Imaging unit, endoscope, and method for manufacturing imaging unit
By using a recessed design in the 3D wiring board and precise positioning technology, the problem of difficult electrode positioning in ultra-small camera units has been solved, enabling easy manufacturing and high-precision alignment of the camera units.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- OLYMPUS MEDICAL SYST CORP
- Filing Date
- 2021-06-29
- Publication Date
- 2026-07-14
Smart Images
Figure CN117320610B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a camera unit having a camera component disposed in a recess of a three-dimensional wiring board, an endoscope including the camera unit having a camera component disposed in a recess of a three-dimensional wiring board, and a method for manufacturing the camera unit having a camera component disposed in a recess of a three-dimensional wiring board. Background Technology
[0002] To reduce invasiveness, it is important to reduce the diameter of the camera unit located at the front end of the endoscope's insertion section.
[0003] Japanese Patent Application Publication No. 2012-18993 discloses a laminated element manufactured by a wafer-level method for the efficient manufacture of small-diameter camera units. In the wafer-level method, the laminated element is manufactured by cutting a laminated wafer, which is composed of multiple camera elements and multiple lens wafers, each including multiple lenses, bonded together.
[0004] International Publication No. 2015 / 082328 (Japanese Patent No. 6533787) discloses a camera unit in which a stacked element including a camera element is housed in a recess of a three-dimensional wiring board. By using a molded interconnect device (MID) as the three-dimensional wiring board, the manufacturing process can be simplified.
[0005] However, in ultra-small camera units, it is not easy to accurately position the bonding electrodes on the bottom surface of the recess and the external electrodes on the back of the stacked elements. In particular, as described later, dimensional deviations are inevitable in MIDs. Therefore, the bonding electrodes are sometimes misidentified as alignment marks used for positioning.
[0006] Existing technical documents
[0007] Patent documents
[0008] Patent Document 1: Japanese Patent Application Publication No. 2012-18993
[0009] Patent Document 2: International Publication No. 2015 / 082328 Summary of the Invention
[0010] The problem that the invention aims to solve
[0011] The purpose of the embodiments of the present invention is to provide an easily manufactured camera unit, an easily manufactured endoscope, and a method for manufacturing an easily manufactured camera unit.
[0012] Methods for solving problems
[0013] The imaging unit of the embodiment includes: a generally rectangular stacked element having a light-receiving surface and a back surface located on the opposite side of the light-receiving surface, and an external electrode for outputting imaging signals on the back surface; and a three-dimensional wiring board having a first main surface and a side surface perpendicular to the first main surface, a bonding electrode and an alignment mark having a bottom surface of a recess in the first main surface, the external electrode of the stacked element disposed in the recess being bonded to the bonding electrode, a protrusion having a protrusion protruding along a first direction parallel to the wall surface of the recess on the side surface, and on the bottom surface, the area of the area where a first region of the bonding electrode imaginarily moves in the first direction overlaps with the alignment mark is less than 50% of the area of the alignment mark.
[0014] Another embodiment of the endoscope includes a camera unit comprising: a generally rectangular stacked element having a light-receiving surface and a back surface located opposite to the light-receiving surface, wherein an external electrode for outputting an image signal is provided on the back surface; and a three-dimensional wiring board having a first main surface and a side surface perpendicular to the first main surface, wherein a bonding electrode and an alignment mark are provided on the bottom surface of a recess in the first main surface, wherein the external electrode of the stacked element disposed in the recess is bonded to the bonding electrode, and a protrusion protruding along a first direction parallel to the wall of the recess is provided on the side surface, wherein on the bottom surface, the area of a first region in which the bonding electrode is imaginarily moved in the first direction overlaps with the area of the alignment mark is less than 50% of the area of the alignment mark.
[0015] In another embodiment of the camera unit manufacturing method, the following steps are included: manufacturing a plurality of three-dimensional wiring boards using injection molding, followed by laser irradiation and film deposition to form a film. Each three-dimensional wiring board has a first main surface and side surfaces perpendicular to the first main surface. Alignment marks and a plurality of bonding electrodes are present on the bottom surface of a recess in the first main surface. In the injection molding, resin is injected into a mold via runners extending from each of the side surfaces. The plurality of three-dimensional wiring boards are monolithically formed into a three-dimensional wiring board with gate cutting portions on the side surfaces by cutting each of the runners. The gate cutting portion protrudes along a first direction parallel to the wall of the recess; the gate cutting portion of the three-dimensional wiring board abuts against one surface of the fixture; using the alignment mark, the external electrode of the generally cuboid stacked element is positioned with the bonding electrode, wherein the stacked element has a light-receiving surface and a back surface and has an external electrode for outputting an image signal on the back surface, and on the bottom surface, the area of the area where the alignment mark and the bonding electrode overlap in a first region that is imaginarily moved in the first direction is less than 50% of the area of the alignment mark; and the external electrode is bonded to the bonding electrode.
[0016] Invention Effects
[0017] According to embodiments of the present invention, an easily manufactured camera unit, an easily manufactured endoscope, and a method for manufacturing an easily manufactured camera unit can be provided. Attached Figure Description
[0018] Figure 1 This is a perspective view of the camera unit according to the first embodiment.
[0019] Figure 2 This is an exploded perspective view of the camera unit according to the first embodiment.
[0020] Figure 3 This is a top view of the camera unit MID according to the first embodiment.
[0021] Figure 4 This is a top view of a portion of the MID of the camera unit in the first embodiment.
[0022] Figure 5 This is a flowchart of the manufacturing method of the camera unit according to the first embodiment.
[0023] Figure 6 This is a plan view illustrating the manufacturing method of the camera unit MID according to the first embodiment.
[0024] Figure 7 This is a plan view illustrating the manufacturing method of the camera unit MID according to the first embodiment.
[0025] Figure 8 This is a perspective view illustrating the manufacturing method of the camera unit according to the first embodiment.
[0026] Figure 9 This is a top view of a portion of the camera unit MID of a variation of the first embodiment 1.
[0027] Figure 10 This is a top view of a portion of the MID of the camera unit in a variation of the first embodiment, Example 2.
[0028] Figure 11 This is a three-dimensional view of the endoscope according to the second embodiment. Detailed Implementation
[0029] Hereinafter, embodiments of the present invention will be described using the accompanying drawings.
[0030] Furthermore, the accompanying drawings based on the implementation method are schematic. The relationship between the thickness and width of each part, the ratio of the thickness of each part, etc., differ from reality. The drawings also include the dimensional relationships between each other and parts with different ratios. Illustrations of some constituent elements and labeling are omitted. The direction of the photographed object is referred to as "up".
[0031] <First Implementation Method>
[0032] Figure 1 and Figure 2 The camera unit 1 shown in this embodiment includes a three-dimensional wiring board 10, a stacked element 20, and a resin 30. Additionally, in Figure 2 The text does not specify resin 30.
[0033] The stacked element 20 has a light-receiving surface 20SA and a back surface 20SB located opposite to the light-receiving surface 20SA, and an external electrode 25 for outputting image signals is located on the back surface 20SB. The stacked element 20 includes an image sensor 21 and an optical system 22 formed by stacking multiple optical elements. The optical elements are, for example, hybrid lens elements (composite elements) having a glass plate and a resin lens, or infrared cut-off filter elements, etc.
[0034] The structure of the optical system 22, namely the structure (thickness, shape), type, quantity, and stacking order of the optical elements, can be modified in various ways according to specifications. A patterned light-shielding film can be attached as an aperture on the main surface of any optical element.
[0035] The stacked element 20 is fabricated using a wafer-level method of dicing a bonding wafer to bond the stacked element to multiple camera element wafers comprising multiple camera elements. The stacked element is composed of multiple optical element wafers, each comprising multiple optical elements. Therefore, the stacked element 20 is cuboid. Alternatively, the stacked element 20 can be fabricated using a wafer-level method of dicing a bonding wafer to which multiple camera elements are bonded.
[0036] The imaging element 21, made of silicon, has a light-receiving portion composed of a CCD or the like. The stacked element 20 (imaging element 21) has solder bumps 29 on the external electrode 25 on its back side 20SB. At least one semiconductor element for processing imaging signals may also be stacked on the lower surface of the imaging element 21. In the stacked element with the semiconductor element, the electrode on the lower surface of the semiconductor element becomes the external electrode 25. Furthermore, a glass cover may be provided on the upper surface of the imaging element 21.
[0037] The three-dimensional wiring board 10 (hereinafter referred to as "wiring board 10") has a first main surface 10SA, a side surface 10SS perpendicular to the first main surface 10SA, and a second main surface 10SB located on the opposite side of the first main surface 10SA. The first main surface 10SA has a recess H10. The recess H10 has four wall surfaces H10SS and a bottom surface H10SB. Two of the four wall surfaces H10SS are parallel to the direction of the side surface 10SS relative to the recess H10 (first direction: Y direction in the figure). The opening of the recess H10 is a generally rectangular shape with curved angles, but it can also be a rectangle.
[0038] The wiring board 10 includes: a main portion 11 having a recess H10; and an extension portion 12 having a third main surface 10SA2 parallel to the first main surface 10SA, and the distance between the third main surface 10SA2 and the second main surface 10SB is shorter than the distance between the first main surface 10SA and the second main surface 10SB. The side surface of the extension portion 12 is a side surface 10SS. Furthermore, the wiring board 10 also has an extension portion 13 on the opposite side of the extension portion 12, separated from the main portion 11. As long as the extension portion 12 has a side surface 10SS with a gate cutting portion (protrusion) 10P (described later), the third main surface 10SA2 may not be parallel to the first main surface 10SA. Furthermore, the extension portion 12 may also have a through hole or be used to mount electronic components.
[0039] The wiring board 10 may also not have the extension sections 12 and 13. In the wiring board without the extension sections 12 and 13, the side of the main section 11 is the side section 10SS.
[0040] like Figure 3 , Figure 4 As shown, a plurality of bonding electrodes 15 and a plurality of alignment marks 16 (16A, 16B) are disposed on the bottom surface H10SB of the recess H10. Although not shown, the bonding electrodes 15 are electrically connected to the electrodes of the second main surface 10SB via surface wiring and through wiring. The bonding electrodes 15 may also be connected to the electrodes of the second main surface 10SB via wiring on the wall of the recess H10, wiring on the first main surface 10SA, and wiring on the side of the main part 11.
[0041] The stacked component 20 is disposed in the recess H10 of the wiring board 10. The external electrode 25 of the stacked component 20 passes through the solder bump 29 (see reference). Figure 2 The light-receiving portion of the image sensor 21 is connected to the electrode of the second main surface 10SB via the external electrode 25, solder bump 29, bonding electrode 15, and through wiring.
[0042] For example, resin 30, which is a thermosetting epoxy resin, seals the gap between the recess H10 and the laminated element 20. While sealing the laminated element 20, resin 30 also alleviates the stress applied to the laminated element 20. To prevent external light from entering from the side of the laminated element 20, resin 30 preferably has light-shielding properties by containing light-shielding particles or the like.
[0043] The alignment between the external electrode 25 of the stacked element 20 and the bonding electrode 15 of the bottom surface H10SB of the recess H10 of the wiring board 10 is performed as follows: using an alignment device, the alignment is first checked against the fixture 50 (see reference). Figure 8At least two alignment marks 16 of the wiring board 10 are then aligned, and the stacked element 20 or the wiring board 10 is moved with reference to the position of the alignment marks 16 so that the stacked element 20 and the wiring board 10 are in a specified relative position.
[0044] For example, the alignment device is based on the search area SA of the bottom surface H10SB of the captured recess H10. Figure 4 The image is used to calculate the correlation coefficient (similarity) with the template (size / shape of alignment mark 16), and geometric shape pattern matching is performed on the scale of its similarity to detect alignment mark 16.
[0045] The wiring board 10 has a protrusion 10P on its side 10SS, which protrudes along a first direction (Y direction in the figure) parallel to two of the four wall surfaces H10SS of the recess H10. As described later, Figure 3 The protrusion 10P shown is a gate cutting portion, therefore the protrusion length (d) of the protrusion 10P is different in the multiple wiring boards 10. Therefore, there is a deviation in the initial position of the multiple wiring boards 10 fixed to the fixture 50.
[0046] Furthermore, due to limitations in the specifications of the stacked elements 20 and the detection capability of the alignment device, the bonding electrode 15 and the alignment mark 16 are of the same shape and size; for example, the bonding electrode 15 is a circle with a diameter of 100 μm, and the alignment mark 16 is also a circle with a diameter of 100 μm. Therefore, when detecting the alignment mark 16, the bonding electrode 15 may be misidentified as the alignment mark 16. If the bonding electrode 15 and the alignment mark 16 are set to have approximately the same shape and approximately the same size, the bonding electrode 15 may also be misidentified as the alignment mark 16.
[0047] Additionally, "approximately the same shape and approximately the same size" means that when the bonding electrode 15 is hypothetically overlapped with the alignment mark 16, which is smaller than the bonding electrode 15, the area of the overlapping region is, for example, more than 60% of the area of the alignment mark 16.
[0048] like Figure 4 As shown, regarding the wiring board 10 of the camera unit 1, on the bottom surface H10SB of the recess H10, the first region A15 of the bonding electrode 15, which is imaginarily moved in the first direction (Y direction), does not overlap with the alignment mark 16.
[0049] Considering the deviation in the protrusion amount of the protrusion 10P, the search area SA of the alignment device is set relatively large in the Y direction. However, by setting the search area SA to exclude the first area A15, the bonding electrode 15 will not be misidentified as the alignment mark 16. The stacked elements 20 and the wiring board 10 can be easily aligned, thus facilitating the manufacture of the camera unit 1.
[0050] <Method for manufacturing camera unit>
[0051] according to Figure 5 The flowchart illustrates the manufacturing method of camera unit 1.
[0052] <Step S10> Injection Molding
[0053] like Figure 6 As shown, multiple wiring boards 10 are manufactured using injection molding. In a mold (not shown) comprising multiple three-dimensional wiring boards, MID resin is injected from a sprue 40 through a runner 41 and from a gate 42. Multiple molded bodies, becoming multiple wiring boards 10, are removed from the mold and connected via the sprue 40 and the runner 41.
[0054] On the surface of a molded body made of MID resin, a region with catalytic activity that can be electrolessly plated is formed by irradiating it with a laser. Furthermore, a through-hole is formed on the bottom surface of the recess H10. Afterward, through an electroless plating process, the molded body becomes a wiring board 10 equipped with a bonding electrode 15, alignment marks 16, etc.
[0055] As already described, the wiring board 10 has a first main surface 10SA and a side surface 10SS perpendicular to the first main surface 10SA, and a bonding electrode 15 and an alignment mark 16 are provided on the bottom surface H10SB of the recess H10 in the first main surface 10SA.
[0056] <Step S20> Gate Cutting
[0057] like Figure 7 As shown, the multiple wiring boards 10 connected by the horizontal runner 41 are cut off at each gate 42, thereby being monolithically divided into wiring boards 10. Therefore, the wiring board 10 has a gate cutting portion 10P protruding on the side 10SS in a first direction parallel to the wall surface H10SS of the recess H10.
[0058] <Step S30> Configure the assistive device
[0059] Although not illustrated, the cuboid stacked element 20 is fabricated using a wafer-level method of cutting and bonding wafers. This bonding wafer is configured to bond multiple imaging elements onto the stacked wafer, which is composed of multiple optical element wafers, each comprising multiple optical elements. The stacked element 20 has solder bumps 29 on the external electrodes 25 of its back surface 20SB.
[0060] like Figure 8 As shown, the wiring board 10 is fixed to the fixture 50. The fixture 50 may also be part of an alignment device. At this time, the gate cutting portion 10P of the wiring board 10 is in contact with one surface of the fixture 50.
[0061] As already explained, the protrusion amount d of the gate cut-out portion 10P protruding from the side 10SS is not fixed in the multiple wiring boards 10.
[0062] <Step S40> Positioning
[0063] Positioning of the bonding electrode 15 of the wiring board 10 and the external electrode 25 of the stacked element 20 is performed while moving at least one of the wiring board 10 and the stacked element 20.
[0064] First, the alignment mark 16 is detected. Depending on the shape of the alignment mark 16, only one alignment mark 16 may be detected, but to improve positioning accuracy, it is preferable to detect at least two alignment marks 16.
[0065] When alignment mark 16 is detected, the position of the bonding electrode 15 relative to the position of alignment mark 16 is estimated. With the position of the external electrode 25 of the stacked element 20 overlapping the estimated position of the bonding electrode 15 of the wiring board 10, the stacked element 20 is inserted into the recess H10 of the wiring board 10.
[0066] For example, the XY coordinates of two of the plurality of bonding electrodes 15 are estimated based on the positions (X coordinate values, Y coordinate values) of the wiring board 10 of the fixture fixed to the worktable of the alignment device. After the holding member holding the stacked element 20 moves to the XY coordinate position of the external electrode 25, the stacked element 20 is moved in the Z direction, thereby inserting the stacked element 20 into the recess H10 of the wiring board 10 in an aligned state. Alternatively, an adhesive may be used to temporarily fix the stacked element 20 to the recess H10.
[0067] The search area SA of the alignment device is set to exclude the first area A15. Therefore, the bonding electrode 15 will not be misidentified as the alignment mark 16.
[0068] <Step S50> Joining
[0069] The wiring board 10 and the stacked components 20 are positioned, for example, in a temporarily fixed state, and subjected to reflow heating. The external electrode 25 and the bonding electrode 15 are bonded by solder bumps 29. Afterwards, resin 30 is injected into the gap between the recess H10 and the stacked components 20 and then cured. When bonding via the solder bumps 29, solder paste can also be pre-applied to the external electrode 25.
[0070] The manufacturing method of the camera unit 1 in this embodiment facilitates the positioning between the wiring board 10 and the stacked components 20.
[0071] <Modifications of the First Embodiment>
[0072] Similar to camera unit 1, camera units 1A and 1B in variations 1 and 2 have the same effect. Therefore, structures with the same function are labeled with the same reference numerals and descriptions are omitted.
[0073] <Variation Example 1>
[0074] like Figure 9 As shown, in the wiring board 10A of the camera unit 1A in this modified example, on the bottom surface H10SB of the recess H10, there is an overlapping area AX where the first region A15, which is imaginarily moved in the first direction (Y direction), overlaps with the alignment mark 16.
[0075] However, the area of the overlapping region AX is 20% of the area of alignment mark 16.
[0076] The search area SA of the alignment device includes the first area A15, but does not include the entire engagement electrode 15, so the engagement electrode 15 will not be misidentified as the alignment mark 16.
[0077] In addition, to prevent misidentification, the area of the overlapping region AX is preferably less than 50% of the area of the alignment mark 16, and particularly preferably less than 30%.
[0078] <Variation Example 2>
[0079] like Figure 10 As shown, in the wiring board 10B of the camera unit 1B in this modified example, the first region A15 where the bonding electrode 15 is imaginarily moved in the first direction (Y direction) and the second region B15 where the bonding electrode 15 is imaginarily moved in the second direction (X direction) perpendicular to the first direction (Y direction) do not overlap with the alignment mark 16.
[0080] The search area (not shown) of the alignment device does not include the first area A15 and the second area B15. Therefore, compared with the imaging unit 1, the bonding electrode 15 of the imaging unit 1B is less likely to be misidentified as the alignment mark 16.
[0081] Furthermore, even if a portion of the alignment mark 16 overlaps with the first region A15 and the second region B15, as long as the sum of the overlapping area of the first region A15 and the alignment mark 16 and the overlapping area of the second region B15 and the alignment mark 16 is less than 50% of the area of the alignment mark 16, the bonding electrode 15 will not be misidentified as the alignment mark 16.
[0082] <Second Implementation Method>
[0083] Figure 11 The endoscope 9 of this embodiment shown includes an insertion part 91, an operation part 92, a universal cable 93, and an endoscope connector 94. The elongated tube-shaped insertion part 91 is inserted into the body cavity of a living organism.
[0084] The endoscope 9 includes camera units 1, 1A, and 1B disposed at the front end 91A of the insertion portion 91. As already explained, camera units 1, 1A, and 1B are easy to manufacture, therefore the endoscope 9 is easy to manufacture.
[0085] Furthermore, the 3D wiring board having the recess H10 for mounting the stacked elements 20 is not limited to being manufactured by MID (Made in China), but can also be manufactured by 3D printing-based processing or machining. The material of the 3D wiring board is not limited to resin, but can also be ceramic or epoxy glass.
[0086] Endoscope 9 is a flexible endoscope for medical use, but the endoscope in other embodiments may be an industrial endoscope or a rigid endoscope with a rigid straight tube as the insertion part.
[0087] This invention is not limited to the embodiments described above, and various changes and modifications can be made without altering the spirit of the invention.
[0088] Label Explanation
[0089] 1, 1A, 1B: Camera units;
[0090] 9: Endoscope;
[0091] 10: 3D wiring board;
[0092] 11: Main parts;
[0093] 11, 12: Extension installation section;
[0094] 15: Bonding electrode;
[0095] 16: Alignment mark;
[0096] 20: Stacked components;
[0097] 30: Resin.
Claims
1. A camera unit, characterized in that, This camera unit has the following features: A generally rectangular stacked element having a light-receiving surface and a back surface located opposite the light-receiving surface, wherein an external electrode for outputting an image signal is located on the back surface; and A three-dimensional wiring board has a first main surface and a side surface perpendicular to the first main surface. A bonding electrode and an alignment mark are provided on the bottom surface of a recess in the first main surface. An external electrode of the stacked element disposed in the recess is bonded to the bonding electrode. A protrusion is provided on the side surface in a first direction parallel to the wall of the recess. On the bottom surface, the area of the first region where the bonding electrode is imaginarily moved in the first direction overlaps with the area of the alignment mark is less than 50% of the area of the alignment mark.
2. The camera unit according to claim 1, characterized in that, The alignment mark does not overlap with the first region.
3. The camera unit according to claim 1, characterized in that, The protrusion is the gate cutting section.
4. The camera unit according to claim 1, characterized in that, The alignment mark is approximately the same shape and approximately the same size as the bonding electrode.
5. The camera unit according to claim 1, characterized in that, The alignment mark and the bonding electrode are generally rectangular or generally circular.
6. The camera unit according to claim 1, characterized in that, The sum of the area of the region where the first region overlaps with the alignment mark and the area of the region where the second region of the bonding electrode is imaginarily moved in a second direction perpendicular to the first direction overlaps with the alignment mark is less than 50% of the area of the alignment mark.
7. An endoscope comprising a camera unit, characterized in that, The camera unit includes: A generally rectangular stacked element having a light-receiving surface and a back surface located opposite the light-receiving surface, wherein an external electrode for outputting an image signal is located on the back surface; and A three-dimensional wiring board has a first main surface and a side surface perpendicular to the first main surface. A bonding electrode and an alignment mark are provided on the bottom surface of a recess in the first main surface. An external electrode of the stacked element disposed in the recess is bonded to the bonding electrode. A protrusion is provided on the side surface in a first direction parallel to the wall of the recess. On the bottom surface, the area of the first region where the bonding electrode is imaginarily moved in the first direction overlaps with the area of the alignment mark is less than 50% of the area of the alignment mark.
8. A method for manufacturing a camera unit, characterized in that, It has the following processes: Multiple three-dimensional wiring boards are manufactured using injection molding, followed by laser irradiation and film deposition. Each three-dimensional wiring board has a first main surface and a side surface perpendicular to the first main surface. Alignment marks and multiple bonding electrodes are provided on the bottom surface of the recess of the first main surface. In the injection molding process, resin is injected into the mold via a transverse runner extending from each of the side surfaces. The plurality of three-dimensional wiring boards are monolithically transformed into three-dimensional wiring boards with gate cutting portions on the side by cutting off each of the horizontal runners, wherein the gate cutting portions protrude along a first direction parallel to the wall surface of the recess; The gate cutting portion of the three-dimensional wiring board abuts against one side of the auxiliary fixture; Using the alignment mark, the external electrode of a generally cuboid stacked element is positioned with the bonding electrode, wherein the stacked element has a light-receiving surface and a back surface and has an external electrode for outputting an image signal on the back surface, and on the bottom surface, the area of the region where the alignment mark and the bonding electrode overlap in a first region of imaginary movement in the first direction is less than 50% of the area of the alignment mark; and The external electrode is joined to the bonding electrode.