JP2011040428A - Package for electronic component, and solid imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a deformation of an electronic component caused by a difference between thermal expansion coefficients of the electronic component and a package, without worsening a strength of the package, as to the package for the electronic component and a solid imaging apparatus. <P>SOLUTION: This package for the electronic component includes an attaching portion provided with a mounting face for fixing the electronic component, and a thermal expansion coefficient regulating member composed with materials different in thermal expansion coefficients in one part. A thermal expansion coefficient of the attaching portion is higher than a thermal expansion coefficient of the electronic component, and a thermal expansion coefficient of the thermal expansion coefficient regulating member is lower than the thermal expansion coefficient of the attaching portion, in the package for the electronic component. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electronic component package and a solid-state imaging device.

  Conventionally, a solid-state imaging device in which a solid-state imaging element is accommodated in a package is known. In such a solid-state imaging device, the solid-state imaging device may be deformed during die bonding or use due to a difference in thermal expansion coefficient between the solid-state imaging device and the package. Therefore, in Patent Document 1 below, a solid-state imaging device is proposed in which a solid-state imaging element is accommodated in a package made of silicon.

JP 2007-287967 A

  In the conventional solid-state imaging device, silicon having the same thermal expansion coefficient as that of the solid-state imaging element made of silicon is used as the material of the package, so that deformation of the solid-state imaging element due to thermal stress or the like can be reduced. However, in the conventional solid-state imaging device, since the entire package to which the solid-state imaging device is die-bonded is formed of silicon, there is a problem that the package is relatively fragile and may be broken.

  The present invention has been made to solve such a conventional problem, and the deformation of the electronic component due to the difference in thermal expansion coefficient between the electronic component such as a solid-state imaging device and the package without reducing the strength of the package. An object of the present invention is to provide an electronic component package and a solid-state imaging device capable of reducing the above.

  According to a first aspect of the invention, there is provided an electronic component package having an attachment portion including a mounting surface for fixing the electronic component and a thermal expansion coefficient adjusting member made of a material having a different coefficient of thermal expansion.

  The electronic component package according to a second aspect is the electronic component package according to the first aspect, wherein the thermal expansion coefficient of the attachment portion is larger than the thermal expansion coefficient of the electronic component, and the thermal expansion coefficient adjusting member has a thermal expansion coefficient. The coefficient is smaller than the thermal expansion coefficient of the attachment part.

  The electronic component package of the third invention is the electronic component package of the second invention, wherein the thermal expansion coefficient adjusting member has a thermal expansion coefficient substantially the same as the thermal expansion coefficient of the electronic component. It is characterized by.

  The electronic component package according to a fourth aspect is the electronic component package according to any one of the first to third aspects, wherein the electronic component is made of a thermosetting resin on the attachment part or the thermal expansion coefficient adjusting member. It is characterized by being joined.

  The electronic component package according to a fifth aspect is the electronic component package according to any one of the first to fourth aspects, wherein the thermal expansion coefficient adjusting member is embedded in the attachment portion. .

  According to a sixth aspect of the invention, there is provided the electronic component package according to any one of the first to fifth aspects of the invention, wherein the attachment portion is made of a resin.

  The electronic component package according to a seventh aspect is the electronic component package according to any one of the first to sixth aspects, wherein a part of the attachment portion is provided between the electronic component and the thermal expansion coefficient adjusting member. It is characterized by interposition.

  An electronic component package according to an eighth invention is the electronic component package according to any one of the first to sixth inventions, wherein the electronic component is directly joined to the thermal expansion coefficient adjusting member. To do.

  A solid-state imaging device according to a ninth aspect includes the electronic component package according to any one of the first to eighth aspects.

  In the present invention, it is possible to reduce the deformation of the electronic component due to the difference in thermal expansion coefficient between the electronic component and the package without reducing the reliability of the electronic component package.

1 is a cross-sectional view schematically showing a first embodiment of a solid-state imaging device of the present invention. It is a top view which shows the state which removed the glass substrate from the solid-state imaging device of FIG. It is explanatory drawing which shows the manufacturing process of the solid-state imaging device of FIG. It is explanatory drawing which shows a deformation | transformation of the solid-state image sensor at the time of die bonding of the conventional solid-state imaging device. It is explanatory drawing which shows the deformation | transformation of the solid-state image sensor at the time of die bonding of the solid-state imaging device of FIG. It is explanatory drawing which shows the dimensional relationship of the solid-state imaging device of FIG. It is sectional drawing which shows typically 2nd Embodiment of the solid-state imaging device of this invention. It is explanatory drawing which shows the modification of the solid-state imaging device of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
1 and 2 show a first embodiment of the solid-state imaging device of the present invention.

  This solid-state imaging device has a glass substrate 11, a solid-state imaging device 13, a package 15, and a thermal expansion coefficient adjusting member 17.

  The glass substrate 11 is made of transparent glass. Instead of the glass substrate 11, a translucent member made of resin or the like may be used. The solid-state image sensor 13 is composed of an element such as a CCD or CMOS configured as a chip. The solid-state image sensor 13 is formed of silicon (for example, linear expansion coefficient 3.5 × 10 −6). The glass substrate 11 and the solid-state imaging device 13 are arranged to face each other with a predetermined interval. On the glass substrate 11 side of the solid-state imaging device 13, a pixel region 13 a that receives light that has passed through the glass substrate 11 is formed. The pixel region 13 a is formed in a portion excluding the outer periphery of the solid-state image sensor 13. A large number of pixels, microlenses, color filters, and the like are arranged in the pixel region 13a. The solid-state image sensor 13 converts light incident on each pixel into an electrical signal. The conductor pattern 19 of the solid-state imaging device 13 is wire-bonded by a wire 23 to a conductor pattern 21 formed in a housing portion of a package 15 (hereinafter referred to as a package body).

  The package main body 15 has an attachment part 15a and a frame part 15b. The package body 15 is formed of an epoxy resin (for example, a linear expansion coefficient of 12 × 10 −6). The shape of the attachment portion 15a (hereinafter referred to as die attach portion) on which an electronic component such as the solid-state image pickup device 13a is placed is not particularly limited, but in the present embodiment, a rectangular shape that matches the outer shape of the solid-state image pickup device 13 is used. is doing. A frame portion 15b is integrally formed along the outer periphery of the die attach portion 15a. A thermal expansion coefficient adjusting member 17 is embedded in the die attach portion 15a. The thermal expansion coefficient adjusting member 17 is made of silicon (for example, linear expansion coefficient 3.5 × 10 −6).

  The solid-state imaging device described above is manufactured, for example, as shown in FIG.

  First, as shown in FIG. 3A, a package body 15 is prepared. A thermal expansion coefficient adjusting member 17 is embedded in the package body 15 in advance. The thermal expansion coefficient adjusting member 17 is made of silicon. The thermal expansion coefficient adjusting member 17 is insert-molded when the package body 15 is molded.

  Next, as shown in FIG. 3B, the solid-state imaging device 13 is bonded to the mounting surface 15c of the package body 15 by die bonding. The die bonding is performed by bonding the solid-state imaging element 13 to a predetermined position of the package body 15 with a die bond material, and then thermosetting the die bond material. A die bond portion 25 is formed between the solid-state imaging device 13 and the package body 15 by die bonding. For the die bond material, for example, an adhesive such as an epoxy resin, an acrylic resin, or a silicon resin is used. The thermosetting temperature is, for example, 150 ° C. to 200 ° C.

  Next, as shown in FIG. 3C, the conductor pattern 19 of the solid-state imaging device 13 is wire-bonded to the conductor pattern 21 of the package body 15 with a wire 23.

  Next, as shown in FIG. 3 (d), the glass substrate 11 is fixed to the upper surface of the frame portion 15 b of the package body 15. The fixing is performed by bonding the glass substrate 11 to the upper surface of the frame portion 15b with, for example, a glass sealing resin, and then thermosetting the glass sealing resin. The thermosetting temperature is, for example, 100 ° C. For the glass sealing resin, for example, an adhesive such as an epoxy resin or a silicon resin is used.

  In the above-described solid-state imaging device, since the thermal expansion coefficient adjusting member 17 is embedded in the package body 15, the thermal expansion coefficients of the solid-state imaging device 13 and the die attach unit 15a can be matched, for example, as shown in FIG. As shown, it is possible to prevent the solid-state imaging device 13 from being deformed in the temperature lowering process after the die bonding material is thermally cured.

  That is, when the thermal expansion coefficient adjusting member 17 is not disposed on the package body 15, as shown in FIG. 4A, the solid-state imaging device 13 and the package are subjected to a temperature drop process after thermosetting the die bond material. Stress in the direction indicated by the arrow A is generated on the adhesive surface with the main body 15. This is because the thermal expansion coefficient of the package body 15 made of resin is larger than the thermal expansion coefficient of the solid-state image sensor 13 made of silicon, and the thermal contraction amount of the package body 15 at the time of temperature drop is larger than the thermal contraction amount of the solid-state image sensor 13. Because it is big. Then, due to the stress in the direction indicated by the arrow A, the solid-state imaging device 13 is deformed so that the pixel region 13a side is convex as shown in FIG.

  On the other hand, in the solid-state imaging device described above, as shown in FIG. 5A, a thermal expansion coefficient adjusting member 17 is embedded in the package main body 15, and the resin portion 15d is interposed between the package main body 15 and the thermal expansion coefficient adjusting member 17. Formed. Therefore, stress in the direction indicated by the arrow B is generated on the bonding surface between the solid-state imaging device 13 and the package body 15 in the temperature drop process after thermosetting the die bond material. Further, stress in the direction indicated by the arrow C is also generated on the surface of the thermal expansion coefficient adjusting member 17 on the solid-state imaging device 13 side. By making the thermal expansion coefficient adjusting member 17 have the same thermal expansion coefficient and the same shape as those of the solid-state imaging device 13, the stresses in the directions indicated by the arrows B and C have the same magnitude in the same direction.

  As shown in FIG. 5B, the stress F acting on the solid-state imaging device 13 and the thermal expansion coefficient adjusting member 17 includes stresses a1 and a2 in the direction along the solid-state imaging device 13 or the thermal expansion coefficient adjusting member 17, and It can be decomposed into stresses b1 and b2 in a direction perpendicular to this stress. The stress in the Y-axis direction (component of b1 in the Y-axis direction) that is the stress that warps the solid-state imaging device 13 is the same as the stress in the Y-axis direction (component of b2 in the Y-axis direction) acting on the thermal expansion coefficient adjusting member 17. Since the sizes are opposite to each other, they are canceled out. Thereby, as shown in FIG.5 (c), the deformation | transformation that the pixel area 13a side of the solid-state image sensor 13 becomes convex is reduced.

  In this package structure, the stress that causes the solid-state image sensor 13 to warp is canceled out with the stress generated in the thermal expansion coefficient adjusting member 17, thereby effectively preventing the deformation of the solid-state image sensor 13. Since the deformation of the solid-state image sensor 13 is prevented, so-called tilting in which the image pickup surface of the solid-state image sensor 13 is tilted with respect to the optical axis of the camera lens can be reduced. Moreover, since the curvature of the imaging surface of the solid-state image sensor 13 reduces, imaging performance can be improved.

  In the solid-state imaging device described above, in addition to preventing the deformation of the solid-state imaging device 13 at the time of manufacture, the solid-state imaging device 13 can also be prevented from being deformed due to heat generated by the solid-state imaging device 13 during use. That is, when the solid-state imaging device 13 generates heat and the resin portion 15d between the solid-state imaging device 13 and the thermal expansion coefficient adjusting member 17 expands and deforms, the thermal expansion coefficient adjusting member 17 suppresses the deformation. Therefore, deformation of the solid-state image sensor 13 can be reduced.

  In the solid-state imaging device described above, since the package body 15 is formed of resin, the strength can be improved and the cost can be reduced compared to the case of forming the package body 15 from silicon. Further, the dimensional accuracy can be improved as compared with the case where the package body 15 is formed of ceramics.

  In the solid-state imaging device described above, the sealing performance can be improved because the solid-state imaging element 13 side of the thermal expansion coefficient adjusting member 17 is covered with the resin portion 15d of the package body 15.

  FIG. 6 shows a more specific example of the package structure described above.

  As shown in FIG. 6A, the thickness of the solid-state imaging device 13 is d1, the thickness of the thermal expansion coefficient adjusting member 17 is d2, and the resin portion 15d between the solid-state imaging device 13 and the thermal expansion coefficient adjusting member 17 is used. The thickness of is d3. From the description of FIG. 5, in order to effectively cancel the stress that warps the solid-state imaging device 13, it is most preferable to set d1 = d2.

Further, considering the symmetry of the arrangement of the solid-state imaging device 13 and the thermal expansion coefficient adjusting member 17 with respect to the package body 15, the structure of FIG. 6B is preferable to the structure of FIG. In FIG. 6B, the surface of the thermal expansion coefficient adjusting member 17 opposite to the solid-state imaging device 13 is exposed on the lower surface of the package body 15 without being covered with resin. In such a structure, by setting d1 = d2, the vertical direction is symmetrical, and thus the warpage of the solid-state imaging device 13 can be more reliably prevented. Even if d1 = d2 is not satisfied, there is an effect of relaxing the stress of the solid-state imaging device 13 and suppressing warpage.
(Second Embodiment)
FIG. 7 shows a second embodiment of the solid-state imaging device of the present invention. In this embodiment, the same elements as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In this embodiment, the thermal expansion coefficient adjusting member 17 is exposed and embedded in the mounting surface 15c of the package body 15A. The solid-state imaging device 13 is directly die-bonded and joined to the exposed surface of the thermal expansion coefficient adjusting member 17.

  The solid-state image sensor 13 and the thermal expansion coefficient adjusting member 17 are made of silicon. The package body 15A is formed of an epoxy resin. The die bonding is performed by bonding the solid-state imaging element 13 to a predetermined position of the thermal expansion coefficient adjusting member 17 with a die bond material, and then thermosetting the die bond material. For the die bond material, for example, an adhesive such as an epoxy resin, an acrylic resin, or a silicon resin is used. The thermosetting temperature is, for example, 150 ° C. to 200 ° C.

In this embodiment, the thermal expansion coefficient adjustment member 17 and the solid-state image sensor 13 have the same thermal expansion coefficient, and the solid-state image sensor 13 is directly die-bonded to the thermal expansion coefficient adjustment member 17. The thermal expansion amounts of the member 17 and the solid-state imaging device 13 are always almost the same. Therefore, it is possible to prevent the solid-state imaging device 13 from being deformed in the temperature lowering process after the die bonding material is thermally cured. Further, it is possible to prevent the solid-state image sensor 13 from being deformed due to heat generated by the solid-state image sensor 13 during use.
(Supplementary items of the embodiment)
As mentioned above, although this invention was demonstrated by embodiment mentioned above, the technical scope of this invention is not limited to embodiment mentioned above, For example, the following forms may be sufficient.

  (1) In the above-described embodiment, the example in which the size of the adhesive surface of the solid-state imaging device 13 and the size of the thermal expansion coefficient adjusting member 17 are the same has been described. For example, FIGS. As shown, the size S2 of the thermal expansion coefficient adjusting member 17 may be made larger than the size S1 of the bonding surface of the solid-state imaging device 13. Thereby, the curvature of the solid-state image sensor 13 can be reduced more.

  (2) In the above-described embodiment, the example in which the thermal expansion coefficient adjusting member 17 is formed into a plate shape without a notch or the like has been described. However, for example, a hole 17a may be formed as shown in FIG. . In this case, it is desirable that the outside size S2 of the thermal expansion coefficient adjusting member 17 is larger than the outside size S1 of the solid-state imaging device 13.

  (3) In the above-described embodiment, the example in which the thermal expansion coefficient adjusting member 17 is integrated has been described. However, for example, as shown in FIG. In this case, it is desirable that the outside size S2 of the thermal expansion coefficient adjusting member 17 is larger than the outside size S1 of the solid-state imaging device 13.

  (4) In the above-described embodiment, the example in which at least one side of the thermal expansion coefficient adjusting member 17 is covered with the resin of the package main body 15A has been described. For example, as shown in FIG. You may make it expose both sides of. In such a structure, heat dissipation performance can be improved by using a metal with good heat dissipation for the thermal expansion coefficient adjusting member 17.

  (5) In the above-described embodiment, the example in which the present invention is applied to the solid-state imaging device in which the solid-state imaging device 13 is fixed to the package bodies 15 and 15A has been described. However, in the electronic component package in which the electronic components are fixed to the package body. Can be widely applied.

  (6) In the above-described embodiment, the example in which the solid-state imaging device 13 and the thermal expansion coefficient adjusting member 17 are formed of silicon has been described. However, as the thermal expansion coefficient adjusting member 17, for example, alkaline glass having a larger thermal expansion coefficient than silicon. 42 alloy or the like may be used.

  (7) In the above-described embodiment, an example in which the package main body 15A is formed of resin has been described. However, for example, ceramics (for example, linear expansion coefficient 6.7 × 10-6) or the like may be used as the package main body 15A.

DESCRIPTION OF SYMBOLS 11 ... Glass substrate, 13 ... Solid-state image sensor, 15 and 15A ... Package main body, 15c ... Mounting surface, 17 ... Thermal expansion coefficient adjustment member.

Claims (9)

An electronic component package comprising: an attachment portion including a mounting surface for fixing an electronic component; and a thermal expansion coefficient adjusting member made of a material having a different coefficient of thermal expansion. The electronic component package according to claim 1,
The thermal expansion coefficient of the attachment part is larger than the thermal expansion coefficient of the electronic component,
The electronic component package according to claim 1, wherein a thermal expansion coefficient of the thermal expansion coefficient adjusting member is smaller than a thermal expansion coefficient of the attachment portion. The electronic component package according to claim 2,
The package for an electronic component, wherein the thermal expansion coefficient adjusting member has a thermal expansion coefficient substantially the same as the thermal expansion coefficient of the electronic component. The electronic component package according to any one of claims 1 to 3,
The electronic component package is bonded to the attachment portion or the thermal expansion coefficient adjusting member by a thermosetting resin. The electronic component package according to any one of claims 1 to 4,
The electronic component package, wherein the thermal expansion coefficient adjusting member is embedded in the attachment portion. The electronic component package according to any one of claims 1 to 5,
The electronic part package is characterized in that the attachment part is made of resin. The electronic component package according to any one of claims 1 to 6,
An electronic component package, wherein a part of the attachment portion is interposed between the electronic component and the thermal expansion coefficient adjusting member. The electronic component package according to any one of claims 1 to 6,
The electronic component package is characterized in that the electronic component is directly joined to the thermal expansion coefficient adjusting member. A solid-state imaging device comprising the electronic component package according to claim 1.

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