As electronic circuit components, NTC thermistors are widely used in temperature detection and temperature compensation for household appliances, new energy vehicle batteries, office automation equipment, industrial, medical, environmental protection, meteorology, food processing equipment and instrument coils. Thermistors are available in several material encapsulation forms, such as epoxy encapsulation, SMD encapsulation, glass encapsulation, etc. The main features of glass-encapsulated NTC thermistors are high temperature resistance, moisture resistance, good stability, high reliability and fast response speed.

As shown in FIG. 1 , the existing glass-encapsulated NTC thermistor includes an NTC resistance chip 11 , two electrode leads 12 and a glass envelope 13 , the glass envelope 13 encapsulates the NTC resistance chip 11 , and the two electrode leads 12 are One end is respectively welded with the electrodes at both ends of the NTC resistor chip 11 , and the other end is respectively protruded from the bottom of the glass bulb 13 .

The manufacturing method of the glass-encapsulated NTC thermistor is as follows: first, one end of the two electrode leads 12 is respectively pasted with silver paste and then welded with the electrodes at both ends of the NTC resistance chip 11; then, a glass sleeve is used to cover the NTC resistance chip 11 and the welding place with the electrode lead 12 ; finally, the glass sleeve is sintered to seal the two ends of the tube to become the glass bulb 13 that encapsulates the NTC resistor chip 11 and the welding place between the NTC resistor chip 11 and the electrode lead 12 .

However, the existing glass-encapsulated NTC thermistors have the following shortcomings:

1) Since the wall of the glass sleeve is very thin and the thickness is only 0.1-0.4mm, the mechanical strength of the obtained glass bulb 13 is relatively low, which leads to the lower mechanical strength of the thermistor product as a whole and is easily damaged;

2) The joint part between the bottom of the glass bulb 13 and the electrode leads 12 is glass, if the force is too large, it will break. When actually installing and using the thermistor, it is often necessary to break the two electrode leads 12. Therefore, the glass bulb 13 It is easy to be damaged. After the glass bulb 13 is broken, the NTC resistor chip 11 cannot be isolated from the outside world, which leads to the drift of the electrical properties of the product and the reduction of the moisture-proof and waterproof capabilities.

Therefore, a ceramic thin film glass encapsulated resistor is produced, which has the advantages of high mechanical strength, high reliability, not easy to damage, simple structure, easy preparation and the like.

The ceramic thin film glass encapsulated resistor includes a resistor chip, a glass shell, a ceramic sheet and two electrode leads. The glass shell is sleeved outside the resistor chip and has an opening at the bottom; the ceramic sheet seals the opening of the glass shell and is fixed with the glass shell. It is provided with two lead holes; one end of the two electrode leads is respectively connected with the electrodes at both ends of the resistance chip, and the other ends are respectively protruded from the two lead holes of the ceramic sheet.

Ceramic thin film glass encapsulated resistors use ceramic thin films and glass to encapsulate the resistor chip together, and use ceramic thin films to replace the glass shell and the connection part of the electrode leads. The mechanical strength of ceramic thin films is much higher than that of glass. When the electrode lead is connected, the glass bulb will not be easily damaged, the product has good sealing performance, and the production qualification rate and reliability are guaranteed. Moreover, the production cost of the ceramic sheet is low, which not only slightly increases the production cost of the product, but also significantly improves the mechanical strength and reliability of the product. At the same time, it can ensure that the product has the fast response speed, high temperature resistance, moisture resistance and good stability of conventional glass-sealed resistors. And all the advantages.

The preparation method of ceramic thin film glass encapsulated resistor includes the following steps:

(1) Alumina ceramic film is prepared by casting method;

(2) punching and punching the alumina ceramic film with a punching machine to prepare multiple ceramic sheets with two lead holes;

(3) The ceramic sheet is sintered at high temperature for later use;

(4) Take a resistor chip, weld one end of the two electrode leads to the electrodes at both ends of the resistor chip, respectively, and insert the other end into the two lead holes of a sintered ceramic sheet, and then take a glass sleeve to The resistance chip is covered, and the glass sleeve is closely attached to the ceramic sheet to obtain an assembled semi-finished product;

(5) sintering the assembled semi-finished product, so that the glass sleeve is formed into a glass bulb and tightly combined with the ceramic sheet to obtain a ceramic film glass encapsulated resistor product.

The ceramic thin-film glass-encapsulated resistor product can be used in large quantities in sensors for printers and copiers.