US-12622092-B2 - Photodetector

US12622092B2US 12622092 B2US12622092 B2US 12622092B2US-12622092-B2

Abstract

The photodetector includes a light receiving element and a package. The package has an accommodation member formed of a ceramic, a wiring including a pad connected to a terminal of the light receiving element by a wire, and a light transmitting member. A bottom wall of the accommodation member has a placement surface to which the light receiving element is attached by an adhesive member. The bottom wall or a side wall of the accommodation member has a pad surface on which the pad is disposed, the pad surface positioned on an opening side of the accommodation member with respect to the placement surface. The side wall has a through hole. At least a portion of an inner end portion of the through hole is positioned on the opening side with respect to a surface of the light receiving element on the opening side.

Inventors

Masaharu Muramatsu
Yasuhito Yoneta
Hiroya Kobayashi
Tetsuya Abe
Kenichiro Taniguchi

Assignees

HAMAMATSU PHOTONICS K.K.

Dates

Publication Date: 20260505
Application Date: 20200828
Priority Date: 20190930

Claims (13)

1 . A photodetector comprising: a light receiving element provided with a light receiving portion and a terminal; and a package accommodating the light receiving element, wherein the package has an accommodation member including a bottom wall, and a side wall defining an opening facing the bottom wall, the accommodation member formed of a ceramic, a wiring including a pad connected to the terminal by a wire, the wiring provided in the accommodation member, and a light transmitting member attached to the side wall such that the opening is covered, wherein the bottom wall has a placement surface to which the light receiving element is attached by an adhesive member, wherein the bottom wall or the side wall has a pad surface on which the pad is disposed, the pad surface positioned at a level between the light transmitting member and the placement surface, wherein the side wall has a through hole allowing ventilation between the inside of the package and the outside of the package, wherein at least a portion of an inner end portion of the through hole is positioned on the opening side with respect to a surface of the light receiving element on the opening side, and a gap is formed between the light receiving element and the side wall, and a width of the gap is smaller than a width of the pad surface in a width direction of the gap.
2 . The photodetector according to claim 1 , wherein at least a portion of the inner end portion of the through hole is positioned on the opening side with respect to the pad surface.
3 . The photodetector according to claim 1 , wherein the through hole has a bent portion.
4 . The photodetector according to claim 3 , wherein an internal surface of the through hole exhibits a rounded shape at the bent portion.
5 . The photodetector according to claim 1 , wherein the through hole is a single hole.
6 . The photodetector according to claim 1 , wherein an inner surface of the side wall has an inside corner portion when viewed in a direction in which the bottom wall and the opening face each other, and wherein the inner end portion of the through hole is positioned at the inside corner portion.
7 . The photodetector according to claim 1 , wherein the side wall has a corner portion when viewed in a direction in which the bottom wall and the opening face each other, and wherein the through hole is formed at the corner portion.
8 . The photodetector according to claim 1 , wherein the side wall includes a plurality of side wall portions, and wherein an outer end portion of the through hole is positioned on an outer surface of a side wall portion having the largest thickness of the plurality of side wall portions.
9 . The photodetector according to claim 1 , wherein a recess portion is formed on an outer surface of the side wall, and wherein an outer end portion of the through hole is positioned in the recess portion.
10 . The photodetector according to claim 1 , wherein the wiring includes a plurality of connection portions extending in a direction in which the bottom wall and the opening face each other on an outer surface of the side wall, and wherein a distance between a connection portion closest to an outer end portion of the through hole of the plurality of connection portions and the outer end portion of the through hole is longer than a distance between the connection portion closest to the outer end portion of the through hole of the plurality of connection portions and a connection portion second closest to the outer end portion of the through hole of the plurality of connection portions.
11 . The photodetector according to claim 1 , wherein a center position of the light receiving portion coincides with a center position of the package in at least a predetermined direction when viewed in a direction in which the bottom wall and the opening face each other.
12 . The photodetector according to claim 1 , wherein the inner end portion of the through hole is positioned on a side opposite to the center position of the light receiving portion with respect to the center position of the package in at least a predetermined direction when viewed in a direction in which the bottom wall and the opening face each other.
13 . The photodetector according to claim 1 , wherein a height difference between the surface of the light receiving element on the opening side and the pad surface is smaller than a thickness of the light receiving element.

Description

TECHNICAL FIELD The present disclosure relates to a photodetector. BACKGROUND ART A photodetector including a light receiving element and a package accommodating the light receiving element, in which the package includes an accommodation member formed of a ceramic and a light transmitting member attached to the accommodation member such that an opening of a recess portion of the accommodation member is covered, is known (for example, refer to Patent Literature 1). An accommodation member formed of a ceramic has excellent heat dissipation and heat resistance compared to an accommodation member formed of a resin, for example. CITATION LIST Patent Literature [Patent Literature 1] Japanese Unexamined Patent Publication No. 2015-216142 SUMMARY OF INVENTION Technical Problem In the photodetector described above, when a wiring is provided in the package, how reliably electrical connection between the wiring and the light receiving element can be performed becomes a problem. On the other hand, how reliably occurrence of dew condensation inside the package can be prevented becomes another problem. An object of the present disclosure is to provide a photodetector in which electrical connection between a wiring provided in a package and a light receiving element accommodated inside the package can be reliably performed and occurrence of dew condensation inside the package can be reliably prevented. Solution to Problem A photodetector according to an aspect of the present disclosure includes a light receiving element provided with a light receiving portion and a terminal, and a package accommodating the light receiving element. The package has an accommodation member including a bottom wall and a side wall defining an opening facing the bottom wall, the accommodation member formed of a ceramic, a wiring including a pad connected to the terminal by a wire, the wiring provided in the accommodation member, and a light transmitting member attached to the side wall such that the opening is covered. The bottom wall has a placement surface to which the light receiving element is attached by an adhesive member. The bottom wall or the side wall has a pad surface on which the pad is disposed, the pad surface positioned on the opening side with respect to the placement surface. The side wall has a through hole allowing communication between the inside of the package and the outside of the package. At least a portion of an inner end portion of the through hole is positioned on the opening side with respect to a surface of the light receiving element on the opening side. In the photodetector of the aspect of the present disclosure, in the accommodation member formed of a ceramic, the pad surface on which the pad of the wiring is disposed is positioned on the opening side of the accommodation member with respect to the placement surface to which the light receiving element is attached by the adhesive member. Accordingly, the adhesive member is unlikely to reach the pad surface. Therefore, the terminal and the pad for the wiring corresponding to each other in the light receiving element are reliably connected to each other by the wire. Moreover, in the photodetector of the aspect of the present disclosure, in the accommodation member formed of a ceramic, at least a portion of the inner end portion of the through hole formed in the side wall is positioned on the opening side of the accommodation member with respect to the surface of the light receiving element on the opening side. Accordingly, the inner end portion of the through hole is unlikely to be blocked by the adhesive member. Therefore, ventilation between the inside and the outside of the package is secured, and occurrence of dew condensation inside the package is reliably prevented. Hence, according to the photodetector of the aspect of the present disclosure, electrical connection between the wiring provided in the package and the light receiving element accommodated inside the package can be reliably performed, and occurrence of dew condensation inside the package can be reliably prevented. In the photodetector of the aspect of the present disclosure, at least a portion of the inner end portion of the through hole may be positioned on the opening side with respect to the pad surface. Accordingly, even if a foreign substance intrudes into the package through the through hole, the foreign substance can be easily captured on the pad surface. Moreover, the light receiving portion of the light receiving element is separated from the inner end portion of the through hole by an amount corresponding to a thickness of the pad surface therebetween. Hence, even if a foreign substance intrudes into the package through the through hole, arrival of the foreign substance at the light receiving portion of the light receiving element can be curbed. In the photodetector of the aspect of the present disclosure, the through hole may have a bent portion. Accordingly, intrusion of a foreign sub