CN-122025319-A - Thick film double-cap resistor assembly capable of avoiding welding spot fracture and double-cap resistor body

Abstract

The invention discloses a thick film double-cap resistor assembly and a double-cap resistor body capable of avoiding welding spot fracture, and relates to the technical field of electronic components, wherein the thick film resistor body and the thin film resistor body form a composite body and are arranged at the topmost layer of a whole module; the whole flexible metal transition layer adopts a snake-shaped metal foil structure, and can effectively absorb and release stress generated by unmatched thermal expansion coefficients between the ceramic substrate and the metal cap through self elastic deformation in the thermal cycle process. And secondly, through the synergistic effect of the tree-shaped fractal micro-channel and the functionally gradient capillary core, active thermal management distributed according to needs is realized by utilizing the phase change working medium and combining the magnetofluid working medium and an external magnetic field, and the generation of thermal stress is reduced from the source. The stress buffering and efficient heat dissipation integrated intelligent monitoring device has the advantages that the problem of welding spot breakage is thoroughly solved through a stress buffering and efficient heat dissipation integrated intelligent monitoring synergistic mechanism, and the power density, the service life and the safety and the reliability of the resistor under different working conditions are remarkably improved.

Inventors

• Shen Jide
• ZHU FENG
• LIN JUN

Assignees

• 安徽格瑞特电子有限公司

Dates

Publication Date

20260512

Application Date

20260402

Priority Date

20251129

Claims (10)

1. 1. A thick film double cap resistor assembly capable of avoiding solder joint breakage, comprising: the thick film resistor body (110) and the thin film resistor body (120) are arranged at the topmost layer of the whole module by forming a composite body; The high-heat-conductivity aluminum nitride ceramic substrate assembly (900) is arranged at the bottoms of the thick film resistor body (110) and the thin film resistor body (120), the high-heat-conductivity aluminum nitride ceramic substrate assembly (900) comprises a ceramic substrate (901), a thin film resistor region, a thick film resistor region and an isolation groove (902), the thin film resistor region is firstly manufactured on the ceramic substrate (901), then the thick film resistor region is manufactured through a laser windowing process, the thick film resistor region and the thin film resistor region are electrically isolated through the isolation groove (902) which is formed by laser scribing, and required electrical interconnection is realized at a specific point through the thick film resistor body (110) and metal connecting discs (800) on two sides of the thin film resistor body (120); The flexible metal transition layer (140) is positioned between two ends of the ceramic substrate (901) and the metal cap (400) connected with the side end of the metal connecting disc (800), the flexible metal transition layer (140) is a snake-shaped metal foil, one end of the flexible metal transition layer is connected with a terminal electrode on the ceramic substrate (901) through high-temperature brazing, and the other end of the flexible metal transition layer is welded with an external lead; the micro-channel phase-change heat sink assembly (130) is closely attached to the whole bottom of the ceramic substrate (901), the micro-channel phase-change heat sink assembly (130) comprises a whole plate (131), the whole plate (131) is made of independent copper or silicon, a tree-shaped fractal micro-channel (135) is formed in the micro-channel through etching or processing, a phase-change working medium is filled in the tree-shaped fractal micro-channel (135), and the micro-channels are denser and form a capillary pump structure under a thick film resistor area; the micro-channel phase change heat sink assembly (130) is tightly attached to the bottom of the ceramic substrate (901) through high-heat-conductivity silicone grease or heat-conductivity glue and is isolated from the electrical loops of the thick film resistor body (110) and the thin film resistor body (120).
2. 2. The thick film double cap resistor assembly of claim 1, wherein the capillary pump structure of the micro-channel phase change heat sink assembly (130) is a functionally graded capillary core, and the capillary pore diameter or surface energy of the capillary core is graded along the direction from the thick film resistor region to the thin film resistor region to generate stronger directional capillary driving force.
3. 3. The thick film double-cap resistor assembly capable of avoiding welding spot breakage according to claim 1, wherein the phase change working medium filled in the tree-shaped fractal micro-channel (135) is magnetic fluid phase change working medium, a resistor protection shell (100) is arranged outside the ceramic substrate (901), and miniature external magnetic field generators (600) for driving the magnetic fluid phase change working medium to flow are symmetrically arranged at two ends of the central axis of the resistor protection shell (100).
4. 4. The thick film double cap resistor assembly capable of avoiding welding spot breakage as claimed in claim 1, wherein a miniature metal strain gauge is arranged in a metal foil deformation area of the flexible metal transition layer (140), and the miniature metal strain gauge is provided with an independent signal leading-out end for being connected to an external monitoring circuit so as to realize real-time monitoring of mechanical stress and temperature of the thick film resistor body (110) and the thin film resistor body (120).
5. 5. The thick film double cap resistor assembly capable of avoiding welding spot breakage according to claim 1, wherein the side end of the isolation groove (902) is connected with an isolation groove supporting rib (903), the isolation groove supporting rib (903) and the ceramic substrate (901) are integrally formed, and the side end of the isolation groove supporting rib (903) is provided with a wire groove (904).
6. 6. The thick film double cap resistor assembly capable of avoiding welding spot breakage as claimed in claim 1, wherein the side end of the metal connecting disc (800) is connected with a metal cap electrical connection part (700), and the metal cap electrical connection part (700) and the metal cap (400) are integrally formed.
7. 7. The thick film double cap resistor assembly capable of avoiding welding spot breakage according to claim 1, wherein tin welding spots (132) are symmetrically arranged at the side ends of the whole plate (131) along the two sides of the central axis of the whole plate, and the side ends of the tin welding spots (132) are respectively connected with a stress monitoring end (133) and a temperature monitoring end (134).
8. 8. The thick film double-cap resistor assembly capable of avoiding welding spot breakage according to claim 1, wherein a phase-change working medium reservoir (136) is arranged in the tree-shaped fractal micro-channel (135) at unequal intervals, the phase-change working medium reservoir (136) is used for storing and stably supplying phase-change working medium, the phase-change working medium reservoir (136) is communicated with the micro-channel (135) in the whole course, so that sufficient working medium supplement can be provided when phase change (such as liquid phase change) occurs in the phase-change working medium, the heat dissipation efficiency is avoided, the heat dissipation efficiency is influenced by working medium shortage in the micro-channel, the self elasticity or volume change can be utilized, the directional flow driving force of the working medium is enhanced by an auxiliary capillary pump structure, the phase-change heat dissipation process is ensured to be stable continuously, a micro-channel working medium outlet (137) and a monitoring interface are arranged at the side end of the capillary pump structure, the micro-channel working medium outlet (137) and the monitoring interface are used as circulation channels of the phase-change working medium on one hand, the directional discharge and supplement of the phase-change working medium in the micro-channel are realized, the continuity of the phase-change heat dissipation cycle is ensured, and the phase-change working medium is used as a state monitoring interface on the other hand, the temperature sensor, the flow sensor and the like sensor is connected, the like, the state of the phase change working medium is improved, the flow and the heat dissipation efficiency is can be improved, and the heat dissipation efficiency is ensured, and the heat dissipation efficiency is realized by the integral heat dissipation data through the heat dissipation structure (130.
9. 9. The thick film double-cap resistor assembly capable of avoiding welding spot breakage according to claim 3, wherein a heat shrinkage tube (200) is arranged at the top of the resistor protection shell (100), an inserting sheet (300) is connected to the top of the heat shrinkage tube (200), an elastic heat conduction buffer medium is filled in the resistor protection shell (100), and the elastic heat conduction buffer medium completely covers the connecting parts of the internal resistor structure, the metal cap and the lead wires.
10. 10. A double cap resistor, characterized in that the thick film double cap resistor assembly capable of avoiding welding spot fracture according to any one of claims 1-9 comprises a double cap resistor, wherein the double cap resistor is a combination (140) of a thick film composite resistor and a flexible metal transition layer.

Description

Thick film double-cap resistor assembly capable of avoiding welding spot fracture and double-cap resistor body Technical Field The invention relates to the technical field of electronic components, in particular to a thick film double-cap resistor assembly and a double-cap resistor body capable of avoiding welding spot breakage. Background The resistor component, especially the resistor of high-power thick film resistor, thin film resistor or its composite structure, is the basic element in modern electronic circuit, and is widely used in the fields of industrial control, new energy, communication base station, automobile electronics, etc. Such resistors are typically fabricated on ceramic substrates with electrical connections and mechanical packaging through metal caps and external leads for high current carrying and ease of installation. At present, when a resistor assembly runs for a long time, particularly frequent power circulation and temperature change are experienced, a common and serious reliability problem exists, namely, fatigue fracture of welding spots is easy to occur, while the improvement scheme in the prior art cannot meet the severe requirements of the fields of aerospace, deep space exploration, high-reliability military electronics, backbone network communication equipment, implanted high-end medical instruments and the like on the extreme reliability of the resistor assembly (such as the requirement of service life exceeding 10 ten thousand hours and failure rate lower than 1 FIT), because the resistor assembly is usually composed of various materials, the thermal expansion coefficient of a ceramic substrate (such as aluminum oxide and aluminum nitride) is obviously different from that of a metal cap and an external copper lead welded on the ceramic substrate, when the resistor is powered on or the power is changed, the temperature of the resistor assembly can be severely fluctuated, different materials can be expanded and contracted, huge cyclic shearing stress is generated at the welding spots between the ceramic substrate and the metal parts, and the generated cyclic thermal stress can not be effectively absorbed or released only by the welding spots. After tens or hundreds of thermal cycles, fatigue microcracks can develop inside the welding spot. These microcracks are continuously expanded and connected with the extension of the service time, and eventually the electrical connection of the welding spots is failed or completely broken, so that a thick film double-cap resistor assembly and a double-cap resistor body capable of avoiding the breaking of the welding spots need to be proposed. Disclosure of Invention The invention aims to provide a thick film double-cap resistor assembly and a double-cap resistor body capable of avoiding welding spot breakage so as to solve the problems in the prior art. In order to achieve the aim, the invention provides the technical scheme that the thick film double-cap resistor assembly capable of avoiding the breakage of welding spots comprises a thick film resistor body and a thin film resistor body, wherein the thick film resistor body and the thin film resistor body form a composite body and are arranged at the topmost layer of the whole module; The high heat conduction aluminum nitride ceramic substrate component is arranged at the bottoms of the thick film resistor body and the thin film resistor body, and comprises a ceramic substrate, a thin film resistor area, a thick film resistor area and an isolation groove, wherein the thin film resistor area is firstly manufactured on the ceramic substrate, the thick film resistor area is manufactured through a laser windowing process, the thick film resistor area and the thin film resistor area are electrically isolated through a laser-scored isolation groove, and the required electrical interconnection is realized at a specific point through the thick film resistor body and the metal connecting discs at the two sides of the thin film resistor body; the flexible metal transition layer is positioned between the two ends of the ceramic substrate and the metal caps connected with the side ends of the metal connecting disc, the flexible metal transition layer is a snake-shaped metal foil, one end of the flexible metal transition layer is connected with the end electrode on the ceramic substrate through high-temperature brazing, and the other end of the flexible metal transition layer is welded with an external lead; The micro-channel phase-change heat sink assembly is closely attached to the whole bottom of the ceramic substrate, the micro-channel phase-change heat sink assembly comprises a whole plate, the whole plate is made of independent copper or silicon, tree-shaped fractal micro-channels are formed in the whole plate through etching or processing, phase-change working media are filled in the tree-shaped fractal micro-channels, and the micro-channels are denser and form a capillary pump structure un