TWI662562B - Resistance material, resistor and method of manufacturing the same - Google Patents

Abstract

The invention discloses a resistance material, a resistor and a manufacturing method thereof. The resistance material includes a plurality of resistance particles, each of which includes a core layer and a cladding layer covering the core layer. The material of the core layer includes a metal or an alloy thereof, and the material of the cladding layer includes graphene, graphite, and nanometer. Carbon tubes, nano carbon balls, or a combination thereof. The invention can meet the requirements of hazardous substances stipulated in the RoHS (Hazardous Substances Restriction Directive) in electrical and electronic products, and its resistance temperature coefficient (TCR) is also low.

Description

Resistive material, resistor and manufacturing method thereof

The invention relates to a resistance material, a resistor and a manufacturing method thereof.

According to the agreement, the European Parliament and the EU Ministerial Council have agreed to ban the use of lead, cadmium, mercury, chromium and other four heavy metals in electrical and electronic equipment since July 2006. Therefore, electronic and electrical products sold to the European Union need to comply with the hazardous substance requirements specified in the RoHS directive for hazardous substances in electrical and electronic products.

In addition, the resistance value of a material changes with temperature. The ratio of the change is called the Temperature Coefficient of Resistance (TCR). All resistors have a common characteristic. After a voltage is applied to the resistor for a period of time, its temperature will rise, so that its resistance value will change with increasing temperature (called temperature drift). Among them, the lower the TCR, the smaller the temperature drift, and the better the characteristics of the resistor.

The object of the present invention is to provide a resistance material, a resistor and a manufacturing method thereof. The resistor of the present invention can meet the hazardous substance requirements (four heavy metals such as lead, cadmium, mercury, chromium, etc.) as stipulated in the RoHS directive for motor and electronic products, and its resistance temperature coefficient (TCR) also Lower.

The invention provides a resistive material, which includes a plurality of resistive particles. Each resistive particle includes a core layer and a coating layer covering the core layer. The material of the core layer includes a metal or an alloy thereof, and the material of the coating layer includes graphene. , Graphite, nano carbon tubes, nano carbon spheres, or a combination thereof.

The invention further provides a resistor, which includes a substrate and a resistance element. The impedance element is disposed on the substrate. The impedance element includes a plurality of impedance particles, and each impedance particle includes a core layer and a coating layer covering the core layer. The material of the core layer includes a metal or an alloy thereof, covering The material of the layer includes graphene, graphite, nano carbon tubes, nano carbon spheres, or a combination thereof.

In one embodiment, the metal is silver, copper, manganese, nickel, gold, aluminum, iron, or tin.

In one embodiment, the resistor further includes two conductive terminals. The two conductive terminals are disposed on the substrate and connected to two sides of the impedance element, respectively.

In one embodiment, the substrate has a first surface, two second surfaces, and a third surface, the impedance element is disposed on the first surface, the two second surfaces are respectively connected to the first surface and the third surface, and two conductive terminals They are respectively disposed on the first surface, and extend to the third surface through the two second surfaces.

In one embodiment, the resistor further includes a protective layer covering the resistive element.

The invention further provides a method for manufacturing a resistor, which comprises: mixing a plurality of resistance particles with a solvent to form a mixed material, wherein the resistance particles include a core layer and a coating layer covering the core layer. The material includes a metal or an alloy thereof, and the material of the cladding layer includes graphene, graphite, a carbon nanotube, a carbon nanosphere, or a combination thereof; setting a mixed material on a substrate; and performing a sintering process on the substrate An impedance element is formed on the material.

In one embodiment, the solvent is water, dimethylformamide, tetrahydrofuran, ketones, alcohols, ethyl acetate, or toluene.

In one embodiment, in the step of disposing the mixed material on the substrate, the disposing is performed by coating, sticking, printing or sputtering.

In one embodiment, the sintering temperature of the sintering process is between 800 ° C and 1050 ° C.

In one embodiment, the manufacturing method further includes: setting two conductive terminals on the substrate, and connecting the two conductive terminals to two sides of the impedance element respectively.

In one embodiment, the manufacturing method further includes: providing a protective layer to cover the impedance element.

As mentioned above, in a resistance material, a resistor and a method for manufacturing the same according to the present invention, the resistance material or the resistance element includes a plurality of resistance particles, and each resistance particle includes a core layer and a coating layer covering the core layer, and the core layer The material of the material includes a metal or an alloy thereof, and the material of the coating layer includes graphene, graphite, a carbon nanotube, a carbon nanosphere, or a combination thereof. In this way, the resistor of the present invention can meet the requirements of the RoHS (Hazardous Substances Restriction Directive) in electrical and electronic products. In addition to the requirements of hazardous substances (four heavy metals such as lead-free, cadmium, mercury, and chromium), its temperature coefficient of resistance (TCR) is also low.

1‧‧‧ resistor

11‧‧‧ Substrate

12‧‧‧Impedance element

121‧‧‧ impedance particles

1211‧‧‧Core layer

1212‧‧‧ Coating

13a, 13b‧‧‧Conductive terminal

14‧‧‧ protective layer

M‧‧‧ mixed materials

S‧‧‧ Solvent

S1‧‧‧First surface

S2‧‧‧Second surface

S3‧‧‧ Third surface

S01 ~ S05‧‧‧step

FIG. 1 is a flowchart of a method for manufacturing a resistor according to a preferred embodiment of the present invention.

2A to 2F are schematic diagrams of a manufacturing process of a resistor according to a preferred embodiment of the present invention.

FIG. 3 is another process step diagram of a resistor manufacturing method according to a preferred embodiment of the present invention.

The following will describe the resistive material, the resistor and the manufacturing method thereof according to the preferred embodiments of the present invention with reference to the related drawings, wherein the same components will be described with the same reference symbols.

Please refer to FIG. 1, FIG. 2A to FIG. 2F, wherein FIG. 1 is a flowchart of a method for manufacturing a resistor 1 according to a preferred embodiment of the present invention, and FIGS. 2A to 2F are preferred implementations of the present invention, respectively. A schematic diagram of the manufacturing process of the resistor 1 of the example.

As shown in FIG. 1, the manufacturing method of the resistor 1 may include: mixing a plurality of resistance particles with a solvent to form a mixed material, wherein the resistance particles include a core layer and a coating layer covering the core layer, and the core The material of the layer includes a metal or an alloy thereof, and the material of the cladding layer includes graphene, graphite, a carbon nanotube, a carbon nanosphere, or a combination thereof (step S01); setting the mixed material on a substrate (step S02) And performing a sintering process to form a resistive element on the substrate (step S03). In the following, please refer to FIGS. 2A to 2F to illustrate the manufacturing process of the resistor 1.

First, as shown in FIG. 2A and FIG. 2B, step S01 is first performed: a plurality of impedance particles 121 are mixed with a solvent S to form a mixed material, wherein the impedance particles 121 include a core layer 1211 and a core layer 1211 A cladding layer 1212. The material of the core layer 1211 includes a metal or an alloy thereof, and the material of the cladding layer 1212 includes graphene, graphite, carbon nanotube (CNT), and carbon. Carbon nanoball, or a combination thereof. Here, the resistive material including the plurality of impedance particles 121 can be mixed in the solvent S and stirred uniformly to obtain a paste-like mixed material. The core layer 1211 of the impedance particle 121 is a metal containing no four heavy metals such as lead, cadmium, mercury, and chromium, such as silver, copper, manganese, nickel, gold, aluminum, A metal such as iron or tin, or an alloy of any combination of the above metals is not limited. In addition, if the material of the coating layer 1212 of the resistance particle 121 is graphite, it may be natural graphite or artificial graphite, which is not limited. In the impedance particle 121 of this embodiment, the purpose of covering the core layer 1211 with the cladding layer 1212 is to quickly conduct heat, avoid burning the resistor 1 when the temperature is too high during use, and at the same time solve the problem of temperature drift of the resistance material and make the TCR Lower.

The solvent S may be, for example, water, dimethylformamide (DMF), tetrahydrofuran (THF), ketones, alcohols, ethyl acetate, or toluene. The solvent S in this embodiment is exemplified by water. In various embodiments, when the solvent S is a ketone, it may be N-methylpyrrolidone (NMP), or acetone; when the solvent S is an alcohol, it may be ethanol (Ethanol), or ethylene glycol. (Ethylene glycol). In addition, the solvent S may be any mixture of the solvents (water, dimethylformamide, tetrahydrofuran, ketones, or alcohols), and is not limited.

In the impedance formula, the resistance value = resistance constant (ρ) × length / area. Therefore, the factors that affect the resistance value may include the material itself (the core layer 1211 and the cladding layer 1212 of the resistance particle 121), the particles of the resistance particle 121 The diameter, the cross-sectional area or thickness of the impedance particles 121, and the process temperature, the designer can control the impedance value of the impedance element 12 (mixed material) by appropriately adjusting the composition components through the above factors.

Next, as shown in FIG. 2C, step S02 is performed: setting the mixed material M on a substrate 11. The substrate 11 may be a rigid substrate or a flexible substrate, and the rigid substrate may be a glass, metal, ceramic, or resin substrate, or a composite substrate. The substrate 11 of this embodiment is an example of a rigid substrate of alumina (Al ₂ O ₃ ). The mixed material M can be disposed on the substrate 11 by means of coating, sticking, printing, or sputtering. Here, the coating may be spray coating or spin coating, and the printing may be inkjet printing or screen printing, which is not limited.

Next, a sintering process is performed to form a resistive element 12 on the substrate 11 (step S03). The sintering temperature of the sintering process may be between 800 ° C. and 1050 ° C. to remove the solvent S (for example, moisture) in the mixed material M and make the molecules of the resistance material (the plurality of impedance particles 121) left in the mixed material M. After rearrangement, the impedance element 12 can be formed on the substrate 11 after being cooled (which may be room temperature cooling). In the embodiment of FIG. 2C, the substrate 11 has a first surface S1, two second surfaces S2, and a third surface S3, and the first surface S1 and the third surface S3 are substrates. 11 are opposite surfaces, and the two second surfaces S2 are located on the left and right sides of the substrate 11, and are respectively connected to the first surface S1 and the third surface S3. In some embodiments, the composition and weight percentage of the impedance element 12 may be as follows: copper powder, 80% to 90%; manganese powder, 5% to 15%; nickel powder, 1% to 10%; tin powder, 1% ~ 10%; carbon, 1% ~ 10%.

In addition, please refer to FIG. 3, which is another flowchart of a method for manufacturing the resistor 1 according to a preferred embodiment of the present invention. Different from FIG. 1, in addition to steps S01 to S03, the manufacturing method of FIG. 3 may further include steps S04 and S05. In step S04, two conductive terminals 13a and 13b are disposed on the substrate 11, and the two conductive terminals 13a and 13b are connected to two sides of the impedance element 12, respectively. Here, the conductive terminals 13a, 13b are metals having good conductivity, such as a single-layer or multilayer structure composed of aluminum, copper, silver, molybdenum, or titanium, or an alloy thereof, and are not limited. As shown in FIG. 2D, the conductive terminals 13a and 13b are respectively disposed on the first surface S1 of the substrate 11, and are respectively connected to both sides of the impedance element 12, and extend to the third surface S3 via the two second surfaces S2. The resistor 1 in this embodiment is a surface-mount device (SMD). In different embodiments, the resistor 1 may also be different types of resistors, and the present invention does not limit the actual appearance of the resistors.

Finally, step S05 is performed: a protective layer 14 is provided to cover the impedance element 12. As shown in FIG. 2E and FIG. 2F, the protective layer 14 is disposed and covered on the impedance element 12 to protect the impedance element 12 from being damaged by foreign objects. In some embodiments, the material of the protective layer 14 is, for example, but not limited to, epoxy or acrylic. It is mentioned here that the order of setting the conductive terminals 13a, 13b of step S04 and the protective layer 14 of step S05 is not limited. The conductive terminals 13a, 13b may be provided first, and then the protective layer 14 may be provided, or vice versa.

Therefore, the resistor 1 of this embodiment is a surface mount device (SMD), which includes a substrate 11, an impedance element 12, two conductive terminals 13 a, 13 b and a protective layer 14. The impedance element 12 is disposed on the substrate 11. The impedance element 12 includes a plurality of impedance particles 121, and each impedance particle 121 includes a core layer 1211 and a cladding layer 1212 covering the core layer 1211. The material of the core layer 1211 includes a metal. Or an alloy thereof, and the material of the cladding layer 1212 includes graphene, graphite, a carbon nanotube, a carbon nanosphere, or a combination thereof. In addition, two conductive terminals 13 a and 13 b are disposed on the substrate 11 and are connected to two sides of the impedance element 12 respectively. In addition, a protective layer 14 covers the impedance element 12 In order to protect the impedance element 12 from foreign matter from damaging its characteristics.

Through the above-mentioned resistive material, the resistor 1 made in this embodiment can meet the requirements of hazardous substances (Road), lead-free, cadmium, mercury, chromium and other heavy metals specified in the RoHS ). In addition, the change rate of the resistance temperature coefficient (TCR, unit of ppm / ° C) of the existing SMD resistor is ± 400ppm / ° C. However, in the resistor 1 of an embodiment of the present invention, the change rate of TCR is only ± 200ppm / ° C. Therefore, the temperature drift of the resistor 1 in this embodiment is also low.

In summary, in a resistance material, a resistor, and a manufacturing method thereof of the present invention, the resistance material or resistance element includes a plurality of resistance particles, and each resistance particle includes a core layer and a coating layer covering the core layer, wherein, The material of the core layer includes a metal or an alloy thereof, and the material of the cladding layer includes graphene, graphite, a carbon nanotube, a carbon nanosphere, or a combination thereof. In this way, in addition to meeting the requirements of hazardous substances (free of four heavy metals such as lead, cadmium, mercury, and chromium) as stipulated in the RoHS directive for hazardous substances in electrical and electronic products, the resistor of the present invention has a resistance temperature The coefficient (TCR) is also low.

The above description is exemplary only, and not restrictive. Any equivalent modification or change made without departing from the spirit and scope of the present invention shall be included in the scope of the attached patent application.

Claims (12)

A resistive material includes a plurality of resistive particles, each of which includes a core layer and a coating layer covering the core layer. The material of the core layer includes a metal or an alloy thereof, and the material of the coating layer includes Graphene, graphite, nano carbon tubes, nano carbon balls, or a combination thereof; wherein the material of the core layer does not include metals of lead, cadmium, mercury, and chromium. A resistor includes: a substrate; and a resistance element disposed on the substrate. The resistance element includes a plurality of resistance particles, and each of the resistance particles includes a core layer and a coating layer covering the core layer. The material of the core layer includes a metal or an alloy thereof, and the material of the cladding layer includes graphene, graphite, a carbon nanotube, a carbon nanosphere, or a combination thereof; wherein the material of the core layer does not include lead, cadmium, Metals of mercury and chromium. The resistor according to item 2 of the patent application scope, wherein the metal is silver, copper, manganese, nickel, gold, aluminum, iron, or tin. The resistor according to item 2 of the scope of patent application, further includes: two conductive terminals, which are arranged on the substrate and connected to two sides of the impedance element respectively. The resistor according to item 4 of the scope of patent application, wherein the substrate has a first surface, two second surfaces, and a third surface, the impedance element is disposed on the first surface, and the two second surfaces are respectively connected The first surface and the third surface, and the two conductive terminals are respectively disposed on the first surface, and extend to the third surface through the two second surfaces. The resistor according to item 2 of the patent application scope further comprises: a protective layer covering the impedance element. A method for manufacturing a resistor includes: mixing a plurality of resistance particles with a solvent to form a mixed material, wherein the resistance particles include a core layer and a coating layer covering the core layer, and the material of the core layer It contains metal or its alloy, and the material of the coating layer includes graphene, graphite, nano carbon tube, nano carbon ball, or a combination thereof; the material of the core layer does not include metal of lead, cadmium, mercury, and chromium; Placing the mixed material on a substrate; and performing a sintering process to form an impedance element on the substrate. The manufacturing method according to item 7 of the scope of the patent application, wherein the solvent is water, dimethylformamide, tetrahydrofuran, ketones, alcohols, ethyl acetate, or toluene. The manufacturing method according to item 7 of the scope of patent application, wherein in the step of setting the mixed material on a substrate, it is set by coating, sticking, printing or sputtering. The manufacturing method according to item 7 of the scope of patent application, wherein the sintering temperature of the sintering process is between 800 ° C and 1050 ° C. The manufacturing method according to item 7 of the scope of patent application, further comprising: setting two conductive terminals on the substrate, and connecting the two conductive terminals to two sides of the impedance element respectively. The manufacturing method according to item 7 of the scope of patent application, further comprising: setting a protective layer to cover the impedance element.