JPH0645118A - Manufacture of rectangular thin film chip resistor - Google Patents

Abstract

PURPOSE:To obtain a rectangular thin film chip resistor, with a substrate having excellent insulating property, at low cost by a method wherein upper face and rear electrodes are formed on the substrate, which was split-formed in advance, using a printing machine and belt-type continuous calculating oven. CONSTITUTION:First, a dividing groove 2 is formed on both front and back sides of a substrate 1. Electrode paste is screen-printed on the substrate, dried up, calcined in a belt-type calcinating oven, and a thin upper-face electrode layer 3 and a thin film rear electrode layer 4 are formed. Then, a thin film resistor 5 is formed on the substrate 1 by sputtering, a resistance pattern 6 is formed by etching, and a heat treatment is conducted. Subsequently, resistance value is corrected, resin paste screen-printing is performed, it is heat-cured, and a protective coating 7 is formed. Besides, the substrate 1 is divided into rectangular substrates 1a, and after a thin film edge-face electrode layer 8 has been formed, a plated layer 9 is formed. As a result, manufacturing process can be simplified, and a low-priced rectangular thin film chip resistor high in insulation can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to a method of manufacturing a rectangular thin film chip resistor used in electronic circuits.

[0002]

2. Description of the Related Art In recent years, with the miniaturization of electronic equipment, there is an increasing demand for miniaturization in order to increase the mounting density of electronic components used in circuit boards. With the progress toward miniaturization of rectangular chip resistors, there is an increasing demand for thin film chip resistors in order to satisfy the characteristics of higher accuracy and lower noise.

An example of a conventional method for manufacturing a rectangular thin film chip resistor is shown in FIG. First, in the conventional manufacturing process, a process A for receiving a heat-resistant insulating substrate (without dividing grooves) 21 made of a high-purity alumina substrate or the like is started, and then a thin film resistor such as Ni-Cr is formed on the insulating substrate 21. Through the sputtering process B for forming the
2 is performed, and then an etching step E for shaping the thin film electrode into an electrode pattern 23 is performed through a sputtering step D for forming a thin film electrode of Ni or the like on the resistance pattern 22. 350 ~ 400 ℃ in nitrogen etc. to make the electrode pattern a stable film.
The heat treatment step F at the temperature is performed. After that, a resistance value correction step G is performed by laser trimming or the like in order to correct the resistance value of the resistance pattern to a predetermined value. Next, in order to protect the resistance pattern 24 whose resistance value has been corrected, a protective coat 25 forming step H of a thermosetting resin is performed. Next, as a preparatory step for dividing the insulating substrate 21 and forming the end face electrode layer 27, a scribing step I of forming a groove 26 for dividing the insulating substrate 21 and the insulating substrate 21 into a strip substrate 21a. A primary substrate dividing step J for dividing is performed, and the end face electrode layer 2 is formed on the end face of the strip-shaped substrate 21a by sputtering or the like.
An end face electrode forming step K for forming 7 is performed. Then, as a preparatory step for plating the exposed electrode surface, a secondary board dividing step L for dividing the strip-shaped board 21a into individual board 21b is performed, and finally reliability for soldering is ensured. Therefore, the electrode plating step M for forming the electrode plating 28 was performed to form the rectangular thin film chip resistor.

[0004]

However, the conventional thin film chip resistor has the following problems. (1) Since the resistor and the upper surface electrode are formed by sputtering, continuous processing is difficult, and many sputtering devices are required for mass production, resulting in high cost. (2) Since a groove for division is formed by laser scribing after forming a pattern on an insulating substrate without a division groove, not only does it impair aesthetics, but microcracks on the substrate easily occur due to thermal shock of the laser, There is a problem that it may cause insulation deterioration.

In order to solve the above-mentioned problems, it is an object of the present invention to provide a prismatic thin film chip resistor which is inexpensive and has an excellent substrate insulating property.

[0006]

In order to achieve the above object, a method of manufacturing a rectangular thin film chip resistor according to the present invention is an insulation having vertical and horizontal dividing grooves provided on the front and back surfaces so as to face each other. A step of forming a pair of thin film upper surface electrode layers and a pair of thin film back surface electrode layers by printing an electrode material composed of a metal organic material on both main surfaces of the substrate and baking the same, and a thin film resistance so as to overlap the pair of upper surface electrode layers. A step of forming a body, a step of correcting the resistance value of the thin film resistor, a step of forming a protective film so as to completely cover the thin film resistor, and a substrate as a preparation step for forming an end face electrode layer. A step of primary division, a step of forming a pair of thin film end surface electrode layers so as to electrically connect the pair of upper surface electrode layers and a pair of back surface electrode layers, and a substrate as a preparation step for electrode plating. And the process of dividing into pieces It is characterized in that a step of the electrode plating on the exposed electrode portions.

[0007]

According to the present invention, the top and back electrodes can be continuously formed by a printer and a belt type continuous firing furnace without using a sputtering device, and the manufacturing process can be simplified, so that the manufacturing cost is reduced and the cost is low. A square thin film chip resistor can be provided.

Further, since an insulating substrate which has been divided and formed in advance is used, it is not necessary to form a groove for dividing by laser scribing as in the conventional case, and thus the insulating property of the substrate is improved.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A method of manufacturing a rectangular thin film chip resistor according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a process diagram showing a method of manufacturing a rectangular thin film chip resistor according to an embodiment of the present invention, and FIG. 2 is a sectional view of a product manufactured by the process of FIG.

First, step A for receiving the 96 alumina substrate 1 having excellent heat resistance and insulation is performed. The front and back surfaces of the 96 alumina substrate 1 are divided into strips and individual pieces, and in order to divide into strips and pieces, the division grooves 2 for dividing in the vertical direction and the horizontal direction (a mold for green sheets are used). Molding) is formed.

Next, A is formed on the surface of the 96 alumina substrate 1.
An electrode paste composed of a metal organic material containing u as a main component is screen-printed and dried, and only the organic component of the metal organic electrode paste is blown onto the back surface of the 96 alumina substrate 1, and only the metal component is baked on the alumina substrate 1. In order to achieve this, a belt type continuous firing furnace is used at a temperature of 850 ° C.
A process B is performed in which the thin film upper surface electrode layer 3 and the thin film back surface electrode layer 4 are simultaneously formed by baking according to a profile with a peak time of 6 minutes and an IN-OUT time of 45 minutes.

Next, Ni--C is formed on the 96 alumina substrate 1.
After the sputtering step C for forming the thin film resistor 5 of r, an etching step D for shaping the thin film resistor 5 into the resistance pattern 6 is performed to make the resistance pattern a stable film.
A heat treatment step E at a temperature of 350 to 400 ° C. is performed in nitrogen.

Then, a resistance value correcting step F is performed by laser trimming in order to correct the resistance value of the resistance pattern 6 to a predetermined value.

Next, in order to protect the resistance pattern whose resistance value has been corrected, a step G of screen-printing a resin pace and thermosetting to form the protective coat 7 is performed.

Next, as a preparatory step for dividing the 96 alumina substrate 1 and forming the thin film end face electrode layer 8, a primary substrate dividing step H for dividing the 96 alumina substrate 1 into strip substrates 1a is performed. An end face electrode forming step I of forming a thin film end face electrode layer 8 of Ni on the end face of the substrate 1a by sputtering is performed.

Then, as a preparatory step for plating the exposed electrode surface, the strip-shaped substrate 1a is separated into individual substrate 1
The secondary substrate dividing step J for dividing into b is performed, and the electrode exposed at the time of soldering the thin film upper surface electrode layer 3, the thin film back surface electrode layer 4, and the thin film end surface electrode layer 8 which are exposed at the end are prevented and at the time of soldering. To ensure the reliability of the
An electrode plating step K for forming the plating layer 9 of i, Sn-Pb is performed.

Through the above steps, a rectangular thin film chip resistor according to an embodiment of the present invention was manufactured as a prototype. Comparison of the resistance variation, resistance temperature characteristic, and current noise characteristic between the rectangular thin film chip resistor of the present invention and the conventional rectangular thin film chip resistor revealed that they were equivalent.

In this embodiment, the firing temperature of the metal organic electrode paste was set to 850 ° C., but this does not limit the firing temperature.

Further, although the metal organic electrode paste is the electrode paste containing Au as a main component, it may be Ni-based or other noble metal-based, and any metal organic electrode paste may be used.

Although the dividing grooves are provided on both sides as the insulating substrate, they may be provided only on one of them.

[0022]

As described above, according to the present invention, a thin film electrode layer can be continuously formed by a printing machine and a belt type continuous firing furnace without using a sputtering device, and the manufacturing process can be simplified. Not only can provide an inexpensive rectangular thin film chip resistor, but also because it uses an insulating substrate that has been pre-divided with dividing grooves, there is no need to form grooves for dividing by laser scribing as in the past. The insulating property of the substrate is improved.

[Brief description of drawings]

FIG. 1 is a process diagram showing a method of manufacturing a prismatic thin film chip resistor according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the manufacture of a prismatic thin film chip resistor according to an embodiment of the present invention.

FIG. 3 is a process diagram showing a method of manufacturing a conventional rectangular thin film chip resistor.

[Explanation of symbols]

 1 96 Alumina substrate 2 Dividing groove 3 Thin film upper surface electrode layer 4 Thin film back surface electrode layer 5 Thin film resistor 7 Protective coat 8 Thin film end surface electrode layer 9 Plating layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Seiji Tsuda 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (1)

[Claims] 1. An electrode material made of a metal organic material is printed on both main surfaces of an insulating substrate having vertical and horizontal dividing grooves provided on at least one of the front and back surfaces so as to be opposed to each other and baked to form a pair. A step of forming a thin film top surface electrode layer and a pair of thin film back surface electrode layers, a step of forming a thin film resistor so as to overlap the pair of thin film top surface electrode layers, and a step of correcting the resistance value of the thin film resistor, A step of forming a protective film so as to completely cover the thin film resistor, a step of primary dividing the substrate as a preparatory step for forming a thin film end face electrode layer, a pair of the thin film top surface electrode layers and a pair of thin film back surfaces A step of forming a pair of thin film end surface electrode layers so as to electrically connect the electrode layers, a step of dividing the substrate into individual pieces as a preparation step for electrode plating, and an electrode plating on the exposed electrode portion And the process of Method for manufacturing a prismatic thin-film chip resistor, characterized in that.