JPH07282957A - Connecting method for connecting terminal of ceramic heater element - Google Patents

Abstract

PURPOSE:To securely connect an electrode and a lead wire terminal by heating a lead wire terminal on the surface of a metal layer, and thereafter, exciting it, also controlling to prevent the overheat. CONSTITUTION:In a ceramic heater element having an electrode, in which a metal layer is fitted to the end surface of a ceramic base body 1, a brazing material 3, in which a lead wire 4 is inserted, is placed on the electrode. After fitting a tip 5 to the brazing material 3, the lead wire 4 is connected to the ceramic heater element heating the tip 5 in the inert gas atmosphere and exciting it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for connecting a ceramic heating element and a metal connecting terminal.

[0002]

2. Description of the Related Art Conventionally, welding, brazing, pressure welding or the like has been known as a means for joining a ceramic heating element such as silicon carbide and a metal terminal. By the way, JP-A-4
In JP-A-141978, by applying vibration while heating a lead terminal mounted on the surface of an electrode made of aluminum or an aluminum alloy adhered to a ceramic substrate by thermal spraying, the lead terminal is intercalated via a metal layer. A lead terminal connection structure for joining with is disclosed. However, in the above-mentioned joining, there is a possibility that the joint portion of the lead terminal may be opened or broken due to the difference in thermal expansion between the ceramic base and the lead terminal while the ceramic heater is energized, and as a result, the reliability of the joint portion I have a problem. Further, in Japanese Unexamined Patent Publication No. 4-306581, after roughening the joint end surface of the ceramic heating element, a metal terminal is temporarily bonded, and then the joint end surface is sprayed with metal from the upper portion of the temporarily bonded metal terminal to obtain an average film. Thickness 1
A joining method is shown which is characterized by forming a sprayed layer having a thickness of 00 to 300 μm. However, with this joining means, the end face of the ceramic heating element must be roughened in advance, which is not suitable for mass production.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is possible to avoid various problems due to temperature rising during heating and to perform bonding in a short time, and to generate highly reliable ceramic heat. It is intended to provide a method for connecting body connection terminals.

[0004]

According to the present invention, in a ceramic heating element having an electrode in which a metal layer is attached to an end face of a ceramic substrate, a brazing material having lead wires inserted therein is placed on the electrode, After stacking the chips on the brazing material,
A method for connecting a connecting terminal of a ceramic heating element, characterized in that the chip is heated in an inert gas and then vibrated.

[0005]

According to the above connection method, a trace amount of oxygen is generally contained in the brazing filler metal, so that the oxide film mainly containing oxygen in the brazing filler metal hinders the joining with the electrode.

However, according to the present invention, the oxide film can be destroyed by heating and then vibrating in an inert gas atmosphere, and as a result, the electrode and the lead wire can be firmly bonded.

Further, since it has a displacement gauge, it can detect that the brazing material is surely melted and can prevent the corrosion of the lead wire due to the heating and heating of the lead wire in the brazing material. The electrode and the lead wire can be joined in a shorter time.

An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic diagram showing a lead wire connecting method, in which a metal layer 2 is formed on the surface of a ceramic substrate 1.
On the end face of the ceramic heater attached by
After brazing the brazing filler metal 3 with the chip 5 having the same or substantially the same thermal expansion coefficient as the ceramic substrate 1, the brazing filler metal 3 is surrounded by the vibrator A and the heater C inserted in the gas impermeable cylinder 6. With the vibration heater D composed of the trowel B, the heat from the vibration heater D propagates through the tip 5 to melt the brazing filler metal 3, and the melting amount of the brazing filler metal is measured by a laser or ultrasonic displacement meter E. The lead wire 4 is sandwiched between the ceramics heater and the chip 5 to obtain a lead wire connection terminal structure having a high bonding strength by being detected by the above method and then vibrating after the heating temperature is prevented from rising. The shape of the ceramic substrate may be a panel shape, a honeycomb shape, or a cylindrical shape, and the metal layer may be aluminum, nickel, or the like.

[0009]

As described above, according to the method for connecting the connecting terminals of the ceramic heating element of the present invention, the oxide film on the surface of the brazing material is destroyed by heating and then vibrating in an inert gas atmosphere. Therefore, the electrode and the lead wire can be firmly bonded to each other. In addition, since it has a displacement gauge, it can detect that the brazing material has melted reliably, and can prevent erosion of the lead wire due to heating and heating of the lead wire in the brazing material. This is a bonding method suitable for mass production, which can bond the electrode and the lead wire in time.

[Brief description of drawings]

FIG. 1 is a schematic view showing a lead wire terminal connecting method of the present invention.

[Explanation of symbols]

 1 Ceramics Base 2 Metal Layer 3 Brazing Material 4 Lead Wire 5 Chip 6 Cylinder A Vibrator B Iron C Heater D Vibratory Heater E Displacement Meter

Claims (2)

[Claims] 1. In a ceramic heating element having an electrode formed by spraying or coating a metal layer on an end surface of a ceramic substrate, a brazing material having lead wire terminals inserted therein is placed on the electrode, and then the ceramic substrate is placed on the brazing material. A method for connecting a connection terminal of a ceramic heating element, comprising: stacking chips having the same or substantially the same coefficient of thermal expansion as that of Example 1, and heating the chips in an inert gas, and then applying vibration. 2. The connecting terminal of the ceramic heating element according to claim 1, wherein the distance from the electrode surface to the heavy wear tip due to melting of the brazing material is measured by a laser displacement meter or an ultrasonic displacement meter. How to connect.