JP2011165775A - Solid-state imaging device and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid-state imaging device that prevents a protrusion of an adhesive into a pixel area, and is superior in airtightness and moisture resistance. <P>SOLUTION: A method of manufacturing the solid-state imaging device includes: a first step of preparing a solid-state image sensor having a pixel area and a supporting region disposed in the outer side of the pixel area and a cover member having a plate part and a frame disposed in the periphery of the plate part, where at least any one of the supporting region and the bottom face of the frame has irregularities; a second step of placing the cover member on the solid-state image sensor so that the frame is supported by the supporting region; a third step of applying an adhesive along the outer side edge of the frame of the cover member placed on the solid-state image sensor; a fourth step of flowing the adhesive so that the adhesive flows into a gap formed between the supporting region and the bottom face of the frame by the existence of the irregularities; and a fifth step of curing the adhesive in a state in which the adhesive flows into the gap. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a solid-state imaging device and a manufacturing method thereof.

  In recent years, with the miniaturization of digital cameras and mobile phones, further miniaturization is required for solid-state imaging devices mounted thereon. Patent Document 1 discloses a solid-state imaging device including a solid-state imaging element (bare chip) and a cover. The solid-state imaging device has a central part in which an active region for converting incident light into electric charges is formed and a peripheral part provided around the central part. The cover has a base portion that faces the active region, and a side portion that is bonded to the peripheral edge portion of the solid-state imaging device by an adhesive.

  In Patent Document 2, a frame portion disposed between a solid-state imaging device chip and a flat plate portion facing the solid-state imaging device chip includes a frame basic portion disposed outside the light receiving portion, and an adhesive layer disposed outside the frame portion. There is disclosed a solid-state imaging device constituted by:

JP 2004-221247 A JP 2002-231919 A

  In the solid-state imaging device disclosed in Patent Literature 1, an adhesive for adhering the side part of the cover to the peripheral part of the solid-state imaging element can be pushed out from between the peripheral part and the side part and spread to the active region side. There is sex. In order to allow the adhesive to be pushed out from between the periphery and the side, it is necessary to ensure a suitable distance between the periphery and the active area. This increases the size of the solid-state imaging device and further the solid-state imaging device including the same. In addition, when the adhesive is pushed out from the periphery and the side to the active area side, the light incident on the adhesive may be reflected by the adhesive and enter the active area, thereby degrading the image quality. There is.

  In the solid-state imaging device disclosed in Patent Literature 2, although the above-mentioned problem in Patent Literature 1 is not present, the frame basic portion and the solid-state imaging device chip are not connected via an adhesive layer. There seems to be a problem in terms of airtightness and moisture resistance of the space between the parts. If an adhesive layer is disposed between the frame base portion and the solid-state imaging device chip in order to solve this problem, the problem of the adhesive protruding to the light receiving portion side as described above arises.

  The present invention has been made in light of the above problem recognition, and an object of the present invention is to provide a solid-state imaging device that prevents the adhesive from protruding into the pixel region and is excellent in airtightness and moisture resistance.

  One aspect of the present invention relates to a method for manufacturing a solid-state imaging device, and the manufacturing method includes a solid-state imaging device having a pixel region and a support region disposed outside the pixel region, and a flat plate portion and a peripheral portion thereof. A cover member having a frame portion, wherein a first step of preparing the solid-state imaging device and the cover member in which at least one of the support region and the bottom surface of the frame portion has an uneven portion; A second step of placing the cover member on the solid-state imaging device so that the frame portion is supported; and an adhesive along the outer edge of the frame portion of the cover member placed on the solid-state imaging device. A third step of applying, and a fourth step of flowing the adhesive so that the adhesive flows into a gap formed between the support region and the bottom surface of the frame portion due to the presence of the uneven portion, The adhesive is Serial and a fifth step of curing the adhesive in a state that has flowed into the gap, to obtain a solid-state imaging device in which the cover member is fixed to the solid-state imaging device.

  According to the present invention, it is possible to provide a solid-state imaging device that prevents the adhesive from protruding into the pixel region and is excellent in airtightness and moisture resistance.

It is a figure which shows the manufacturing method of the solid-state imaging device of 1st Embodiment of this invention. It is a figure which shows the manufacturing method of the solid-state imaging device of 1st Embodiment of this invention. It is a figure which shows the solid-state imaging device of 1st Embodiment of this invention. It is a figure which shows the solid-state imaging device of 2nd Embodiment of this invention. It is a figure which shows the solid-state imaging device of 3rd Embodiment of this invention. It is a figure which shows the manufacturing method of the solid-state imaging device as 4th Embodiment of this invention.

  A solid-state imaging device according to a first embodiment of the present invention will be described with reference to FIG. In the first step shown in FIG. 1A, a solid-state imaging device 2 and a cover member 3 are prepared. The solid-state imaging device 2 includes a pixel area 21 in which a plurality of light receiving elements (photoelectric conversion elements) are two-dimensionally arranged, and a support area 29 arranged outside the pixel area 21. The pixel area 21 can include an effective pixel area. The light incident surface of the pixel region 21 is a light receiving surface 22. The pixel region 21 may have a color filter disposed on the light incident side of the light receiving element (not shown). The pixel region 21 may further include a planarization film disposed on the color filter (not shown). The solid-state imaging device 2 can also have a microlens 23 disposed in the pixel region 21. The solid-state imaging device 2 can be a CCD image sensor or a CMOS image sensor.

  The cover member 3 is a flat plate portion 31 that is disposed opposite to the pixel region 21 on the first surface side of the solid-state imaging device 2 and is spaced apart from the pixel region 21, and a frame that is disposed in the peripheral portion of the flat plate portion 31. Part 32. The cover member 3 includes the flat plate portion 31 and the frame portion 32, thereby having a structure having a concave portion on the side facing the solid-state imaging device 2. The recess has a size larger than that of the pixel region 21. The cover member 3 can be made of a translucent member such as glass, resin, crystal, or the like. The cover member 3 can be configured as an integrated structure of the flat plate portion 31 and the frame portion 32 by a method such as polishing, etching, or molding with a mold of a light-transmitting material. Or the cover member 3 may be comprised by couple | bonding the frame part 32 with the flat plate part 31 which has translucency. When the frame portion 32 is coupled to the flat plate portion 31, the frame portion 32 may be made of a light-shielding material such as metal. The support region 29 of the solid-state imaging device 2 supports the bottom surface of the frame portion 32 of the cover member 3.

  At least one of the support region 29 of the solid-state imaging device 2 and the bottom surface of the frame portion 32 of the cover member 3 is provided with an uneven portion, and between the support region 29 and the bottom surface of the frame portion 32 due to the presence of the uneven portion. A gap 24 is formed. Here, an example will be described in which the microlens 23 of the solid-state imaging device 2 is also disposed in the support region 29 and the uneven portion is the microlens 23.

  In the second step shown in FIG. 1B, the cover member 3 is placed on the first surface of the solid-state imaging device 2 (the surface having the pixel region 21). Since at least one of the support region 29 of the solid-state imaging device 2 and the bottom surface of the frame portion 32 has an uneven portion, a gap 24 is formed between the support region 29 and the bottom surface of the frame portion 32. Fig.2 (a) is an enlarged view of the area | region A in FIG.1 (b).

  In the example mainly described in the first embodiment, the solid-state imaging device 2 has a microlens 23 on the outer side in addition to the pixel region 21, and the uneven portion is on the outer side of the pixel region 21 of the solid-state imaging device 2. The microlens 23 is provided. That is, the gap 24 is formed by the microlens 23. A space 33 is formed between the solid-state imaging device 2 and the cover member 3. Since the micro lens 23 has a lens shape, the gap 24 is a path that leads from the space portion 33 to the outer space of the cover member 3.

  In the third step shown in FIG. 1C, the adhesive 4 is applied along the outer peripheral edge of the cover member 3. Here, the uncured adhesive 4 is applied along the outer peripheral edge of the cover member 3 in a state where a load is applied from above to the cover member 3 placed on the solid-state imaging device 2. Thereby, the adhesive 4 is disposed so as to be in contact with both the outer end of the cover member 3 and the surface of the solid-state imaging device 2 on the outer side.

  In the fourth step shown in FIG. 1 (d), the adhesive 4 flows (moves) so that the adhesive 4 flows into the gap 24. FIG. 2B is an enlarged view of region B in FIG. Since the adhesive 4 applied along the outer peripheral edge of the cover member 3 is uncured, it has fluidity. Then, the adhesive 4 enters the gap 24 through the opening of the gap 24 exposed at the outer end of the cover member 3 and flows (moves) in the gap 24 toward the pixel region 21 side (inner side).

  The dimension of the gap 24 can be set so that, for example, the uncured adhesive 4 can flow through the gap 24 by capillary action. The height of the gap 24 is preferably in the range of 0.1 to 100 microns, more preferably in the range of 0.1 to 50 microns. In addition to the capillary phenomenon or instead of the capillary phenomenon, the adhesive 4 is pressurized with a fluid such as air, or the pressure in the space outside the cover member 3 is made higher than the atmospheric pressure, so that the space inside the cover member 3 In other words, a pressure difference may be provided between the space portion 33 and the outer space. Even in this case, the uncured adhesive 4 can be moved.

  In the fifth step shown in FIG. 1 (e), the adhesive 4 is cured with the adhesive 4 flowing into the gap 24, and the cover member 3 is fixed to the solid-state imaging device 2. Here, after the adhesive 4 starts to enter the gap 24, before it protrudes into the inside of the frame portion 32 from between the support region 29 and the bottom surface of the frame portion 32 (that is, protrudes from the gap 24 to the space portion 33. The adhesive 4 is cured before). Thereby, the cover member 3 can be fixed to the solid-state imaging device 2 without causing the adhesive 4 to protrude to the pixel region 21 side. here. The protruding means that the adhesive 4 moves to the pixel region 21 side from the inner end of the cover member 3. As described above, according to the first embodiment, it is not necessary to provide an area around the pixel area 21 to allow the adhesive 4 to protrude. Therefore, it is possible to reduce the size of the solid-state imaging device 2 and further the solid-state imaging device in which the solid-state imaging device 2 is incorporated. Furthermore, according to the first embodiment, the adhesive 4 can be provided on a part or the whole of the contact surface between the solid-state imaging device 2 and the cover member 3. Therefore, the adhesive strength can be increased, and the airtightness and moisture resistance can be improved.

  As a method for curing the adhesive 4 moving through the gap 24, methods such as heating, humidification, and ultraviolet irradiation can be used according to the specifications or curing characteristics of the adhesive 4. In particular, when an ultraviolet curable adhesive that is cured by irradiation of ultraviolet rays is used as the adhesive 4, the flow of the adhesive 4 can be stopped immediately because of its rapid curing property, and the protrusion is surely prevented. Can do. The ultraviolet rays can be applied to the adhesive 4 through the frame portion 32 by the ultraviolet irradiation device 43. Note that it is not necessary to completely cure the adhesive 4 flowing in the gap 24 by performing a single curing step, and if the adhesive 4 is cured to a sufficient extent to suppress the protrusion of the adhesive 4. Good. The adhesive 4 can be further cured by performing a subsequent additional curing step. Through the above process, the solid-state imaging device 11 in which the cover member 3 is fixed to the solid-state imaging device 2 is obtained.

  The uneven portion provided on at least one of the support region 29 of the solid-state imaging device 2 and the bottom surface of the frame portion 32 of the cover member 3 will be described. In order to form a gap 24 between the support region 29 of the solid-state image sensor 2 and the bottom surface of the frame portion 32 of the cover member 3, at least one of the support region 29 of the solid-state image sensor 2 and the bottom surface of the frame portion 32 is an uneven portion. Is formed.

  As the concavo-convex portion provided on the solid-state imaging device 2 side, the concavo-convex portion having any shape may be used, and it is preferable that the concavo-convex portion exhibits a capillary phenomenon. When the concave and convex portion is formed by the microlens 23, the microlens 23 provided on the pixel region 21 only needs to be provided outside the pixel region 21, and the concave and convex portion can be formed in the forming process of the microlens 23. it can.

  As the concavo-convex portion provided on the bottom surface of the frame portion 32 of the cover member 3, a concavo-convex portion that similarly exhibits a capillary phenomenon is suitable. As the shape, for example, a randomly arranged uneven part or an uneven part in which a groove for continuously communicating the space part 33 and the outer space of the cover member 3 is preferably formed. May be.

  The concavo-convex portion of the frame portion 32 of the cover member 3 can be formed by at least one method of machining, polishing, and blasting, for example. In the polishing process or the blast process, the uneven part (that is, the gap 24) can be easily provided on the entire bottom surface of the frame part 32. In this case, since the adhesive 4 can be permeated widely into the bottom surface of the frame portion 32, airtightness and moisture resistance are improved.

  FIG. 3 is a diagram illustrating a solid-state imaging device 1 in which the solid-state imaging device 11 shown in FIG. In the solid-state imaging device 2, the second surface side opposite to the first surface side on which the cover member 3 is disposed is fixed to the mounting member 8 via the adhesive 7. The solid-state imaging device 2 has an electrode pad 25 outside the region where the cover member 3 is mounted, and the mounting member 8 has a terminal 82 outside the region where the solid-state imaging device 2 is mounted. The electrode pad 25 of the solid-state imaging device 2 and the terminal 82 of the mounting member 8 are connected by a conductive member 5 such as a metal wire. Further, in the solid-state imaging device 1, the periphery of the mounting member 8, the solid-state imaging device 2, and the cover member 3 is sealed with a sealing member 6.

  As the mounting member 8, for example, a lead frame, a printed wiring board, a flexible wiring board, a hollow package having a cavity structure, or the like can be adopted. In the example shown in FIG. 3, the mounting member 8 is a printed wiring board, and includes a substrate 81 formed of a material such as ceramic or glass epoxy, and a terminal 82 disposed on the surface of the substrate 81. Further, the printed wiring board as the mounting member 8 has a wiring pattern arranged on the surface or inside of the substrate 81. Further, the metal wire as the conductive member 5 transmits a signal between the solid-state imaging device 2 and the mounting member 8 or supplies power to the solid-state imaging device 2. With such a configuration, in the solid-state imaging device 1, the airtightness and moisture resistance of the space 33 are further enhanced.

  A solid-state imaging device according to a second embodiment of the present invention will be described with reference to FIG. 4A and 4B are an enlarged cross-sectional view and a plan view of the solid-state imaging device according to the second embodiment, respectively. FIG. 4A corresponds to the area A in FIG. 1B and the part shown in FIG. 2A, and is the same as the configuration of the first embodiment except for the part shown in FIG. It is.

  In the solid-state imaging device of the first embodiment shown in FIG. 1, the gap 24 is formed between the cover member 3 and the solid-state imaging device 2, but in the solid-state imaging device of the second embodiment shown in FIG. They differ in terms of blocking. In the second embodiment, the solid-state imaging device 2 includes a blocking portion 41 having a contact surface 411 that is in close contact with the bottom surface of the frame portion 32 of the cover member 3. The blocking portion 41 prevents the gap 24 from communicating from the outer space of the cover member 3 to the inner space (space portion 33). The blocking part 41 is typically configured along the entire circumference of the frame part 32, whereby the gap 24 is completely blocked by the blocking part 41. The close contact surface 411 of the blocking portion 41 is disposed so as to be in close contact with the inner region 321 of the bottom surface of the frame portion 32. The blocking part 41 may be provided in the frame part 32 of the cover member 3. Alternatively, the blocking part 41 may be provided on both the solid-state imaging device 2 and the frame part 32. That is, the blocking part 41 can be provided on at least one of the solid-state imaging device 2 and the frame part 32.

  At least one of the solid-state imaging device 2 and the outer region 322 on the bottom surface of the frame portion 32 is provided with an uneven portion on the contact surface between the solid-state imaging device 2 and the frame portion 32. The uneven portion can be, for example, a microlens 23 provided in the solid-state imaging device 2. A gap 24 is formed between the outer region 322 on the bottom surface of the frame portion 32 and the solid-state imaging device 2 by the uneven portion. The widths of the inner region 321 and the outer region 322 of the frame part 32 can be determined in consideration of the adhesive strength between the frame part 32 and the solid-state imaging device 2, airtightness, moisture resistance, and the like. Increasing the width of the outer region 322 increases the adhesive strength, airtightness, and moisture resistance.

  With the above structure, the adhesive 4 applied along the outer end of the frame portion 32 and entering the gap 24 can be reliably dammed. Thereby, it is possible to more reliably prevent the adhesive 4 from protruding in the direction of the pixel region 21 (or the space portion 33). Further, the adhesive 4 can be cured without considering the flow rate of the adhesive 4.

  The blocking part 41 can be formed using, for example, the same material as that of the microlens 23. In this case, an additional process for forming the blocking part 41 is unnecessary. However, the blocking part 41 may be formed in a process separate from the process of forming the microlens 23 or the uneven part.

  A solid-state imaging device according to a third embodiment of the present invention will be described with reference to FIG. FIG. 5 corresponds to the region A in FIG. 1B and the portion shown in FIG. 2A, and the configuration other than the portion shown in FIG. 5 is the same as that of the first embodiment. In the third embodiment, an uneven portion 34 is formed on the bottom surface of the frame portion 32 of the cover member 3, thereby forming a gap 24. The uneven portion 34 can be formed by a method such as blasting, polishing, or etching. Alternatively, the uneven portion 34 may be formed by machining such as drilling. According to blasting, polishing, and etching, the uneven portion 34 can be easily provided over the entire bottom surface of the frame portion 32. By forming the gap 24 over the entire bottom surface of the frame portion 32, the adhesive 4 can be widely flowed. This is advantageous for improving airtightness and moisture resistance.

  In the example illustrated in FIG. 5, the uneven portion is not formed on the surface of the solid-state image sensor 2. However, for example, an uneven portion as shown in the first embodiment may be formed on the surface of the solid-state image sensor 2. . As in the second embodiment, a blocking portion 41 that prevents the gap 24 from communicating from the outer space of the cover member 3 to the inner space (space portion 33) may be provided. The blocking part 41 may be provided in the frame part 32 of the cover member 3, may be provided in the solid-state image sensor 2, or may be provided in both the solid-state image sensor 2 and the frame part 32. That is, the blocking 41 can be provided on at least one of the solid-state imaging device 2 and the cover member 3.

  A method for manufacturing a solid-state imaging device as a fourth embodiment of the present invention will be described with reference to FIG. FIG. 6 corresponds to the step shown in FIG. 1D (step of allowing the adhesive to flow into the gap), and the other steps are shown in FIGS. 1A, 1B, 1C, and 1E. It is the same as the process. About a structure of a solid-state image sensor, it can follow 1st-3rd embodiment.

  In the fourth embodiment, in the step of causing the adhesive 4 to flow into the gap 24, a pressure difference is formed between the space 33 that is the inner space of the cover member 3 and the outer space of the cover member 3. Assuming that the pressure of the space 33 is V1 and the pressure of the outer space of the cover member 3 is V2, the flow of the adhesive 4 into the gap 24 is promoted by satisfying V1 <V2, and the gap 24 having various shapes The inflow of the adhesive 4 can be facilitated. Further, the promotion of the inflow of the adhesive 4 into the gap 24 is effective for shortening the process time.

  The pressure difference represented by V1 <V2 can be formed, for example, by setting the pressure in the space 33 to a pressure lower than the atmospheric pressure and the pressure in the outer space of the cover member 3 to the atmospheric pressure. This can be realized, for example, by performing the process up to the step of applying the adhesive 4 along the outer end of the frame portion 32 of the cover member 3 in a vacuum or reduced pressure environment, and then releasing to atmospheric pressure.

  Alternatively, the pressure difference represented by V1 <V2 can be formed, for example, by setting the pressure in the space 33 to atmospheric pressure and the pressure in the outer space of the cover member 3 to a pressure higher than atmospheric pressure. This can be achieved, for example, by carrying out under atmospheric pressure until the step of applying the adhesive 4 along the outer end of the frame portion 32 of the cover member 3 and then increasing the pressure of the processing environment.

Claims (9)

A method of manufacturing a solid-state imaging device,
A cover member having a solid-state imaging device having a pixel region and a support region disposed outside the pixel region, and a flat plate portion and a frame portion disposed in the peripheral portion thereof, wherein the support region and the bottom surface of the frame portion A first step of preparing the solid-state imaging device and the cover member at least one of which has an uneven portion;
A second step of placing the cover member on the solid-state imaging device so that the frame portion is supported by the support region;
A third step of applying an adhesive along the outer edge of the frame portion of the cover member placed on the solid-state imaging device;
A fourth step of causing the adhesive to flow so that the adhesive flows into a gap formed between the support region and the bottom surface of the frame portion due to the presence of the uneven portion;
A fifth step of curing the adhesive with the adhesive flowing into the gap,
A method for manufacturing a solid-state imaging device, comprising: obtaining a solid-state imaging device having the cover member fixed to the solid-state imaging device. At least one of the solid-state imaging device and the cover member has a blocking portion that prevents the gap from communicating from the outer space of the cover member to the inner space of the cover member.
The method for manufacturing a solid-state imaging device according to claim 1. Microlenses are provided in the pixel region and the support region,
The concavo-convex portion is a microlens provided in the support region.
The method of manufacturing a solid-state imaging device according to claim 1 or 2. In the first step, the concavo-convex portion is formed by at least one method of machining, polishing, and blasting.
The method for manufacturing a solid-state imaging device according to any one of claims 1 to 3. The height of the gap is in the range of 0.1 to 100 microns,
The method for manufacturing a solid-state imaging device according to claim 1, wherein: The adhesive is an ultraviolet curable adhesive, and the adhesive is irradiated with ultraviolet rays in the fifth step.
The method for manufacturing a solid-state imaging device according to claim 1, wherein: In the fourth step, the adhesive is caused to flow into the gap by capillary action.
The method for manufacturing a solid-state imaging device according to any one of claims 1 to 6. In the fourth step, the adhesive is caused to flow into the gap by making the pressure in the outer space of the cover member higher than the pressure in the inner space of the cover member.
The method for manufacturing a solid-state imaging device according to any one of claims 1 to 6. A solid-state imaging device having a pixel region and a support region disposed outside the pixel region, and a cover member having a flat plate portion and a frame portion disposed in the periphery thereof, and the frame portion is supported by the support region A solid-state imaging device,
A microlens is provided in the pixel region and the support region of the solid-state imaging device,
The cover member is fixed to the solid-state imaging device by an adhesive disposed in a gap formed between the support region and the bottom surface of the frame portion due to the presence of the microlens provided in the support region.
A solid-state imaging device.

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