JPH10319127A - Semiconductor radiation detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor radiation detector that is strong against vibration such as shock and a temperature change and humidity, has a simple structure and has less parts, and has less assembly man-hour. SOLUTION: Alumina wires 4a and 4 are subjected to ultrasonic bonding to a lower electrode 21 and an upper electrode 22 of a detection element 2, and the detection element 2 is adhered and retained on a substrate 1b by an insulation adhesive 3a. The other edge of the alumina wire is subjected to ultrasonic bonding to a pattern 11b for lower electrode and a pattern 12 for upper electrode being formed on each substrate 1b. An electrical connection is secured by wire bonding and the detection element 2 is firmly adhered and retained by the insulation adhesive 3a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor radiation detector having a structure in which a semiconductor radiation detection element is held on a substrate.

[0002]

2. Description of the Related Art FIG. 4 is a sectional view showing a structure near a semiconductor radiation detecting element (hereinafter abbreviated as a detecting element) in an example of a conventional semiconductor radiation detector (hereinafter abbreviated as a detector). is there. The detection element 2 is, for example, a pn junction type or a hetero junction type diode using a high resistivity silicon single crystal plate, and has a lower electrode 21 and an upper electrode 22 on both surfaces. When a reverse bias voltage is applied to this diode to form a depletion layer near the junction, a large potential gradient in the depletion layer separates electron-hole pairs generated in the detection element 2 by radiation. The separated electron-hole pairs are detected as electric signals.

[0003] Such a detecting element 2 is adhered and held by a conductive adhesive 3 on a substrate 1 on which a wiring pattern is formed. The conductive adhesive 3 also has a role of electrically connecting the lower electrode 21 of the detection element 2 and the lower electrode pattern 11 of the substrate 1. The upper electrode 22 of the detecting element 2 and the upper electrode pattern 12 of the substrate 1 are connected by the aluminum wire 4 wire-bonded by the ultrasonic bonding method. The lower electrode pattern 11 and the upper electrode pattern 12 are connected to a detection element bias power supply and a signal processing unit (not shown).

FIG. 5 is a sectional view showing a structure near a detecting element in another example of a conventional detector. The substrate 1a is placed on the base plate 61 of the pressure storage case 6, and a ring-shaped lower electrode pattern 11a is formed on the outer peripheral portion of the upper surface of the substrate 1a. The detection element 2 is placed on a conductive packing 51 disposed on the lower electrode pattern 11a,
A conductive packing 52 is placed on the upper electrode 22, and an upper electrode pattern 62 formed on the upper and lower surface of the pressure storage case 6 is in contact with the conductive packing 52. In this state, when the base plate 61 is screwed into the screw formed on the lower inner surface of the pressurized storage case 6, the lower electrode 21 of the detection element 2 and the substrate
The lower electrode pattern 11a of 1a, the upper electrode 22 of the detecting element 2 and the upper electrode pattern 62 of the pressurized storage case 6 are pressurized via the conductive packings 51 and 52, respectively, and become electrically conductive. At the same time, the detection element 2 is held by the two conductive packings 51 and 52.

In the structure shown in FIG. 4, the detecting element 2 is adhered and held on the substrate 1 by the conductive adhesive 3, but the conductive adhesive 3 contains a large amount of metal filler and thus is not sufficient. Since it has no adhesive strength (approximately 1/5 to 1/10 of the case without metal filler), it is bonded by external force such as thermal stress or vibration due to the difference in thermal expansion coefficient between the detection element 2 and the substrate 1 or humidity. A part of the layer may be peeled off, or an electrical contact state may be unstable, and vibration may generate noise. At present, there is no conductive adhesive having both conductivity and adhesive strength.

In the case of the structure shown in FIG. 5, the detecting element 2 is supported by upper and lower conductive packings 51 and 52, and there is a problem that the detecting element 2 vibrates due to an impact or the like to generate noise. The structure is complicated, the number of parts is large, and the assembling also takes time.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a structure which is resistant to vibrations such as impacts, temperature changes and humidity, has a simple structure, has a small number of parts, and has a small number of assembly steps. An object of the present invention is to provide a detector having an element holding / wiring structure.

[0008]

According to the present invention, there is provided a detecting element for detecting radiation, a substrate for holding the detecting element, and an electric device for applying a voltage from a power supply to the detecting element and extracting an electric signal from the detecting element at the same time. In the detector including the wiring, the bias power supply for the detection element, and the signal processing unit, a portion of the electric wiring directly connected to the detection element is a wire-bonded wire, and the detection element has an insulating adhesive. The adhesive is held on the substrate by the agent.

The electrical connection is stabilized by directly connecting a wire to the electrode of the detection element by wire bonding, and an insulating adhesive having a high adhesive strength is used to adhere and hold the detection element on the substrate. The detection element can be securely and firmly adhered and held on the substrate. Also,
One end of a wire from the wire-bonded detection element is wire-bonded to a wiring pattern formed on the substrate. By wire bonding one end of the wire to the wiring pattern on the substrate, the length of the wire can be shortened, and the formation of the electrical wiring becomes more reliable and easier.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the detector according to the present invention will be described with reference to examples. FIG. 1 is a sectional view showing a structure near a detecting element in an embodiment of a detector according to the present invention, and FIGS. 2 and 3 are sectional views showing a manufacturing method of the embodiment. The detector according to the present invention includes a lower electrode 21 and an upper electrode 22 formed on both surfaces of the detection element 2, and a lower electrode pattern 11b and an upper electrode pattern formed on a substrate 1b for connecting the respective electrodes. Connection with the pattern 12 by a wire bonding method;
And the substrate 1b are firmly bonded with an insulating adhesive 3a.

The structure and manufacturing method will be described below with reference to FIGS. FIG. 2 shows a first example of the manufacturing method. First, the jig 7 is set with the detection element 2 with the lower electrode 21 facing upward.
The aluminum wire 4a is wire-bonded on the lower electrode 21 by an ultrasonic bonding method, and the other end of the aluminum wire 4a is cut to a required length (FIG. 2A). Next, an insulating adhesive 3a such as an epoxy-based adhesive is applied to the bonding position of the detection element 2 on the substrate 1b, and the detection element 2 bonded with the aluminum wire 4a is turned with the lower electrode 21 side downward. The adhesive 3a is placed on the adhesive 3a, and the adhesive 3a is heated and cured by applying a necessary load, so that the detection element 2 and the substrate 1b are bonded. After the bonding, the other end of the aluminum wire 4a is connected to the lower electrode pattern 11b by ultrasonic bonding [FIG. 2 (b)], and the upper electrode 22 of the detecting element 2 and the upper electrode pattern 12 are connected to the aluminum wire 4a. Connected by the ultrasonic bonding method (FIG. 2C), and the substrate of the detecting element 2
Complete bonding and electrical wiring on 1b.

Since the electric wiring between the detecting element 2 and the substrate 1b is carried out by the wire bonding method, the connection is ensured, and there is no instability unlike the connection by the conductive adhesive. Further, since the detection element 2 and the substrate 1b are bonded with the insulating adhesive 3a having a high bonding strength, the detection element 2 is firmly held, and a highly reliable holding state is realized.

The manufacturing method shown in FIG. 3 uses the lower electrode 21 on the substrate 1b.
The lower electrode 21 and the lower electrode pattern 11b are connected by the ultrasonic bonding method of the aluminum wire 4a [FIG. 3 (a)], and the lower electrode 21 and the lower electrode pattern 11b are turned upside down and the insulating adhesive is attached. It is bonded to a predetermined position on the substrate 1b by the agent 3a (FIG. 3B). Thereafter, although not shown, the upper electrode 22 and the upper electrode pattern 12 are connected in the same manner as in the case of FIG. 1, and the bonding and holding of the detection element 2 on the substrate 1b and the electric wiring are completed.

In the above embodiment, an example of the ultrasonic bonding method using an aluminum wire has been described as an electrical connection method of the detection element 2. However, other wire bonding methods, such as a thermocompression bonding method using a gold wire, are similarly used. It is valid. Also,
Although the example in which the aluminum wire 4a is bonded to the electrode pattern on the substrate has been described, it is also possible to directly bond the aluminum wire 4a to a case (not shown), and in this case, there is no need to form a wiring pattern on the substrate. .

[0015]

According to the present invention, a detecting element for detecting radiation, a substrate holding the detecting element, an electric wiring for applying a voltage from a power supply to the detecting element and extracting an electric signal from the detecting element at the same time, In a detector including a bias power supply for a detection element and a signal processing unit, a portion of the electric wiring directly connected to the detection element is a wire-bonded wire, and the detection element is mounted on a substrate by an insulating adhesive. , The electrical connection to the detection element is stabilized, and the detection element can be securely and firmly adhered to the substrate.

Further, since one end of the wire from the wire-bonded detection element is wire-bonded to the wiring pattern formed on the substrate, the length of the wire can be shortened, and the formation of electric wiring can be further improved. Reliable and easy. Therefore, it is possible to provide a detector that is resistant to vibration such as impact, temperature change, and humidity, has a simple structure, has a small number of parts, and has a small number of assembly steps, and has a detection element holding / wiring structure.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a structure near a detecting element in an embodiment of a detector according to the present invention.

2A and 2B show an example of a manufacturing method according to the embodiment, in which FIG. 2A is a cross-sectional view showing a wire bonding step to a lower electrode, and FIG.
Is a cross-sectional view of a state where the lower electrode is wired to the substrate,
(C) is a cross-sectional view showing a state in which the upper electrode is also wired.

3A and 3B show another example of the manufacturing method according to the embodiment, in which FIG. 3A is a cross-sectional view showing a wire bonding step to a lower electrode, and FIG.
Is a cross-sectional view of the state where it is bonded to the substrate

FIG. 4 is a cross-sectional view showing a structure near a detecting element in an example of a conventional detector.

FIG. 5 is a cross-sectional view showing a structure near a detecting element in another example of the conventional detector.

[Explanation of symbols]

 1, 1a, 1b Substrate 11, 11a, 11b Lower electrode pattern 12 Upper electrode pattern 2 Detector 21 Lower electrode 22 Upper electrode 3 Conductive adhesive 3a Adhesive 4, 4a Aluminum wire 5 Conductive packing 6 Pressure storage Case 61 Base plate 62 Upper electrode pattern 7 Jig

Claims (2)

[Claims] 1. A semiconductor radiation detecting element for detecting radiation, a substrate holding the semiconductor radiation detecting element, and an electric wiring for applying a voltage from a power supply to the semiconductor radiation detecting element and simultaneously extracting an electric signal from the semiconductor radiation detecting element. A semiconductor radiation detector comprising: a bias power supply for the semiconductor radiation detection element; and a signal processing unit, wherein a portion of the electrical wiring directly connected to the semiconductor radiation detection element is a wire-bonded wire, A semiconductor radiation detector, wherein the radiation detection element is adhered and held on a substrate by an insulating adhesive. 2. The semiconductor radiation detector according to claim 1, wherein one end of a wire from the wire-bonded semiconductor radiation detection element is wire-bonded to a wiring pattern formed on a substrate.