JPS58107605A - Method of producing chip resistor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a chip resistor, and an object of the present invention is to provide a method for manufacturing a glazed chip resistor that is inexpensive, has excellent solderability, and is easy to mass produce. It is.

Conventionally, a glaze type chip resistor has a cross-sectional structure shown in FIG. 1, in which Ag-PCI type baked electrodes 4 are formed on both ends and both sides of a heat-resistant insulating substrate 1 made of alumina or the like.
A glaze resistor 2 made of ruthenium oxide or the like is formed by baking in the center, and a protective coat 3 is applied on the resistor 2.

In addition, the 4 parts of the Aq-Pd-based electrodes are coated with Ni or Cu to prevent "solder erosion" during soldering.
etc. ρ secondary electrode, and Sn or an-pb 3
A plating coat 6 for the next electrode is applied.

1 fence Sho 58-107605 (2) The problem is that the cost of Aq-Pd baked electrodes is high, and although "solder erosion" during soldering has been considerably improved, there are concerns about this depending on the soldering conditions. , and furthermore, there are problems with Aq migration.

The present invention provides a method for manufacturing a chip resistor that eliminates the above-mentioned drawbacks, and includes applying Aq acid to the electrode portions including the ends and each end face of the glaze resistor film provided at required locations on a heat-resistant insulating substrate. After applying and drying the paste containing the component, fine metal particles containing the Aq acid component are precipitated in this area by heat treatment, and electrodes are formed by electroless plating on top of the metal particles to form a chip resistor. .

That is, the glaze type chip resistor formed according to the present invention has a plated electrode of Ni, Cu, etc. (in some cases, an 8° Or 8°-pb.

This eliminates the fear of "solder erosion" during soldering, which is one of the major problems of the conventional method.

In addition, the conventional Aq-Pd electrode suffers from the above 1.
In order to prevent this, secondary electrodes and tertiary electrodes are formed, but in the present invention, the electrodes formed by electroless plating can be used sufficiently for practical use, so a reduction in the number of man-hours is expected. Moreover, the cost of conventional Aq-Pd-based electrodes is high, and the recent rise in the price of precious metals has become an even bigger problem.

In the present invention, base metal Ni by electroless plating,
Since it uses Cu or the like, it can significantly reduce costs. Furthermore, since there is a risk of Aq migration in an Aq-Pd electrode, an improvement is desired, but there is no such concern in the present invention.

Next, the configuration of the present invention will be explained in detail with reference to the drawings.

Fig. 2 is a cross-sectional view showing an example of a chip resistor obtained by the method of the present invention. -Nitric acid mixture 12 is a glaze-based resistance film, and ruthenium oxide-based film is usually used.This glaze resistance film is printed on the required areas using screen printing, and after drying, it is fired before or after aso'c. This process forms a resistive film. Reference numeral 14 denotes a metal fine particle layer containing the A9 component which serves as a catalyst nucleus for electroless plating, and this is made by applying an active paste containing an Aq acid component to the electrode portion including the ends and each end surface of the glaze resistive film, drying it, and then drying it. The metal particles containing the Aq acid component are precipitated on the surface of the electrode section by heat treatment.

The Aq components in this active paste include Aq fine powder with a particle size of 2μ or less or metal Aq and I after baking heat treatment,
CM output AqNO3, AqCO3, AqOl fx
Which Aq compound is used.

Aq easily becomes metal Aq by heat treatment, does not cause surface oxidation, and is a component suitable for the purpose of the present invention because it is inexpensive among noble metals.

The metal components other than A9 are single metals or alloys of other noble metals and base metals. Preferably, 7 base; base metals Ni, Cu, Al, Zn, Sn
, W, Mo, Fe, Co.

Among Cr, Ni is preferable. Aq and base metal powders with a particle size of 2μ or less are preferred.

If it exceeds 2u, the adhesion between the substrate and the film and the electrical properties will deteriorate, as well as the printing properties of the paste will deteriorate.

The composition ratio of the Aq acid component base metal component is A9 component 0.5 to 1
00% by weight, base metal component 99.6-0% by weight,
A more preferable range is 6 to 80% by weight of the Aq component and 96 to 20% by weight of the base metal component. The reason for this is that if the Aq acid component ratio is too low compared to the base metal component ratio, an oxide film is likely to form during heat treatment.

Uniform electroless plating becomes difficult, adhesion to the substrate decreases, and electrical characteristics deteriorate. Furthermore, when the Aq acid component ratio is too high, the adhesion to the substrate tends to decrease. In addition, by adding 0.01 to 6% by weight of Pd component to the above metal component, activation for plating is strengthened, uniformly plated electrodes are easily formed, and adhesive strength and electrical properties are improved; 1971-107605 (3) Moreover, there is no cost advantage, which is not preferable.

For the same reason, addition of 0.2 to 0.6% by weight is more preferable.

The composition range in the paste of metal materials consisting of the above components is 0
．． If the metal component is too small (1 to 30% by weight), it becomes extremely difficult to form a uniform plating, and the adhesive strength with the substrate becomes low. On the other hand, if the amount is too large, adhesive strength tends to decrease, electrical properties tend to deteriorate, and cost benefits decrease, which is not preferable. For the above reasons, a more preferable composition range is 6 to 30%.

The vehicle used for the active paste is a resin such as ethyl cellulose, polyvinylpyrrolidone, or polyvinyl butyral dissolved in a solvent such as alcohol, cellosolve, or terpineol, and the above Aq acid component is mixed with this vehicle to form the active paste.

Ω Although the above active paste provides sufficient adhesive strength, 0.5 to 6% by weight of glass powder or Bi2O3, B2O3°9Bay25b2O3. The adhesive strength can be further improved by adding a low melting point oxide such as Pbo (including those that become oxides after firing). In addition, since B2O3 also has the function of suppressing the oxidation of active metals, glass powder also contains B2O3.
Those containing 2O3 are preferred.

If these components are less than O,S weight ratio, the effect will not be sufficient, and if it exceeds 6% by weight, the adhesive strength will decrease! It has a negative effect on the characteristics.

After the active paste is applied and dried, it is heat-treated to precipitate fine metal particles containing the Aq acid component, and this heat treatment is preferably carried out in the air at a temperature in the range of 250 to 860°C. Below this lower limit, the resin components of the active paste will not be completely burned and will remain mixed in, resulting in the failure of uniform electroless plating deposition and deterioration of connection strength, resulting in the electrode not having sufficient functionality. Become.

Further, at temperatures exceeding this upper limit, metal fine particles cannot be formed in a good state due to dissolution or oxidation of metal components, and therefore a plating film with good electrode function cannot be formed. In the present invention, the metal fine particle layer containing the Aq acid component precipitated by the C1 heat treatment has an average thickness of 1 μm or less, is straight, and has no conduction.

After forming the metal fine particle layer, a metal film layer 15 is formed thereon by electroless plating. Usually, electroless plating of Ni or Cu is used for this electroless plating. Furthermore, in order to improve solderability, an electroplated layer 16 of Sn and 5n-Pb is usually formed on this plating film. Note that, prior to the electroless plating, a plating resist layer 13 is formed to protect the brace resistance film. Furthermore, prior to electroless plating, the metal fine particle layer is subjected to a substitution treatment in a bath solution containing Pd ions, thereby making it more active for plating and forming uniform plating. When performing Ni plating with a metal fine particle layer containing only the Aq acid component, a Pd substitution treatment is required.

A glazed tip resistor is manufactured through each of the above steps.

Hereinafter, the present invention will be explained based on examples.

11 Many identical patterns (3.2 x 1.6
A ruthenium oxide-based glaze resistor paste was printed on the required portions of each pattern of the alumina porcelain substrate formed with fi), dried at 120°C, and then fired at 860°C.
A glaze resistance film was formed.

Next, after dividing this substrate along the horizontal grooves, the end portions of the resistive film and the electrode portions of each end surface were divided by VcO to Aq of 100% by weight.
An active paste was applied using a vehicle containing 0.06 to 40% by weight of a metal component consisting of a base metal component of 100-0% by weight of an acid component, the balance being polyvinylpyrrolidone as a resin component, and terpineol as a solvent. The Aq acid component used was Aq powder and AqNO3 with an average particle size of 1 μm or less, and the base metal component used a whole range powder with an average particle size of 1 μm or less. After drying this substrate at 120°C for 10 minutes,
A heat treatment was performed at a temperature of 100° C. for 30 minutes to precipitate a metal fine particle layer. Next, a plating resist was applied to the portions of the glaze resistive film excluding the electrode portions and hardened.

(4) After immersing in a solution and performing Pd substitution treatment, nickel sulfate,
N1- whose main components are sodium citrate and sodium hypophosphite
Plating was performed for 1Q minutes using a P-based electroless plating solution, and a N1-P plating film of about 4 μm was deposited on the electrode portion to form a plating electrode. In addition, in the - example, boron hydride was used as the reducing agent, and a film of about 4 μm of N1-B plating was formed.

In addition, in the case of electroless Cu plating, copper sulfate, EDTA
Plating was performed for 40 minutes with a plating solution containing , caustic soda, and forcolin to obtain a film with a thickness of about 3μ. Furthermore, 5
When forming the n-Pb layer, a eutectic solder layer of approximately 3 μm was deposited by electroplating. This substrate was divided along vertical grooves to create chip resistors.

As a conventional example, the electrode part is a baked electrode of Aq-Pd paste, and an electrolytic Cu plating of 1 μm is applied thereon.
, eutectic ET plating with a thickness of 3 μm was used.

The adhesive strength was examined and the results are shown in the table below.

The solderability was determined by performing solder dipping at 260° C. for 6 seconds and evaluating the soldered state. In addition, the adhesive strength of electroless plating is determined by using an alumina porcelain substrate and forming a plating electrode with a diameter of φ by the method of the present invention on the surface of the substrate.
The adhesive strength was measured by soldering.

Below is a margin of 17 pages. In the above table, numbers 1 to 7 are examples in which the ratio of the base metal component to the Aq acid component was varied, and those within the scope of the present invention gave good results. Figures 8 to 14 are data when the amount of metal components in the paste was changed, and if the amount of ingredients is less than the range of the present invention, the plating will not be deposited uniformly, and if it exceeds the range of the present invention, the characteristics tend to deteriorate. was seen. 1616 is an example in which the Aq compound is used alone. A1-6~24
All of the examples in which the type of μs metal powder was changed showed good results. Nos. 425 to 31 are examples in which the influence of the heat treatment temperature of the paste was investigated, and defects in plating precipitation were observed even when the temperature was above or below the range of the present invention. 432
Examples 36 to 36 were examples in which glass powder and low melting point oxide were added to the paste, and improvements in adhesive strength were observed within the scope of the present invention. Jit37 is an example in which the surface of the insulating substrate is roughened, and the adhesive strength is slightly improved compared to that without roughening. In the case of Pace 18.38, electroless plating started more slowly than in the case of Pd treatment, and the deposition state tended to be slightly inferior, and the adhesive strength also deteriorated slightly. Samples 39 and 40 are examples in which a 5n-Pb electroplated layer is not formed after Ni plating, and the solderability is slightly inferior to that in the case where a 5n-Pb layer is present. There was no big difference in the solderability between N1-P and Ni-H, but the solderability of N1-B was slightly better. 44
1.42 is an example in the case of electroless Cu plating. 4
43 and 44 are conventional examples using Aq-Pd based baked paste electrodes, which are good when a Cu layer and a 5n-Pb layer are provided, but solder is poor when a Cu layer and a 5n-Pb layer are not provided. Adhesion becomes poor.

As is clear from the above description, according to the method of the present invention, Ni can be easily and precisely deposited at required locations.

Base metal electrodes such as Cu can be formed, and the electrodes have excellent adhesive strength and solderability. Furthermore, the method of the present invention provides Aq
Page 19: No migration occurs.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of a conventional glaze type chip resistor, and FIG. 2 is a sectional view showing an example of a glaze type chip resistor obtained by the present invention. 11...Heat-resistant insulating substrate, 12...Glaze-based resistive film, 13...Plating resist, 1
4...Metal fine particle layer containing Aq acid component, 16...
... Electroless plating film, 16... Electroplating film. Name of agent: Patent attorney Toshio Nakao and 1 other person1,
＼ Kuma Sho 58-107605 (7)

Claims (1)

Scope of Claims: (1) A9 component 0.0.
A paste consisting of a metal component of 6 to 100% by weight, 0.1 to 30% by weight, and the remainder organic vehicle is applied, dried, and then heat-treated in a temperature range of 266 to 850"C to form metal fine particles on the electrode part. A method for manufacturing a chip resistor, which comprises depositing and forming a plated electrode of N1 or Cu on the electrode by electroless plating. (2) The metal component in the paste is 0.5 to 100% of the A9 component.
Weight% and Ni, Cu, Fe, Co, Zn, Mo, AI
! , am. Base metal component containing at least one of W and Cτ 98.6
The method for manufacturing a chip resistor according to claim 0, characterized in that the amount of the chip resistor is 0 to 0% by weight. (3) Aq acid component: Aq powder with a particle size of 2p or less and a silver compound that precipitates as a metal after heat treatment, base 2...
. Claim No. 1, characterized in that the metal component is a metal powder or alloy powder having a powder particle size of 2μ or less.
2) Method for manufacturing the chip resistor described in section 2). (4) A method for manufacturing a chip resistor according to claim (1), characterized in that the surface of the insulating substrate is roughened by physical or chemical treatment. (6) After depositing and forming metal fine particles on the electrode part, this substrate is
A method for manufacturing a chip resistor according to claim 1, characterized in that a substitution treatment is performed with a solution containing d ions, and then an electroless plating treatment is performed. (6) Glass powder and low Melting point oxide 0
．． The method for manufacturing a chip resistor according to claim 1, characterized in that 6 to 5 weight % is contained. (7) MI construction of a chip resistor according to claim 0), characterized in that, before electroless plating, a plating resist is applied and hardened to a portion of the glaze resistor film where a resistance portion is to be formed. Method. (8) A method for manufacturing a chip three-page resistor according to claim (1), characterized in that after electroless plating, a Sn or 5n-Pb plating film is formed on the 'electrode part by electroplating. .