Electronic component assembly with thermally conductive structure for image sensor

Abstract

An electronic component assembly with thermal pads for heat dissipation having thermal vias coupling an image sensor and a camera board member is provided. The electronic component assembly can include a circuit board having at least one thermal pad disposed on a top surface of the circuit board, and an image sensor disposed on the top surface of the circuit board having at least one conductive pad disposed at at least one corner of the image sensor. The at least one thermal pad is coupled to the at least one conductive pad of the image sensor, and the at least one thermal pad is formed by a plurality of first thermal vias that penetrate the thermal pad and the circuit board to transfer heat of the image sensor.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Provisional Application Serial No. 62 / 944,611, filed December 6, 2019, which is incorporated herein by reference in its entirety. Background Technology

[0003] Instruments and systems used to view, record, and analyze the results of biological and chemical tests and assays typically require instrument configurations such as charge-coupled device (CCD) cameras, complementary metal-oxide-semiconductor (CMOS) imagers, or other such image sensors. Figure 1 The older CCD and CMOS package designs shown leave a lot of space on the back of the image sensor for attaching a cold finger for heat dissipation. For example, Figure 2(a) provides a schematic representation of the Sony ICX 695CCD image sensor, where the boxed areas indicate the areas where the cold finger may contact the image sensor.

[0004] However, more modern CMOS image sensors (such as the Sony IMX 178 image sensor shown in Figures 2(b) and 2(d), or the Sony IMX183 image sensor shown in Figure 2(c)) have a grid array architecture and therefore do not have much usable area for finger-shaped cooler contacts for heat dissipation.

[0005] All other things being equal, the heat conduction using a conventional finger-shaped cooler is proportional to the area of ​​the image sensor and can be determined by the following equation:

[0006]

[0007] in:

[0008] Q = Thermal conductivity (W)

[0009] K = Thermal conductivity of the material (W / mK)

[0010] A = Cross-sectional area

[0011] T 热 = Higher temperature (°C or °K)

[0012] T 冷 =Lower temperature (°C or °K)

[0013] d = material thickness

[0014] Therefore, the older image sensor in Figure 2(a), the Sony ICX695 (with an area of ​​160 mm²), 2The heat conduction is less than that of the more modern image sensor Sony IMX178 (with an area of ​​8.75 mm²) shown in Figure 2(b). 2 It conducts heat 18.3 times faster; and the older image sensor in Figure 2(a), the Sony ICX695 (with an area of ​​160 mm²), is shown in Figure 2(a). 2 The heat conduction is better than that of the more modern image sensor Sony IMX183 (with an area of ​​20 mm²) in Figure 2(c). 2 It conducts heat 8 times faster.

[0015] However, some existing image sensors include pads located at the corners of the image sensor, as shown in Figure 2(d). Even if the corner pads are not directly connected to each other through vias inside the image sensor body, heat will be carried away by bulk heat conduction within the image sensor body when the corner pads are cooler than the bulk silicon of the image sensor pixel plane. Summary of the Invention

[0016] There is still a need in the art for improved design and technology of image sensor assemblies having thermally conductive structures for dissipating heat from the image sensor to maintain a controlled temperature for image sensor operation.

[0017] Embodiments of the present invention relate to an electronic component assembly having thermal pads with thermal vias for transferring heat from an image sensor, and an image sensor assembly having heat dissipation from the image sensor by active cooling of a thermoelectric cooling element (TEC).

[0018] According to an embodiment of the present invention, an electronic component assembly may include: a circuit board including at least one thermal pad disposed on a top surface of the circuit board; and an image sensor disposed on the top surface of the circuit board, including at least one conductive pad disposed at at least one corner of the image sensor; wherein the at least one thermal pad is coupled to the at least one conductive pad of the image sensor; and wherein the at least one thermal pad is formed by a plurality of first thermal vias penetrating the thermal pad and the circuit board to transfer heat from the image sensor. The electronic component assembly may further include a thermally conductive layer disposed on a bottom surface of the circuit board, wherein the thermally conductive layer is made of metal, has a circular or annular shape, and has a plurality of second thermal vias penetrating the thermally conductive layer and spaced apart therein to transfer heat. Furthermore, the electronic component assembly may further include a thermal composite material applied between a corner region of the image sensor and a corner region of the thermal pad including the thermal vias, and the thermal composite material extends along the length of the first thermal pad. The electronic component assembly may further include a cooling structure coupled to the circuit board to transfer heat, wherein the cooling structure includes at least one finger-shaped cooler structure that protrudes through a through-hole in the circuit board and contacts the surface of the image sensor to transfer heat. Furthermore, the electronic component assembly further includes a lens mount for mounting a lens, wherein the lens mount and the image sensor are horizontally disposed on the same surface of the top surface of the circuit board.

[0019] In another embodiment, an image sensor assembly may include: a cooling structure including at least one thermoelectric cooling element (TEC); a circuit board disposed on the cooling structure; an imaging sensor; and a lens. The image sensor assembly may further include an image sensor cover disposed on the image sensor, a lens in direct or indirect contact with the image sensor cover via a silicone pad or graphoil, a lens outer cylinder in contact with the image sensor cover, a heat sink structure coupled to the cooling structure, and a plurality of fasteners coupling the lens outer cylinder to the heat sink structure, wherein the image sensor assembly includes a cavity structure or a cavity-free structure. Furthermore, heat can be transferred from the lens outer cylinder to the silicone pad or graphoil, from the silicone pad or graphoil to the image sensor cover, from the image sensor cover to the image sensor, from the image sensor to the circuit board, from the circuit board to the cooling structure, and from the cooling structure to the heat sink. The image sensor cover may be configured as a solid block with minimal thermal conductivity attached to the image sensor, or a bag attached to some or all of the image sensor, to provide heat to the top surface to prevent condensation when the image sensor is cooled. Heat can be additionally transferred via a circuit board having corner pads, center fingers, or both. The image sensor assembly may additionally include multiple pads and multiple (e.g., three) reduced areas disposed between the lens outer barrel and the circuit board to reduce heat transfer from the lens outer barrel. The pads contact the circuit board at the reduced areas and form intermediate gaps to block stray light from reaching the image sensor. The image sensor assembly may further include multiple washers (preferably in the form of Bavarian washers) disposed between the multiple pads and the circuit board for tilt adjustment. The image sensor assembly may further include a lens mount for mounting the lens, and the image sensor and lens mount may be horizontally disposed on the same plane on the top surface of the circuit board, or the image sensor and lens mount may be configured to vertically overlap the top surface of the circuit board. Attached Figure Description

[0020] Figure 1 It is a perspective view of a cooled camera imager with a finger-shaped cooler, based on related technologies.

[0021] Figures 2(a), 2(b), and 2(c) are schematic representations of the Sony ICX695 image sensor, the Sony IMX178 image sensor, and the Sony IMX183 image sensor, respectively; and Figure 2(d) is a view of the back or electrical contact side of the Sony IMX178 image sensor according to related technologies.

[0022] Figure 3This is a top view of an image sensor assembly according to an embodiment of the present invention, the image sensor assembly having an image sensor and a camera board and having thermal pads having thermal vias coupling the image sensor and the camera board.

[0023] Figure 4 yes Figure 3 A close-up view of one of the thermal pads, showing a thermal pad with thermal vias coupling an image sensor and a camera board according to an embodiment of the present invention.

[0024] Figure 5 yes Figure 3 The schematic diagram of the image sensor assembly shown illustrates the position of the thermal via relative to the corner pad on the image sensor according to an embodiment of the present invention.

[0025] Figure 6 and Figure 7 This is a rear view of a prototype image sensor assembly according to an embodiment of the present invention, wherein the four corner areas are visible in light green, and the outer and inner boundaries of the thermal conductive layer on the back of the circuit board are outlined in red.

[0026] Figure 8 This is a magnified three-dimensional schematic diagram (with the thickness dimension magnified 10 times for viewing) representing an image sensor assembly according to an embodiment of the present invention, showing thermal pads with thermal vias coupling the image sensor and camera board.

[0027] Figure 9 This is a perspective view of an image sensor assembly having a thermally conductive layer on the bottom surface of a camera plate 200 according to an embodiment of the present invention.

[0028] Figures 10(a)-10(c) This is a combination mode of visible light and 8-14μm mid-infrared (MIR) images of an image sensor assembly according to an embodiment of the present invention. Figures 10(d)-10(e) This refers to the corresponding temperature distribution of the image sensor assembly according to an embodiment of the present invention.

[0029] Figure 11 An image sensor comprising multiple signal pads is shown according to an embodiment of the present invention.

[0030] Figures 12(a) and 12(b) are top views of an image sensor assembly showing a copper heat sink plate according to an embodiment of the present invention, wherein the green line in Figure 12(a) indicates a finger-shaped cooler.

[0031] Figure 13 This is a schematic diagram of an image sensor assembly according to an embodiment of the present invention, including a cooling structure protruding through a through-hole in the camera plate to contact the surface of the image sensor for heat transfer.

[0032] Figures 14(a)-14(d) This is a schematic diagram of an image sensor assembly according to an embodiment of the present invention, which respectively (a) has a thermal pad with a thermal via arrangement and a finger cooler, (b) has only a thermal pad with a thermal via arrangement, (c) has only a finger cooler, and (d) has neither a thermal pad with a thermal via arrangement nor a finger cooler.

[0033] Figure 15 This is a schematic diagram of an image sensor assembly according to an embodiment of the present invention, wherein a thermal composite material may be applied between a corner region of the image sensor and a corner region of a thermal pad including a thermal via, and the thermal composite material extends along the length of the thermal pad.

[0034] Figure 16 This is a perspective view of an image sensor assembly including a lens mount for mounting a lens, and the lens mount and the image sensor are arranged horizontally on the same surface of a camera plate according to an embodiment of the present invention.

[0035] Figure 17 This is a cross-sectional view of a passively cooled image sensor assembly according to an embodiment of the present invention.

[0036] Figure 18 This is a perspective view of an image sensor assembly with active cooling by a thermoelectric cooling element (TEC) according to an embodiment of the present invention.

[0037] Figure 19 This is an exploded view of an image sensor assembly with active cooling by a thermoelectric cooling element (TEC) according to an embodiment of the present invention.

[0038] Figure 20 This is an exploded view of an image sensor assembly with active cooling by a thermoelectric cooling element (TEC) according to an embodiment of the present invention, showing the thermal communication and heat flow paths through the image sensor assembly.

[0039] Figure 21 This is a cross-sectional view of an actively cooled image sensor assembly according to an embodiment of the present invention.

[0040] Figure 22 This is a cross-sectional view of a conventional image sensor assembly based on related technologies, showing ten parts between the image sensor and the lens.

[0041] Figures 23-24 This is a cross-sectional view of an image sensor assembly having active cooling by a thermoelectric cooling element (TEC) and having multiple gaskets and washers according to an embodiment of the present invention.

[0042] Figure 25This is a cross-sectional view of an image sensor assembly according to an embodiment of the invention, which is actively cooled by a thermoelectric cooling element (TEC) and has multiple gaskets and washers, showing that the lens outer barrel is tilted.

[0043] Figure 26 This is an assembly diagram of a first bag of sealed desiccant with an image sensor cap according to an embodiment of the present invention.

[0044] Figure 27 This is an exploded view of a first bag of sealed desiccant with an image sensor cap according to an embodiment of the present invention.

[0045] Figure 28 This is another exploded view of a first bag of sealed desiccant with an image sensor cap according to an embodiment of the present invention, the first bag having a structure to prevent particles from entering.

[0046] Figure 29 This is an assembly diagram of a second bag of sealed desiccant with an image sensor cap according to an embodiment of the present invention.

[0047] Figure 30 This is an exploded view of a second bag of sealed desiccant with an image sensor cap according to an embodiment of the present invention.

[0048] Figure 31 and Figure 32 These are, respectively, a top view and a side view of a second bag containing a sealed desiccant according to an embodiment of the present invention.

[0049] Figure 33 This is an isometric view of an image sensor assembly from the top side according to an embodiment of the present invention, showing a plated surface beneath which filled thermal vias are disposed.

[0050] Figure 34 This is a schematic diagram of an image sensor assembly according to an embodiment of the present invention, showing multiple plated surfaces inside a camera plate.

[0051] Figure 35 This is a schematic diagram of an image sensor assembly according to an embodiment of the present invention, wherein a thermal composite material in the image sensor assembly may be applied along the entire periphery of the image sensor for heat conduction and sealing. Detailed Implementation

[0052] Embodiments of the present invention relate to an electronic component assembly having thermal pads with thermal vias for transferring heat from an image sensor, and an image sensor assembly having heat dissipation from the image sensor by active cooling of a thermoelectric cooling element (TEC).

[0053] Example 1: An electronic component assembly with thermal pads having thermal vias that couple an image sensor and a camera board.

[0054] refer to Figure 3 Electronic component assemblies (such as image sensor assembly 100) may include an image sensor 300, which includes an image sensor pixel array 310 and at least one conductive pad 320; and a camera board 200 disposed below the image sensor 300 and coupled to corner or other non-electrical functional pads of the image sensor 300, and including at least one thermal pad 340 disposed on the top surface of the camera board 200. The at least one thermal pad 340 extends below the image sensor 300 and is directly attached to the at least one conductive pad 320, such as... Figure 3 He Ru Figure 5 As shown.

[0055] Image sensor pixel array 310 is disposed on the top surface of image sensor 300 and may be CCD, CMOS, organic image sensor or other such image sensor. At least one conductive pad 320 is disposed on at least one corner region of the top surface of image sensor 300 and coupled to at least one thermal pad 340, thereby cooling image sensor pixel array 310 to maintain image sensor pixel array 310 within the operating temperature range.

[0056] In some embodiments, the thermal pad 340 may be arranged on the top surface of the camera assembly 200 and extending along the edge of the lateral surface or other surface of the corner region of the image sensor 300 to draw heat energy from the image sensor pixel array 310 toward a heat sink (not shown) to dissipate heat or to redirect heat energy to another element of the image sensor assembly 100. One advantage of such an arrangement is that the thermal pad 340 extends the heat removal path beyond the image sensor 300.

[0057] In one embodiment, the thermal pad 340 may have a plurality of first thermal vias 345 extending through the thermal pad 340 and through the camera plate 200 to the bottom surface of the camera plate 200 for heat transfer. The thermal vias are heat-conducting conduits through which heat is conducted. At least one of the plurality of first thermal vias 345 preferably has a cylindrical shape and is preferably made of a metal such as copper (Cu) or a copper alloy. Furthermore, at least one of the plurality of first thermal vias 345 may be hollow or filled with a thermally conductive material.

[0058] Furthermore, according to embodiments of the present invention, instead of Cu fingers having through holes extending upward through the camera plate 200 and contacting the bottom surface of the image sensor 300, a plurality of first thermal vias 345 can be directly disposed below the conductive pads 320 of the image sensor 300, with or without solder paste, on the top surface of the via template of the camera plate 200. The plurality of first thermal vias 345 can be filled with a thermally conductive material, smoothed, and plated. Solder paste (if present) can be placed on the top surface of the plurality of first thermal vias 345 such that when the solder paste melts, it directly contacts the bottom surface of the image sensor 300.

[0059] Compared to conventional image sensor components, this arrangement can reduce dark current by about half.

[0060] In one embodiment, at least one conductive pad 320 may be thermally or electrically connected to each other. The at least one conductive pad 320 may include a signal pad for transmitting or receiving signals for the operation of the image sensor pixel array 310.

[0061] Figure 4 This is according to an embodiment of the present invention. Figure 3 A close-up view of one of the thermal pads 340, in which multiple thermal vias 345 couple the image sensor 300 and the camera board 200.

[0062] Figure 5 This is according to an embodiment of the present invention. Figure 3 A schematic diagram of the image sensor assembly 100. At least one thermal pad 340 is disposed on the surface of the camera board 200, extends below the image sensor 300 and is directly attached to at least one conductive pad 320.

[0063] Figure 6 and Figure 7 This is a rear view of a prototype image sensor assembly 100 according to an embodiment of the present invention, wherein the four corner areas are visible in light green, and the outer and inner boundaries of the copper plane on the back of the circuit board are outlined in red.

[0064] like Figure 6 As shown, the camera plate 200 may include a heat-conducting layer 400 on its bottom surface, top surface, or both surfaces. The heat-conducting layer 400 may be made of metal, preferably copper (Cu) or a copper alloy, and preferably has a circular or annular shape. The heat-conducting layer 400 may be formed with a plurality of second heat-perforations 410, which are spaced apart and penetrate the heat-conducting layer 400 to increase heat transfer from the front surface of the camera plate 200 and any connecting planes within the camera plate 200 to the rear surface of the camera plate 200. The heat-conducting layer 400 is composed of… Figure 7 The area between the red outer circle and the red inner shape is indicated. The four corner pads with multiple through-holes can be coated with an adhesive (such as epoxy).

[0065] In one embodiment, the thermally conductive layer 400 and the first heat-perforation hole 345 and Figure 7 The second heat-conducting hole 410 shown intersects with the second heat-conducting hole, thereby allowing for better lateral heat dissipation compared to having the heat-conducting layer 400 only on the top and bottom surfaces of the camera plate 200. The heat-conducting layer 400 may have a thickness of, for example, 35 μm.

[0066] In one embodiment, the thermally conductive layer 400 may be arranged as a laminated structure having a plurality of thermally conductive layers.

[0067] Figure 8 This is a three-dimensional magnified schematic diagram (with the thickness dimension magnified 10 times for viewing) of an image sensor assembly 100 according to an embodiment of the present invention, showing the thermal pad 340, through which the thermal via 345 passes. Figure 8 At least one conductive pad 320, indicated by the area in the red circle, couples the image sensor 300 and the camera board 200.

[0068] Figure 9 This is a perspective view of an image sensor assembly 100 having a heat-conducting layer 400 on the bottom surface of a camera plate 200 according to an embodiment of the present invention.

[0069] refer to Figures 10(a)-10(c) The image sensor assembly 100 acquires combined mode visible light and 8-14 μm mid-infrared (MIR) microscopic images, and Figures 10(d)-10(e) Showing from Figures 10(a)-10(c) The corresponding temperature distribution of the image sensor assembly is shown in Figure 10(b). The horizontal line in Figure 10(b) indicates the location where the temperature distribution is plotted. Note that the image sensor 300 is a rectangle with slightly darker centers in the four corner thermal pads 340. When the thermally conductive layer 400 is attached to the back of the image sensor 300 via solder joints between at least one conductive pad 320 and the thermal pads 340 to allow passive heat dissipation, at least one corner thermal pad 340 is significantly cooled, and the image sensor 300 is cooler than the camera board 200.

[0070] like Figure 11As shown, the image sensor 300 may further include multiple signal pads for transmitting or receiving signals, and these signal pads may be thermally connected to the camera board 200 for heat dissipation to maintain the operation of the image sensor at a controlled temperature. If the signal pads are grounded signal pads, they can be connected to the back of the camera board 200 via conductive materials such as vias or planes. Red circles indicate the locations of connections from the pads to the pixel plane within the image sensor 300. Blue circles traverse the internal circuitry of the component.

[0071] To further improve heat dissipation efficiency, the image sensor assembly 100 may further include a cooling structure coupled to the camera plate 200. The cooling structure may include at least one finger-shaped cooler or other form of thermal extension(s) sized to protrude through a through-hole in the camera plate 200 to contact the surface of the image sensor 300 for heat transfer, as shown in FIG12. Figure 13 As shown.

[0072] In one embodiment, such as Figure 15 As shown, the image sensor assembly 100 may further include a thermal composite material disposed between a corner region of the thermal pad 340 and a corner region of the image sensor 300, and extending along the length of the thermal pad for heat conduction.

[0073] Furthermore, according to embodiments of the present invention, instead of Cu fingers having through holes extending upward through the camera plate 200 and contacting the bottom surface of the image sensor 300, the image sensor assembly 100 may further include a third plurality of thermal vias 345, which may be directly disposed below the image sensor 300 with or without solder paste on the top surface of the through-hole template of the camera plate 200. The third plurality of thermal vias may be filled with a thermally conductive material, smoothed, and plated. Solder paste (if present) may be placed on the top surface of the third plurality of thermal vias such that when the solder paste melts, it directly contacts the bottom surface of the image sensor 300.

[0074] Figures 12(a) and 12(b) are top views illustrating an image sensor assembly of a copper heat sink plate according to an embodiment of the present invention, wherein the green line in Figure 12(a) indicates a finger-shaped cooler. For comparison, Figure 33 This is an isometric view of an image sensor assembly from the top side according to an embodiment of the present invention, showing a plated surface beneath which filled thermal vias are disposed. Figure 33 The blue perimeter in the image represents the third layer of heat-perforated holes located on the plated surface beneath it.

[0075] Figure 34This is a schematic diagram of an image sensor assembly according to an embodiment of the present invention, showing multiple plated surfaces inside a camera plate 200. Filled heat-perforated vias can be provided on the multiple plated surfaces inside the camera plate. The heat-perforated vias terminate at ( Figure 34 The lowest (bottom) plated surface is covered by a coating, and the middle plated surface is located within the camera plate 200. A third set of heat-perforated holes are also plated on the back side, providing a smooth surface for contact with Cu or other metal components to conduct heat away.

[0076] Figure 35 This is a schematic diagram of an image sensor assembly 100 according to an embodiment of the present invention. The thermal composite material in the image sensor assembly 100 can be applied along the entire periphery of the image sensor 300 for heat conduction and sealing to prevent moisture from entering below the image sensor 300.

[0077] In one embodiment, after the camera plate 200 has a smooth surface without any holes, multiple holes are drilled into the smooth surface of the camera plate 200 and cleaned. Multiple through-hole tubes are then plated into each of the multiple holes. Next, the through-hole tubes are filled with epoxy resin and covered with Cu. A sanding operation may be additionally performed to smooth all the thermal vias. Any thermal vias not covered by the solder mask are then plated.

[0078] In one embodiment, the gap between the edge of the camera plate 200 and the edge of the image sensor 300 is sealed along the edge. This seal, together with the seal described above on the upper surface of the camera plate 200 surrounding the edge of the image sensor 300, seals the bottom surface of the image sensor 300 on which the contacts of the image sensor 300 are disposed, thereby suppressing short circuits.

[0079] In another embodiment, instead of sealing from the edge of the upper surface of the camera plate 200 all the way to the edges of the image sensor 300 and the bottom surface of the camera plate 200, as well as the holes on the image sensor 300, an underfill material is applied underneath to suppress condensation. For example, the underfill material can be a reprocessable underfill sealant for ball grid arrays (BGAs), chip-scale packages (CSPs), or wafer-level chip-scale packages (WL-CSPs). It should be noted that for thermal conductivity purposes, thermal adhesive can still be applied to the corners of the image sensor 300 or all the way to the edge of the upper surface of the camera plate 200.

[0080] In one embodiment, a conformal coating may be applied to the mask area to suppress condensation-related short circuits of electronic components. Specifically, on the upper surface of the camera plate 200, a conformal coating is applied around the image sensor 300 and extends outwards to the gasket light seal. Further conformal coating may be applied outside the gasket light seal and extended to locations where thermal testing indicates the surface temperature of the camera plate 200 is below ambient temperature or where no electronic components are exposed. Additionally, if electronic components are exposed on the bottom surface, a conformal coating may be applied to the bottom surface of the camera plate 200. Furthermore, if the camera plate 200 has a smooth backplate in direct contact with the TEC, a conformal coating may be applied around the edges of the cooled Cu portion of the camera plate 200. Examples of conformal coatings include, but are not limited to, spherical tops and dam-and-fill sealants.

[0081] In one embodiment, to further improve thermal performance, the image sensor assembly 100 may further include a lens mount 400 for mounting a lens, and act as a heat sink by placing the lens mount 400 directly on the top surface of the camera plate 200. The lens mount 400 and the image sensor 300 are horizontally disposed on the same surface of the camera plate 200, as shown below. Figure 16 As shown.

[0082] In cases where precise flatness between the lens 600 and the image sensor 300 is not achievable, depending on the method by which the lens 600 and the image sensor 300 are formed or mounted on the camera plate 200, sufficient flatness is desired to allow for better heat dissipation.

[0083] Dark currents of image sensors with four different cooling structures were measured, and the results are summarized in Table 1. Note that significantly lower dark currents were achieved when the lens was directly mounted on the camera plate 200 compared to when the lens was not directly mounted on the camera plate 200.

[0084] Table 1

[0085]

[0086]

[0087] Furthermore, since the lens is directly mounted on the camera plate 200, there is no intermediate mounting bracket and a rear focus adjustment ring, which increases the point tolerance and reduces the number of parts between the lens 600 and the image sensor 300 by at least two.

[0088] Figure 17 This is a cross-sectional view of a passively cooled image sensor assembly according to an embodiment of the present invention.

[0089] Example 2: Image sensor assembly with active cooling by TEC

[0090] refer to Figures 14(a)-14(d) Four different configurations are shown: (a) the image sensor assembly 100 has both a thermal pad with a thermal via arrangement and a finger cooler; (b) the image sensor assembly 100 has only a thermal pad with a thermal via arrangement; (c) the image sensor assembly 100 has only a finger cooler; and (d) the image sensor assembly 100 has neither a thermal pad with a thermal via arrangement nor a finger cooler.

[0091] The simulation results of the temperature distribution for these three configurations are summarized in Table 2, compared to the image sensor assembly 100 which has neither thermal pads with thermal vias nor finger coolers.

[0092] Note that image sensor assemblies 100 with only thermal pads with heat through holes and those with only finger coolers are less efficient at heat dissipation than image sensor assemblies 100 with both thermal pads with heat through holes and finger coolers. When thermal pads with heat through holes are used in combination with finger coolers, the image sensor temperature decreases by approximately 2°C. Of the four configurations, the image sensor assembly without either thermal pads with heat through holes or finger coolers has a heat dissipation efficiency that is approximately 22°C lower.

[0093] refer to Figure 18 The image sensor assembly 700, which is actively cooled by a thermoelectric cooling element (TEC), is shown according to an embodiment of the present invention.

[0094] refer to Figure 19 The image sensor assembly 700 may include: a lens outer barrel 710; a contact material 720 (such as a silicone pad or other thermally conductive, compressible material (such as foamed graphite or direct physical connection)), the contact material 720 having or not having thermal paste, disposed below the lens outer barrel 710 to conduct heat from the lens outer barrel 710 to the top surface of the image sensor cover 730 disposed below the contact material 720; a foam light seal 740 disposed around the image sensor 750 and the image sensor cover 730; a camera plate 755 on which the image sensor 750 is disposed, the camera plate 755 being disposed below the foam light seal 740; a heat conductor 760 disposed below the camera plate 755; a single-stage or multi-stage TEC 770 disposed below the heat conductor 760; and a heat sink 780 disposed below the TEC. Below 770; and multiple fasteners 790, such as screws for coupling the lens outer barrel 710 and the heat sink 780. The screws comprise metals, such as copper, used to maximize heat conduction.

[0095] Table 2

[0096]

[0097] Simulation at TEC temperature (cold side = -15°C, hot side = 45°C)

[0098] The cross-sectional dimensions are 4mm × 4mm.

[0099] In one embodiment, an image sensor cover 730, arranged to protect an element of an image sensor (not shown), may be hollow, connected to an image sensor 750, and contain a drying gas. A desiccant material may be placed within and held in place by the hollow image sensor cover 730 to absorb any moisture that diffuses in through the hollow image sensor cover 730 or the adhesive joints(s) in the assembly.

[0100] In another embodiment, the image sensor cover 730 may be in the form of at least one solid block attached to the image sensor 750. The at least one solid block of the image sensor cover 730 may be made of acrylic and glass. Note that acrylic has a low thermal conductivity of 0.18 W / mK, which is suitable for insulation, but its thermal expansion is higher than that of glass, making it difficult to bond with glass.

[0101] In another embodiment, at least one solid block of the image sensor cover 730 may be made of borosilicate with a thermal conductivity of 1.2 W / mK.

[0102] In another embodiment, the image sensor cover 730 may be in the form of at least one bag attached to the image sensor 750, with or without a desiccant contained within the bag. When at least one bag of the image sensor cover 730 does not contain a desiccant, a drying gas (such as argon) may flow through the bag to remove any moisture generated. At least one bag of the image sensor cover 730 may be made of acrylic or borosilicate glass.

[0103] The temperature of the image sensor was measured for different cooling structures of the image sensor cover 730, and the results are summarized in Table 3. The image sensor cover 730 may include (1) a solid block made of acrylic with a thickness of 12 mm; (2) a bag made of acrylic with a thickness of 12 mm; (3) solid blocks made of acrylic, each with a thickness of 6 mm; (4) a bag made of acrylic with a thickness of 6 mm; (5) a solid block made of borosilicate with a thickness of 6 mm; (6) a bag made of borosilicate with a thickness of 6 mm; and (7) a bag made of borosilicate with a thickness of 12 mm. Note that when the image sensor cover 730 includes four solid blocks made of borosilicate with a thickness of 6 mm, a significantly lower image sensor temperature can be achieved.

[0104] Table 3

[0105]

[0106]

[0107] Figure 26 This is an assembly diagram of a first bag of sealed desiccant with an image sensor cap according to an embodiment of the present invention.

[0108] Figure 27 This is an exploded view of a first bag of sealed desiccant with an image sensor cap according to an embodiment of the present invention.

[0109] Figure 28 This is another exploded view of a first bag of sealed desiccant with an image sensor cap according to an embodiment of the present invention, the first bag having a structure to prevent particles from entering.

[0110] Figure 29 This is an assembly diagram of a second bag of sealed desiccant with an image sensor cap according to an embodiment of the present invention.

[0111] Figure 30 This is an exploded view of a second bag of sealed desiccant with an image sensor cap according to an embodiment of the present invention.

[0112] Figure 31 and Figure 32 These are, respectively, a top view and a side view of a second bag containing a sealed desiccant according to an embodiment of the present invention.

[0113] In another embodiment, the second bag containing the sealed desiccant may be made of three machined, water-jet-cut, or laser-cut parts, the second bag having a smooth lower part with a hole for connection to an image sensor, four sidewall parts, and a smooth top part.

[0114] An image sensor 750 is disposed on the top surface of the camera plate 755 and may be a CCD, CMOS, organic image sensor, or other such imager coupled to the TEC 770, thereby allowing cooling of the image sensor to maintain its operating temperature range. If the component is disposed on the back side of the camera plate 755, an intermediate high thermal conductivity heat conductor 760 may be positioned between the back surface of the camera plate 755 and the TEC 770. The TEC 770 may draw heat from the image sensor to a heat sink 780, which may dissipate the heat or redirect it to another element of the image sensor assembly 700.

[0115] In one embodiment, the TEC can be configured to transfer heat away from the image sensor within the device in any suitable manner, for example, by direct coupling to the image sensor, or indirectly by using a thermally conductive material (such as a finger-shaped cooler structure) if necessary or desired.

[0116] In one embodiment, the image sensor assembly 700 may include a chamber structure in which a sample region, an image sensor, and an optical path are sealed, or a chamberless structure in which a sample region, an image sensor, and an optical path are not sealed by a chamber.

[0117] Figure 20 Thermal communication and heat flow paths within an image sensor assembly 700 according to an embodiment of the present invention are illustrated. Heat is transferred upwards through a plurality of fasteners 790 to a lens outer barrel 710; from the lens outer barrel 710 to a contact material 720; from the contact material 720 to an image sensor cover 730; from the image sensor cover 720 to an image sensor 750; from the image sensor 750 to a camera plate 755; from the camera plate 755 to a thermal conductor 760 if a thermal conductor 760 is present, and from the camera plate 755 to a TEC 770 if a thermal conductor 760 is not present; from the thermal conductor 760 to the TEC 770; and from the TEC 770 to a heat sink 780.

[0118] In one embodiment, an image sensor assembly 700 with active cooling by a thermoelectric cooling element (TEC) may include a lens mount for mounting a lens, the lens mount and the image sensor 750 being horizontally disposed on the same surface of a camera plate 755 to limit the number of parts between the image sensor 750 and the lens, thereby reducing or eliminating the need for lens tilt alignment.

[0119] Figure 21 This is a cross-sectional view of an actively cooled image sensor assembly according to an embodiment of the present invention.

[0120] Figure 22This is a cross-sectional view of a conventional image sensor assembly, showing ten components between the image sensor and the lens. In contrast, in an embodiment according to the invention... Figure 21 In the actively cooled image sensor assembly, there are only three parts between the image sensor and the lens.

[0121] In one embodiment, the image sensor assembly 700 may further include a plurality of gaskets 780 disposed between the lens outer barrel 710 and the camera plate 755 to reduce heat transfer from the lens outer barrel 710 by reducing the contact area with the metal and blocking light. The gaskets 780 may include compressible, deformable, or deflectable foam or similar elastic internal components. Furthermore, the image sensor assembly 700 may include a plurality of washers 790 (preferably Bainck's washers) disposed between the plurality of gaskets 780 and the camera plate 755, or between components of a multi-lens mount for tilt adjustment.

[0122] refer to Figure 23 and Figure 24 The image sensor assembly 700, which is actively cooled by a thermoelectric cooling element (TEC) according to an embodiment of the present invention, is shown. The image sensor assembly 700 includes a plurality of pads 780 and a plurality of washers 790.

[0123] The primary purpose of the gasket 780 is to reduce heat transfer from the heated lens outer barrel, which comes into contact with the image sensor cover (such as a bag or solid block). Waste heat is used to keep the front of the bag or solid block sufficiently warm to prevent condensation from forming on the surface of the image sensor cover. Furthermore, the contact area between the lens outer barrel 710 and the camera plate 755 is reduced to several small areas, with the gasket contacting the camera plate 755, and the gasket 780 forming an intermediate space to block light from entering the image sensor.

[0124] Figure 25 This is a view of an image sensor assembly 700 according to an embodiment of the invention, actively cooled by a thermoelectric cooling element (TEC) and having multiple gaskets 780 and multiple washers 790, showing that the lens outer barrel is tilted. Because the washers are there, and the washers are flexible and compressed, tilting adjustments can be made if needed, by loosening the screws to allow the compressed Bavarian washers to push the mounting bracket slightly outward. Note that the lens outer barrel is tilted 1 degree relative to the blue line. Note the separation of the right outer barrel attachment surface, where the uncompressed Bavarian washer is exposed.

[0125] In one embodiment, the image sensor assembly 700 may have a two-piece lens mount, wherein the first piece is flat-mounted on a circuit board, the second piece is initially disposed plane-to-plane and can be configured to tilt relative to the circuit board, and the lens is mounted on the second piece. The two-piece lens mount allows for easy assembly, post-assembly inspection for tilt, and if no tilt is found, no adjustment is required to suppress stress from the localized compression of the circuit board by the gaskets.

[0126] In one embodiment of the uncooled version, a dark current of 0.11e- / pixel / second was measured at room temperature, which is 8.18 times lower than the 0.9e- / pixel / second dark current measured at room temperature by the conventional Sony IMX178 image sensor system.

[0127] In another embodiment, for an image sensor assembly with active cooling by a TEC, a dark current of 0.025e- / pixel / second was measured at a temperature of 17°C.

[0128] The present invention includes, but is not limited to, the following exemplary embodiments.

[0129] Example 1. An electronic component assembly, comprising:

[0130] A circuit board, the circuit board including at least one thermal pad disposed on the top surface of the circuit board; and

[0131] An image sensor is disposed on the top surface of the circuit board, including at least one conductive pad disposed at at least one corner of the image sensor;

[0132] The at least one thermal pad is coupled to the at least one conductive pad of the image sensor, and the at least one thermal pad is formed by a plurality of first thermal vias penetrating the thermal pad and the circuit board (e.g., for transferring heat from the image sensor).

[0133] Example 2. The electronic component assembly as described in Example 1 further includes a thermally conductive layer disposed on the bottom surface of the circuit board.

[0134] Example 3. An electronic component assembly as described in Example 2, wherein the thermally conductive layer is made of metal.

[0135] Example 4. An electronic component assembly as described in Example 2, wherein the thermally conductive layer has a circular or annular shape.

[0136] Example 5. An electronic component assembly as described in Example 2, wherein the thermal conductive layer is formed having a plurality of second thermal vias that penetrate the thermal conductive layer to transfer heat.

[0137] Example 6. An electronic component assembly as described in Example 2, wherein the second thermal vias are spaced apart in the thermally conductive layer.

[0138] Example 7. An electronic component assembly as described in Example 3, wherein the metal comprises copper (Cu) or a copper alloy.

[0139] Example 8. The electronic component assembly as described in Example 2 further includes a thermal composite material applied between a corner region of the image sensor and a corner region of the thermal pad including a thermal via, and the thermal composite material extends along the length of the thermal pad to contact the top surface of the circuit board.

[0140] Example 9. An electronic component assembly as described in Example 1, wherein at least one of the plurality of first heat passages has a cylindrical shape.

[0141] Example 10. An electronic component assembly as described in Example 1, wherein at least one of the plurality of first heat holes is made of copper (Cu) or a copper alloy.

[0142] Example 11. An electronic component assembly as described in Example 1, wherein at least one of the plurality of first heat holes is filled with a thermally conductive material.

[0143] Example 12. An electronic component assembly as described in Example 1, wherein the at least one conductive pad comprises a plurality of conductive pads electrically connected to each other.

[0144] Example 13. The electronic component assembly as described in Example 1 further includes a cooling structure coupled to the circuit board (e.g., for heat transfer).

[0145] Example 14. An electronic component assembly as described in Example 13, wherein the cooling structure includes at least one finger-shaped cooler structure.

[0146] Example 15. An electronic component assembly as described in Example 13, wherein the cooling structure protrudes through a through-hole in the circuit board and contacts the surface of the image sensor (e.g., for heat transfer).

[0147] Example 16. The electronic component assembly as described in Example 1 further includes (e.g., a lens mount for mounting a lens) a lens mount and the image sensor being horizontally disposed on the same surface of the circuit board.

[0148] Example 17. An image sensor assembly, comprising:

[0149] A cooling structure, the cooling structure including at least one thermoelectric cooling element (TEC);

[0150] A circuit board, which is disposed on the cooling structure;

[0151] Image sensors; and so on.

[0152] lens.

[0153] Example 18. The image sensor assembly as described in Example 17 further includes an image sensor cover disposed on the image sensor.

[0154] Example 19. An image sensor assembly as described in Example 18, wherein the lens is directly or indirectly coupled to the image sensor cover.

[0155] Example 20. The image sensor assembly as described in Example 19 further includes a lens outer barrel that contacts the image sensor cover.

[0156] Example 21. The image sensor assembly as described in Example 20 further includes a heat sink structure coupled to the cooling structure.

[0157] Example 22. The image sensor assembly as described in Example 21 further includes a plurality of fasteners coupling the lens outer barrel to the heat sink structure.

[0158] Example 23. An image sensor assembly as described in Example 22, wherein the image sensor assembly includes a structure having a chamber or a structure not having a chamber.

[0159] Example 24. An image sensor assembly as described in Example 17, wherein heat is transferred directly or indirectly from the lens outer barrel to the image sensor cover, from the image sensor cover to the image sensor, from the image sensor to the circuit board, from the circuit board to the cooling structure, and from the cooling structure to the heat sink via a contact material.

[0160] Example 25. The image sensor assembly as described in Example 23 further includes a plurality of pads and a plurality of reduced contact areas, the plurality of pads being disposed between the lens outer barrel and the circuit board to reduce heat transfer from the lens outer barrel, the pads contacting the circuit board at the plurality of reduced contact areas and the pads forming an intermediate gap to block stray light from reaching the image sensor.

[0161] Example 26. The image sensor assembly as described in Example 25 further includes a plurality of washers (e.g., for tilt adjustment) respectively disposed between the plurality of pads and the circuit board.

[0162] Example 28. The image sensor assembly as described in Example 17 further includes (e.g., a lens mount for mounting a lens), the image sensor and the lens mount being horizontally disposed on the same surface of the circuit board.

[0163] Example 29. The image sensor assembly as described in Example 17 further includes (e.g., a lens mount for mounting a lens), wherein the image sensor and the lens mount are configured to overlap vertically on the top surface of the circuit board.

[0164] Example 30. An image sensor assembly as described in Example 22, wherein the plurality of fasteners includes at least one screw, the at least one screw comprising metal (e.g., to increase or maximize thermal conductivity).

[0165] Example 31. The image sensor assembly as described in Example 26, wherein the plurality of washers includes at least one Bavarian washer.

[0166] Those skilled in the art of gel and blot imaging will recognize from the preceding detailed description, the accompanying drawings, and the claims that modifications and alterations can be made to embodiments of the invention without departing from the scope of the invention as defined in the following claims.

[0167] All patents, patent applications, provisional applications and publications mentioned or cited herein are incorporated herein by reference in their entirety (including all figures and tables) to the extent that they are inconsistent with the explicit teachings of this specification.

[0168] It should be understood that the examples and embodiments described herein are for illustrative purposes only, and various modifications or changes thereto will be suggested to those skilled in the art and will be included within the spirit and scope of this application.

Claims

1. An electronic component assembly, comprising: A circuit board, the circuit board including at least one thermal pad disposed on the top surface of the circuit board; as well as An image sensor is disposed on the top surface of the circuit board, including at least one conductive pad disposed on at least one corner region of the top surface of the image sensor; The at least one thermal pad is directly attached to the at least one conductive pad of the image sensor; and The at least one thermal pad is formed having a plurality of first thermal vias that penetrate the at least one thermal pad and the circuit board.

2. The electronic component assembly of claim 1, further comprising a thermally conductive layer disposed on the bottom surface of the circuit board.

3. The electronic component assembly as claimed in claim 2, characterized in that, The heat-conducting layer is made of metal and is formed to have a plurality of second heat-permeable holes that penetrate the heat-conducting layer to transfer heat.

4. The electronic component assembly of claim 1, further comprising a thermal composite material applied between a corner region of the image sensor and a corner region of the thermal pad including the first thermal via, and the thermal composite material extending along the length of the thermal pad to contact the top surface of the circuit board.

5. The electronic component assembly as claimed in claim 1, characterized in that, At least one of the plurality of first heat passages has a cylindrical shape.

6. The electronic component assembly as claimed in claim 1, characterized in that, At least one of the plurality of first heat passages is filled with thermally conductive material.

7. The electronic component assembly as claimed in claim 1, characterized in that, The at least one conductive pad includes a plurality of conductive pads electrically connected to each other.

8. The electronic component assembly as claimed in claim 1, characterized in that, At least one of the plurality of first heat passages is formed of copper (Cu) or a copper alloy.

9. The electronic component assembly of claim 1, further comprising a cooling structure coupled to the circuit board.

10. The electronic component assembly as claimed in claim 1, characterized in that, The plurality of first thermal vias are directly disposed below the conductive pads of the image sensor on the top surface of the circuit board, and wherein the plurality of first thermal vias are filled with thermally conductive material, ground and plated.

11. The electronic component assembly as claimed in claim 9, characterized in that, The cooling structure protrudes through a through-hole in the circuit board and contacts the surface of the image sensor.

12. The electronic component assembly of claim 1, further comprising a lens mount, the lens mount and the image sensor being horizontally disposed on the same surface of the top surface of the circuit board.

13. The electronic component assembly as claimed in claim 2, characterized in that, The heat-conducting layer has a circular or annular shape.

14. The electronic component assembly as claimed in claim 1, characterized in that, The at least one conductive pad includes a plurality of conductive pads electrically connected to each other, and The plurality of first thermal vias are directly disposed below the conductive pads of the image sensor on the top surface of the circuit board, and the plurality of first thermal vias are filled with thermally conductive material, ground and plated.

15. An image sensor assembly, comprising: A cooling structure, the cooling structure including at least one thermoelectric cooling element (TEC); A circuit board disposed on the cooling structure, the circuit board including at least one thermal pad disposed on the top surface of the circuit board; An image sensor, the image sensor including at least one conductive pad disposed on at least one corner region of a top surface of the image sensor, wherein the at least one thermal pad is directly attached to the at least one conductive pad of the image sensor; and lens.

16. The image sensor assembly of claim 15, further comprising an image sensor cover disposed on the image sensor, a contact material disposed between the lens and the image sensor cover, a lens outer shell in contact with the image sensor cover, a heat sink structure coupled to the cooling structure, and a plurality of fasteners coupling the lens outer shell to the heat sink structure.

17. The image sensor assembly as claimed in claim 15, characterized in that, The image sensor assembly may have a chamber structure or a non-chamber structure.

18. The image sensor assembly of claim 16, further comprising a plurality of pads and a plurality of reduced contact areas, the plurality of pads being disposed between the lens outer barrel and the circuit board to reduce heat transfer from the lens outer barrel, the pads contacting the circuit board at the plurality of reduced contact areas and the pads forming an intermediate gap to block stray light from reaching the image sensor.

19. The image sensor assembly of claim 18, further comprising a plurality of washers disposed between the plurality of gaskets and the circuit board.

20. The image sensor assembly of claim 15, further comprising a lens mount, wherein the image sensor and the lens mount are horizontally disposed on the same plane on the top surface of the circuit board.

21. The image sensor assembly of claim 15, further comprising a lens mount, wherein the image sensor and the lens mount are configured to overlap vertically on the top surface of the circuit board.

22. The image sensor assembly as claimed in claim 15, characterized in that, The at least one thermal pad is formed having a plurality of first thermal vias that penetrate the at least one thermal pad and the circuit board. Wherein, the at least one conductive pad includes a plurality of conductive pads electrically connected to each other, and The plurality of first thermal vias are directly disposed below the conductive pads of the image sensor on the top surface of the circuit board, and the plurality of first thermal vias are filled with thermally conductive material, ground and plated.

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