JP2853938B2 - Solid-state image sensor package - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-state image pickup device package, and more particularly to a structure of a package in which a solid-state image pickup device is dropped into a package and adhered thereto.

[0002]

2. Description of the Related Art A solid-state imaging device is used for an electronic endoscope, a movie camera, and the like for displaying an image of a body to be observed such as a body cavity.
pled Device). The CCD is attached, for example, to the distal end of an electronic endoscope (electronic scope). By inserting the electronic endoscope into the object to be observed, the CCD converts an image in the object to be displayed on a monitor. Can be caught.

FIG. 4 shows an example of a conventional mounting structure of a solid-state image pickup device.
The CCD 1 is dropped into the housing 3 having the step of the package 2, and the CCD 1 is adhered to the bottom surface of the package 2 by a conductive adhesive such as a silver paste (or an insulating adhesive such as an epoxy adhesive). Further, the CCD 1 has its terminals connected to the terminals of the step portion on the package 2 side by bonding wires 4, and pins 5 for connecting to signal lines are provided on the bottom side of the package 2.

Further, a cover glass 6 is attached to the upper surface of the package 2 in, for example, an airtight state, and nitrogen (N
₂ ) Gas etc. are enclosed. That is, although not shown, a color filter, a microlens, and the like are stacked on the upper surface of this type of CCD 1 to protect the color filter and the microlens (separation from moisture, oxidation prevention, etc.). Is filled with nitrogen gas and the CCD as shown
The light gap between the microlens 1 and the cover glass 6 ensures the light condensing action of the microlens.
Note that an objective lens system is disposed on the upper surface of the cover glass 6 via, for example, a prism, and an image in the body to be observed reaches an image area on the upper surface of the CCD 1 via the objective lens system, the prism, and the like.

[0005]

However, in the above-mentioned conventional solid-state imaging device package, when the CCD 1 is bonded to the housing 3 of the package 2, the silver paste 100 protruding from the lower surface of the CCD 1 extends to the upper surface of the CCD 1. And there is a problem that the electrical connection may be obstructed. That is, in the above bonding, the silver paste is dropped on the center of the bottom surface of the package 2 and the package 2 is vibrated while the CCD 1 is placed thereon, so that the silver paste spreads over the entire lower surface of the CCD 1. At this time, since the amount of the silver paste is slightly increased, as shown in FIG. 4, the silver paste 100 protruding from the lower surface of the CCD 1 is placed on the upper surface of the CCD 1 from between the CCD 1 and the wall of the storage unit 3. Will be reached. The silver paste 100 is a conductive adhesive to serve to connect the ground terminal on the lower surface of the CCD 1 to the terminal (ground terminal or the like) of the package 2.
Contact with the terminal on the upper surface of the CCD 1, the terminal of the step portion of the package 2, or the bonding wire 4, a disadvantage such as a short circuit occurs.

For this reason, conventionally, the clearance t between the side surface of the CCD 1 and the wall of the storage section 3 is set to a certain length, and the silver paste 100 which has protruded into the space formed by the clearance t is stored. . However, in this case, there is a problem that the bonding wire 4 must be lengthened, the clearance t of the CCD 1 with respect to the storage section 3 cannot be minimized, and the package itself becomes large.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to prevent the conductive adhesive from protruding to the upper surface side of the solid-state imaging device and to increase the clearance between the solid-state imaging device and the storage section. An object of the present invention is to provide a solid-state imaging device package that can be set to a minimum.

[0008]

In order to achieve the above object, the present invention has a bottom substrate to which a solid-state image sensor is fixed with an adhesive, and a storage hole, and connects the solid-state image sensor by wire bonding. A substrate for wire bonding provided with terminals for mounting on the upper surface, an intermediate substrate having a storage hole disposed between the substrate for wire bonding and the bottom substrate, and laminating the plurality of substrates. The storage portion of the solid-state imaging device is formed, and the width of the storage hole of the intermediate substrate is set to be larger than the width of the storage hole of the wire bonding substrate. When these substrates are stacked, the storage hole of the wire bonding substrate is formed. A gap for accommodating the protruding adhesive when the solid-state imaging device is adhered is formed below the edge.

[0009]

According to the above arrangement, the adhesive disposed between the lower surface of the solid-state image sensor and the bottom of the housing during die bonding protrudes from the bonding surface when vibration is applied in the bonding process. The surplus adhesive flows into the gap from the bottom of the storage section and is stored in the gap. Therefore, the adhesive does not protrude to the upper surface side of the solid-state imaging device.

[0010]

FIG. 1 shows a sectional configuration of a solid-state imaging device package according to an embodiment, and FIG. 2 shows a cutaway perspective view of the package. In FIG. 1, a package 10 of the embodiment has four ceramic plates 11A and 11A.
B, 11C, and 11D are stacked, and the CCD 1 is die-bonded in a storage portion 12 formed by rectangular holes of the ceramic plates 11A to 11C.
In the four ceramic plates 11A to 11D, the first
The plate 11A serves to provide an air gap between the CCD 1 and a cover glass arranged on the upper surface of the package 10, and the second plate 11B has terminals connected to terminals of the CCD 1 by bonding wires 13 as shown in the figure. 14 (FIG. 2)
Is formed.

The third plate 11C serves to form a gap 15 for accommodating the silver paste, and the hole width of the third plate 11C is larger than the hole width of the second plate 11B by a predetermined length. As a result, the illustrated gap 15 is formed. The fourth plate 11D serves as a bottom plate of the storage unit 12.

As shown in FIG. 2, a terminal 16 for connecting a signal line is formed on the upper surface of the end of the third plate 11C, and the terminal 16 is connected to the terminal 14 of the second plate 11B.
Are connected via a through hole 17 or the like.

FIG. 3 is an exploded perspective view of the entire solid-state image pickup device package. When die bonding is performed, a silver paste 18 is dripped into the storage section 12 of the package 10 as shown in FIG. Then, the CCD 1 is placed thereon with the image area facing upward. And then
For example, when vibration is applied to the package 10, the silver paste 18 spreads over the entire lower surface of the CCD 1, and the silver paste 18 protruding from the end flows into the gap 15 as shown in FIG. . Therefore, unlike the conventional case, the silver paste 18 is prevented from protruding from the upper surface of the CCD 1 and coming into contact with other terminals or the like, thereby preventing a short circuit.

Further, since the silver paste 18 does not protrude to the upper surface side as described above, the clearance t between the CCD 1 and the storage section 12, that is, the gap between the side surface of the CCD 1 and the hole wall of the second plate 11B. Can be set to the minimum. Accordingly, the width of the package 10 can be reduced accordingly, which can contribute to the reduction in the diameter of the electronic endoscope, and the length of the bonding wire 13 can be reduced.

The CCD 1 bonded and stored in the storage section 12 is electrically connected to the package 10 by wire bonding between the terminal 20 shown in FIG. Connected. Thereafter, the cover glass 21 is adhered to the upper surface of the package 10. At this time, if the nitrogen (N ₂ ) gas is sealed (the nitrogen gas need not be sealed), the assembly of the package 10 is completed.

In the above embodiment, the gap 15 for accommodating the silver paste 18 is formed at the position of the third plate 11C. However, the present invention is not limited to this.
Alternatively, another structure such as providing a groove of an appropriate size and forming a gap across the fourth plate 11D can be adopted.

[0017]

As described above, according to the present invention,
The width of the storage hole of the intermediate substrate is set larger than the width of the storage hole of the substrate for wire bonding. Since a gap for accommodating the protruding adhesive is formed, the excess silver paste etc. from the bonding surface flows into the accommodation gap and does not protrude to the upper surface side of the solid-state imaging device, thereby avoiding inconvenience such as short circuit. can do.

Further, in setting the clearance between the solid-state imaging device and the storage section, it is not necessary to consider the protrusion of the silver paste, so that the clearance can be minimized, which contributes to the reduction in the diameter of the electronic endoscope. And the length of the hosing wire can be shortened.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a solid-state imaging device package according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a state in which the package of the embodiment is cut.

FIG. 3 is an exploded perspective view showing the entire configuration of the package according to the embodiment before assembly.

FIG. 4 is a cross-sectional view showing a configuration of a conventional package.

[Explanation of symbols]

 1 ... CCD, 2,10 ... Package, 3,12 ... Storage, 15 ... Gap, 18 ... Silver paste.

Claims (1)

(57) [Claims] (1)Bottom for fixing solid-state image sensor with adhesive
Surface board, It has a storage hole, and the solid-state imaging device
Wire bonder with terminals on the upper surface for connection
A substrate for Between this wire bonding substrate and the bottom substrate
And an intermediate substrate having a storage hole,
A plurality of substrates are laminated to form a storage section for the solid-state imaging device.
Along with The width of the storage hole of the intermediate substrate is
Set the width larger than the width of the board storage hole, and stack these boards.
When layered, the edge of the storage hole of the wire bonding substrate
When sticking the solid-state image sensor to the lower side, it protruded
Form a gap to hold the adhesive Characterized by
Solid-state image sensor package.