JPH0697471A - Infrared detector device and assembling method thereof - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain an infrared detector with little noise and high reliability, and an assembly method thereof. [Structure] Two electrode portions 3a formed at both end portions of the light-receiving layer 2 of the infrared detection element 10a are extended to the back surface of the substrate, and the back surface of the substrate is opposed to the insulative submount 5, and the above-mentioned 2 Electrode pattern 6 on insulating sub-mount 5 so that two electrode parts 3a do not short-circuit
Then, the electrode pattern 6 on the insulating submount 5 and the conductive lead are wire-bonded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared detecting device and a method of manufacturing the same, and more particularly, to a change in electric conductivity of an infrared detecting element which is electrically supplied to the outside through a conductive lead arranged around the element. The present invention relates to a photoconductive infrared detector configured to be taken out as a signal and a method for assembling the same.

[0002]

2. Description of the Related Art FIG. 5 shows a structure of a conventional photoconductive infrared detector, FIG. 5 (a) is a perspective view thereof, and FIG. 5 (b) is an infrared detector shown in FIG. 5 (a). It is sectional drawing which shows the structure of a detection element. In FIG. 5 (b), 10 is an infrared detecting element, and the infrared detecting element 10 is an upper surface of the CdTe substrate 1, the light receiving layer 2 made of CdHgTe disposed on the CdTe substrate 1, and the upper surface of the light receiving layer 2. The electrode part 3 formed on the
The light receiving layer 2 between them is the light receiving portion 4. Then, as shown in FIG. 5A, the infrared detecting element 10 is soldered onto the conductive submount 15, and the infrared detecting element 1 is
No. 0 electrode portion 3 and the conductive lead 8 disposed on the conductive submount 15 via the insulating portion 7 are connected to the wire 9
Wire-bonding is performed to form a photoconductive infrared detector.

Next, the operation will be described. Light receiving layer 2
Is formed of a compound semiconductor such as CdHgTe having a narrow band cap, and when infrared light having an energy larger than that of the band cap enters from the light receiving unit 4,
Excess carriers are generated in the light-receiving layer 2, and the change in the electric conductivity of the element due to the excess carriers is taken out to the outside as an electric signal through the electrode portion 3, the wire 9 and the lead portion 8 on both sides of the element.

[0004]

The conventional infrared detecting device is constructed as described above, and the semiconductor layer constituting the light receiving layer of the infrared detecting element disposed on the submount is mechanically fragile, Since the light receiving layer 2 made of the CdHgTe crystal as described above is mechanically very fragile, when the electrode portion 3 formed on the light receiving layer and the conductive lead 8 are wire-bonded, the light receiving layer 2 immediately below the bonding portion is formed. There is a problem in that cracks occur in the electrical signals, and the cracks cause noise in an electric signal to deteriorate the device characteristics and reduce the reliability of the device.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an infrared detection device having less noise and improved reliability, and an assembling method thereof.

[0006]

SUMMARY OF THE INVENTION In an infrared detecting device and its assembling method according to the present invention, an electrode portion of an infrared detecting element is extended to a back surface of a substrate of the infrared detecting element to insulate the back surface of the substrate of the infrared detecting element. Facing the sex submount,
The electrode part is soldered to the electrode pattern, and the electrode pattern and the conductive lead are wire-bonded.

Further, in the infrared detecting device and the assembling method thereof according to the present invention, a metal film which does not contact the electrode portion is formed on the back surface of the substrate of the infrared detecting element, and the electrode pattern is formed on the insulating submount. When forming a metal film that does not contact and soldering the electrode part and the electrode pattern,
These metal films are soldered at the same time.

Further, in the infrared detector and the manufacturing method thereof according to the present invention, the electrode pattern is formed at a position lower than the uppermost surface of the insulative submount, and the electrode portion and the electrode pattern are soldered. Thus, the back surface of the substrate of the infrared detecting element and the uppermost surface of the submount are brought into contact with each other.

Further, in the infrared detecting device and the method for manufacturing the same according to the present invention, the light receiving layer side of the infrared detecting element is made to face the insulating submount, and the electrode portion formed on the light receiving layer is made of an insulating material. The electrode pattern formed on the submount is soldered, and the electrode pattern and the conductive lead are wire-bonded.

[0010]

In the present invention, since the wire bonding is performed on the electrode pattern on the submount, the infrared detecting device can be assembled without causing cracks in the light receiving layer of the infrared detecting element.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 is a view for explaining a structure and an assembling process of a photoconductive infrared detecting device according to a first embodiment of the present invention. FIG. 1 (a) is a structure of an infrared detecting element. FIG. 1 (b) is a sectional view showing the joining process of the infrared detecting element and the submount, and FIG. 1 (c) is a perspective view of the infrared detecting device.

In the figure, the same reference numerals as those in FIG. 5 designate the same or corresponding parts, and 10a is an infrared detecting element,
In the infrared detection element 10a, an electrode portion 3a extending from the end of the light receiving surface 4 of the light receiving layer 2 made of CdHgTe to the light receiving layer 2 and the side wall portion of the CdTe substrate 1 to the back surface of the substrate 1.
Are formed. Also, 5 is an insulating Cebu mount,
Reference numeral 6 denotes two electrode patterns formed on the upper surface of the insulating Cebu mount 5 so as not to contact each other.

Next, the assembly process will be described. First, Fig. 1
As shown in (a), the two electrode portions 3a of the infrared detecting element 10a should not come into contact with each other along the side walls (the light receiving layer 2 and the side wall of the substrate 1) of the element from both side ends of the upper surface of the light receiving layer 2. To the back surface of the element (back surface of the substrate 1). Here, the electrode portion 3a is formed by metallization such as Cr-Au.

Next, as shown in FIG. 1 (b), two electrode patterns 6 which are not in contact with each other are formed in predetermined regions on an insulating submount 5 made of, for example, boron nitride / silicon carbide. The two electrode portions 3a formed on the back surface of the infrared detection element 10a are soldered to the two electrode portion patterns 6 so that the two electrode portions 3a are not short-circuited. The electrode pattern 6 is formed by metallizing Cr-Au or the like.

Next, as shown in FIG. 1 (c), the conductive leads 8 and the electrode pattern portion 6 which are disposed via the insulating member 7 in a predetermined region on the submount 5 are wire-bonded. . Although not shown here, the conductive lead 8
Is also formed in a region close to the other electrode pattern 6 on the submount 5, and the conductive lead 8 (not shown) and the other electrode pattern 6 are also wire-bonded.

In the method for assembling the infrared detecting device of this embodiment, a wire for electrically connecting the conductive lead 8 and the infrared detecting element 10a is bonded to the electrode portion 3a of the infrared detecting element 10a. Since the electrode pattern 6 on the submount 5 is wire-bonded,
The electrode portions 3a, 3b of the infrared detection element 10a are not cracked in the light receiving layer 2 of the infrared detection element 10a.
Can be electrically connected to the conductive lead 8,
It is possible to obtain an infrared detection device with less noise and improved reliability.

(Embodiment 2) FIG. 2 is a sectional view showing a joining process of an infrared detecting element and a submount in an assembling process of a photoconductive infrared detecting device according to a second embodiment of the present invention. 1, the same reference numerals as those in FIG. 1 denote the same or corresponding portions, and 10b denotes an infrared detection element, 11, 1
2 is a metal film for soldering. Further, in this embodiment, the soldering metal film 1 which does not contact the two electrode portions 3a is provided at the center of the back surface of the substrate 1 of the infrared detecting element 10b.
1 has a metal film 12 for soldering which does not contact the two electrode patterns 6 at the center of the upper surface of the insulative submount 5, and when the electrode part 3a and the electrode pattern 6 are soldered, The metal films 11 and 12 for soldering are simultaneously joined, and then a wire is bonded to the electrode pattern 6 in the same manner as in the first embodiment. In this soldering, the two electrode portions 3a are prevented from shooting through the metal films 11 and 12.

In the assembling process of the infrared detector of this embodiment, the two electrode portions 3a and the two electrode patterns 6 are formed.
Substrate 1 formed separately from these, in addition to bonding with
Since the metal film 11 on the back surface and the metal film 12 on the submount 5 are bonded by soldering, the infrared detection element 10b is mounted on the submount 5 in comparison with the first embodiment.
The metal film 11 can be more firmly adhered to the upper part, and the heat generated in the infrared detecting element 10b during operation is generated by the metal film 11,
Since heat is radiated to the submount 5 through 12, the reliability of the device can be further improved.

(Embodiment 3) FIG. 3 is a sectional view showing a joining process of an infrared detecting element and a submount in an assembling process of a photoconductive infrared detecting device according to a third embodiment of the present invention. The same reference numerals as those in FIG. 1 denote the same or corresponding portions, and 5a is an insulating submount in which a region where the electrode pattern 6 is formed is formed in a concave shape.
In this embodiment, as shown in FIG.
The two electrode patterns 6 formed in the concave portion of a and the two electrode portions 3a on the back surface of the substrate 1 of the infrared detection element 10a are joined by soldering, and then the electrode patterns 6 are formed in the same manner as in the first embodiment. Then wire is bonded.

In the assembling process of the infrared detecting device of this embodiment, the two electrode portions 3a on the rear surface of the substrate 1 of the infrared detecting element 10a and the two electrode patterns formed in the concave portion of the insulating submount 5a are formed. Since 6 and 6 are soldered to each other, the back surface 1 of the substrate of the infrared detection element 10a and the uppermost surface of the submount 5a come into contact with each other, and the infrared detection element 10b
The heat generated during the operation can be efficiently radiated to the submount 5, and the reliability of the device can be further improved.

(Embodiment 4) FIG. 4 is a sectional view showing an assembling process of an infrared detector according to a third embodiment of the present invention. In the drawing, the same reference numerals as those in FIGS. Indicates the same or corresponding parts. In this embodiment, as shown in the drawing, the two electrode portions 3 formed on the surface of the light receiving layer 2 of the infrared detection element 10 are directly soldered to the two electrode patterns 6 on the upper surface of the insulating submount 5, After that, a wire is bonded to the electrode pattern 6 in the same manner as in the first embodiment. In this infrared detector, light is incident from the transparent CdTe substrate 1 side.

In the assembling process of the infrared detecting device of the present embodiment, the two electrode portions 3 on the surface of the light receiving layer 2 of the infrared detecting element 10 are directly attached to the electrode portion pattern 6 on the insulating submount 5. Since soldering is employed, it is not necessary to extend the electrode portion 3 to the back surface of the substrate 1 of the infrared detection element 10 as in the first to third embodiments, and the assembly process can be simplified.

[0023]

As described above, according to the present invention, the electrode portion of the infrared detecting element is soldered to the electrode pattern on the insulating Cebu mount, and the electrode pattern and the conductive lead are wire-bonded. Therefore, there is an effect that the infrared detecting element does not crack at the time of wire bonding, the noise is small, and the infrared detecting device having high reliability can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a structure and an assembling process of a photoconductive infrared detector according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing one step in the assembling process of the photoconductive infrared detector according to the second embodiment of the present invention.

FIG. 3 is a cross-sectional view showing one step in the assembling process of the photoconductive type infrared detector according to the third embodiment of the present invention.

FIG. 4 is a cross-sectional view showing one step in the assembling process of the photoconductive type infrared detector according to the fourth embodiment of the present invention.

5A and 5B are a perspective view and a cross-sectional view showing a structure of a conventional photoconductive infrared detector and an infrared detector constituting the infrared detector.

[Explanation of symbols]

1 CdTe substrate 2 Light receiving layer made of CdHgTe 3 Electrode part 4 Light receiving part 5, 5a Insulating submount 6 Electrode pattern 7 Insulating part 8 Conductive lead 9 Wires 10, 10a, 10b Infrared detecting element 11 CdTe On the back surface of the substrate Formed metal film for soldering 12 Metal film for soldering formed on insulating submount 15 Conductive submount

Claims (8)

[Claims] 1. An infrared detecting element disposed on an insulative submount, wherein an electric current is passed between the two electrode portions of an infrared detecting element having electrode portions formed on both end portions of its light receiving layer. A photoconductive infrared detecting device configured to take out a change in electric conductivity of the above as an electric signal from the above two electrode portions through two conductive leads provided on the submount to the outside. Each of the two electrode portions extends along the side surface of the infrared detection element to the back surface side, and the two electrode portions are short-circuited to each one of the two electrode patterns formed on the insulating submount. Infrared detection device, characterized in that it is soldered so as not to do so, and each of the two electrode patterns is wire-bonded to one of the two conductive leads. 2. The infrared detection device according to claim 1, wherein an isolated metal film that does not come into contact with the two electrode portions is formed on the back surface side of the infrared detection element, and the isolated metal film is provided on the insulating submount. An infrared detector characterized in that an isolated metal film that does not contact two electrode patterns is formed and these two metal films are soldered. 3. The infrared detection device according to claim 1, wherein the two electrode patterns are formed at a position lower than the uppermost surface of the insulative submount by one step, and the back surface of the infrared detection element is insulated from the insulation. Infrared detector characterized by being in contact with the uppermost surface of a flexible submount. 4. An infrared detecting element, which is disposed on an insulating submount and has electrode portions formed on both end portions of its light-receiving layer, by passing a current between the two electrode portions to thereby detect the infrared detecting element. A photoconductive infrared detecting device configured to take out a change in electric conductivity of the above as an electric signal from the above two electrode portions through two conductive leads provided on the submount to the outside. The light-receiving layer side of the infrared imaging element faces the insulating submount, and the two electrode portions formed on both end portions of the light-receiving layer do not contact each other formed on the insulating submount. The two electrode portions are soldered to each one of the two electrode patterns so as not to short-circuit, and each of the two electrode patterns is wire-bonded to one of the two conductive leads. Infrared detecting apparatus characterized by being grayed. 5. An infrared detecting element, which is disposed on an insulating submount and has electrode portions formed on both end portions of its light-receiving layer, by passing a current between the two electrode portions to thereby detect the infrared detecting element. In the method for assembling the photoconductive infrared detecting device, the change in the electric conductivity of is extracted as an electric signal from the two electrode portions to the outside through the two conductive leads provided on the submount, The electrode portions formed on both end portions of the light receiving layer of the infrared detection element are connected to two electrode patterns formed on the insulating submount that do not contact each other so that the two electrode portions do not short-circuit. The step of soldering, and the two conductive leads provided on the insulative submount are respectively connected to two conductive leads that are formed on the insulative submount and are not in contact with each other. Assembly method of the infrared detection device, characterized in that it comprises a step of wire bonding to each one pole pattern. 6. The method for assembling the infrared detection device according to claim 5, wherein the electrode portions formed at both end portions of the light receiving layer of the infrared detection element are extended to the back surface of the substrate of the infrared detection element. A method for assembling an infrared detection device, characterized in that the back surface of the substrate is opposed to the insulating submount to perform the soldering. 7. The method for assembling the infrared detection device according to claim 6, wherein a metal film that does not come into contact with the electrode portion and the electrode pattern is provided on the back surface of the substrate of the infrared detection element and the upper surface of the insulating submount. Respectively, and when the electrode portion and the electrode pattern are soldered, these metal films are soldered to each other. 8. The method of assembling the infrared detection device according to claim 6, wherein the electrode pattern is formed at a position lower than the uppermost surface of the insulating submount by one step, and the back surface of the infrared detection element and the back surface of the infrared detection element are formed. A method for assembling an infrared detection device, characterized in that the electrode portion and the electrode pattern are soldered so that the uppermost surface of an insulative submount contacts.