KR102021667B1 - Method of fabricating highly conductive low-ohmic chip resistor having electrodes of base metal or base-metal alloy - Google Patents

Abstract

Low resistance chip resistors with high conductivity are fabricated. The chip resistor has an electrode of a base metal or base metal alloy. Base metal or base metal alloy electrodes and resistor layers are made through thick film printing with sintering at low temperatures in air. At this time, thick film doughs made of inexpensive low reduction potential metals (such as aluminum (Al) or nickel (Ni)) are formed through screen printing and sintering. Then, a layer of inexpensive low reduction potential metal is used as a sacrificial layer to be immersed in a metal solution having a high reduction potential. At this time, the wet chemical alternating reaction is processed to obtain a metal electrode having a high reduction potential. Alternatively, the sacrificial layer can be immersed in a mixed solution of several different metals with high reduction potential to process wet chemical alternating reactions to obtain mixed metal alloys with different configurations. As such, the present invention elicits the traditional feature of producing electrodes of base metals or base metal alloys via heat treatment only under high temperature reducing atmospheres. The present invention greatly reduces the manufacturing cost of base metal or base metal alloy electrodes on the market. In addition, the efficiency at the technical level is significantly improved by combining thick film printing.

Description

METHOD OF FABRICATING HIGHLY CONDUCTIVE LOW-OHMIC CHIP RESISTOR HAVING ELECTRODES OF BASE METAL OR BASE-METAL ALLOY}

The present invention relates to manufacturing low resistance chip resistors; More particularly, it relates to the expulsion of the traditional feature of using heat treatment at high temperature reduction for manufacturing base metal or base metal alloy electrodes, wherein the base metal or base metal alloy electrodes and resistor layers significantly reduce the manufacturing cost. It is manufactured through thick film printing with sintering at low temperature in air.

Nowadays, if the thick film printed electrode is an expensive precious metal type (such as silver (Ag) or palladium (Pd)), it can be formed through sintering at high temperature in air. Conversely, if the thick film printed dough is an inexpensive base metal type (such as copper (Cu) or nickel (Ni)), it must be sintered in a reducing atmosphere to prevent oxidation of the base metal at high temperatures.

Furthermore, current production for alloy electrodes or resistors requires high temperatures under an appropriate sintering atmosphere, where all individual metal materials are synthesized into alloy materials as a necessary element for subsequent production processes. However, alloy materials are very expensive because they require high temperatures under a suitable sintering atmosphere.

Unlike precious metal materials (such as Ag and Pd) to make metal electrodes, base metal materials (such as Cu and Ni) can be easily oxidized during heat treatment. Therefore, traditionally, when producing a thick film base metal or base metal alloy electrode, thick film formation through screen printing is used and heat treatment has to be processed at high temperature under a reducing atmosphere for producing the thick film base metal or base metal alloy electrode. Base metal oxidation can be prevented, but will increase manufacturing costs. Therefore, the prior arts cannot meet the needs of all users in practical use.

The main object of the present invention is to produce a base metal or base metal alloy electrode and resistor layer through thick film printing with sintering at low temperature in air.

Another object of the present invention is to obtain a metal electrode having a high reduction potential, wherein a thick-film paste made of an inexpensive metal having a low reduction potential (such as aluminum (Al) or Ni) is screened. Formed through printing and sintering; The layer of inexpensive metal is then used as a sacrificial layer immersed in a metal solution having a high reduction potential to process a wet chemical alternation reaction to obtain a metal electrode having a high reduction potential; Alternatively, the sacrificial layer can be immersed in a mixed solution of several different metals with high reduction potential to process wet chemical alternating reactions to obtain alloys of metals with different configurations.

It is another object of the present invention to withdraw the traditional feature of using heat treatment in a high temperature reducing atmosphere for producing a base metal or base metal alloy electrode, wherein the manufacturing cost of the base metal or base metal alloy electrode is greatly improved in the market and ; Efficiency is also significantly improved at the technical level, combined with thick film printing.

In order to achieve the above objects, the present invention is a method of manufacturing a highly conductive low resistance chip resistor having an electrode of a base metal or base metal alloy, which method comprises: (a) printing the terminal electrodes and the resistor layer; Sintering, (b) plating, (c) processing the heat treatment, (d) printing and sintering the inner coating layer, (e) laser cutting, (f) printing the outer coating layer And sintering, (g) printing the code layer, (h) splitting into strips, (i) printing side terminal electrodes with edges, (j) splitting into cubes, and ( k) electroplating, wherein step (a) comprises (a1) printing two rear terminal electrodes on the rear surface of the substrate, (a2) the entire front surface of the substrate opposite the rear surface Two to cover Printing the battered dough, and (a3) sintering the substrate in a sinter furnace at a high temperature of 200-900 ° C .; The two rear terminal electrodes are Al or tin (Sn) which are not spaced apart and have a low reduction potential; The thick dough comprises a front terminal electrode and a resistor layer; The front terminal electrode and the resistor layer are Al or Sn having the low reduction potential; The front terminal electrode and the resistor layer are thereby integrally obtained without an interface therebetween; With the thick dough comprising the front terminal electrode and the resistor layer, the two rear terminal electrodes are thereby constrained to the substrate; In step (b), processing the wet chemical alternating reaction to obtain a front terminal electrode of Al or Sn and the resistor layer which will have a higher reduction potential value compared to the reducing potential of Al or Sn before the wet chemical alternating reaction. The thick dough is immersed as a sacrificial layer in a base metal solution of Cu, Ni, or CuNi alloy having a high reduction potential; The wet chemical alternating reaction is processed by dip-plating or electroplating; In step (c), the front terminal electrode and the resistor layer are dried in air; Step (d) printing the inner coating layer on the resistor layer (d1), and (d2) sintering the substrate to sinter the inner coating layer and the resistor layer together at a temperature of 150 to 700 ° C. Delivering to; The inner coating layer is the same size as the resistor layer and does not contact the front terminal electrode; In step (e), the substrate is transferred to a laser cutting device for cutting the resistor layer with a laser passing through the inner coating layer; The necessary adjusting groove is cut from the resistor layer by the laser to modify the resistance of the resistor layer; Step (f) includes (f1) printing and forming an outer coating layer on the surface of the inner coating layer, and (f2) putting together a portion of the outer coating layer, the inner coating layer and the front terminal electrode. Transferring the substrate to a sinter furnace for sintering at a temperature of ˜250 ° C .; The outer coating layer has a larger size than the inner coating layer and is in contact with the portion of the front terminal electrode; And the remaining portion of the front terminal electrode is exposed; A protective layer is formed comprising the outer coating layer and the inner coating layer; In step (g), an identification code printed layer is formed on the protective layer to represent the chip register; In step (h), the entire sheet of the substrate is transferred to a rolling device for splitting into strips in a rolling cutting manner; (I) printing (i1) a conductive material on the two side surfaces of the strips of the substrate to obtain two side terminal electrodes at two ends of the outer coating layer, and (i2) Sintering the strips of the substrate in a sinter furnace at a temperature of 150-250 ° C .; The side terminal electrodes cover the front terminal electrode and the rear terminal electrodes; The side terminal electrodes, the front terminal electrode and the rear terminal electrodes are thereby sintered together; The side terminal electrodes are in contact with the front terminal electrode and connected to the resistor layer; The front terminal electrode is thereby connected and conducted separately to the two rear terminal electrodes, respectively, on two sides of the strips of the substrate; In step (j), the strips of the substrate are broken into cubes with the rolling device; The strips of the substrate comprise the cubes inherently connected to break into independent ones; Each of the cubes is independent of the protective layer comprising the front terminal electrode, the resistor layer, the two rear terminal electrodes, the two side terminal electrodes, and the inner coating layer and the outer coating layer. Including; In step (k), each independent of the cubes is electroplated with Ni and Sn in a plating bath to form a plated layer for each of the side terminal electrodes; Ni protects the front terminal electrode; The chip resistor is also soldered onto the printed circuit board (PCB) with Sn. In this way, a new method of manufacturing a highly conductive low resistance chip resistor with electrodes of the base metal or base metal alloy is obtained.

The invention will be better understood from the following detailed description of the preferred embodiment according to the invention, in conjunction with the accompanying drawings.
1 is a flowchart showing a preferred embodiment according to the present invention.
2A and 2B are cross-sectional views showing the structure of the prior art and the present invention.
3 is a diagram showing thick doughs obtained after a wet chemical alternating reaction.
4A and 4B show the microstructures of thick doughs.
5A and 5B are diagrams showing electrical characteristics.

The following description of the preferred embodiment is provided to understand the features and structures of the present invention.

A flowchart showing a preferred embodiment according to the invention; Cross-sectional views showing prior art and structures of the present invention; Figures showing thick doughs and their microstructures obtained after a wet chemical alternating reaction; 1-5B, which are drawings showing electrical properties, as shown in the drawings, the present invention relates to a method of manufacturing a highly conductive low resistance chip resistor having an electrode of a base metal or base metal alloy. to be. Ceramic substrates with alumina oxide are used to produce chip resistors using wet thick dough printing, which includes printing and sintering terminal electrodes and a resistor layer; Plating; Processing the heat treatment; Printing and sintering the inner coating layer; Laser cutting; Printing and sintering the outer coating layer; Printing the code layer; Splitting into strips; Printing side terminal electrodes with edges; Splitting into cubes; And electroplating. Through the above steps, a low resistance chip resistor with high conductivity is manufactured.

1, the present invention comprises the following steps:

(a) printing and sintering the terminal electrodes and the resistor layer (100): first, two spaced apart unconnected rear terminal electrodes 12 of aluminum (Al) or tin (Sn) having a low reduction potential; ) Is printed and formed at appropriate locations on the back surface of the substrate 10. Thereafter, a thick dough 11 of Al or Sn having a low reduction potential is printed over the entire front surface of the substrate 10, which includes the front terminal electrode 11a and the resistor layer 11b. Thus, the front terminal electrode 11a and the resistor layer 11b of the same material having a low reduction potential are integrally formed without an interface therebetween. Subsequently, the substrate 10 is transferred to a sinter furnace for sintering at a high temperature of 200 to 900 ° C. Thus, a thick dough comprising two rear terminal electrodes 12 of Al or Sn having a low reduction potential, and a front terminal electrode 11a of Al or Sn having a low reduction potential and a resistor layer 11b are thereby produced. It is constrained to the substrate 10. At this time, the front terminal electrode 11a having a low reduction potential is a high solid content Al electrode (including a high Al content and a high glass content) or a low solid content porous material. Al electrode.

(b) Plating step 101: Al or Sn thick dough 11 having a low reduction potential obtained after printing and forming is sacrificed to be immersed in a base metal solution having a reduction potential higher than that of Al or Sn. It is used as a layer to obtain the front terminal electrode 11c and the resistor layer 11d, which are base metals or base metal alloys having a reduction potential higher than that of Al or Sn, through a wet chemical alternating reaction. . That is, the thick dough 11 of Al or Sn is immersed as a sacrificial layer in a base metal solution having a high reduction potential when processing wet chemical alternating reactions by immersion plating or electroplating. The front terminal electrode 11c and the resistor layer 11d, which are a base metal or base metal alloy having a higher reduction potential than that of Al or Sn before the alternating reaction, are obtained.

(c) processing the heat treatment (102): the front terminal electrode 11c and the resistor layer 11d of base metal or base metal alloy having a high reduction potential obtained after deposition or electroplating are dried in air. Or more sintered under cold reducing atmosphere.

(d) printing and sintering the inner coating layer (103): the inner coating layer 132 is printed on the resistor layer 11d of the base metal or base metal alloy obtained after further sintering under a drying or reducing atmosphere; Is formed. The inner coating layer 132 has the same size as the resist layer 11d of the base metal or base metal alloy and does not contact the front terminal electrode 11c of the base metal or base metal alloy. Subsequently, the substrate 10 is transferred to a sinter furnace to be sintered at a temperature of 150 to 700 ° C. so that the inner coating layer 132 and the resistor layer 11d of the base metal or base metal alloy are sintered together. At this time, the inner coating layer 132 is mainly an insulator based on glass.

(e) Laser Cutting Step 104: Substrate 10 is transferred to a laser cutting device for cutting the resist layer 11d of the base metal or base metal alloy using a laser penetrating the inner coating layer 132. . Adjusting grooves of the appropriate shape (such as 'I', 'L', '-', etc.) may be used to modify the resistance of the resist layer 11d of the base metal or base metal alloy. It is cut from the resistor layer 11d of the alloy.

(f) Printing and Sintering the Outer Coating Layer (105): The outer coating layer 131 is printed and formed on the surface of the inner coating layer 132. The outer coating layer 131 has a larger size than the inner coating layer 132 and contacts a portion of the front terminal electrode 11c of the base metal or base metal alloy. The remaining portion of the front terminal electrode 11c of the base metal or base metal alloy is exposed. Subsequently, the substrate 10 is transferred to a sinter furnace for sintering at a temperature of 150 to 250 ° C., so that a portion of the outer coating layer 131, the inner coating layer 132 and the front terminal electrode 11c are sintered together. . A protective layer 13 is formed that includes an outer coating layer 131 and an inner coating layer 132. At this time, the outer coating layer 131 is an insulating material mainly composed of epoxy resin.

(g) Printing the Code Layer (106): A layer printed with an identification code, such as a resistor type, resistance value, and the like, is formed on the protective layer 13 to represent the chip register.

(h) Splitting into Strips 107: The entire sheet of substrate 10 is transferred to a rolling device for splitting into strips in a rolling cutting manner.

(i) printing the side terminal electrodes with edges 108: strip of substrate 10 so that the conductive material forms two side terminal electrodes 14 at two ends of the outer coating layer 131. Are printed on two sides of the. The side terminal electrodes 14 may include a front terminal electrode 11c of a base metal or a base metal alloy; And rear terminal electrodes 12. After printing the side terminal electrodes 14 with edges, the strips of the substrate 10 are sintered in a sinter furnace at a temperature of 150-250 ° C. The side terminal electrodes 14, the front terminal electrode 11c of the base metal or base metal alloy, and the rear terminal electrodes 12 are thereby sintered together. The front terminal electrode 11c of the base metal or base metal alloy is thereby connected and conducted separately to the two rear terminal electrodes 12 separately on the two sides of the strips of the substrate 10. The side terminal electrodes 14 are in contact with the front terminal electrode 11c of the base metal or base metal alloy and are also connected to the resistor layer 11d of the base metal or base metal alloy. At this time, the side terminal electrodes 14 are metal electrodes of copper (Cu), nickel (Ni), or a combination thereof.

(j) Splitting into Cubes (109): After sintering the side terminal electrodes 14, the strips of the substrate 10 are split into cubes using a rolling device. The strips of the substrate 10 include cubes that are inherently connected to be split into independent ones; Also independent of each of the cubes is the front terminal electrode 11c of the base metal or base metal alloy, the resistor layer 11d of the base metal or base metal alloy, the two rear terminal electrodes 12 having a low resistance potential, Two side terminal electrodes 14 and a protective layer 13 comprising an inner coating layer 132 and an outer coating layer 131.

(k) Electroplating Step 110: Each of the cubes forms a plated layer 15 for each of the side terminal electrodes 14, which are electroplated with Ni and Sn through the plating process. At this time, the plated layer 15 will include a plated Ni layer and a plated Sn layer; A layer of Ni in the plated layer 15 protects the front terminal electrode 11c of the base metal or base metal alloy; The layer of Sn in the plated layer 15 is soldered onto the printed circuit board (PCB); and the front terminal electrode 11c of the base metal or base metal alloy is, for example, a vehicle, a base station, an LED, or the like. It is used in the application of chip resistors to prevent sulfidation.

In this way, a new method of manufacturing a highly conductive low resistance chip resistor with electrodes of the base metal or base metal alloy is obtained.

The original structure shown in FIG. 2A produced through the original procedure is modified by the present invention. The original structure prints two front terminal electrodes 21 and two rear terminal electrodes 22 above and below the substrate 20, respectively. Thereafter, hot sintering is processed. Thereafter, the resistor layer 23 is printed for sintering again. Thereafter, the protective layer 24, the side terminal electrodes 25 and the plated layer 26 are formed as follows. In its original structure, the front terminal electrodes 21 and the resistor layer 23 can be clearly distinguished, where an interface exists between the front terminal electrodes 21 and the resistor layer 23. The presence of the interface will affect the resistance characteristics of low resistance (<10 ohm) chip resistors for production.

The new structure of the chip resistor manufactured in accordance with the present invention is shown in Figure 2b. The front terminal electrode of Al or Sn having a low reduction potential is integrally formed with a resistor layer of the same material. There is no interface resistance present between the front terminal electrode of Al or Sn with a low reduction potential and the resistor layer. Thus, the present invention greatly assists in the stability of the low resistance (<10 ohm) resistance characteristics for production.

The wet chemical alternating reaction used in the present invention to produce chip resistors is shown in FIG. 1. Manufacturing has three main differences. The first difference is that a thick dough of Al or Sn with low reduction potential is printed to cover the entirety of the front terminal electrode and resistor layer of Al or Sn with low reduction potential. After hot sintering has been processed, the second difference is that the deposition plating alternating reaction is processed by immersing a thick dough of Al or Sn into a base metal solution having a high reduction potential as a sacrificial layer. For example, a thick dough of Al or Sn with a low reduction potential is immersed in a copper sulphate solution or a Ni sulphate solution. Wherein Cu ions reduce Al or Sn having a low reduction potential to obtain a Cu front terminal electrode and a Cu resistor layer; Or Ni ions reduce Al or Sn having a low reduction potential to obtain a Ni front terminal electrode and a Ni resistor layer. Alternatively, a thick dough of Al or Sn having a low reduction potential is immersed in a solution of copper sulfate and Ni sulfate. At this time, Cu and Ni ions simultaneously reduce Al or Sn having a low reduction potential to obtain a front terminal electrode and resistor layer of an alloy of Cu and Ni for a low resistance chip resistor. Fabrication of the low resistance chip resistors includes a Cu front terminal electrode and a Cu resistor layer; Ni front terminal electrode and Ni resistor layer; Or electroplating may be used to form the front terminal electrode and resistor layers of Cu and Ni alloys. A third difference is that after deposition or electroplating, the front terminal electrode and resistor layer, of the base metal or base metal alloy, is dried in synchronous or more sintered under a cold reducing atmosphere. Other manufacturing steps are the same as those used to manufacture traditional chip resistors.

As explained above, in the new production according to the invention the base metal is sintered in air, in which Al (or Sn) thick dough with a low reduction potential is printed and sintered. Then, since the Al thick dough has a lower reduction potential than Cu and Ni, the alternating reaction oxidizes Al to Al ions, as shown in FIG. 3, while simultaneously converting the base metal Cu and Ni ions to the metal Cu and Ni. Can be processed to reduce.

Reduction potential (E ° / V) Al ³⁺ _(aq) + 3e ^- ↔ Al _(s) -1.662 Sn ⁴⁺ _(aq) + 4e ^- ↔ Sn _(s) -0.136 Cu ²⁺ _(aq) + 2e ^- ↔ Cu _(s) +0.342 Ni ²⁺ _(aq) + 2e ^- ↔ Ni _(s) -0.257 Mn ²⁺ _(aq) + 2e ^- ↔ Mn _(s) -1.185

In other words, the present invention provides that a thick film Al or Sn electrode having a low reduction potential is printed and sintered in air and bound to a substrate; The alternating reaction then uses a new fabrication technique, which is used to reduce Al or Sn to Cu or Ni at the base metal electrode, where a thick film Al or Sn electrode with a low reduction potential is used as a sacrificial layer in the alternating reaction. . The sacrificial layer in the alternating reaction is not only a microstructure of the electrode with Al replaced by Cu, shown in FIG. 4A, but also can be used to manufacture the base metal electrode; It can be used to impregnate a solution of different ions to make alloys with different content ratios, such as the CuNi (52/48) alloy shown in FIG. 4B.

CuNi low resistance chip resistors made in accordance with the present invention are compared to conventional thick film printed silver-palladium (AgPd) low resistance chip resistors, as shown in FIGS. 5A and 5B. Basically, CuNi low resistance chip resistors manufactured through wet chemical alternating reactions according to the present invention have properties and reliability quite similar to conventional thick film printed AgPd low resistance chip resistors. The CuNi low resistance chip resistors manufactured according to the present invention also pass a 1000 hour long life test, which shows the same performance as conventional AgPd low resistance chip resistors. However, compared to conventional thick film printed AgPd low resistance chip resistors, the new thick film printed CuNi low resistance chip resistors produced via the wet chemical alternating reaction according to the present invention have better resistance-temperature characteristics.

Table 2 compares materials and processes for manufacturing low resistance chip resistors. Conventional chip resistors predominantly use AgPd alloys, which not only make use of expensive retrogrades, but also have a temperature coefficient of resistance (TCR) that is too high to meet market requirements. TCRs of CuNi or copper-manganese (CuMn) alloys can be improved by screen printing, sintering under reducing atmosphere, thin film sputtering, surface mounting, and punching, but during low resistance chip resistor fabrication, Manufacturing costs are still too high to be competitive in the market. CuNi low resistance chip resistors produced through wet reaction with thick film printing in accordance with the present invention have not only good resistance-temperature characteristics, but also excellent material and manufacturing costs.

alloy AgPd CuNi CuMn material Thick Film AgPd Dough Thick Film CuNi Dough Cu, Ni target Thick Film Al Dough + CuNi Solution CuMn Cube CuMn Strip process Screen printing Screen printing Sputtering Screen printing + wet process (electroplating) Surface mounted Punching rescue Forward contact_register Front contact + register Front contact + register Integrated Integrated Integrated Heat treatment Air sintering Helium sintering Helium sintering N / A (Helium Annealing) N / A N / A Resistor layer thickness <10 μm <10 μm <1-3㎛ 10 μm <
<100 μm 100 μm 1-2mm Resistance range 100mΩ-1Ω 100mΩ-1Ω 100mΩ-50Ω 50mΩ-10Ω 50mΩ-100mΩ 10mΩ-50Ω TCR 400 ppm 100 ppm 100 ppm 100 ppm 100 ppm 100 ppm Material cost Very expensive high price Less expensive cheap Very expensive Very expensive Manufacturing cost cheap high price high price cheap Less expensive high price

The present invention proposes a method for producing electrodes and resistor layers of base metals or base metal alloys with thick film printing at low temperatures in air. At this time, thick film dough made of inexpensive low reduction potential metal (such as Al or Ni) is formed through screen printing and sintering; The layer of inexpensive low reduction potential metal is then used as a sacrificial layer which is subsequently immersed in a metal solution having a high reduction potential to process a wet chemical alternating reaction to obtain a metal electrode having a high reduction potential. Alternatively, the sacrificial layer can be immersed in a mixed solution of several different metals with high reduction potential to process wet chemical alternating reactions to obtain alloys of mixed metals in different configurations. Thus, the present invention elicits the traditional feature that the electrodes of the base metal or base metal alloy are produced only by heat treatment under high temperature reducing atmosphere. The present invention significantly improves the manufacturing cost of base metal or base metal alloy electrodes in the market; Thick film printing is combined to significantly improve efficiency at the technical level.

In summary, the present invention is a method of manufacturing a highly conductive low resistance chip resistor having electrodes of a base metal or base metal alloy, wherein the base metal or base metal alloy electrode is produced in air under low temperature and is also a base metal or base. The manufacturing cost of metal alloy electrodes can be significantly reduced in the market.

The preferred embodiments disclosed herein are not intended to limit the scope of the invention unnecessarily. Therefore, simple changes or modifications belonging to the scope and equivalents of the instructions and claims disclosed herein for patent are all within the scope of the present invention.

Claims (10)

A method of manufacturing a highly conductive low resistance chip resistor having electrodes of a base metal or base metal alloy,
(a) printing and sintering the terminal electrodes and the resistor layer, which steps are:
(a1) printing two rear terminal electrodes on a first surface of the substrate, wherein the two rear terminal electrodes are a first base metal that is not spaced apart and that also has a low reduction potential;
(a2) printing a thick dough to cover the entire second surface of the substrate opposite the first surface of the substrate, wherein the thick dough comprises a front terminal electrode and a resistor layer; The front terminal electrode and the resistor layer are the first base metal having a low reduction potential; The front terminal electrode and the resistor layer are thus also integrally obtained without an interface therebetween; And
(a3) sintering the substrate in a sinter furnace at a high temperature of 200-900 ° C., wherein the two rear terminal electrodes are thus joined together with the thick dough comprising the front terminal electrode and the resistor layer. Is constrained to the substrate;
(b) plating, this step:
The thick dough is higher than the first base metal to obtain a front terminal electrode and a resistor layer of base metal material that have a reduction potential higher than that of the first base metal through a wet chemical alternating reaction. Immersing as a sacrificial layer in a base metal solution having a reduction potential, wherein the wet chemical alternating reaction is processed by a plating method selected from the group consisting of immersion plating and electroplating;
(c) processing the heat treatment, the step being:
Drying the front terminal electrode and the resistor layer in air;
(d) printing and sintering the inner coating layer, which steps:
(d1) printing an inner coating layer on the resistor layer, wherein the inner coating layer is the same size as the resistor layer and does not contact the front terminal electrode; And
(d2) transferring the substrate to a sinter furnace for sintering the inner coating layer and the resistor layer together at a temperature of 150-700 ° C .;
(e) laser cutting, this step:
Transferring the substrate to a laser cutting device for cutting the resistor layer with a laser penetrating the inner coating layer, wherein an adjustment groove is used by the laser to modify the resistance of the resistor layer. Cut from;
(f) printing and sintering the outer coating layer, which steps are:
(f1) printing and forming an outer coating layer on the surface of the inner coating layer, wherein the outer coating layer has a larger size than the inner coating layer and is in contact with a portion of the front terminal electrode; And the remaining portion of the front terminal electrode is exposed; And
(f2) transferring the substrate to a sinter furnace for sintering the outer coating layer, the inner coating layer and the portion of the front terminal electrode together at a temperature of 150 to 250 ° C., wherein the outer coating layer And a protective layer comprising the inner coating layer;
(g) printing the code layer, which steps are:
Obtaining a layer having an identification code printed on the protective layer to represent a chip register;
(h) splitting into strips, this step:
Transferring the entire sheet of the substrate to a rolling device for splitting into strips in a rolling cutting manner;
(i) printing the side terminal electrodes with edges, wherein:
(i1) printing a conductive material on the two side surfaces of the strips of the substrate to obtain two side terminal electrodes at two ends of the outer coating layer, wherein the side terminal electrodes are connected to the front terminal. Cover an electrode and the rear terminal electrodes; And
(i2) sintering the strips of the substrate in a sinter furnace at a temperature of 150-250 ° C., wherein the side terminal electrodes, the front terminal electrode and the rear terminal electrodes are thereby sintered together; The side terminal electrodes are in contact with the front terminal electrode and connected to the resistor layer; The front terminal electrode is thereby also connected to and conductive with the two rear terminal electrodes at the two sides of the strips of the substrate, respectively;
(j) splitting into cubes, this step:
Splitting the strips of the substrate into cubes with the rolling device, wherein the strips of the substrate include the cubes originally connected to break into independent ones; And each of the cubes comprises the front terminal electrode, the resistor layer, the two rear terminal electrodes, the two side terminal electrodes, and the protective layer comprising the inner coating layer and the outer coating layer. ; And
(k) electroplating, comprising:
Electroplating a first metal and a second metal to form a plated layer 15 for each side terminal electrodes 14 of the cubes, wherein the first metal formed through the electroplating is Protect the front terminal electrode; Wherein said second metal is used for soldering said chip resistor onto a printed circuit board (PCB). 2. The high conductivity of claim 1, wherein in step (a), the first base metal is selected from the group consisting of aluminum (Al) and tin (Sn). Is a method of manufacturing a low resistance chip resistor. The method of claim 1, wherein in step (b), the base metal solution comprises a copper sulfate solution, a nickel sulfate solution; And a copper sulphate and nickel sulphate solution. 20. A method of manufacturing a highly conductive low resistance chip resistor having an electrode of a base metal or base metal alloy. The method of claim 1, wherein in step (b), the base metal solution is at least one second base metal solution having a higher reduction potential than the first base metal; The ions of the at least one second base metal may further reduce the first base metal in the wet chemical alternating reaction. How to manufacture. The base metal of claim 4, wherein the at least one second base metal is selected from the group consisting of copper (Cu), nickel (Ni), and both copper (Cu) and nickel (Ni). A method of making a highly conductive low resistance chip resistor having electrodes of a base metal alloy. The method of claim 1, wherein in step (b), the base metal material is selected from the group consisting of copper (Cu), nickel (Ni), and alloys of copper (Cu) and nickel (Ni), A method of making a highly conductive low resistance chip resistor having electrodes of a base metal or base metal alloy. 2. The low conductivity chip resistor of claim 1, wherein in step (c), the heat treatment further comprises sintering under a cold reducing atmosphere. How to prepare. The method of claim 1, wherein in step (k), the first metal is nickel (Ni) and the second metal is tin (Sn). How to manufacture low resistance chip resistors. The electrode of the base metal or base metal alloy according to claim 1, wherein the front terminal electrode is used for the application of a sulfided chip resistor and the application is selected from the group consisting of a vehicle, a base station, an LED, and the like. A method of manufacturing a low resistance chip resistor with a high conductivity. 10. The method of claim 1, wherein the chip resistor has a resistance between 50 milliohms and 10 ohms.

Images