CN112712950A - Power resistor and preparation method thereof - Google Patents
Power resistor and preparation method thereof Download PDFInfo
- Publication number
- CN112712950A CN112712950A CN202011507638.6A CN202011507638A CN112712950A CN 112712950 A CN112712950 A CN 112712950A CN 202011507638 A CN202011507638 A CN 202011507638A CN 112712950 A CN112712950 A CN 112712950A
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- Prior art keywords
- electrode layer
- heat dissipation
- palladium electrode
- layer
- full
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- 238000002360 preparation method Methods 0.000 title abstract description 8
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims abstract description 64
- 238000003466 welding Methods 0.000 claims abstract description 60
- SWELZOZIOHGSPA-UHFFFAOYSA-N palladium silver Chemical compound [Pd].[Ag] SWELZOZIOHGSPA-UHFFFAOYSA-N 0.000 claims abstract description 56
- 230000017525 heat dissipation Effects 0.000 claims abstract description 44
- 238000007747 plating Methods 0.000 claims abstract description 38
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 32
- 239000000919 ceramic Substances 0.000 claims abstract description 21
- 239000000758 substrate Substances 0.000 claims abstract description 21
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 claims abstract description 14
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 15
- 229910052802 copper Inorganic materials 0.000 claims description 15
- 239000010949 copper Substances 0.000 claims description 15
- 230000004907 flux Effects 0.000 claims description 13
- 238000000034 method Methods 0.000 claims description 7
- 238000009713 electroplating Methods 0.000 claims description 4
- 239000007787 solid Substances 0.000 claims description 4
- 229910000679 solder Inorganic materials 0.000 claims description 3
- 238000004519 manufacturing process Methods 0.000 claims description 2
- 239000011800 void material Substances 0.000 abstract description 8
- 238000005476 soldering Methods 0.000 description 19
- 238000010438 heat treatment Methods 0.000 description 6
- 239000011248 coating agent Substances 0.000 description 4
- 238000000576 coating method Methods 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000012774 insulation material Substances 0.000 description 2
- 230000001788 irregular Effects 0.000 description 2
- 239000003960 organic solvent Substances 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000005496 eutectics Effects 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 238000002791 soaking Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01C—RESISTORS
- H01C1/00—Details
- H01C1/14—Terminals or tapping points or electrodes specially adapted for resistors; Arrangements of terminals or tapping points or electrodes on resistors
- H01C1/142—Terminals or tapping points or electrodes specially adapted for resistors; Arrangements of terminals or tapping points or electrodes on resistors the terminals or tapping points being coated on the resistive element
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01C—RESISTORS
- H01C1/00—Details
- H01C1/08—Cooling, heating or ventilating arrangements
- H01C1/084—Cooling, heating or ventilating arrangements using self-cooling, e.g. fins, heat sinks
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01C—RESISTORS
- H01C17/00—Apparatus or processes specially adapted for manufacturing resistors
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01C—RESISTORS
- H01C17/00—Apparatus or processes specially adapted for manufacturing resistors
- H01C17/28—Apparatus or processes specially adapted for manufacturing resistors adapted for applying terminals
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01C—RESISTORS
- H01C7/00—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material
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- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Manufacturing & Machinery (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Details Of Resistors (AREA)
Abstract
The invention relates to a power resistor and a preparation method thereof, wherein the power resistor comprises a resistor body, the resistor body comprises a ceramic substrate, a full-coverage silver palladium electrode layer and a heat dissipation plate, the full-coverage silver palladium electrode layer is arranged on the back surface of the ceramic substrate in a covering mode, the heat dissipation plate is arranged on the full-coverage silver palladium electrode layer, and a nickel plating layer and a tin plating layer are arranged on the full-coverage silver palladium electrode layer. During preparation, a fully-covered silver-palladium electrode layer is arranged on the back surface of the ceramic substrate in the resistor body in a covering manner; welding a heat dissipation plate on the full-coverage silver palladium electrode layer; and plating a nickel layer and a tin layer on the full-coverage silver palladium electrode layer. And the heat dissipation plate and the full-coverage silver palladium electrode layer are welded in a hot plate welding mode, and the temperature of the welding hot plate is 230 ℃. The invention can improve the welding performance of the heat dissipation plate and the full-coverage silver palladium electrode layer, can ensure that the welding voidage is less than 1 percent, and the maximum aperture of the welding void is not more than 0.5mm, greatly reduces the welding voidage, improves the welding efficiency by more than 50 percent, and further improves the heat dissipation efficiency of the power resistor.
Description
Technical Field
The invention relates to the technical field of electronic devices, in particular to a power resistor and a preparation method thereof.
Background
The power resistor is obtained by preparing a silver palladium electrode layer and a resistance layer on a ceramic substrate, covering a dielectric layer on the resistance layer, leading out pins on the silver palladium electrode layer to be used as leading-out ends of the power resistor, preparing a fully-covered silver palladium electrode layer on the back of the ceramic substrate, and welding the fully-covered silver palladium electrode layer of the ceramic substrate with a heat-radiating copper plate (see figure 1).
When the power resistor is used, the power resistor is fixedly installed on the system radiator in a screw or solder welding mode so as to effectively conduct heat generated in the working process of the resistor, the resistance layer generates heat in the working process of the power resistor, the heat is mainly conducted to the system radiator through the heat-radiating copper sheet in a heat conduction mode, the temperature rise of the power resistor is reduced, and the heat generated by the resistance layer and the heat radiation can reach heat balance finally, so that the power of the power resistor is improved.
One of the criteria for measuring the welding quality is the welding void ratio, the welding void is formed by the fact that a large amount of gas generated by heating the organic solvent in the welding process cannot be discharged, and the thermal conductivity of the gas is (0.005-0.5) W.m-1.k-1The thermal insulation material is basically a thermal insulator, the thermal resistance is large, and irregular holes in a welding surface can cause uneven heat transfer of the power resistor, so that the heat transfer efficiency is low, and the thermal insulation material becomes a main reason for failure caused by uneven heating of the power resistor during working. The lower the welding voidage of the ceramic substrate and the heat-dissipating copper plate, the higher the heat-dissipating efficiency of the power resistor.
In the prior art, the welding flux used for welding the large-area ceramic substrate and the heat dissipation copper sheet of the power device is provided with the soldering paste and the soldering lug, although the welding holes can be greatly reduced by using a vacuum welding mode, the welding void ratio is still over 10 percent, and the vacuum welding efficiency is low, mainly because the welding bonding force of the welding interface of the ceramic substrate and the heat dissipation copper sheet is not enough, a large amount of gas generated in the heating process of the soldering paste and the organic solvent in the soldering lug can not be discharged, and the generated gas is sealed on the welding surface to form some irregular voids. Therefore, it is an urgent need to reduce the solder void ratio to improve the heat dissipation performance of the power resistor.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a power resistor, which improves the heat dissipation efficiency.
In order to achieve the purpose, the invention adopts the following technical scheme: the utility model provides a power resistor, includes the resistor body, the resistor body includes ceramic substrate, the whole cover set up in the full coverage silver palladium electrode layer on the ceramic substrate back and set up in the heating panel on the full coverage silver palladium electrode layer, have nickel coating and tin coating in proper order on the full coverage silver palladium electrode layer.
Preferably, the tin-plated layer has a thickness of 5 to 18 μm.
Preferably, the heat dissipation plate is a heat dissipation copper plate made of red copper.
Preferably, the heat dissipation plate is provided with a nickel plating layer.
Preferably, the thickness of the nickel plating layer is 4 to 10 μm.
Preferably, the nickel plating layer and the tin plating layer on the full-coverage silver palladium electrode layer and the nickel plating layer on the heat dissipation plate are prepared by electroplating.
Preferably, the nickel plating layer and the tin plating layer on the full-coverage silver palladium electrode layer and the nickel plating layer on the heat dissipation plate are prepared by chemical nickel plating.
Preferably, the heat dissipation plate is welded on the full-coverage silver palladium electrode layer through a soldering lug, and a solid soldering flux layer is arranged on the soldering lug.
Preferably, the resistor body further comprises a silver palladium electrode layer and a resistance layer which are arranged on the front surface of the ceramic substrate, a dielectric layer covering the resistance layer, and a pin led out from the silver palladium electrode layer.
The invention also provides a preparation method of the power resistor, which comprises the following steps:
a fully-covered silver palladium electrode layer is arranged on the back surface of the ceramic substrate in the resistor body in a covering manner;
welding a heat dissipation plate on the full-coverage silver palladium electrode layer;
and sequentially plating a nickel layer and a tin layer on the full-coverage silver palladium electrode layer.
Preferably, the heat dissipation plate and the full-coverage silver palladium electrode layer are welded by adopting a hot plate welding method, and the welding hot plate temperature is 230 ℃.
Compared with the prior art, the invention has the beneficial effects that:
the invention can improve the welding performance of the heat dissipation plate and the full-coverage silver palladium electrode layer, can ensure that the welding voidage is less than 1 percent, and the maximum aperture of the welding void is not more than 0.5mm, greatly reduces the welding voidage, improves the welding efficiency by more than 50 percent, and further improves the heat dissipation efficiency of the power resistor.
The invention is further described below with reference to the accompanying drawings and specific embodiments.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
Fig. 1 is a schematic diagram of a power resistor in the prior art.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It will be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
It is also to be understood that the terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the specification of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.
It should be further understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.
Fig. 1 is a schematic diagram of a power resistor in the prior art. The power resistor comprises a ceramic substrate, a silver palladium electrode layer and a resistance layer which are arranged on the front surface of the ceramic substrate, a dielectric layer covering the resistance layer, pins led out from the silver palladium electrode layer, a full-coverage silver palladium electrode layer and a heat dissipation plate, wherein the full-coverage silver palladium electrode layer is arranged on the back surface of the ceramic substrate in a covering mode, and the heat dissipation plate is arranged on the full-coverage silver palladium electrode layer.
In the embodiment, the existing functional resistor is improved, and the fully covered silver palladium electrode layer is provided with the tin plating layer.
In this embodiment, in order to improve the heat transfer efficiency of the power resistor, the area of the heat conducting interface should be increased as much as possible, so that the fully-covered silver-palladium electrode layer is prepared on the back surface of the ceramic substrate, the palladium content in the fully-covered silver-palladium electrode layer is 15%, and the thickness of the silver-palladium electrode layer is (15 ± 4) μm. The nickel plating layer and the tin plating layer are sequentially arranged on the full-covering silver palladium electrode layer, the thickness of the nickel plating layer is 4-7 mu m, the weldability of the heat dissipation plate and the full-covering silver palladium electrode layer can be improved, and the welding void ratio is reduced. Specifically, the thickness of the tin-plated layer is 5 to 18 μm.
In this embodiment, the heat dissipation plate may be a heat dissipation copper plate made of red copper. In order to improve the heat dissipation efficiency of the power resistor, red copper with a better thermal conductivity coefficient can be selected as the heat dissipation copper plate of the power resistor in the embodiment.
In this embodiment, the heat dissipation plate is provided with a nickel plating layer. The nickel plating layer can improve the weldability of the heat radiating plate and prevent red copper from being oxidized, and particularly, the thickness of the nickel plating layer is 4-10 mu m (nickel plating on copper).
The nickel plating method of the nickel plating layer in this embodiment is various, for example, the nickel plating layer in this embodiment can be prepared by electroplating. And welding the heat dissipation plate with the electroplated nickel layer with the fully covered silver-palladium electrode layer, and inspecting the welding voidage by using X-rays after welding, wherein the welding voidage is about 5 percent, and the maximum aperture of the welding void exceeds 0.5 mm.
The nickel-plated layer in the embodiment can also be prepared by chemical nickel plating. Welding the heat dissipation plate with the chemical nickel plating layer with the full-coverage silver palladium electrode layer, and detecting the welding voidage by using X-rays after welding, wherein the welding voidage is less than 1%, and the maximum aperture of the welding voidage is not more than 0.5 mm.
In this embodiment, the heat dissipation plate is welded to the full-coverage silver-palladium electrode layer through a soldering lug, and a solid soldering flux layer is arranged on the soldering lug. The prior soldering tin sheet is usually used, soldering flux (with the mark YZ-2) which can be cleaned by alcohol is soaked, a heat dissipation plate and a full-covering silver palladium electrode layer are welded together on a heating plate, the soaking amount of the soldering flux is not easy to control in welding, a large amount of gas generated by heating cannot be completely discharged, soldering flux residue exists, and a cavity is formed in a welding layer. The flux pre-coating soldering lug is used, the conventional no-clean soldering flux is used, the thickness of the soldering flux can be accurately controlled through equipment, solid soldering flux is formed, welding cavities and flux residues are reduced during welding, manual coating of the soldering flux is omitted, and production efficiency is improved.
The preparation method of the power resistor in the above embodiment may be improved based on the existing conventional preparation method, and for example, includes:
a fully-covered silver palladium electrode layer is arranged on the back surface of the ceramic substrate in the resistor body in a covering manner;
welding a heat dissipation plate on the full-coverage silver palladium electrode layer;
and sequentially plating nickel and tin layers on the full-coverage silver palladium electrode layer by adopting an electroplating or chemical mode.
In addition, according to the conventional method, the welding cavity can be greatly reduced by using a vacuum eutectic welding mode and a vacuum reflow welding mode, but the welding cavity rate is still over 10 percent, and the vacuum welding efficiency is low. In the embodiment, the heat dissipation plate and the full-coverage silver-palladium electrode layer are welded by using a hot plate welding mode, the temperature of the welding hot plate is 230 ℃, and the welding efficiency is improved by more than 50% compared with that of the conventional vacuum welding mode.
While the invention has been described with reference to specific embodiments, the invention is not limited thereto, and various equivalent modifications and substitutions can be easily made by those skilled in the art within the technical scope of the invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (10)
1. The power resistor comprises a resistor body, wherein the resistor body comprises a ceramic substrate, a full-coverage silver palladium electrode layer and a heat dissipation plate, the full-coverage silver palladium electrode layer is arranged on the back face of the ceramic substrate in a full-coverage mode, the heat dissipation plate is arranged on the full-coverage silver palladium electrode layer, and the full-coverage silver palladium electrode layer is sequentially provided with a nickel plating layer and a tin plating layer.
2. The power resistor of claim 1 wherein the tin-plated layer has a thickness of 5-18 μm and the nickel-plated layer has a thickness of 4-7 μm.
3. The power resistor according to claim 1 or 2, wherein the heat dissipation plate is a heat dissipation copper plate made of red copper.
4. The power resistor according to claim 3, wherein the heat dissipation plate has a nickel plating layer thereon.
5. The power resistor according to claim 4, wherein the thickness of the nickel plating layer on the heat radiating plate is 4 μm to 10 μm.
6. The power resistor according to claim 4, wherein the nickel plating layer and the tin plating layer on the fully-covered silver palladium electrode layer and the nickel plating layer on the heat dissipation plate are prepared by electroplating.
7. The power resistor according to claim 4, wherein the nickel plating layer and the tin plating layer on the fully covered silver palladium electrode layer and the nickel plating layer on the heat dissipation plate are chemically prepared.
8. The power resistor according to claim 1, wherein the heat dissipation plate is soldered to the all-over silver-palladium electrode layer by a solder pad on which a solid flux layer is disposed.
9. A method for preparing a power resistor according to any one of claims 1 to 8, comprising:
a fully-covered silver palladium electrode layer is arranged on the back surface of the ceramic substrate in the resistor body in a covering manner;
welding a heat dissipation plate on the full-coverage silver palladium electrode layer;
and sequentially plating a nickel layer and a tin layer on the full-coverage silver palladium electrode layer.
10. The method for manufacturing a power resistor according to claim 9, wherein the heat dissipation plate and the fully-covered silver-palladium electrode layer are welded by hot plate welding, and the temperature of the welded hot plate is 230 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011507638.6A CN112712950A (en) | 2020-12-18 | 2020-12-18 | Power resistor and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011507638.6A CN112712950A (en) | 2020-12-18 | 2020-12-18 | Power resistor and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112712950A true CN112712950A (en) | 2021-04-27 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011507638.6A Pending CN112712950A (en) | 2020-12-18 | 2020-12-18 | Power resistor and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112712950A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114023519A (en) * | 2021-09-18 | 2022-02-08 | 盛雷城精密电阻（江西）有限公司 | Ultrahigh frequency radio frequency resistor |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201984910U (en) * | 2010-12-31 | 2011-09-21 | 深圳意杰（Ebg）电子有限公司 | Baseboard directly welded plane type power resistor |
| CN102506515A (en) * | 2011-09-21 | 2012-06-20 | 中国电子科技集团公司第十八研究所 | Small-sized high-reliability thermoelectric refrigerator |
| CN103050205A (en) * | 2012-12-19 | 2013-04-17 | 中国振华集团云科电子有限公司 | Manufacturing method for radio frequency power resistor |
| CN104752544A (en) * | 2015-03-27 | 2015-07-01 | 日芯光伏科技有限公司 | Solar receiver assembly structure |
| CN205582647U (en) * | 2016-04-25 | 2016-09-14 | 深圳意杰（Ebg）电子有限公司 | Noninductive power resistor of thick film |
-
2020
- 2020-12-18 CN CN202011507638.6A patent/CN112712950A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201984910U (en) * | 2010-12-31 | 2011-09-21 | 深圳意杰（Ebg）电子有限公司 | Baseboard directly welded plane type power resistor |
| CN102506515A (en) * | 2011-09-21 | 2012-06-20 | 中国电子科技集团公司第十八研究所 | Small-sized high-reliability thermoelectric refrigerator |
| CN103050205A (en) * | 2012-12-19 | 2013-04-17 | 中国振华集团云科电子有限公司 | Manufacturing method for radio frequency power resistor |
| CN104752544A (en) * | 2015-03-27 | 2015-07-01 | 日芯光伏科技有限公司 | Solar receiver assembly structure |
| CN205582647U (en) * | 2016-04-25 | 2016-09-14 | 深圳意杰（Ebg）电子有限公司 | Noninductive power resistor of thick film |
Non-Patent Citations (2)
| Title |
|---|
| 张青等: "法兰焊接工艺对射频功率电阻性能的影响", 《电子元件与材料》 * |
| 沈月荣: "《电子实训工艺技术教程》", 30 June 2017 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114023519A (en) * | 2021-09-18 | 2022-02-08 | 盛雷城精密电阻（江西）有限公司 | Ultrahigh frequency radio frequency resistor |
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