical detection unit 1 has a housing 2. The housing 2 comprises a first housing part 3 and a separate second housing part 4. When the housing 2 is closed, with the two housing parts 3 and 4 abutting and connected, a receiving space 5 is formed, or rather, bounded by the walls of the housing parts 3 and 4. At least one circuit board 6 of the optical detection unit 1 is arranged in this receiving space 5. In this embodiment, the optical detection unit 1 has at least one bearing pin 7, preferably several such bearing pins 7. These are arranged on the first housing part 3 in this embodiment. In particular, they are formed integrally with the first housing part 3.Housing parts 3 and / or 4 can, for example, be made of die-cast aluminum.

[0040] Figure 1 shows a state in which the circuit board 6 is already arranged in the first housing part 3 and at least one bearing pin 7 is mounted on it. The circuit board 6 has a pin receptacle 8, which is a through-hole 9. Thus, the bearing pin 7 in Figure 1 extends completely through this through-hole 9 from below, so that it projects upwards beyond the circuit board 6.

[0041] Figure 1 also shows further components of the optical detection unit. This can be a rotating mirror 10. It can also include a laser unit and a receiver unit 11 or 12.

[0042] As can also be seen in Fig. 1, the optical detection unit 1 also has at least one retaining dome 13. In particular, several retaining domes 13 are provided here. The position and number are merely examples. Preferably, a corresponding number of bearing pins 7 are provided. Thus, in the assembled final state of the optical detection unit 1, a bearing pin 7 and an associated retaining dome 13 always interact locally with each other, in particular mechanically, in order to permanently fix the circuit board 6, in particular in all three spatial directions, in the housing 2.

[0043] As can be seen, the retaining domes 13 are pin-shaped. In particular, they are formed integrally with the second housing part 4.

[0044] As can also be seen in Fig. 1, the optical detection unit 1 has a positioning compensation element 14. This is preferably arranged at a free end of a hold-down dome 13. A positioning compensation element 14 can be a paste, in particular a thermally conductive paste. It can be an annular element, as shown by way of example in Fig. 1. The size of the ring can be adapted to the front end or the surface of the front end of a hold-down dome 13.

[0045] Starting from the situation shown in Fig. 1, the optical detection unit 1 can then be mounted by placing one housing part 3, 4 onto the other housing part 3, 4. As can be seen in the vertical section view in Fig. 2, for example, the second housing part 4 can be placed onto the first housing part 3 along arrow P. In particular, this is a linear assembly movement.

[0046] This achieves a situation where a hold-down dome 13 with a positioning compensation element 14 locally engages a top surface 6a of the circuit board 6 at a point on a bearing journal 7. As can also be seen in Fig. 2, the hold-down dome 13 has a receptacle 15. This receptacle is blind-shaped and open on the side facing the bearing journal 7. This allows the bearing journal 7 to be inserted axially into the hold-down dome 13. As can also be seen in Fig. 2, the bearing journal 7 is formed on a preferably pin-shaped base 16 of the first housing part 3, or extends upwards from it. In one embodiment, the circuit board 6 sits on this base 16 with a bottom surface 6b, and the bearing journal 7 extends completely through the through-hole 9.

[0047] As can also be seen in Fig. 2, the bearing journal 7 is preferably conical. This means that it is tapered, or more tapered, on the side facing away from the base 16 than on the side facing the base 16.

[0048] Fig. 3 shows the assembled final state of the optical detection device 1. It can be seen that the bearing pin 7 is inserted into and positioned in the receptacle 15, and the positioning compensation element 14 rests directly on the top surface 6a.

[0049] This ensures that the fixed position of the circuit board 6 is achieved and permanently maintained. In particular, this positioning compensation element 14 can then also be cured.

[0050] Figure 4 shows an enlarged view of the area in Figure 3 where the bearing journal 7, the retaining dome 13, and the positioning compensation element 14 are visible. The insertion of the conical bearing journal 7 into the receptacle 15 in the direction of the longitudinal axis A of these components is evident. The bearing journal 7 can also be described as a retaining pin for the circuit board 6. The circuit board 6 is held in the housing 2, in particular without screws.

Claims

Patent claims 1. Optical detection unit (1) with a housing (2) in which a receiving chamber (5) is formed in which at least one circuit board (6) is arranged, wherein the housing (2) has at least one bearing pin (7), and the circuit board (6) has a pin receptacle (8) into which the bearing pin (7) engages, characterized in that the housing (2) has at least one retaining dome (13) with which the circuit board (6) is held, wherein a positioning compensation element (14) is arranged between the circuit board (6) and the retaining dome (13).

2. Optical detection unit (1) according to claim 1 , characterized in that the positioning compensation element (14) is designed as an elastic and / or flexible element.

3. Optical detection unit (1) according to claim 1 or 2, characterized in that the positioning compensation element (14) is a paste.

4. Optical detection unit (1) according to claim 3, characterized in that the paste is a thermally conductive paste.

5. Optical detection unit (1) according to one of the preceding claims, characterized in that the hold-down dome (13) has a receptacle (15) on the side facing the circuit board (6) into which the bearing pin (7) projects with a pin part which extends through the pin receptacle (8) designed as a through hole (9).

6. Optical detection unit (1) according to one of the preceding claims, characterized in that the hold-down dome (13) is designed in a pin-like manner.

7. Optical detection unit (1) according to one of the preceding claims, characterized in that the bearing pin (7) is conical.

8. Optical detection unit (1) according to one of the preceding claims, characterized in that the bearing pin (7) is arranged on a first housing part (3) of the housing (2), in particular is formed integrally therewith.

9. Optical detection unit (1) according to claim 8, characterized in that the hold-down dome (13) is arranged on a second housing part (4) of the housing (2) which is separate from the first housing part (3), in particular is formed integrally with it.

10. Optical detection unit (1) according to claims 8 and 9, characterized in that the two housing parts (3, 4) are detachably connected to each other, in particular screwed together.

11. Optical detection unit (1) according to one of the preceding claims, characterized in that the circuit board (6) is held in the housing (2) without screws.

12. Optical detection unit (1) according to one of the preceding claims, characterized in that it is a LIDAR sensor.

13. Method for mounting an optical detection unit (1), in particular according to one of the preceding claims, comprising the following steps: Providing a first housing part (3) of a housing (2) of the optical detection unit (1), wherein the first housing part (3) has at least one bearing pin (7); Providing a second housing part (4) of the housing (2) of the optical detection unit (1), wherein the second housing part (4) has at least one retaining dome (13); Inserting a circuit board (6) into the first housing part (3) such that the bearing pin (7) engages in a pin receptacle (8) of the circuit board (6); Applying a positioning compensation element (14) to a top side (6a) of the circuit board (6) and / or to the hold-down dome (13); Applying one housing part (3, 4) to the other housing part (3, 4) such that the housing (2) is formed and the circuit board (6) is held in its position in the first housing part (3) and the positioning compensation element (14) is arranged between the circuit board (6), in particular directly resting on it, and the retaining dome (13), in particular a front end of the retaining dome (13) facing the circuit board (6).

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