Package

Abstract

The package (800) has: a mounting surface (SM) for mounting an electronic component (902); a cavity (CV); and a mounting surface (SF) for mounting a cover (906) via an adhesive layer (907). The package (800) has: a bottom (811) made of ceramic and having a mounting surface (SM); and a frame (812) made of ceramic and having a mounting surface (SF). The mounting surface (SF) of the frame (812) has an inner end (EI) adjacent to the cavity (CV) and an outer end (EO) opposite to the inner end (EI) in each of at least one cross-sections extending inside and outside the cavity (CV), and has a convex shape protruding in the thickness direction. Compared with the most protruding part (PP) of the convex shape, at least one of the inner end (EI) and the outer end (EO) is lower by more than 10 μm.

Description

Technical Field

[0001] The present invention relates to a package, and in particular to a package for electronic components. Background Art

[0002] Solid-state imaging elements such as charge-coupled devices (CCDs) or complementary metal oxide semiconductors (CMOS) are widely used in digital cameras, camcorders, and other imaging devices. In the manufacture of an imaging device, usually, an imaging component having an airtightly sealed solid-state imaging element (for example, an electronic component called a "CMOS / CCD package") is first prepared, and then the imaging component is mounted on the imaging device. Typically, the component has: an imaging element; a ceramic package having a cavity for accommodating the imaging element; and a cover that seals the cavity. In most cases, the cover and the package are fixed by bonding the cover to the mounting surface of the frame of the package using an adhesive layer.

[0003] In recent years, larger imaging elements are sometimes used, and on the other hand, the size of the imaging module (CMOS / CCD package) is required to be further reduced. The size of the imaging module can be reduced by reducing the width of the mounting surface to which the cover is bonded. However, this method easily leads to a decrease in the bonding strength of the cover. Therefore, a technology is desired that ensures a sufficiently high bonding strength while reducing the width of the mounting surface.

[0004] Japanese Patent Publication No. 2018-166201 (Patent Document 1) discloses a substrate for a camera device. The substrate for a camera device has a ceramic wiring substrate (package) and a frame-shaped member made of metal. The ceramic wiring substrate includes: a base portion having a mounting area for a camera element on the upper surface and having a rectangular shape when viewed from above; and a frame portion (frame portion) that is arranged on the base portion and surrounds the mounting area and has a rectangular shape when viewed from above. The frame-shaped member is joined to the upper surface of the frame portion via a joining member, and has a protrusion that protrudes outward from the side of the ceramic wiring substrate. Regarding the height of the upper surface of the frame-shaped member from the upper surface of the frame portion, the height at the corner of the frame portion is lower than the height at the center of the side of the frame portion. According to the content claimed in the above-mentioned bulletin, the height of the upper surface of the frame-shaped member from the upper surface of the frame body is lower at the corners of the frame body than at the center of the side of the frame body. Therefore, when the cover body is joined to the upper surface of the frame-shaped member via the bonding material (adhesive layer), the thickness of the bonding material at the corners of the cover body is thicker than that at other parts, and the bonding strength of the cover body is high.

[0005] Prior Art Literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2018-166201 Summary of the invention

[0008] Problems to be solved by the invention

[0009] According to the technology of the above-mentioned publication, by locally increasing the thickness of the adhesive layer at the corner of the frame, it is possible to improve the bonding strength near the corner of the frame. However, the bonding strength cannot be improved at a position away from the corner. Moreover, as an additional component to the usual structure, a frame-shaped component made of metal is required, so the manufacturing cost of the package body is significantly increased.

[0010] The present invention has been made to solve such a problem, and an object of the present invention is to provide a package capable of improving the bonding strength of an adhesive layer bonding a frame portion and a cover body without using a special additional member.

[0011] Means for solving problems

[0012] A package according to one embodiment of the present invention has: a mounting surface for mounting electronic components; a cavity located on the mounting surface; and an assembly surface of a cover body for sealing the cavity assembled via an adhesive layer. The package has a bottom, a frame, and a wiring portion. The bottom is made of ceramic and has a mounting surface. The frame is made of ceramic, surrounds the cavity on the outside of the mounting surface on the bottom, and has an assembly surface. The wiring portion connects the inside of the cavity with the outside of the cavity. The assembly surface of the frame has an inner end adjacent to the cavity and an outer end opposite to the inner end in each of at least one section extending inside and outside the cavity, and has a convex shape protruding in the thickness direction. At least one of the inner end and the outer end is at least 10 μm lower than the most protruding part of the convex shape.

[0013] The outer end of the convex shape of the mounting surface may be configured to be 10 μm or more lower than the most protruding portion of the convex shape of the mounting surface. The inner end and the outer end of the convex shape of the mounting surface may be configured to be 10 μm or more lower than the most protruding portion of the convex shape of the mounting surface. The outer end of the convex shape of the mounting surface may be configured to be lower than the inner end of the convex shape of the mounting surface. The distance in the thickness direction between the most protruding portion of the convex shape of the mounting surface and the inner end and the outer end of the mounting surface may be within 100 μm.

[0014] At least one section may include a first section and a second section. In the first section, the most protruding portion has a first height position, and at least one of the inner end and the outer end is lower than the first height position by more than 20 μm. In the second section, the most protruding portion has a second height position, and at least one of the inner end and the outer end is lower than the second height position by more than 10 μm and less than 20 μm. The second height position of the second section is lower than the first height position of the first section.

[0015] Effects of the Invention

[0016] According to one embodiment of the present invention, the mounting surface of the frame has a convex shape in which at least one of the inner end and the outer end is lower than the most protruding part by more than 10 μm in a cross-sectional view extending inside and outside the chamber. By accumulating the adhesive layer in such a lowered area, it becomes easy to sufficiently ensure the thickness of the adhesive layer in the cross-sectional view without using a special additional component. Therefore, the bonding strength of the adhesive layer bonding the frame to the cover body can be improved.

[0017] The outer end of the convex shape can be configured to be 10 μm or more lower than the most protruding part of the convex shape. As a result, it is easy to ensure the thickness of the adhesive layer more fully at the outer end of the convex shape. Therefore, it is possible to suppress the situation where the peeling between the frame and the cover body starts to progress due to the force from the outside of the package acting near the outer end of the convex shape.

[0018] The inner and outer ends of the convex shape can be configured to be 10 μm or more lower than the most protruding part of the convex shape. This makes it easier to ensure the thickness of the adhesive layer at both the inner and outer ends of the convex shape. Therefore, it is possible to prevent the peeling between the frame and the cover from starting at the end of the adhesive layer.

[0019] The outer end of the convex shape can be configured to be lower than the inner end of the convex shape. This can reduce the amount of adhesive layer to a certain extent and prevent the frame and cover from peeling off due to the force from outside the package acting near the outer end of the convex shape.

[0020] The distance in the thickness direction between the most protruding part of the convex shape and the inner end and the outer end can be within 100 μm. This can reduce the amount of the adhesive layer to a certain extent and spread the adhesive layer over both the inner end and the outer end of the convex shape.

[0021] The objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a cross-sectional view schematically showing the structure of an electronic device in one embodiment of the present invention.

[0023] Figure 2 It is a rough representation Figure 1 A cross-sectional view of the structure of a package body.

[0024] Figure 3 It is a rough representation Figure 2 A top view of the structure of the frame portion.

[0025] Figure 4 It is along Figure 3 A partial cross-sectional view of the frame portion along line IV-IV.

[0026] Figure 5 yes Figure 4 A first variation of .

[0027] Figure 6 yes Figure 4 A second variation of .

[0028] Figure 7 yes Figure 4 A third variant of .

[0029] Figure 8 It is a plan view schematically showing the structure of a frame portion according to a modified example.

[0030] Fig. 9 are respectively along Figure 8 A cross-sectional view of the frame portion taken along line IXa-IXa and line Ixb-Ixb. DETAILED DESCRIPTION

[0031] Hereinafter, embodiments of the present invention will be described based on the drawings.

[0032] Figure 1 as well as Figure 2 These are cross-sectional views schematically showing the structure of the electronic device 900 in this embodiment and the structure of the package 800 used for manufacturing the electronic device 900 .

[0033] Package 800( Figure 2 ) has: electronic component 902 ( Figure 1 ) mounted on the mounting surface SM; the cavity CV located on the mounting surface SM; and the mounting surface SF to which the cover 906 for sealing the cavity CV is mounted via the adhesive layer 907. The package body 800 has a base 810 and a wiring portion 820. The base 810 includes: a bottom 811 having a mounting surface SM; and a frame 812 surrounding the cavity CV on the outside of the mounting surface SM on the bottom 811. The frame 812 has a mounting surface SF.

[0034] The bottom 811 and the frame 812 included in the base 810 are respectively made of ceramic. The ceramic is substantially made of an insulator, so that the base 810 can function as an insulating member. As long as this function can be ensured, the ceramic does not necessarily have to be made of an insulator as a whole. For example, a small amount of non-insulating particles can be dispersed in the insulating particles that account for the majority of the volume.

[0035] The mounting surface SM preferably has a mounting surface SM having a size including a rectangle having a long side of 10 mm or more. For example, the mounting surface SM is a rectangle having a long side of 10 mm or more. The mounting surface SM may also have a mounting surface SM having a size including a square having a side of 10 mm or more. In addition, a square is a type of rectangle in terms of geometrical definition.

[0036] The frame 812 is provided on the bottom 811, on the outside of the mounting surface SM, to surround the chamber CV. The frame 812 may have a ceramic fired surface as the mounting surface SF. Here, the wording "as-fired" means a state in which the surface is maintained in a sintered state without surface processing. Therefore, the "fired surface" is a surface in an "as-fired" state. In other words, the "fired surface" refers to the external surface of a ceramic product after sintering. Therefore, a ground surface is not a fired surface. In addition, the mounting surface SF of the frame 812 is not limited to the fired surface, and may be, for example, a ground surface.

[0037] The wiring portion 820 connects the inside of the chamber CV with the outside of the chamber CV. In other words, the wiring portion 820 extends from the chamber CV and passes through the base 810. Specifically, the wiring portion 820 has: an external electrode terminal 821, which is arranged on the outside of the chamber CV; an internal wiring 822, which passes through the base 810; and an internal electrode terminal 823, which faces the chamber CV. The internal wiring 822 can be composed of at least any one of an internal electrode layer and a via wiring. The material of the wiring portion 820 is substantially composed of a conductor so that the wiring portion 820 can function as a wiring member. As long as the function can be ensured, the material does not necessarily have to be completely composed of a conductor as a whole. For example, an insulator area may be dispersed in a conductor area that occupies a major proportion in volume.

[0038] Electronic component 902( Figure 1 ) is bonded to the internal electrode terminal 823 via the bonding layer 901. Thus, the electronic component 902 is mounted on the mounting surface SM via the bonding layer 901 and the internal electrode terminal 823. The electronic component 902 may have a size including a rectangle having a long side of more than 10 mm, for example, a size including a square having a side of more than 10 mm. The electronic component 902 may be a solid-state imaging element. A solid-state imaging element is, for example, a CMOS image sensor. Generally, CMOS image sensors are particularly excellent as solid-state imaging elements having a larger imaging portion as required for SLRs, some surveillance cameras, and industrial cameras. The planar shape of the solid-state imaging element may be a rectangle having a long side of more than 10 mm, or may be a roughly square having a side of more than 10 mm. The size and type of the electronic component 902 are not particularly limited.

[0039] The cover 906 is mounted on the mounting surface SF of the frame 812 via the adhesive layer 907. Thus, the cavity CV of the package 800 is sealed. The adhesive layer 907 is composed of, for example, a resin adhesive. The adhesive layer 907 can be directly in contact with the mounting surface SF and the cover 906, respectively. In the case where the electronic component 902 is a solid-state imaging element, at least a portion of the cover 906 is substantially transparent to the imaging light, and typically, the entire cover 906 is substantially transparent to the imaging light.

[0040] Figure 3 The frame portion 812 ( Figure 2 ) is a top view of the structure. Figure 4 It is along Figure 3 A partial cross-sectional view of the frame portion 812 taken along line IV-IV.

[0041] The frame portion 812 is a cross-sectional view extending inside and outside the chamber CV ( Figure 4 ) has a mounting surface SF, facing the chamber CV ( Figure 2 ) and an outer surface SO located outside the cavity CV. In this cross-sectional view, the mounting surface SF has an inner end EI adjacent to the cavity CV and an outer end EO opposite to the inner end EI. In addition, in this cross-sectional view, the mounting surface SF has a convex shape protruding in the thickness direction. Figure 4 In the embodiment, the mounting surface SF has a convex shape that protrudes upward in the longitudinal direction.

[0042] At least one of the inner end EI and the outer end EO is lower than the most protruding portion PP of the convex shape by 10 μm or more. Figure 4 In the figure, at least one of the inner end EI and the outer end EO is more than 10 μm away from the height position PT of the most protruding part PP of the convex shape in the vertical direction. In addition, the height position PT represents a position corresponding to a horizontal line including the most protruding part PP, and the horizontal line is a straight line parallel to the horizontal plane of the package 800. The horizontal plane of the package 800 is the mounting surface SF ( Figure 3 ). The approximate plane can be obtained by moving along Figure 3 The surface profile of the mounting surface SF measured by the dashed line LC is calculated by fitting the plane. The dashed line LC may be the center line in the width direction of the frame portion 812. In addition, the surface profile may be measured optically.

[0043] In this embodiment, the outer end EO of the convex shape is lower than the most protruding part PP of the convex shape by more than 10 μm. Furthermore, the inner end EI of the convex shape is also lower than the most protruding part PP of the convex shape by more than 10 μm. That is, the inner end EI and the outer end EO of the convex shape are lower than the most protruding part PP of the convex shape by more than 10 μm.

[0044] The thickness direction ( Figure 4 The distance in the longitudinal direction of the Figure 4 In the embodiment, the distance in the longitudinal direction between the height position PT of the most protruding portion PP of the convex shape and each of the inner end EI and the outer end EO is within 100 μm.

[0045] In addition, in this embodiment, the wiring portion 820 ( Figure 2 ) penetrates the bottom 811, but as a modification, a wiring portion for connecting to the electronic component 902 by a bonding wire may be provided. In this case, the inner surface SI may be provided at a position sufficiently away from the mounting surface SF (specifically, at a height position PT ( Figure 4 ) is more than 100 μm downward), and a step shape is provided for supporting an electrode pad for bonding a bonding wire. In addition, as a modification, a wiring portion that passes through the bottom 811 and the frame 812, or a wiring portion that passes through the frame 812 may also be provided, for example, the wiring portion may also be a lead frame.

[0046] According to this embodiment, the mounting surface SF of the frame portion 812 has a convex shape in which at least one of the inner end EI and the outer end EO is lower than the most protruding portion PP by more than 10 μm in a cross-sectional view extending inside and outside the chamber CV. Figure 1 ), in this cross-sectional view, it is easy to sufficiently ensure the thickness of the adhesive layer 907 without using a special additional member. Therefore, the bonding strength of the adhesive layer 907 that bonds the frame 812 and the cover 906 can be improved.

[0047] The outer end EO of the convex shape can be configured to be lower than the most protruding part PP of the convex shape by more than 10 μm. As a result, it is easy to ensure a sufficient thickness of the adhesive layer 907 at the outer end EO of the convex shape. Therefore, it is possible to suppress the start of the peeling between the frame 812 and the cover 906 due to the force from the outside of the package 800 acting near the outer end EO of the convex shape.

[0048] The inner end EI and the outer end EO of the convex shape can be configured to be 10 μm or more lower than the most protruding part PP of the convex shape. As a result, it is easy to ensure a sufficient thickness of the adhesive layer 907 at both the inner end EI and the outer end EO of the convex shape. Therefore, it is possible to prevent the peeling between the frame 812 and the cover 906 from starting at the end of the adhesive layer 907.

[0049] The distance in the thickness direction between the most protruding portion PP of the convex shape and the inner end EI and the outer end EO is preferably within 100 μm. This can reduce the amount of adhesive layer 907 to a certain extent and allow the adhesive layer 907 to cover both the inner end EI and the outer end EO of the convex shape.

[0050] Figure 5 As the frame portion 812 ( Figure 4 ) of the first modified example. In the frame 812a, the most protruding portion PP is in a cross-sectional view ( Figure 5 ) has a flat portion. As a result, the mounting surface SF of the frame portion 812a can more stably support the cover body 906 ( Figure 1 ).

[0051] Figure 6 As the frame portion 812 ( Figure 4 ) of the second modified example. In the cross-sectional view of the frame 812b extending inside and outside the chamber CV ( Figure 6 ), the outer end EO of the convex shape of the mounting surface SF is lower than the inner end EI of the convex shape of the mounting surface SF. Thus, the amount of the adhesive layer 907 can be suppressed to a certain extent, and the peeling between the frame 812 and the cover 906 caused by the force from the outside of the package 800 acting near the outer end EO of the convex shape can be suppressed.

[0052] Figure 7 As the frame portion 812 ( Figure 4 ) is a frame portion 812c of a third variation of the present invention. In this variation, the outer end EO of the convex shape is lower by more than 10 μm compared to the most protruding portion PP of the convex shape (in other words, compared to the height position PT), while the inner end EI is not substantially lowered. In addition, in this variation, the portion of the frame portion 812c that is higher than the outer end EO is regarded as the portion in which the frame portion 812c has a convex shape. As another variation, the inner end EI of the convex shape may be lower by more than 10 μm compared to the most protruding portion PP of the convex shape (compared to the height position PT), while the outer end EO is not substantially lowered.

[0053] In the above, the line IV-IV ( Figure 3 ) in the cross-sectional view of the mounting surface SF. Alternatively or together with this, a convex shape of the mounting surface SF may be provided along a line AA ( Figure 3), a convex shape described in the present embodiment or its modified example is formed in the cross-section along line IV-IV. In the case where convex shapes are provided on both sides, the convex shape in the cross-section along line IV-IV and the convex shape in the cross-section along line AA do not necessarily have to be the same shape. As the above-mentioned rectangular shape, a square shape which is a kind of rectangular shape can also be used. More preferably, the assembly surface SF of the frame portion 812 has the convex shape described in the present embodiment or its modified example in any cross-section throughout the chamber CV and outside the chamber CV. In this case, the bonding strength can be improved throughout the entire circumference of the frame portion 812.

[0054] Figure 8 The frame portion 812 ( Figure 3 ) is an overhead view of the structure of the frame portion 812V of a modified example. Fig. 9 is the line IXa-IXa( Figure 8 ) and along the line IXb-IXb ( Figure 8 ) is a diagram of a second cross-sectional view VCb. In the first cross-sectional view Vca, the most protruding portion Ppa has a first height position PTa. At least one of the inner end EIa and the outer end Eoa is lower than the first height position Pta by more than 20 μm. In the second cross-sectional view VCb, the most protruding portion PPb has a second height position PTb. At least one of the inner end EIb and the outer end Eob is lower than the second height position PTb by more than 10 μm and less than 20 μm. The second height position PTb of the second cross-sectional view VCb is lower than the first height PTa of the first cross-sectional view Vca.

[0055] According to the above-mentioned modification, the adhesive layer 907 (see Figure 1 ) In the process of joining the frame portion 812V to the cover body 906, the relative position of the frame portion 812V and the cover body 906 in the thickness direction is mainly determined by the height position Pta of the most protruding portion Ppa and the characteristics of the adhesive layer 907 (for example, the viscosity of the adhesive layer 907 before curing and the size of the filler in the adhesive layer 907). Therefore, compared with the interval between the most protruding portion Ppa and the cover body 906, the interval between the most protruding portion PPb that is lower than the most protruding portion Ppa and the cover body 906 is larger. Therefore, a large amount of adhesive layer 907 is accumulated between the most protruding portion PPb and the cover body 906. Therefore, the bonding strength in the second cross-sectional view VCb where the most protruding portion PPb is located can be improved.

[0056] Here, in the first cross-sectional view Vca, at least one of the inner end EIa and the outer end Eoa is lower than the first height position Pta by more than 20 μm, while in the second cross-sectional view VCb, at least one of the inner end EIb and the outer end Eob is lower than the second height position PTb by more than 10 μm and less than 20 μm. Thus, the situation in which the mounting surface SF has an excessively low portion in the second cross-sectional view VCb is avoided.

[0057] In addition, the frame 812V ( Figure 8 ) can extend substantially along the side SD of the rectangle. The rectangle has a first direction ( Figure 8 A pair of first sides along the lateral direction (in the horizontal direction), and a pair of first sides along the second direction ( Figure 8 For example, the first cross-sectional view VCa is about the first side, and the second cross-sectional view VCb is about the second side. More specifically, the first cross-sectional view VCa may be a field of view through the midpoint of the first side, and further, the second cross-sectional view VCb may be a field of view through the midpoint of the second side. The length of the first side and the length of the second side may be different from each other, for example, the first side is longer than the second side.

[0058] The above-mentioned embodiments and modifications can be freely combined with each other.

[0059] The present invention has been described in detail, but the above description is illustrative in all aspects and the present invention is not limited thereto. It should be understood that numerous modifications not shown in the examples can be conceived without departing from the scope of the present invention.

[0060] Explanation of symbols

[0061] 800: Encapsulation

[0062] 810: Base

[0063] 811: Bottom

[0064] 812, 812a~812c, 812V: frame

[0065] 900: Electronic devices

[0066] 902: Electronic components

[0067] 906: Cover

[0068] 907: Adhesive layer

[0069] CV: Chamber

[0070] EI, EIa, EIb: Inner end

[0071] EO, EOa, EOb: Outer end

[0072] PP, PPa, PPb: Most protruding part

[0073] SF: Mounting surface.

Claims

1. A package having a mounting surface for mounting an electronic component, a cavity located on the mounting surface, and a mounting surface of a cover body mounted via an adhesive layer for sealing the cavity, wherein: The package body comprises: a bottom portion, which is made of ceramic and has the mounting surface; a frame portion made of ceramic, surrounding the cavity on the bottom outside the mounting surface and having the mounting surface; and A wiring part that connects the inside of the chamber with the outside of the chamber, The mounting surface of the frame portion has an inner end adjacent to the cavity and an outer end opposite to the inner end in each of at least one cross-section extending inside and outside the cavity, and has a convex shape protruding in the thickness direction, and at least either the inner end or the outer end is lower than the most protruding portion of the convex shape by more than 10 μm, The at least one cross-section includes a first cross-section and a second cross-section, In the first cross-section, the most protruding portion has a first height position, and at least one of the inner end and the outer end is lower than the first height position by 20 μm or more. In the second cross-section, the most protruding portion has a second height position, and at least one of the inner end and the outer end is lower than the second height position by 10 μm or more and less than 20 μm. The second height position of the second cross-section is lower than the first height position of the first cross-section.

2. The package according to claim 1, wherein: The outer end of the convex shape of the mounting surface is lower than the most protruding portion of the convex shape of the mounting surface by 10 μm or more.

3. The package according to claim 1, wherein: The inner end and the outer end of the convex shape of the mounting surface are each lower than the most protruding portion of the convex shape of the mounting surface by 10 μm or more.

4. The package according to any one of claims 1 to 3, wherein: The outer end of the convex shape of the mounting surface is lower than the inner end of the convex shape of the mounting surface.

5. The package according to any one of claims 1 to 3, wherein: A distance in the thickness direction between the most protruding portion of the convex shape of the mounting surface and each of the inner end and the outer end of the mounting surface is within 100 μm.

6. The package according to any one of claims 1 to 3, wherein: The outer end of the convex shape of the mounting surface is lower than the inner end of the convex shape of the mounting surface, A distance in the thickness direction between the most protruding portion of the convex shape of the mounting surface and each of the inner end and the outer end of the mounting surface is within 100 μm.

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