KR20040016605A - assembling method of gas sensor - Google Patents

Abstract

PURPOSE: A method for assembling a gas sensor detecting device is provided to improve thermal characteristics of the gas sensor detecting device and to simplify an assembling process for the gas sensor detecting device. CONSTITUTION: A plurality of sensor chips including a heater layer, such as a platinum layer or a cermet thin film heater, a catalyst layer, and an electrode layer are formed on an entire surface of a ceramic substrate. Then, the sensor chips formed on the ceramic substrate are cut into an individual sensor chip by using a dicer. The sensor chip is assembled into a stem through a die bonding process. The heater electrode is directly connected to an upper portion of a pin of the step through the die bonding process. The catalyst electrode is connected to the other pin by using a wire bonding device.

Description

Assembly method of gas sensor detection element {assembling method of gas sensor}

In the method of assembling a thick film and a thin film gas sensor sensing element, an assembly method by wire welding or wire bonding is conventionally used to connect a substrate and a pin of a stem.

The assembling method by the welding method is a method of assembling a thick film-type ceramic sensing element and is assembled by floating in the air as shown in [Fig. 4] a to improve thermal characteristics.

The wire bonding method is a method of assembling a thin-film gas sensor sensing element. The device is fixed by die bonding to a package and assembled by wire bonding, or after the wire bonding, the die bonding adhesive is thermally weakened so that the adhesive force is lost. The tension causes the chip to float in the air.

However, in the conventional method, the sensing element assembly method by the welding method takes not only a long assembly time but also an assembly equipment, which is an expensive equipment, causing a rise in product prices.

While the wire bonding method can be easily assembled, only thin film gas sensor sensing devices fabricated using MEMS technology on a silicon wafer are assembled in consideration of thermal characteristics.

Accordingly, an object of the present invention is to provide a method for assembling a gas sensor sensing element as shown in [Fig. 1] in order to improve thermal characteristics and simplify the assembly method.

FIG. 1 is an assembly schematic diagram of a gas sensor sensing device assembled into a package by a mixing process by wire bonding and die bonding.

[Figure 2] is a schematic diagram of a contact combustion gas sensor assembly in which a gas sensor sensing element is assembled into a package by die bonding.

FIG. 3 is an assembly diagram of a semiconductor gas sensor assembled by die bonding of a gas sensor sensing element in a packag.

4 is a schematic diagram of a conventional gas sensor sensing device assembly.

In the present invention, a catalyst, a heater, and an electrode pattern are formed of a thin film and a thick film. In the case of a semiconductor type, a catalyst electrode is assembled through wire bonding, a heater electrode is assembled by die bonding, or a heater material is placed on a pin. Paste) and directly assembled by die bonding. In the case of the contact combustion type, die-bonding was conducted with a conductive material on the pins to be directly connected to the pins.

In the present invention, in order to minimize the size of the gas sensor to reduce the heat capacity to reduce the power consumption and increase the sensitivity, the chip is precisely cut to the minimum size that can handle the chip through precise dicing work to improve the uniformity of the product as well as the thermal characteristics. It was.

The sensor assembled by the present invention has the effect of reducing the power consumption by reducing the assembly time and thermal properties.

Claims (4)

Using a precision dicer, the sensor chip is precisely cut and the tolerance is minimized by using a precision dicer on the ceramic substrate. Manufacturing method to manufacture sensor chip In assembling the sensor chip on the stem, in the case of the semiconductor sensor, the heater electrode is directly connected by die bonding to the upper part of the pin of the stem, and the catalyst electrode is wired to another pin (wire, aluminum, nickel, etc.) by using wire bonding equipment. How to connect using In assembling the sensor chip on the Stem, in the case of the contact combustion sensor, the sensor chip having the catalyst and the heater electrode is directly bonded by die bonding to the two pins of the stem, and the sensor chip having the compensation element and the heater electrode is die bonded to the other two pins. This is a structure in which compensation element and sensing element are assembled in one package. In assembling the sensor chip on the stem, in the case of a semiconductor sensor, the sensor structure directly connects the catalyst electrode and the heater electrode by die-bonding the four pins of the stem.