JP2015073017A - Semiconductor device and electronic camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device and an electronic camera capable of improving reliability in connection of an electrode that is jointed, even if a stress occurs which is caused by a difference between a linear expansion coefficient of a chip and a liner expansion coefficient of a substrate.SOLUTION: A semiconductor device 1 includes a semiconductor chip 2 containing a first electrode part 2b, and a substrate 3 containing a second electrode part 3b which is press-contacted to the first electrode part 2b without being bonded to the first electrode part 2b. One or both of the first and second electrode parts 2b, 3b are protruding parts in hemispherical shape.

Description

  The present invention relates to a semiconductor device and an electronic camera using the same.

  As an example of a solid-state imaging device which is an example of a semiconductor device, FIG. 4 of the following Patent Document 1 shows a wiring board in which a light passage hole is formed and the light passage hole is closed on one surface of the wiring board. An image pickup unit comprising a cover glass bonded with an adhesive and a solid-state image pickup device (bare chip image pickup device) bump-bonded to the other surface of the wiring board so as to close the light passage hole is disclosed. Has been.

  In this solid-state imaging device, the bump bonding is performed by applying an anisotropic conductive paste adhesive to the electrodes of the wiring board and thermocompressing gold ball bumps installed on the solid-state imaging element. The electrode and the gold ball bump of the solid-state image sensor are fixed.

JP 2000-147346 A

  However, in the conventional solid-state imaging device, due to the stress caused by the bimetal effect due to the difference between the linear expansion coefficient of the bare chip imaging element and the linear expansion coefficient of the wiring board, the reliability decreases due to poor electrical connection, Degradation of imaging performance due to warping of the imaging surface of the bare chip imaging device will be caused.

  Such a situation is the same for semiconductor devices other than the solid-state imaging device, except that the imaging performance is lowered.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a semiconductor device capable of improving the reliability of electrical connection and an electronic camera using the same.

  The following aspects are presented as means for solving the problems. A semiconductor device according to a first aspect includes a semiconductor chip having a first electrode portion, and a substrate having a second electrode portion that is in pressure contact with the first electrode portion without being fixed to the first electrode portion And one or both of the first and second electrode portions form hemispherical convex portions.

  A semiconductor device according to a second aspect is the semiconductor device according to the first aspect, wherein an adhesive that bonds the semiconductor chip and the substrate and generates a curing shrinkage force between the first electrode part and the second electrode part is provided. , Which is provided.

  The semiconductor device according to a third aspect is the semiconductor device according to the first or second aspect, wherein the one of the first and second electrode portions has a hemispherical convex portion, and the first and second electrode portions The other has a flat surface against which the convex portion abuts.

  In the semiconductor device according to a fourth aspect, in the first or second aspect, the one of the first and second electrode portions forms a hemispherical convex portion, and the first and second electrode portions The other of these has a recessed part which receives a part of said convex part.

  The semiconductor device according to a fifth aspect is the semiconductor device according to any one of the first to fourth aspects, wherein the semiconductor chip has an imaging region, and the substrate has an opening at least in a region corresponding to the imaging region. A wiring substrate disposed on the imaging region side with respect to the semiconductor chip, and is disposed so as to cover the opening and is fixed to a surface of the substrate opposite to the semiconductor chip. The semiconductor device is a solid-state imaging device.

  A semiconductor device according to a sixth aspect is the semiconductor device according to any one of the first to fourth aspects, wherein the semiconductor chip has an imaging region, the substrate has translucency, and the substrate covers the imaging region. The semiconductor device is a solid-state imaging device.

  An electronic camera according to a seventh aspect includes the semiconductor device according to any one of the first to sixth aspects.

  ADVANTAGE OF THE INVENTION According to this invention, the semiconductor device which can improve the reliability of an electrical connection, and an electronic camera using the same can be provided.

1 is a schematic cross-sectional view schematically showing a solid-state imaging device according to a first embodiment of the present invention. It is the partially expanded schematic sectional drawing which expanded a part in FIG. FIG. 2 is a partially enlarged schematic cross-sectional view schematically showing a state in which the angle between the semiconductor chip and the wiring board is changed near one side of the semiconductor chip of the solid-state imaging device shown in FIG. 1. It is a schematic sectional drawing which shows typically the electronic camera by the 2nd Embodiment of this invention. It is a partially expanded schematic sectional drawing which shows typically the solid-state imaging device by the 3rd Embodiment of this invention. It is a partially expanded schematic sectional drawing which shows typically the solid-state imaging device by the 4th Embodiment of this invention. It is a schematic sectional drawing which shows typically the solid-state imaging device by the 5th Embodiment of this invention.

  Hereinafter, a semiconductor device and an electronic camera according to the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a schematic cross-sectional view schematically showing a solid-state imaging device 1 as a semiconductor device according to the first embodiment of the present invention. FIG. 2 is a partially enlarged schematic cross-sectional view in which a part of FIG. 1 is enlarged.

  The solid-state imaging device 1 according to the present embodiment includes a semiconductor chip 2 having an imaging region 2a, a wiring board 3, and a translucent plate 4 as a translucent member.

  In the present embodiment, the semiconductor chip 2 is an image sensor such as a CMOS or CCD configured as a chip, and a plurality of pixels (not shown) are two-dimensionally arranged in the imaging region 2a. The semiconductor chip 2 photoelectrically converts incident light incident on the imaging region 2a via the translucent plate 4 and outputs an image signal. For example, a read circuit (not shown) that reads the image signal by driving the pixel and a processing circuit (for example, an AD conversion circuit) that processes the output signal may be mounted on the semiconductor chip 2.

  In the present embodiment, the substrate material of the semiconductor chip 2 is silicon, and the semiconductor chip 2 is a so-called silicon chip. However, in the present invention, the substrate material of the semiconductor chip 2 is not necessarily limited to silicon.

  In the present embodiment, a flexible wiring board is used as the wiring board 3. A circuit component may be mounted on the wiring board 3 so as to mount a predetermined circuit, or only the relay wiring may be mounted without mounting the circuit component. The wiring board 3 has an opening 3 a formed at least in a region facing the imaging region 2 a of the semiconductor chip 2.

  The electrode part 2 b is formed on the upper surface (surface on the imaging region 2 a side) near the outer periphery of the semiconductor chip 2, and the electrode part 3 b is formed on the lower surface around the opening 3 a in the wiring substrate 3. The electrode part 2b of the semiconductor chip 2 is electrically connected to a wiring (not shown) formed on the semiconductor chip 2, and the electrode part 3b of the wiring board 3 is a wiring (not shown) formed on the wiring board 3. ) And are electrically connected.

  The electrode portion 2b of the semiconductor chip 2 and the electrode portion 3b of the wiring board 3 are pressed against each other without being fixed to each other, and thereby the two electrode portions 2b and 3b are electrically connected. In the present embodiment, the electrode portion 3b of the wiring board 3 has a hemispherical convex portion, and the electrode portion 2b of the semiconductor chip 2 has a flat surface (upper surface in FIG. 2) with which the electrode portion 3b abuts. Yes. The electrode portion 3b forming the hemispherical convex portion can be constituted by, for example, a solder or the like, or can be constituted by a so-called resin bump in which a hemispherical resin is used as a core and a conductive film such as a metal film is formed on the surface layer side. . The electrode part 3b having a flat surface can be made of a metal such as gold or aluminum, for example. In addition, it is preferable to make small the friction coefficient of the surface of electrode part 2b, 3b.

  In the present embodiment, the semiconductor chip 2 and the wiring substrate 3 are bonded between the vicinity of the outer periphery of the semiconductor chip 2 and the periphery of the opening 3a in the wiring substrate 3 (including the vicinity of the electrode portions 2b and 3b). An adhesive 6 is formed so that the airtightness of the space between the imaging region 2a and the translucent plate 4 is maintained. The adhesive 6 is formed by a known method so that a curing shrinkage force acts between the electrode part 2 b of the semiconductor chip 2 and the electrode part 3 b of the wiring substrate 3. As the adhesive 6, it is preferable to use a resin having a high elastic deformation rate. Specifically, for example, an underfill material of model number FP5120 (having an elastic modulus of 4.8 GPa) manufactured by Henkel is used. be able to.

  The translucent plate 4 is disposed so as to cover the opening 3 a of the wiring substrate 3 on the upper surface (surface opposite to the wiring substrate 3) side of the wiring substrate 3, and is fixed to the upper surface of the wiring substrate 3. ing. In the present embodiment, an adhesive 7 is formed between the upper surface around the opening 3 a in the wiring substrate 3 and the translucent plate 4. Thereby, the translucent plate 4 is fixed to the upper surface of the wiring board 3. If necessary, a spacer member or the like may be interposed between the translucent plate 4 and the wiring board 3. In the present embodiment, the adhesive 7 is provided over the entire circumference of the opening 3a in the wiring board 3 so that the airtightness of the space between the imaging region 2a and the translucent plate 4 is maintained. The space between the translucent plate 4 and the wiring board 3 is sealed.

  As a material of the translucent plate 4, for example, glass for measures against α rays (glass in which the amount of α rays emitted is sufficiently reduced), quartz that is an optical low-pass filter, or the like can be used.

  FIG. 3 is a partially enlarged schematic cross-sectional view schematically showing a state in which the angle between the semiconductor chip 2 and the wiring board 3 is changed in the vicinity of one side of the semiconductor chip 2 of the solid-state imaging device 1 shown in FIG. This corresponds to FIG.

  In the present embodiment, the electrode portion 2b of the semiconductor chip 2 and the electrode portion 3b of the wiring board 3 are in pressure contact with each other without being fixed to each other, and the electrode portion 3b of the wiring board 3 forms a hemispherical convex portion. The second electrode portion 2b has a flat surface with which the electrode portion 3b is brought into contact. Therefore, in the present embodiment, the adhesive 6 is elastically deformed, and the state shown in FIG. 2 is changed from the state shown in FIG. The semiconductor chip 2 and the wiring board 3 have a degree of freedom that the angle between the semiconductor chip 2 and the wiring board 3 can be changed to some extent as shown in FIG. For this reason, according to the present embodiment, even if there is a difference in coefficient of linear thermal expansion between the semiconductor chip 2 and the wiring board 3 as compared with the case where the electrodes 2b and 3b are fixed with solder or the like. The possibility of separation between the electrode portion 2b and the electrode portion 3b due to the stress due to the bimetal effect due to the environmental temperature change is reduced, and the imaging surface of the semiconductor chip 2 due to the stress due to the bimetal effect due to the environmental temperature change ( The warping of the imaging area 2a) is reduced. Therefore, according to the present embodiment, it is possible to improve the reliability of the electrical connection between the electrode portions 2b and 3b, and to reduce the deterioration of the imaging performance due to the warp of the imaging surface of the semiconductor chip 2. .

  In the present invention, contrary to the present embodiment, the electrode portion 2b of the semiconductor chip 2 has a hemispherical convex portion, and the electrode portion 3b of the wiring board 3 has a plane on which the electrode portion 2b abuts. You may have.

[Second Embodiment]
FIG. 4 is a schematic cross-sectional view schematically showing an electronic camera 100 according to the second embodiment of the present invention.

  The solid-state imaging device 1 according to the first embodiment is incorporated in the body 101 of the electronic camera 100 according to the present embodiment. The electronic camera 100 according to the present embodiment is configured as a single-lens reflex type electronic still camera. However, the solid-state imaging device 1 according to the first embodiment is different from other electronic still cameras, video cameras, and mobile phones. You may incorporate in various electronic cameras, such as a camera mounted in.

  In electronic camera 100 according to the present embodiment, body 101 is provided with interchangeable photographic lens 102. The subject light that has passed through the photographing lens 102 is reflected upward by the quick return mirror 103 and forms an image on the screen 104. The subject image formed on the screen 104 is observed from the finder observation window 107 through the eyepiece lens 106 from the penta roof prism 105. When the release button (not shown) is fully pressed, the quick return mirror 103 jumps upward, and the subject image from the photographing lens 102 enters the solid-state imaging device 1 described above.

  The solid-state imaging device 1 is positioned and fixed in the body 101 by being attached to the body 101 via a bracket (not shown) and a position adjusting mechanism (not shown).

  According to the present embodiment, since the solid-state imaging device 1 according to the first embodiment is used, it is possible to improve the reliability of electrical connection and reduce the deterioration of imaging performance. it can.

[Third Embodiment]
FIG. 5 is a partially enlarged schematic cross-sectional view schematically showing a solid-state imaging device 11 according to the third embodiment of the present invention, and corresponds to FIG. 5, elements that are the same as or correspond to those in FIG. 2 are given the same reference numerals, and redundant descriptions thereof are omitted.

  The solid-state imaging device 11 according to the present embodiment differs from the solid-state imaging device 1 according to the first embodiment in that not only the electrode portion 3b of the wiring board 3 but also the electrode portion 2b of the semiconductor chip 2 are hemispherical. It is the point which has made the convex part.

  Also in this embodiment, the same advantages as those in the first embodiment can be obtained.

  The solid-state imaging device 11 according to the present embodiment can be used in place of the solid-state imaging device 1 in the electronic camera 100 according to the second embodiment. This is the same for each solid-state imaging device described later.

[Fourth Embodiment]
FIG. 6 is a partially enlarged schematic cross-sectional view schematically showing a solid-state imaging device 21 according to the fourth embodiment of the present invention, and corresponds to FIG. 6, elements that are the same as or correspond to those in FIG. 2 are given the same reference numerals, and redundant descriptions thereof are omitted.

  The solid-state imaging device 21 according to the present embodiment is different from the solid-state imaging device 1 according to the first embodiment in that the electrode portion 2b of the semiconductor chip 2 forms the hemispherical convex portion of the wiring board 3. It is a point which has the recessed part which receives a part of. For example, after forming the electrode part 2b made of gold or the like whose upper surface in FIG. 6 is a flat surface on the semiconductor chip 2, the electrode part 3b forming the hemispherical convex part of the wiring substrate 3 is replaced with the electrode part 2b of the semiconductor chip 2. A concave portion is formed in the electrode portion 2b by pressing the upper surface and the upper surface is recessed, and after the electrode portion 3b is once separated from the electrode portion 2b, the electrode portion 3b may be brought into contact with the electrode portion 2b.

  According to the present embodiment, since a part of the electrode part 3b forming the hemispherical convex part of the wiring board 3 is received in the concave part of the electrode part 2b of the semiconductor chip 2, the semiconductor chip 2 and the wiring board 3 2 does not have a degree of freedom of movement in the lateral direction in FIG. 2, but the contact between the semiconductor chip 2 and the wiring substrate 3 is maintained in the vicinity of the electrode parts 2b and 3b while maintaining the pressure contact state between the electrode parts 2b and 3b. The degree of freedom that the angle changes to some extent. Therefore, the present embodiment can provide the same advantages as those of the first embodiment.

  In addition, according to the present embodiment, since a part of the electrode part 3b forming the hemispherical convex part of the wiring substrate 3 is received in the concave part of the electrode part 2b of the semiconductor chip 2, the electrode parts 2b, 3b Since the contact area between the electrodes increases, the contact resistance between the electrode portions 2b and 3b decreases.

  In the present invention, contrary to the present embodiment, the electrode part 2b of the semiconductor chip 2 forms a hemispherical convex part, and the electrode part 3b of the wiring board 3 covers a part of the electrode part 2b of the semiconductor chip 2. You may have the recessed part to receive.

[Fifth Embodiment]
FIG. 7 is a schematic cross-sectional view schematically showing a solid-state imaging device 31 according to the fifth embodiment of the present invention, and corresponds to FIG. 7, elements that are the same as or correspond to those in FIG. 1 are given the same reference numerals, and redundant descriptions thereof are omitted.

  The solid-state imaging device 31 according to the present embodiment differs from the solid-state imaging device 1 according to the first embodiment in that the wiring board 3, the translucent plate 4, and the adhesive 7 are replaced with a translucent wiring. A substrate 32 is used, and a flexible wiring substrate 33 is bonded to the wiring substrate 32 via bumps 34.

  As the wiring board 32, for example, a glass plate made of glass for preventing α rays (glass with a sufficiently reduced emission amount of α rays) can be used.

  An electrode portion 2b is formed on the upper surface (surface on the imaging region 2a side) near the outer periphery of the semiconductor chip 2, and an electrode portion 32b is formed on the lower surface of the wiring board 32 at a position corresponding to the electrode portion 2b.

  The electrode portion 2b of the semiconductor chip 2 and the electrode portion 32b of the wiring substrate 32 are pressed against each other without being fixed to each other, thereby electrically connecting both the electrode portions 2b and 32b. In the present embodiment, the electrode part 32b of the wiring substrate 32 has a hemispherical convex part, and the electrode part 2b of the semiconductor chip 2 has a plane on which the electrode part 32b abuts. On the contrary, the electrode part 2b of the semiconductor chip 2 may be a hemispherical convex part, and the electrode part 32b of the wiring board 32 may have a flat surface on which the electrode part 2b abuts. Alternatively, both the electrode portions 2b and 32b may form a hemispherical convex portion, one of the electrode portions 2b and 32b forms a hemispherical convex portion, and the other of the electrode portions 2b and 32b protrudes from the convex shape. You may have the recessed part which receives a part of part.

  The adhesive 6 described above is formed between the vicinity of the outer periphery of the semiconductor chip 2 and the wiring substrate 32 (including the vicinity of the electrode portions 2b and 32b), whereby the electrode portion 2b and the electrode 32b are pressed against each other. At the same time, the airtightness of the space between the imaging region 2a and the wiring board 32 is maintained.

  Although not shown in the drawing, on the lower surface of the wiring board 32, electrode pads to which the bumps 34 are bonded and wirings connecting the electrode pads and the electrode portions 32b are also formed. The semiconductor chip 2 is connected to the outside through the electrode portions 2 b and 32 b, the wiring and electrode pads on the lower surface of the wiring substrate 32, the bumps 34, and the flexible wiring substrate 33. As the bumps 34, metal bumps such as Au stud bumps are used.

  Also in the present embodiment, as in the first embodiment, the reliability of the electrical connection between the electrode portions 2b and 32b can be improved, and the imaging performance due to the warp of the imaging surface of the semiconductor chip 2 Can be reduced.

  Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments.

  For example, in the first to fourth embodiments, a flexible wiring board is used as the wiring board 3. However, in the present invention, a rigid wiring board may be used as the wiring board 3.

  Moreover, although each said embodiment and those modifications are examples which applied this invention to the solid-state imaging device, this invention is applicable also to various semiconductor devices other than a solid-state imaging device. The present invention is particularly suitable for a semiconductor device used in an environment with a large temperature change.

DESCRIPTION OF SYMBOLS 1,11,21,31 Solid-state imaging device 2 Semiconductor chip 2a Imaging area 2b Electrode part 3 Wiring board 3a Opening part 3b Electrode part 4 Translucent board (translucent member)
6,7 Adhesive

Claims (7)

A semiconductor chip having a first electrode portion;
A substrate having a second electrode portion pressed against the first electrode portion without being fixed to the first electrode portion;
With
One or both of the first electrode portion and the second electrode portion are hemispherical convex portions.   The semiconductor device according to claim 1, further comprising an adhesive that adheres the semiconductor chip and the substrate and generates a curing shrinkage force between the first electrode portion and the second electrode portion. The one of the first and second electrode portions has a hemispherical convex portion,
3. The semiconductor device according to claim 1, wherein the other of the first and second electrode portions has a flat surface with which the convex portion comes into contact. The one of the first and second electrode portions has a hemispherical convex portion,
3. The semiconductor device according to claim 1, wherein the other of the first and second electrode portions has a concave portion that receives a part of the convex portion. The semiconductor chip has an imaging region;
The substrate is a wiring substrate having an opening in at least a region corresponding to the imaging region and disposed on the imaging region side with respect to the semiconductor chip,
A translucent member disposed so as to cover the opening and fixed to a surface of the substrate opposite to the semiconductor chip;
The semiconductor device is a solid-state imaging device.
The semiconductor device according to claim 1, wherein: The semiconductor chip has an imaging region;
The substrate has translucency;
The substrate is arranged to cover the imaging region;
The semiconductor device is a solid-state imaging device.
The semiconductor device according to claim 1, wherein:   An electronic camera comprising the semiconductor device according to claim 1.

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