Sensor module

Abstract

[Problem] To provide a sensor module that can suppress the generation of resin burrs and can improve workability. [Solution] This sensor module (100) comprises a sensor element, a first case (11), a second case (12), and a groove (70). The first case (11): has an opening end section including a first welding region; and houses the sensor element. The second case (12) has a bonding surface (123) that includes a second welding region (50) that, by being welded to the first welding region, forms a welded section. The groove (70) is formed in at least either the first welding region or the second welding region (50).

Description

Technical Field

[0001] The present technology relates to, for example, a sensor module mounted on a vehicle.

Background Art

[0002] For example, electronic components and optical components installed outside the vehicle (outdoors), such as a rear view camera unit for an automobile, are housed in a case having waterproof and dustproof properties. As such a case, for example, as described in Patent Document 1, a front case and a rear case are known to be joined by welding by irradiation with laser light. In a case having such a structure, a so-called resin burr occurs in which the molten resin generated by the irradiation with laser light protrudes to the outer peripheral side of the joining region between the front case and the rear case, which easily causes a defective appearance of the product.

[0003] In order to solve such a problem, for example, Patent Document 2 describes a welding method in which laser light is irradiated onto the joining surface of an absorbent resin material that absorbs laser light and a transmissive resin material that transmits laser light to weld both resin materials. A technique for forming grooves capable of accommodating molten resin on both sides of the scanning locus of laser light on the joining surface of the transmissive resin material is described.

[0004] In addition, Patent Document 3 describes providing a stepped structure for fitting the case body and the cover member on the joining surface between the bottomed cylindrical case body and the cover member, and forming a welding portion on the inner side of the case body with respect to this stepped structure.

Prior Art Documents

Patent Documents

[0005] [[ID=3l]]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

[0006] However, in the structure described in Patent Document 1, space is required to provide the grooves on both sides of the welding area, which is the scanning area of ​​the laser beam. This increases the size of the joint surface between the two resin materials by the amount of the groove formation area, hindering product miniaturization. Similarly, in the structure described in Patent Document 2, space is required to provide the stepped structure on the outer circumference of the welding area where the laser beam is irradiated, also hindering product miniaturization. Furthermore, the structures in Patent Documents 1 and 2 require precise adjustment of the laser irradiation position on the parts, which makes them susceptible to variations in part dimensions. Therefore, there is a need to reduce cosmetic defects, eliminate the need to remove excess material and precisely adjust the laser irradiation position to improve workability (productivity), and miniaturize the product.

[0007] In light of the above circumstances, the objective of this technology is to provide a sensor module that can suppress the generation of resin burrs and improve workability. [Means for solving the problem]

[0008] To achieve the above objective, a sensor module according to one embodiment of this technology comprises a sensor element, a first case, a second case, and a groove. The first case described above has an open end including a first welding region and houses the sensor element. The second case described above has a joint surface that includes a second welding region which forms a welded portion by welding with the first welding region described above. The groove is formed in at least one of the first welding region and the second welding region.

[0009] In the sensor module described above, the molten portions of the first case and the second case can be directed to the groove. As a result, the outflow of the molten portions to the outside of the first case and the second case is suppressed, and defects in appearance can be reduced.

[0010] The groove may be formed over the entire circumference of the first welding region or the second welding region.

[0011] The groove portion may be formed continuously around the entire circumference of the first welding region or the second welding region.

[0012] The groove portion may include a plurality of first grooves formed in parallel around the entire circumference of the first welding region or the second welding region.

[0013] The number of the multiple first grooves described above is three or more, and the multiple first grooves may be formed more densely on the outside of the first welding region or the second welding region.

[0014] Of the multiple first grooves described above, the cross-sectional area of ​​the first groove located on the outermost side of the joint surface may be larger than the cross-sectional area of ​​the first groove located on the innermost side of the joint surface.

[0015] Of the plurality of first grooves described above, the width or depth of the first groove located on the outermost side of the joint surface may be greater than the width or depth of the first groove located on the innermost side of the joint surface.

[0016] The groove portion may further include a plurality of second grooves extending in a direction intersecting the plurality of first grooves.

[0017] The open end further has a stepped surface formed outside the first welded region and parallel to the first welded region, and the joining surface further has a parallel surface formed outside the second welded region and parallel to the second welded region, and the stepped surface and the parallel surface may face each other with a gap in between.

[0018] The first case may be made of a resin material that absorbs laser light of the predetermined wavelength, and the second case may be made of a resin material that transmits laser light of the predetermined wavelength.

[0019] The groove portion may be filled with the melted resin material of the first case or the second case.

[0020] The sensor element may be an imaging element.

[0021] The first case and the second case may be joined by laser welding.

Brief Description of Drawings

[0022] [Figure 1] It is an overall perspective view of a sensor module according to an embodiment of the present technology, where (A) is a view seen from the front side and (B) is a view seen from the back side. [Figure 2] It is a longitudinal sectional view of the sensor module. [Figure 3] It is an enlarged view of the welded portion in FIG. 2. [Figure 4] (A) is an exploded perspective view of the sensor module, and (B) is an enlarged view of part A in (A). [Figure 5] (A) is a sectional view near the welded portion of the sensor module, and (B) is a sectional view similar to FIG. 3 for explaining the welding process between the first case and the second case in the sensor module. [Figure 6] (A) is an exploded perspective view of a sensor module according to a second embodiment of the present technology, and (B) is an enlarged view of part B in (A). [Figure 7] It is a longitudinal sectional view of the welded portion in the sensor module. [Figure 8] It is an explanatory diagram of the overflow suppression rate of the molten resin. [Figure 9] It is a perspective view of the main part according to a third embodiment of the present technology.

Embodiments for Carrying Out the Invention

[0023] The embodiments of this technology will be described below with reference to the drawings.

[0024] <First Embodiment> [Sensor module configuration] Figures 1(A) and 1(B) are overall perspective views of the sensor module 100 according to the first embodiment of this technology. Figure 2 is a longitudinal cross-sectional view of the sensor module 100. Figure 3 is an enlarged view of the welded portion W in Figure 2. In each figure, the X, Y, and Z axes represent three mutually orthogonal axes, and the Z axis corresponds to the optical axis direction of the sensor module 100.

[0025] The sensor module 100 of this embodiment is a camera module for in-vehicle use. The sensor module 100 is, for example, placed outside a vehicle body (object to be mounted) (not shown), and captures images of the front, rear, or side of the vehicle depending on the mounting position. For example, a sensor module 100 mounted on the front of the vehicle (e.g., the front grille) captures images of the environment in front of the vehicle. A sensor module 100 mounted on the rear (e.g., above the license plate) captures images of the environment behind the vehicle. A sensor module 100 mounted on the side of the vehicle (e.g., on the top of the pillars (A-pillar, B-pillar, and the rearmost pillar (C-pillar, D-pillar)) or on the side mirrors) captures images of the environment to the side of the vehicle.

[0026] As shown in Figures 1 and 2, the sensor module 100 includes a housing 10, a sensor substrate 20, a lens barrel member 30, and the like.

[0027] The housing 10 is a case unit formed by combining a front case 11 as a first case and a rear case 12 as a second case in the optical axis direction (Z axis direction). The front case 11 and the rear case 12 are typically made of injection-molded synthetic resin material.

[0028] The front case 11 has a front portion 111 formed substantially perpendicular to the optical axis direction (Z axis direction), and a side portion 112 extending from the periphery of the front portion 111 toward the rear case 12. In this embodiment, the shape of the front portion 111 and the side portion 112 as viewed from the Z axis direction is substantially rectangular. The front case 11 is hollow, and a space is formed in the area surrounded by the front portion 111 and the side portion 112 for housing the sensor substrate 20, lens barrel member 30, etc.

[0029] The front portion 111 of the front case 11 has an opening 113 in its center (see Figure 2), into which the lens barrel member 30 is fitted, as will be described later. The front case 11 also has an open end 114 at the end of the side portion 112 on the rear case 12 side, which is welded to the rear case 12 (see Figure 3). The open end 114 is formed in a substantially rectangular shape corresponding to the outer shape of the front portion 111. Note that the shape of the front portion 111 and the open end 114 are not limited to a rectangle, but may be formed in other shapes such as a circle or a triangle.

[0030] The rear case 12 is formed in a roughly rectangular shallow dish shape, having a bottom surface 121 formed substantially vertically in the front-rear direction, and an extended side surface 122 that protrudes toward the front case 11 from near the periphery of the bottom surface 121. A rectangular annular joining surface 123 is formed on the outer circumference of the side surface 122 of the bottom surface 121, which is welded to the open end 114 of the front case 11 (see Figure 3). In this embodiment, as will be described later, the joining surface 123 is joined to the open end 114 by laser welding, thereby integrating the front case 11 and the rear case 12.

[0031] The lens barrel member 30 is positioned inside the front case 11. The lens barrel member 30 has a lens barrel portion 301 that fits into the opening 113 in the optical axis Z direction via a seal ring 31. The lens barrel portion 301 is a cylindrical part that supports the photographic lens 302, which protrudes forward from the opening 113 towards the front of the front case 11.

[0032] The sensor board 20 is placed inside the housing 10. The sensor board 20 has a front board 21 facing the front portion 111 of the front case 11, a rear board 22 facing the bottom portion 121 of the rear case 12, and a spacer 23 placed between the front board 21 and the rear board 22.

[0033] The front substrate 21 and the rear substrate 22 are made of rigid double-sided wiring boards such as glass epoxy substrates, and the opposing distance between each substrate is defined by a spacer 23. The front substrate 21 and the rear substrate 22 are mechanically and electrically connected via a substrate connector (BtoB connector) not shown. The sensor substrate 20 is not limited to the example of being made of two substrates, the front substrate 21 and the rear substrate 22, but may be made of a single substrate.

[0034] An image sensor 24 is mounted on the front substrate 21 as a sensor element. The image sensor 24 is an image sensor such as a CMOS (Complementary Metal-Oxide Semiconductor) or CCD (Charge Coupled Device). The front substrate 21 is bonded to the lens barrel 301 via bonding material 32 and cushioning material 33, and the image sensor 24 is positioned on the optical axis of the imaging lens 302.

[0035] The rear circuit board 22 is electrically connected to a connector 60 provided on the bottom surface 121 of the rear case 12 via a flexible wiring board 80. The connector 60 is for electrically connecting the sensor board 20 to the vehicle body, and power is supplied from the vehicle body to the sensor board 20, and an image signal (output signal of the image sensor 24) is transmitted from the sensor board 20 to the vehicle body via the connector 60.

[0036] Although not shown, the housing 10 contains a shielding case for blocking electromagnetic noise, a dustproof sheet, a heat dissipation sheet, and the like, surrounding the sensor substrate 20. The shielding case functions as a biasing member that biases the lens barrel member 30 and the sensor substrate 20 joined to it toward the front case 11, with one end engaging with the periphery of the lens barrel member 30 and the other end elastically contacting the inner surface of the bottom portion 121 of the rear case 12.

[0037] The front case 11 and the rear case 12 are joined by laser welding. In this embodiment, the front case 11 is made of a synthetic resin material that absorbs laser light L of a predetermined wavelength (see Figure 5(A)). The rear case 12 is made of a synthetic resin material that is transparent to laser light L.

[0038] Examples of resin materials that absorb or transmit laser light L include general-purpose resins such as AS (acrylonitrile styrene) resin and ABS (acrylonitrile butadiene styrene) resin, PC (polycarbonate) resin, mixed resins of ABS and PC, PA (polyamide) resin, and PBT (polybutylene terephthalate) resin.

[0039] The absorption or transmission of laser light L can be adjusted, for example, by the amount of laser absorbing material mixed into the resin. Carbon black can be used as the absorbing material. By adjusting the amount of absorbing material added, the absorption rate (or transmission rate) of laser light L can be arbitrarily adjusted. It is preferable to use the same type of matrix resin for the resin material that absorbs laser light L and the resin material that transmits laser light L. This increases the affinity between the resins at the joint and improves the welding strength. Furthermore, the transmission rate can be adjusted by changing the thickness of the resin. Increasing the thickness of the resin will lower the transmission rate of the resin. Conversely, decreasing the thickness of the resin will increase the transmission rate of the resin.

[0040] In this embodiment, the laser light L used for welding is, for example, a red laser light or infrared laser light with a wavelength of 800 nm to 1100 nm. The transmittance of the laser light L in the resin material that is transparent to the laser light L is 30% or more, more preferably 40% or more. The spot diameter of the laser light L is, for example, 1 mm.

[0041] [Details of the welded area] As shown in Figures 2 and 3, the front case 11 has an open end 114 that includes a first welding region 40 and houses the sensor element 24. The welding region here refers to the area where the front case 11 and the rear case 12 are welded together by the irradiated laser light L. In this embodiment, the area to be welded is the irradiation area of ​​the laser light L. The first welding region 40 is formed in a substantially rectangular shape corresponding to the outer shape of the front portion 111, but is not limited to a rectangle and may be formed in other shapes such as a circle or a triangle, corresponding to the shape of the open end 114. Furthermore, it is preferable that the first welding region 40 is provided so as to be parallel to the XY plane with respect to the second welding region 50, which will be described later.

[0042] As shown in Figures 2 and 3, the rear case 12 has a joint surface 123 that includes a second welding region 50 which forms a welded portion W by welding with the first welding region 40. The joining surface 123 is rectangular and annular in shape, and as will be described later, the first welding region 40 and the second welding region 50 are welded together by irradiation with laser light L, thereby integrating the front case 11 and the rear case 12 and forming the housing 10.

[0043] As shown in Figure 3, the joint surface 123 includes a first welding region 40 of the front case 11 and a second welding region 50 to be welded. The second welding region 50 is formed in a rectangular annular shape, but is not limited to this, and can be formed in a shape corresponding to the first welding region 40 to be welded. Corresponding shapes here refer to relationships such that, for example, if the first welding region 40 is rectangular, the second welding region 50 is also rectangular, and if the first welding region 40 is circular, the second welding region 50 is also circular, similar to the first welding region 40.

[0044] The welded portion W refers to the portion formed by the welding of the first welding region 40 and the second welding region 50. That is, the welded portion W refers to the portion where the front case 11 and the rear case 12 are welded together by resin melted by the irradiation of the first welding region 40 and the second welding region 50 with laser light L. Preferably, the welded portion W is formed around the entire circumference of the first welding region 40 and the second welding region 50. This ensures the sealing performance of the welded portion W between the front case 11 and the rear case 12. The melted resin is not limited to resin that has absorbed laser light L and been heated and melted, but also includes resin that is transparent, for example, resin that has melted due to the heat generated by an absorbent resin.

[0045] As shown in Figure 3, the opening end 114 of the front case further has a stepped surface 116 parallel to the first welding region 40, formed outside the first welding region 40 via a stepped portion 115. The stepped portion 115 is formed to extend downward in Figure 3 from the first welding region 40 toward the stepped surface 116. Preferably, the stepped portion 115 is formed perpendicular to the first welding region 40. Preferably, the stepped surface 116 is parallel to the first welding region 40, but is not limited to this. Furthermore, the stepped surface 116 is provided around the entire circumference of the rear case 12 along the first welding region 40, but is not limited to this.

[0046] Furthermore, as shown in Figure 3, the joint surface 123 of the rear case further has a parallel surface 124 parallel to the second welding region 50. The parallel surface 124 is formed on the outside of the second welding region 50 (on the opposite side from the inside of the housing 10 with respect to the second welding region 50). The parallel surface 124 is a plane that extends outward from the second welding region 50 in the Y-axis direction, and faces each other in the Z-axis direction with a gap between it and the stepped surface 116. It is preferable that the parallel surface 124 is a surface parallel to the second welding region 50, but of course it is not limited to this. Moreover, the parallel surface 124 is also provided around the entire circumference along the second welding region 50, similar to the stepped surface 116, but it is not limited to this.

[0047] In Figure 3, it is preferable that the width Y1 of the stepped surface 116 along the Y-axis direction and the width Y2 of the parallel surface 124 along the Y-axis direction are equal. In other words, when viewing the sensor module 100 from the optical axis direction (Z-axis direction), it is preferable from the viewpoint of miniaturizing the sensor module 100 that the outer peripheral end of the stepped surface 116 and the outer peripheral end of the parallel surface 124 are at the same position relative to each other. The above widths Y1, Y2 and the height of the stepped portion 115 are not particularly limited and can be designed arbitrarily.

[0048] As described above, the stepped portion 115 and stepped surface 116 of the open end 114 and the parallel surface 124 of the joining surface 123 face each other with a predetermined gap between them. This allows molten resin to be contained within the space partitioned by the stepped portion 115, the stepped surface 116, and the parallel surface 124, even if it spills out from the welded portion W. This prevents the resin from spilling out onto the outer surface of the housing 10, thus eliminating the risk of causing defects in the appearance of the product.

[0049] [Details of the groove] Figure 4(A) is an exploded perspective view of the sensor module 100 of this embodiment, and Figure 4(B) is an enlarged view of part A in Figure 4(A) (part of the joining surface 123 of the rear case 12). Figure 5(A) is a cross-sectional view of the welded portion W between the open end 114 and the joining surface 123 of the rear case 12. Figure 5(B) is a cross-sectional view similar to Figure 5(A) illustrating the laser welding process between the open end 114 and the joining surface 123.

[0050] As shown in Figures 4(A) and (B), a groove 70 is provided in the joint surface 123 of the rear case. As shown in Figure 4(A), the groove 70 is formed along the entire circumference of the second welding region 50 where the open end 114 and the joint surface 123 face each other and are welded. Furthermore, the groove 70 is formed continuously along the entire circumference of the second welding region 50. Continuously along the entire circumference means that the groove 70 is formed along the second welding region 50 without interruption. For example, it is like drawing a circle in one stroke and returning to the starting position. Of course, the groove 70 may also be formed discontinuously (intermittently) along the entire circumference of the second welding region 50.

[0051] Furthermore, the groove portion 70 includes a plurality of first grooves 71 formed in parallel around the entire circumference of the second welding region 50. The plurality of first grooves 71 refer to, for example, three grooves arranged in a row as shown in Figure 4(B), but are not limited to this, and may be two or three or more. The plurality of first grooves 71 are formed at equal intervals along the second welding region 50 as shown in Figure 4(B). Also, as will be described later, the plurality of first grooves 71 do not have to be formed at equal intervals.

[0052] In this embodiment, a groove 70 is provided in the second welding region 50, but as will be described later, a groove 70 may be provided in the first welding region 40, or a groove 70 may be provided in both the first welding region 40 and the second welding region 50. In other words, the groove 70 only needs to be formed in at least one of the first welding region 40 and the second welding region 50.

[0053] [Manufacturing method for sensor modules] During the manufacturing of the sensor module 100, the lens barrel member 60, the sensor board 20, etc. are sequentially assembled inside the front case 11, and then the joint surface 123 of the rear case 12 is brought into contact with the open end of the front case 11. At this time, the sensor board 20 is electrically connected to the connector 30 via the flexible wiring board 40.

[0054] Next, as shown in Figure 5(A), while pressing the rear case 12 toward the front case 11 with a constant pressure P, laser light L is irradiated from the rear case 12 side toward the opening end 114. The front case 11 is made of a resin material that absorbs laser light L, and the rear case 12 is made of a resin material that transmits laser light L. Therefore, the laser light L passes through the rear case 12 and is irradiated onto the opening end 114 of the front case 11. The laser light L is scanned in a rectangular ring shape along the opening end 114. The laser light L may be a continuous wave or a pulsed wave.

[0055] The area of ​​the open end 114 irradiated by the laser light L is heated by the absorption of the laser light L and partially melts. In this embodiment, since the stepped surface 116 with the above configuration is provided on the outer peripheral edge of the open end 114, only the inner peripheral region of the open end 114 (first welding region 40) where the stepped surface 116 is not provided melts.

[0056] Due to heat conduction from the molten portion (first welding region 40) of the open end 114, the joint surface 123 (mainly the second welding region 50) facing the first welding region 40 also partially melts. Subsequently, as the molten portions of the first welding region 40 and the joint surface 123 (mainly the second welding region 50) cool and solidify, the front case 11 and the rear case 12 are welded to each other. Since the laser beam L is continuously scanned in the circumferential direction of the rectangular annular open end 114, welding is continuously performed over the entire circumferential region of the open end 114. This ensures a seal between the joint surface 123 of the front case 11 and the rear case 12.

[0057] In the above explanation, the laser light L was irradiated and scanned along the entire circumference of the first welding region 40, but this is by no means limited to this, and the laser light may be irradiated only partially over the first welding region 40.

[0058] In this embodiment, as shown in Figure 5(A), the groove 70 is provided in the second welding region 50, so during laser welding, the laser light L is irradiated onto the second welding region 50, including the groove 70. Then, as shown in Figure 5(B), the resin molten by the laser light L is filled into the groove 70. This prevents the molten resin from spilling out of the housing 10. Furthermore, by suppressing the spillage of resin, the width of the parallel surface 124 and the stepped surface 116 can also be narrowed, making it possible to miniaturize the product. The molten resin referred to here is not limited to the resin that constitutes the front case 11. In other words, the groove 70 can accommodate the molten resin of at least one of the front case 11 or the rear case 12.

[0059] In addition, since the irradiation range of the laser beam L on the joint surface 123 becomes the second welding region 50, the effort required to precisely adjust the irradiation position of the laser beam L, such as adjusting the irradiation position of the laser beam L to the inside of the housing 10 within the second welding region 50 to prevent the molten resin from spilling out, can be eliminated, thereby improving work efficiency. Furthermore, since the molten resin enters the groove 70, the welding strength between the front case 11 and the rear case 12 can be increased by the resin that enters the groove 70 (anchor effect). The groove 70 acts as a relief for the molten resin, but in addition, when the molten resin enters the groove 70, it also acts as a welding region W. Therefore, since there is no need to separately provide a structure that only provides the relief effect to the side of the laser beam's scanning trajectory (irradiation range), it contributes to miniaturization of the joint surface 123 and, consequently, the housing 10.

[0060] Furthermore, the interior of each groove 70 (each first groove 71) does not need to be completely filled with molten resin; some voids may remain.

[0061] The formation locations of the multiple first grooves 71 are not particularly limited. Typically, the first grooves 71 are formed to cover the entire area of ​​the second welding region 50, but are not limited to this, and may be formed at positions biased toward the outer circumference (parallel surface 124 side) of the joint surface 123.

[0062] Furthermore, while the spacing of the first grooves 71 is typically constant, the spacing may be varied from region to region so that it becomes denser towards the outside of the second welding region 50. For example, the spacing between the first grooves 71 may gradually narrow as you move towards the outside of the joint surface 123, or only an arbitrary number of first grooves 71 on the outer periphery may be targeted, and their spacing may be set to become narrower towards the outer periphery.

[0063] Furthermore, among the multiple first grooves 71, the cross-sectional area of ​​the first groove 71 located on the outermost side of the joint surface 123 may be larger than the cross-sectional area of ​​the first groove 71 located on the innermost side of the joint surface 123. Also, among the multiple first grooves 71, the width or depth of the first groove 71 located on the outermost side of the joint surface 123 may be larger than the width or depth of the first groove 71 located on the innermost side of the joint surface 123.

[0064] As described above, the first grooves 71 are formed more densely on the outer circumference side of the joint surface 123 than on the inner circumference side, which further suppresses the molten resin caused by the irradiation of the laser light L from spilling out to the outside of the housing 10.

[0065] The cross-sectional area of ​​the first groove 71 refers to the area of ​​the cross-section created when the first groove 71 is cut in the direction of its depth. Furthermore, the width of the first groove 71 refers to its opening width.

[0066] In this embodiment, as shown in Figure 5 and other figures, the cross-section of the groove 70 (first groove 71) is approximately semicircular, but it is not limited to this, and may be rectangular, V-shaped, U-shaped, or the like.

[0067] <Second Embodiment> Figure 6(A) is an exploded perspective view of the sensor module 200 according to the second embodiment of this technology, Figure 6(B) is an enlarged view of part B in Figure 6(A), and Figure 7 is an enlarged cross-sectional view of the welded portion. Hereinafter, the configurations that differ from the first embodiment will be mainly described, and the same reference numerals will be used for the same components as in the first embodiment, and their descriptions will be omitted or simplified.

[0068] This embodiment differs from the first embodiment in that the groove 70 is provided at the open end 114 of the front case 11. In this embodiment, the groove 70 is provided in the first welding region 40 at the open end 114. Similar to the first embodiment, the groove 70 is formed continuously around the entire circumference of the first welding region and consists of a plurality of grooves (first grooves 71) arranged in parallel to each other. In this embodiment as well, the number, arrangement pitch, shape, and other configurations of the first grooves 71 are the same as in the first embodiment, so their description is omitted.

[0069] Here, we will explain the effect of the groove 70 in suppressing the overflow of molten resin. Figure 8 is an explanatory diagram of the effect of suppressing the overflow of molten resin. As shown in Figure 8, let c be the width of the first welding region 40 along the Y-axis, d be the amount of sinking of the rear case 12 relative to the front case 11 during welding, a be the width of the bottom of the groove 70 (first groove 71) along the Y-axis, b be the depth of the groove 70 (first groove 71), and n be the number of first grooves 71. Then, if we let S be the molten resin overflow suppression rate, which is the quantitative ratio of the resin contained in the groove 70 to the molten resin generated during welding, then its value is given by the following formula. S = (n × a × b) ÷ (c × d) × 100 [%]

[0070] Typically, a higher suppression rate S indicates a greater suppression of molten resin overflow. However, if the first term (n × a × b) on the right-hand side is excessively large, the welding strength tends to decrease due to a reduction in the welding area. Therefore, a suitable suppression rate is, for example, 10-40%, and more preferably 10-30%.

[0071] <Third Embodiment> Figure 9 is an enlarged view of the main part of the front case 11 showing a third embodiment of this technology. The following description will mainly focus on the configurations that differ from the first embodiment, and the same reference numerals will be used for components similar to those in the second embodiment, and their descriptions will be omitted or simplified.

[0072] This embodiment differs from the embodiments described above in that the groove 70 further includes a plurality of first grooves 71 and a plurality of second grooves 72. Here, an example is described in which the groove 70 is formed at the open end 114 (second welding region 50) of the front case 11, but it is not limited to this, and the same applies when the groove 70 is formed at the joint surface (first welding region 40) of the rear case 12.

[0073] As shown in Figure 9, the multiple second grooves 72 are formed in a direction that intersects with the multiple first grooves 71. The direction of intersection is typically perpendicular to the multiple first grooves 71, but is not limited to this, and may be a direction that intersects the multiple first grooves 71 diagonally. Furthermore, the multiple second grooves 72 do not need to be formed in the same direction. Preferably, each of the second grooves 72 is formed continuously so as to communicate with the outer and inner sides of the opening end 114.

[0074] According to this embodiment, since the groove portion 70 includes a plurality of first and second grooves 71, 72, the amount of molten resin that can be contained in the groove portion 70 can be increased. This further suppresses the overflow of molten resin onto the outer surface of the housing.

[0075] Furthermore, since the second groove 72 is formed to connect the outer and inner circumferences of the opening end 114, air remaining in the groove 70 during welding can be released to the inner or outer circumference of the housing 10 via the second groove 72. This prevents welding defects caused by the expansion of residual air in the groove 70 during welding and ensures stable welding strength.

[0076] The second groove 72 may be formed to communicate only with the inner circumference of the housing 10. In this case, molten resin that cannot be contained in the groove 70 during welding can be preferentially guided to the inner circumference of the housing 10, thereby suppressing the generation of resin burrs on the outer surface of the housing 10.

[0077] Furthermore, the cross-sectional areas of the multiple first grooves 71 and the multiple second grooves 72 do not need to be the same; one of them may be larger than the other. Also, the cross-sectional area of ​​the multiple second grooves 72 may be configured to increase towards the outside. This allows for more space to be filled with molten resin on the outside, thereby suppressing resin overflow.

[0078] Furthermore, the number of grooves in the multiple first grooves 71 and the multiple second grooves 72 can be appropriately designed as needed.

[0079] <Variation> The technology disclosed herein can be applied to a variety of products. For example, the technology disclosed herein may be implemented as a sensor module mounted on any type of mobile device, such as automobiles, electric vehicles, hybrid electric vehicles, motorcycles, bicycles, personal mobility devices, airplanes, drones, ships, robots, construction machinery, or agricultural machinery (tractors).

[0080] Furthermore, although the above embodiments have described a camera module as an example of the sensor module 100, it is not limited to this. For example, a sensor equipped with a ranging sensor such as LIDAR (Light Detection and Ranging) or TOF (Time of Flight) may be used as the sensor element. This technology can also be used in modules.

[0081] Furthermore, this technology can also be configured as follows. (1) Sensor element and A first case having an open end including a first welding region and housing the sensor element, A second case having a joint surface including a second welding region that forms a welded portion by welding with the first welding region, A groove formed in at least one of the first welding region and the second welding region A sensor module equipped with the following features. (2) The sensor module described in (1) above, The groove is formed around the entire circumference of the first welding region or the second welding region. Sensor module. (3) The sensor module described in (2) above, The groove is formed continuously around the entire circumference of the first or second welding region. Sensor module. (4) The sensor module described in (2) above, The groove portion includes a plurality of first grooves formed in parallel around the entire circumference of the first welding region or the second welding region. Sensor module. (5) The sensor module described in (4) above, The number of the plurality of first grooves is three or more, and the plurality of first grooves are formed more densely towards the outside of the first welding region or the second welding region. Sensor module. (6) A sensor module as described in (4) or (5) above, Of the plurality of first grooves, the cross-sectional area of ​​the first groove located on the outermost side of the joint surface is greater than the cross-sectional area of ​​the first groove located on the innermost side of the joint surface. Sensor module. (7) A sensor module as described in (4) or (5) above, Of the plurality of first grooves, the width or depth of the first groove located on the outermost side of the joint surface is greater than the width or depth of the first groove located on the innermost side of the joint surface. Sensor module. (8) A sensor module described in any one of (4) to (7) above, The groove portion further includes a plurality of second grooves extending in a direction intersecting the plurality of first grooves. Sensor module. (9) A sensor module described in any one of (1) to (8) above, The open end is formed outside the first welding region and further has a stepped surface parallel to the first welding region. The joining surface is formed outside the second welding region and further has a parallel surface parallel to the second welding region, The stepped surface and the parallel surface face each other with a gap in between. Sensor module. (10) A sensor module described in any one of (1) to (9) above, The first case is made of a resin material that absorbs laser light of a predetermined wavelength, The second case is made of a resin material that transmits laser light of the predetermined wavelength. Sensor module. (11) The sensor module described in (10) above, The groove is filled with the molten resin material of the first case or the second case. Sensor module. (12) A sensor module described in any one of (1) to (11) above, The aforementioned sensor element is an image sensor. Sensor module. (13) A sensor module described in any one of (1) to (12) above, The first case and the second case are joined together by laser welding. Sensor module. [Explanation of symbols]

[0082] 11…Front case (first case) 12…Rear case (second case) 20...Sensor board 30... Telescope tube 40...First welding area 50...Second welding area 60… Connector 70… Groove 71... The first groove 72... The second trench 100,200... Sensor Modules 114...Open end 123...Joint surface L... Laser light

Claims

1. Sensor element and A first case having an open end including a first welding region and housing the sensor element, A second case having a joint surface including a second welding region that forms a welded portion by welding with the first welding region, A groove formed in at least one of the first welding region and the second welding region It is equipped with, The groove portion is formed along the circumferential direction of the first welding region or the second welding region and includes a plurality of first grooves formed in parallel. Of the plurality of first grooves, the width or depth of the first groove located on the outermost side of the joint surface is greater than the width or depth of the first groove located on the innermost side of the joint surface. Sensor module.

2. A sensor module according to claim 1, The groove is formed around the entire circumference of the first welding region or the second welding region. Sensor module.

3. A sensor module according to claim 2, The groove is formed continuously around the entire circumference of the first or second welding region. Sensor module.

4. A sensor module according to claim 1, The number of the plurality of first grooves is three or more, and the plurality of first grooves are formed more densely towards the outside of the first welding region or the second welding region. Sensor module.

5. A sensor module according to claim 1, Of the plurality of first grooves, the cross-sectional area of ​​the first groove located on the outermost side of the joint surface is greater than the cross-sectional area of ​​the first groove located on the innermost side of the joint surface. Sensor module.

6. A sensor module according to claim 1, The groove portion further includes a plurality of second grooves extending in a direction intersecting the plurality of first grooves. Sensor module.

7. A sensor module according to claim 2, The open end is formed outside the first welding region and further has a stepped surface parallel to the first welding region. The joining surface is formed outside the second welding region and further has a parallel surface parallel to the second welding region, The stepped surface and the parallel surface face each other with a gap in between. Sensor module.

8. A sensor module according to claim 1, The first case is made of a resin material that absorbs laser light of a predetermined wavelength. The second case is made of a resin material that transmits laser light of the predetermined wavelength. Sensor module.

9. A sensor module according to claim 8, The groove is filled with the molten resin material of the first case or the second case. Sensor module.

10. A sensor module according to claim 1, The aforementioned sensor element is an image sensor. Sensor module.

11. A sensor module according to claim 1, The first case and the second case are joined together by laser welding. Sensor module.

Images