CN212647977U - Power non-inductive resistor in plane thick film - Google Patents

Abstract

The utility model discloses a plane thick film medium power noninductive resistor, including shell, alumina plate and resistance thick liquids layer, the sintering of resistance thick liquids layer is on alumina plate, and ceramic back printing heat conduction silver thick liquid, pin and conductive silver thick liquids layer welding are in the same place. The utility model provides a power noninductive resistor in plane thick film, the direct sintering of resistance thick liquids layer is on alumina plate to adopt individual layer potsherd (aluminium oxide) structure, the individual layer moulds shell structure, simple structure, the heat conductivity is high, and heat dispersion is good, and the cost is lower.

Description

Power non-inductive resistor in plane thick film

Technical Field

The utility model relates to a power electronic components field especially relates to a power noninductive resistor in plane thick film.

Background

At present, thick-film high-power resistors sold in the market have high requirements on the medium area and the heat dissipation effect on a ceramic substrate, namely the rated power of the resistor is in direct proportion to the medium area on the ceramic substrate, and the ceramic substrate is soldered with a metal bottom plate for the purposes of installation and heat dissipation. Since the two materials have different coefficients of thermal expansion, the welding process can cause severe deformation of the metal base plate, with the larger the base plate area, the more severe the deformation. The bonded bottom plate type resistor has the self heat dissipation efficiency limitation, so that the bonded bottom plate type resistor is only applicable to the field of power resistors less than or equal to 300W.

In order to solve the problems, a solution is provided in the market, the copper sheet is welded and fixed between the first ceramic sheet and the second ceramic sheet, a sandwich shape is formed by vacuum welding, deformation of the ceramic substrate and metal caused by different thermal expansion coefficients during welding is effectively compensated, the heat dissipation effect of the bottom plate is ensured, and the thick-film high-power resistor is suitable for thick-film high-power resistors with the thickness of more than 250W. However, the sandwich structure is too complex, and the alumina ceramic is used as the ceramic, so that the heat-conducting property is poor.

Meanwhile, a solution is provided, a welding mode is not adopted, and the thermal resistance of the product is reduced due to the single-layer aluminum oxide plate ceramic structure. The heat dissipation effect of the bottom plate is fundamentally ensured, and the high-power non-inductive resistor is suitable for planar thick film high-power resistors with the power of more than 600W. But the price of the product is relatively high.

The 250W planar rear resistor adopts the mode that the bottom plate is welded, the sandwich structure is adopted, the process is complex, the implementation performance is poor, and the cost is overhigh due to the adoption of the single-layer alumina substrate.

SUMMERY OF THE UTILITY MODEL

For solving prior art's above-mentioned problem, the utility model provides a power noninductive resistor in plane thick film does not adopt the welded mode, and the individual layer moulds the shell, and individual layer aluminium oxide potsherd structure, potsherd back printing silver thick liquid reduce the thermal resistance of product. The heat dissipation effect of the base plate is fundamentally ensured, and the high-power non-inductive resistor is suitable for a 250W plane thick film medium-power non-inductive resistor.

In order to achieve the above purpose, the utility model discloses the following technical scheme of accessible solves:

the utility model provides a plane thick film medium power noninductive resistor, includes alumina plate, conductive silver thick liquid layer, resistance thick liquid layer and pin, conductive silver thick liquid layer and resistance thick liquid layer printing are in alumina plate is last and the sintering solidification, alumina plate back printing heat conduction silver thick liquid, the pin welding is in on the conductive silver thick liquid layer, then whole putting into the shell again and add the embedment silica gel that has reinforcing insulating properties.

Further, a 95% Al2O3 porcelain piece and a compression spring are arranged between the shell and the alumina plate, one end of the compression spring is arranged on the 95% Al2O3 porcelain piece, and the other end of the compression spring is propped against the shell.

Further, still include a plurality of wiring copper posts, a plurality of wiring copper posts and shell are moulded plastics integratively.

Furthermore, a wire through hole is formed in the center of the wiring copper column, and the pin is welded on the wiring copper column in the assembling process.

Further, alumina plate is individual layer aluminium oxide ceramic wafer structure, the direct sintering of resistance thick liquids layer is on the aluminium oxide ceramic wafer, aluminium oxide ceramic wafer back printing heat conduction silver thick liquid.

Furthermore, the conductive silver paste layer is printed and sintered in the middle of the aluminum oxide plate, and the resistance paste layers are printed, sintered and solidified at two ends of the aluminum oxide plate.

Advantageous effects

Compared with the prior art, the utility model provides a power noninductive resistor in plane thick film adopts individual layer aluminium oxide potsherd structure, compares with current three layer construction (sandwich shape) and current individual layer aluminium oxide base board, and the cost is lower, and technology is simpler, and the direct printing of thick liquids layer is on aluminium oxide potsherd, back printing heat conduction silver thick liquid, and there is compression spring in the middle of, and the individual layer moulds the shell, and heat transfer efficiency is high, has fundamentally guaranteed the radiating effect of bottom plate.

Drawings

FIG. 1 is an exploded view of the structure of a planar thick film medium power non-inductive resistor

In the figure:

1 alumina plate 2 conductive silver paste layer 3 resistance paste layer

4-pin 595% Al2O3 porcelain 6 compression spring

7 wiring copper column 8 shell

Detailed Description

The following description of the embodiments of the present invention is provided by way of specific examples, and other advantages and effects of the present invention will be readily apparent to those skilled in the art from the disclosure herein.

Referring to fig. 1, the utility model provides a power non-inductive resistor in plane thick film, including alumina plate 1, conductive silver thick liquid layer 2, resistance thick liquid layer 3 and pin 4, conductive silver thick liquid layer 2 and resistance thick liquid layer 3 printing are on alumina plate 1 and sintering solidification, and pin 4 welds on conductive silver thick liquid layer 2. And printing heat-conducting silver paste on the back of the aluminum oxide plate 1, then integrally placing the aluminum oxide plate into the shell 8, and encapsulating silica gel to enhance the insulating property.

Wherein, there are 95% Al2O3 porcelain 5 and pressure spring 6 between shell 6 and alumina plate 1, and pressure spring 6 one end sets up on 95% Al2O3 porcelain 5, and the other end withstands shell 8, guarantees that alumina plate 1 and installation face contact are inseparable.

Wherein, still include a plurality of wiring copper post 7, a plurality of wiring copper posts 7 and shell 8 mould plastics integratively.

Wherein, there is the line through-hole at wiring copper post 7 center, and pin 4 welds on wiring copper post 7 in the assembling process.

Wherein, alumina plate 1 is the ceramic chip architecture of single-deck aluminium oxide, and resistance thick liquids layer 3 is directly sintered on alumina ceramic chip 1, and the printing of aluminium oxide ceramic chip back is led heat conduction silver thick liquid.

The conductive silver paste layer 2 is printed and sintered in the middle of an alumina plate, and the two ends of the alumina plate are printed and sintered with solidified resistance paste layers 3.

Compare in prior art's condition, the utility model provides a power noninductive resistor in plane thick film adopts individual layer potsherd structure, and alumina plate 1 adopts high performance alumina ceramic preparation, and insulating properties is good, and back printing silver thick liquid has the compaction of compaction porcelain spare, and the thermal resistance is < 0.22 ℃/W. The utility model provides a single-layer ceramic wafer structure, porcelainous back printing heat conduction silver thick liquid, the direct sintering of thick liquids layer has reduced thermal contact resistance on alumina plate, has reduced the production link, has improved the radiating effect of product greatly, is applicable to 250W's medium power resistor.

In this embodiment, the conductive silver paste layer is printed and sintered on the alumina plate 1, then the resistance paste layer 3 made of silver palladium paste or ruthenium paste is printed and sintered (passing through 850 ℃) on both ends of the alumina plate 1, then glass encapsulation is performed, the back surface is printed with the conductive silver paste, and then the pins 4 are soldered on the conductive silver paste layer.

The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, as any modifications, equivalents, improvements and the like made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.

Claims (6)

1. The utility model provides a plane thick film medium power noninductive resistor, its characterized in that, includes alumina plate, conductive silver thick liquid layer, resistance thick liquid layer and pin, conductive silver thick liquid layer and resistance thick liquid layer printing are in alumina plate is last and the sintering solidification, alumina plate back printing heat conduction silver thick liquid, the pin welding is in on the conductive silver thick liquid layer, then wholly put into the shell again and add the embedment silica gel that has reinforcing insulating properties.

2. The planar thick film medium power noninductive resistor of claim 1, wherein a 95% Al2O3 porcelain and a compression spring are arranged between said housing and said alumina plate, said compression spring having one end disposed on said 95% Al2O3 porcelain and the other end abutting against said housing.

3. The planar thick film medium power noninductive resistor of claim 1 or 2, further comprising a plurality of copper wiring posts, wherein the plurality of copper wiring posts and the housing are integrally molded.

4. The planar thick film medium power noninductive resistor of claim 3, wherein the wiring copper pillar has a through-hole in the center, and the pin is soldered to the wiring copper pillar during the assembly process.

5. The planar thick film medium power noninductive resistor of claim 1, wherein the alumina plate is a single-layer alumina ceramic plate structure, the resistance paste layer is directly sintered on the alumina ceramic plate, and the back of the alumina ceramic plate is printed with heat conductive silver paste.

6. The planar thick film medium power non-inductive resistor of claim 1, wherein said conductive silver paste layer is printed and sintered in the middle of an alumina plate, and said resistance paste layer is printed, sintered and cured at both ends of said alumina plate.

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