JPH02224202A - Manufacture of chip-type fixed resistor - Google Patents

Abstract

PURPOSE:To obtain a chip-type fixed resistor having a reduced size and a reduced weight and radiating heat satisfactorily by a simple manufacturing process by a method wherein a film resistor and a glass protective layer are successively formed on the surface of a ceramic substrate and then electrodes are formed. CONSTITUTION:A precise alumina substrate 1 with a thickness of 0.2mm is employed as a ceramic substrate. After through-holes are formed in the substrate 1, resistance paste is applied to the substrate 1 by screen printing and baked to form a film resistor 2. After overcoat glass 3 is applied to the film resistor 2 by screen printing, the glass is baked to form a protective film. Copper conductor paste is applied to the obtained film resistor 2 and the protective film 3. Then the substrate 1 is baked in a nitrogen atmosphere to form electrode conductors 4 and 5. With this constitution, a chip-type fixed resistor having a reduced size and a reduced weight can be manufactured simply and, moreover, a chip-type fixed resistor radiating heat satisfactorily can be attained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a chip-type fixed resistor to be mounted on a circuit board, and more specifically relates to a method for manufacturing a chip-type fixed resistor to be mounted on a circuit board, and more specifically, it relates to a method for manufacturing a chip-type fixed resistor to be mounted on a circuit board. The present invention relates to a method for manufacturing a chip-type fixed resistor that uses a substrate to form a small, lightweight, and simple electrode structure.

[Prior Art] Resistors mounted on circuit boards include thick film chip resistors, thick film resistors, and thin film resistor chips.

Conventionally, the general manufacturing of chip type fixed resistors is 0.4mm x 0.4mm with a break line for chocolate break.
o. On a 5 mm thick alumina substrate, a conductive paste that will become a contact electrode with a resistance element is printed and fired. Furthermore, after printing and firing a resistor paste that will become a resistor, trimming is performed to correct the resistance value. Next, overcoat glass is printed and fired.

The electrode on the thick film substrate obtained by printing and firing in this manner is cut into two parts at the center, a conductive paste is printed on the cut surface, and the electrode is fired.

This is then cut along the plate line to form the shape of a chip resistor.

[Problems to be Solved by the Invention] However, an alumina substrate is usually used as a ceramic substrate for such a chip type fixed resistor, but conventionally, the thickness of this alumina substrate is 0.4 f.
Because of the thickness of f1111 to 0.501111, the thickness of the manufactured chip type fixed resistor is large, which makes it impossible to reduce the mounting space. Since the coating is formed on all the side surfaces, the manufacturing method is complicated and is not preferred as an industrial manufacturing method. Furthermore, since the alumina substrate is thick, there are problems such as insufficient dissipation of heat generated from the film resistor.

Therefore, as a result of various studies regarding the above-mentioned problems, the inventor of the present invention has found that by making the alumina substrate as thin as possible and connecting the electrodes on the top and bottom surfaces through through holes, it is possible to easily use a thin substrate. It was discovered that it is possible to achieve smaller size and lighter weight. The present invention has been made based on this knowledge.

Therefore, an object of the present invention is to provide a method for manufacturing a chip-type fixed resistor that is simple, compact, lightweight, and has good heat dissipation.

[Means for Solving the Problems] The object of the present invention is to provide a method for manufacturing a chip type fixed resistor in which a film resistor and a glass protective layer are sequentially formed on the surface of a ceramic substrate, and then electrodes are formed. Next (b)
This has been achieved by a method for manufacturing a chip-type fixed resistor characterized by comprising the steps of (e).

(a) As a ceramic substrate, 0.05+nmN0.2
(b) forming through holes for electrode connection on the alumina substrate; (c) forming a film resistor and glass on the surface of the alumina substrate having the obtained through holes; a step of sequentially forming a protective layer; (d) a step of printing electrodes on the top surface, bottom surface and through-hole portions of the alumina substrate by screen printing to electrically connect the top surface and the bottom surface; (e) then, Before cutting the alumina substrate obtained in step (d), a step of measuring the resistance value of the resistor formed on the alumina substrate and adjusting the resistance value by laser trimming; I will explain in detail.

The chip fixed resistor mounted on the circuit board used in the present invention can be formed as either a thin film or a thick film, but is preferably formed using thick film technology. As an insulating substrate used for a chip fixed resistor, an ultra-thin ceramic substrate, especially an alumina substrate, is preferable, and its thickness is preferably in the range of 0.05 aunN0.2 mm, and 0.05 m.
If it is less than 0.2 m, the mechanical strength will not be sufficient, and if it exceeds 0.2 m, it will not be possible to achieve a reduction in size and weight.

In the present invention, terminal electrodes are provided on both sides of the substrate, and these are connected in advance through through holes. This connection is printed by screen printing at the same time as printing the top and bottom surfaces of the alumina substrate.

As the resistance paste used in the present invention, RuO2
type, Bi, 03 type, InO2 type, PdO-Ag type, etc., and as the conductive plate, Cu, Pd-8g,
A paste containing a metal or alloy such as Pt-Ag, Au, Pt-Au, Pd-Au, etc. is used, and as a protective film, for example, a glass coat is used, but these materials are not normally used in this technical field. It is something that can be done.

For the application of the resistive paste and conductive paste used in the present invention, and the formation and firing of the protective film, ordinary thick film manufacturing techniques are used, and it is particularly preferable to use a screen printing method as the printing method.

Measurement of the resistance value of the chip resistor used in the present invention, laser trimming, etc. are performed before dividing (dicing) the resistor.

As mentioned above, the chip type fixed resistor manufactured according to the present invention is mainly used mounted on a high-precision and high-performance circuit board, but it can be mounted by wire bonding or soldering. Methods commonly used in circuit mounting techniques such as the above are applied.

[Example] Next, the present invention will be described in more detail with reference to the drawings, but this is one embodiment of the present invention, and the present invention is not limited thereto.

Embodiment FIG. 1 is a front view showing a chip type fixed resistor manufactured by the manufacturing method of the present invention, in which 1 is an alumina substrate,
2 is a film resistor, 3 is a glass protective film, 4 is an electrode conductor on the upper surface, and 5 is an electrode conductor on the lower surface. 6 is an opening formed from a through hole, and 7 is a connecting portion between the electrode on the upper surface and the electrode on the lower surface. Further, FIG. 2 is a sectional view of the chip type fixed resistor of FIG. 1.

Hereinafter, the method for manufacturing a chip type fixed resistor of the present invention will be specifically explained using FIG. 2.

First, as shown in FIG. 2, a dense alumina substrate 1 with a thickness of 0.2 mm is used as a ceramic substrate.
After forming through-holes on this alumina substrate 1, a resistive paste (1700 series, manufactured by DuPont) was printed using a screen printing method, and the film was baked at a firing peak temperature of 850°C for 10 minutes and a total time of 60 minutes. shaped resistor 2
was formed.

Next, overcoat glass 3 was printed as a protective film by a screen printing method, and then fired. Copper conductor paste (6001, manufactured by DuPont) was printed on the obtained film resistor 2 and protective film 3 by screen printing using DuPont's binary method. During printing, by screen-printing the top surface while vacuum suctioning from below the substrate, the conductor paste is sucked and the walls of the through-holes are also printed.This allows the top or bottom surface and side surfaces to be simultaneously printed as individual resistors. printed. The substrate was fired in a nitrogen atmosphere at a firing peak temperature of 600° C. for 5 minutes and a total time of 30 minutes to form electrode conductors 4 and 5.

After measuring the resistance value of the thus obtained chip resistor and correcting the resistance value by laser trimming, the alumina substrate 1 was cut along the scribe line to obtain a chip type fixed resistor.

[Effects of the Invention] The present invention provides a chip-type fixed resistor that can easily produce a smaller and lighter chip-type fixed resistor using the manufacturing method described in the claims, and that also has good heat dissipation. A vessel is obtained.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a chip type fixed resistor manufactured by the manufacturing method of the present invention, and FIG.
FIG. 3 is a cross-sectional view of the chip-type fixed resistor shown in the figure. Explanation of symbols 1...Alumina substrate 2...Membrane resistor 3...Protective film 4.5...Electrode 6...Opening part formed from through hole 7...Connection part

Claims (1)

[Claims] A method for manufacturing a chip-type fixed resistor in which a film resistor and a glass protective layer are sequentially formed on the surface of a ceramic substrate, and then electrodes are formed, comprising the following steps (a) to (e). A method for manufacturing a chip-type fixed resistor, characterized by comprising: (a) As a ceramic substrate, 0.05mm to 0.2m
(b) forming through holes for electrode connection on the alumina substrate; (c) forming a film resistor and glass on the surface of the alumina substrate having the obtained through holes; a step of sequentially forming a protective layer; (d) a step of printing electrodes on the top surface, bottom surface and through-hole portions of the alumina substrate by screen printing to electrically connect the top surface and the bottom surface; (e) then, Before cutting the alumina substrate obtained in step (d), a step of measuring the resistance value of the resistor formed on the alumina substrate and adjusting the resistance value by laser trimming, etc.