JP2008159823A - Solid-state imaging device and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid-state image sensing device capable of reducing an image-surface curve without fitting a holding material on the rear of an image-sensing element and capable of decreasing the dispersion of the curve of the image-sensing element. <P>SOLUTION: A curved-shaped projecting section 8 having an inner periphery more projected to the side of the image-sensing element 1B than an outer periphery is formed to one surface of a wiring board 6B. The image-sensing element 1B is joined with the projecting section 8, and the image-sensing surface 10 of the image-sensing element 1B is curved. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a solid-state imaging device used for a camera-equipped mobile phone device or the like.

FIG. 8 shows a solid-state imaging device disclosed in Patent Document 1.
An image sensor 1 such as a MOS image sensor or a CCD image sensor is mounted via a holding material 2. 3 is a cover glass. An imaging lens 4 is disposed in front of the solid-state imaging device. Reference numeral 5 denotes a lens barrel. The imaging device 1 follows the curved holding surface of the holding material 2 to reduce the curvature of field caused by the aberration of the imaging lens 4, and the resolution is different between the central portion and the peripheral portion of the image. It has improved the deterioration of the imaging characteristics that make the image quality non-uniform.

FIG. 9 shows a solid-state imaging device of Patent Document 2.
In this solid-state imaging device, the imaging element 1A is flip-chip mounted on the wiring board 6. 3A is a cover glass, 4 is an imaging lens, and 20 is a sealing resin. Here, the thermal expansion coefficients of the image pickup device 1A and the wiring board 6 are selected so that the thermal expansion coefficient of the wiring board 6 is larger than that of the image pickup element 1A. At the time of mounting, the shrinkage rate of the wiring board 6 increases due to the cooling action after heat bonding, and the interval between the joint portions outside the image sensor 1A is shortened, so that a compression force is applied to the image sensor 1A. It is formed using a method of bending.
JP 2004-63776 A JP 2004-146633 A

  By appropriately selecting the difference in coefficient of thermal expansion between the image sensor 1A and the wiring board 6 as in Patent Document 2, the curvature of field can be obtained without providing the holding material 2 on the back surface of the image sensor 1 as in Patent Document 1. Can be reduced.

However, the configuration of Patent Document 2 has a problem that the variation in the curvature of the image sensor 1A is large.
SUMMARY OF THE INVENTION An object of the present invention is to provide a solid-state imaging device that can reduce the curvature of field without providing a holding material on the back surface of the imaging device, and that can reduce the variation in the curvature of the imaging device as compared with the prior art. .

  The solid-state imaging device according to claim 1 of the present invention mounts an imaging device on one surface of a wiring board, and detects light incident from the other surface of the wiring substrate toward the one surface with the imaging device. A solid-state image pickup device, wherein a curved protrusion having an inner periphery protruding toward the image sensor rather than an outer periphery is provided on the one surface of the wiring board, and the image sensor is joined to the protrusion of the wiring board The imaging surface of the imaging element is curved.

  In the method of manufacturing the solid-state imaging device according to claim 2 of the present invention, when mounting the imaging device on one surface of the wiring board, the protruding electrode is formed on the imaging surface side of the imaging device, and the center is from the outer periphery. The curved portion of the tool having a concave curved portion is held in a state where the imaging device is curved by bringing the surface opposite to the imaging surface of the imaging device into contact with the curved portion. The imaging element is brought into contact with the projecting electrode of the imaging element and a land formed on a curved projection having an inner circumference protruding toward the imaging element on the one surface of the wiring board. And the wiring board are bonded to each other, and then the imaging element is detached from the tool.

  The solid-state imaging device according to a third aspect of the present invention is the solid-state imaging device according to the first aspect, wherein the wiring board corresponds to the protrusion formed on one surface on the imaging element side and the imaging is on the other surface. A recess having a shape curved in a direction approaching the element side is formed.

  In the method for manufacturing a solid-state imaging device according to claim 4 of the present invention, when mounting the imaging device on one surface of the wiring board, a protruding electrode is formed on the imaging surface side of the imaging device and held in a flat plate shape. The image pickup device is flip-flop mounted on the wiring substrate, the flip-flop mounted wiring substrate of the image pickup device is placed in a mold, and the wiring substrate and the image pickup device protrude toward the image pickup device. It is characterized by shape | molding as follows.

A solid-state imaging device according to a fifth aspect of the present invention is the solid-state imaging device according to the first aspect, wherein the wiring board has a through hole or a recess formed in the center of the protrusion.
According to a sixth aspect of the present invention, when the imaging device is mounted on one surface of the wiring board, the protruding electrode is formed on the imaging surface side of the imaging device, and the through hole is formed in the center. Alternatively, the image pickup device is flip-flop mounted on the wiring board formed with a recess and held in a flat plate shape, and the wiring board mounted with the flip-flop of the image pickup device is placed in a mold, and the wiring board and the image pickup device are It is characterized in that it is shaped so as to protrude toward the image sensor side.

  According to this configuration, the imaging surface side of the imaging device is pressed against a curved protrusion formed on the wiring board to cause the imaging device to bend, which is caused by the aberration of the imaging lens used in combination with the solid-state imaging device. Field curvature can be reduced.

Embodiments of the present invention will be described below with reference to FIGS.
(Embodiment 1)
1 to 4 show the first embodiment.

FIG. 1 shows a cross-sectional view and a rear view of a solid-state imaging device A of the present invention, and FIG. 2 shows an optical system of a camera configured by combining the solid-state imaging device A and an imaging lens 4.
An image sensor 1B such as a MOS image sensor or a CCD image sensor is flip-flop mounted on one surface of the wiring board 6B. The wiring board 6B has a board body 7 made of a light-transmitting material, and a curved projection 8 having an inner circumference projecting toward the image sensor 1B rather than the outer circumference on the one surface of the board body 7. It is integrally formed. Lands 12 are formed on the one surface of the substrate body 7 corresponding to the positions of the wiring patterns 9 and the protruding electrodes 11 disposed outside the imaging surface 10 of the imaging device 1B.

3 and 4 show the manufacturing process.
In FIG. 3A, the protruding electrode 11 is formed on the electrode located outside the imaging surface 10 of the imaging device 1B. The image sensor 1B is formed on a flexible substrate.

  In FIG.3 (b), the surface of the imaging device 1B on the opposite side to the imaging surface 10 is brought into contact with the bending portion 14 of the tool 13, and the imaging device 1B is held in a curved state. The center of the curved portion 14 is recessed from the outer periphery. As a specific holding method of the imaging device 1B in the tool 13, holding by air suction can be given as an example. Further, as shown in FIG. 4, the alignment of the image sensor 1B in the tool 13 is performed by arranging a mirror 16 between the position confirmation camera 15 and the tool 13, and the position confirmation camera 15 via the mirror 16 at the solid line position. Then, it is determined whether the left position of the image sensor 1B in the curved portion 14 of the tool 13 is a specified position, and the position confirmation camera 15 passes the mirror 16 at the virtual line position to the right side of the image sensor 1B in the curved portion 14 of the tool 13. It is determined whether the position is a specified position and aligned with the target position.

  In FIG.3 (d), the protruding electrode 11 of the image pick-up element 1B is pressed on the land 12 of the board | substrate body 7 of the wiring board 6B with the tool 13, and is hold | maintained as shown in FIG.4 (c). In this embodiment, the protruding electrode 11 and the land 12 are made of, for example, gold of the same material, and the surface of the protruding electrode 11 and the land 12 is activated by ultraviolet irradiation or the like, and the protruding electrode of the image sensor 1B. 11 is pressed and held on the land 12 of the board body 7 of the wiring board 6B by the tool 13, whereby the bump electrode 11 and the land 12 can be joined at room temperature.

  After the joining of the protruding electrode 11 and the land 12 is completed, the tool 13 is removed, and the sealing resin 20 is filled around the imaging surface 10 of the imaging device 1B and solidified between the imaging device 1B and the wiring board 6B. Assembly is complete.

  As described above, the imaging surface 10 of the imaging device 1B can be curved following the protrusions 8 formed on the wiring board 6B, so that the aberration of the imaging lens 4 used in combination with the solid-state imaging device is corrected. By forming the protruding portion 8 having a shape, the curvature of field of the imaging lens 4 can be reduced with very little variation. In addition, it is not necessary to provide a holding material having a curved holding surface on the surface opposite to the imaging surface 10 side of the image pickup device 1B, and a reduction in thickness can be realized.

(Embodiment 2)
FIG. 5 shows the second embodiment.
In the wiring board 6B according to the first embodiment, the protrusion 8 is integrally formed on the one surface of the substrate body 7, and the back surface of the protrusion 8 is formed flush with the other surface of the substrate body 7. However, in the case of the wiring board 6C according to the second embodiment, the protrusion 8 is integrally formed on one surface of the substrate body 7, and the other of the substrate body 7 corresponds to the position of the protrusion 8. The difference is that a concave portion 21 having a shape curved in a direction approaching the image sensor 1B is formed on the rear surface of the protrusion 8 on the surface. The rest is the same as in the first embodiment.

Note that the wiring substrate 6C has the protrusions 8 and the recesses 21 before the image pickup device 1B is flip-flop mounted.
In this case, a thinner substrate body 7 can be used than in the case of the first embodiment, and weight reduction can be realized when the material is the same.

(Embodiment 3)
FIG. 6 shows a third embodiment.
The wiring board 6C in the second embodiment has the protrusion 8 and the recess 21 formed before the image pickup device 1B is flip-flop mounted. In the third embodiment, the wiring board 6C is molded after the image pickup device 1B is flip-flop mounted. Has been. A thermoplastic resin was used as the substrate body 7.

  FIG. 6A shows a flip-flop mounting process of the image sensor 1B. The image sensor 1B is flip-flop mounted on a flat wiring board 6C. Next, as shown in FIG. 6B, the wiring board 6B and the imaging device are sandwiched between the upper die 22 and the lower die 23 as shown in FIG. 6B. The element 1B can be heat-molded so as to protrude toward the image pickup element 1B, and finished in the same shape as FIG.

  According to this configuration, only the molding shown in FIG. 6B is curved surface processing, and the front-end process can be executed in a plane and the flip-flop mounting of the image sensor 1B can be executed.

(Embodiment 4)
FIG. 7 shows a fourth embodiment.
In the second embodiment and the third embodiment, the flat wiring board 6C has no through hole in the protrusion 8, but in this fourth embodiment, the wiring is as shown in FIGS. 7 (a) and 7 (b). A through hole 24 is formed in the center of the protrusion 8 in the substrate 6C.

  In this case, it is easy to perform the molding process particularly when the imaging element 1B is molded after flip-flop mounting as in the third embodiment. Here, the through hole 24 is formed in the protrusion 8 in the wiring substrate 6C. However, the same effect can be expected if a recess is formed in the center of the protrusion 8 in the wiring substrate 6C instead of the through hole 24. .

  In the above embodiment, the case where the bonding method is room temperature bonding has been described as an example, but an ACF / ACP (Anisotropic Conductive Film / Paste) bonding method using an anisotropic conductive film or paste, non-conductive A CF / NCP (Non Conductive Film / Paste) bonding method using a film / paste can be performed in the same manner.

  The present invention can contribute to miniaturization of a mobile device such as a mobile phone device with a camera.

Sectional drawing and rear view of the solid-state imaging device of Embodiment 1 of this invention Sectional view of the optical system of the camera using the solid-state imaging device of the embodiment Sectional drawing which shows the manufacturing process of the embodiment Sectional drawing of the position detection process of the image pick-up element hold | maintained at the tool of the embodiment Sectional drawing of the solid-state imaging device of Embodiment 2 of this invention Sectional drawing which shows the manufacturing process of the solid-state imaging device of Embodiment 3 of this invention. Sectional drawing and top view of the solid-state imaging device of Embodiment 4 of this invention Sectional view of a conventional solid-state imaging device Sectional view of another conventional solid-state imaging device

Explanation of symbols

A Solid-state imaging device 4 Imaging lens 1B Imaging element 6B Wiring board 7 Substrate body 8 of wiring board 6B Projection 9 of wiring board 6B Wiring pattern 10 Imaging surface 11 of imaging element 1B Projecting electrode 12 Land 13 Tool 14 Curve of tool 13 Part 20 sealing resin

Claims (6)

A solid-state imaging device in which an imaging device is mounted on one surface of a wiring board, and light incident on the one surface from the other surface of the wiring substrate is detected by the imaging device,
Provided on one surface of the wiring board is a curved-shaped protrusion whose inner periphery protrudes toward the image sensor rather than the outer periphery;
A solid-state imaging device in which the imaging element is joined to the protrusion of the wiring board and the imaging surface of the imaging element is curved. When mounting the image sensor on one side of the wiring board,
A protruding electrode is formed on the imaging surface side of the imaging device,
The curved portion of the tool having a curved portion whose center is recessed from the outer periphery is held in a state where the imaging device is curved by contacting the surface opposite to the imaging surface of the imaging device,
The projecting electrode of the image pickup element in the curved state and the land formed on the one surface of the wiring board on the curved protrusion with the inner periphery protruding toward the image pickup element from the outer periphery. A method for manufacturing a solid-state imaging device in which the imaging device is detached from the tool after the imaging device and the wiring board are bonded together. The wiring board is formed with a concave portion curved in a direction approaching the imaging element side on the other surface corresponding to the protrusion formed on one surface on the imaging element side. The solid-state imaging device described. When mounting the image sensor on one side of the wiring board,
A protruding electrode is formed on the imaging surface side of the imaging device,
Flip-flop mounting the image sensor on the wiring board held in a flat plate shape,
A method for manufacturing a solid-state imaging device, wherein the wiring board on which the flip-flop of the imaging element is mounted is placed in a molding die, and the wiring board and the imaging element are molded so as to protrude toward the imaging element. The solid-state imaging device according to claim 1, wherein the wiring board has a through hole or a recess formed in the center of the protrusion. When mounting the image sensor on one side of the wiring board,
A protruding electrode is formed on the imaging surface side of the imaging device,
Flip-flop mounting of the imaging element on the wiring board formed in the center with a through hole or recess formed in a flat plate shape,
A method for manufacturing a solid-state imaging device, wherein the wiring board on which the flip-flop of the imaging element is mounted is placed in a molding die, and the wiring board and the imaging element are molded so as to protrude toward the imaging element.

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