JPH01212401A - Resistor - Google Patents

Abstract

PURPOSE:To unnecessitate the discrimination of the obverse and the reverse of the title resistor by a method wherein the same indications are provided on the two adjacent surface of an insulated element body having almost same width and thickness. CONSTITUTION:A resistor film 2 is formed at least on one surface of an insulated element body 1 having almost the same width and thickness, its surface is coated with an electrically insulated film 3, external electrodes 4 are provided on both ends of said insulated element body 1, and the same indications 5 are provided on the adjacent two surface. As a result, the screening of direction is unnecessitated when a mounting work is conducted, and the obverse-reverse discriminating mechanism in an automatic mounting machine to be used for a printed board is unnecessitated.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a resistor used in an electronic circuit.

Conventional resistors have external electrodes on both ends of a resistor formed on an insulating element, so some resistors, such as chip resistors, do not have lead wires, while others have lead wires. be.

Further, the display of the resistance value etc. is provided only on either the upper or lower surface of the resistor.

Furthermore, in its manufacturing method, □: A strip-shaped insulating element with a large number of low resistances formed therein, with slits formed in advance according to the chip shape, and external electrodes fired, are then broken to form a single resistor. was.

<Problems to be Solved by the Invention> In the conventional resistor described above, the display is provided only on one side of the resistor, so when automatically mounting it on a printed circuit board etc., it is difficult to load the bulk cassette. Therefore, a mechanism for determining the front and back sides is required, which increases the cost.

In addition, the front/back discrimination mechanism tends to cause chip clogging in the mounting machine, reducing mounting reliability.

In addition, the break in manufacturing process i is performed using the slit as a reference, but at this time diagonal cracks and deformation cracks are likely to occur.
The dimensional accuracy is also poor, leading to poor packaging due to snags during bulk supply.

Furthermore, this break forms a resistor,
Since the external electrode is a three-sided electrode, when it is mounted as a chip on a printed circuit board, it is easy to receive the tensile force generated by solder melting during soldering, and the chip stands 1i! There is also the problem that elephants can easily wake up.

In view of the problems of conventional resistors as described above, it is an object of the present invention to provide a resistor that does not require discrimination between front and back and has good mounting performance.

Means for Solving the Problems> This invention has been made to solve the above problems, and consists of forming a resistive film on at least one surface of an absolute element body having approximately the same width and thickness; The present invention provides a resistor in which the resistor is covered with an insulating film, external electrodes are provided at both ends, and the same markings are given on two adjacent surfaces.

<Example> Figures 1 and 2 show examples of the present invention.
is an insulating body made of, for example, porcelain and has a width and thickness that are approximately equal, and a resistor of 1g12 is provided on at least one surface of this insulating body 1.
is formed, its surface is covered with electrical insulation 13, and external electrodes 4 are provided at both ends of the insulating element body 1.

Thereafter, the same display 5 is applied to two adjacent sides.

3 to 10 show an example of the manufacturing process of the resistor of the present invention.

What is shown in FIG. 3 is a first mask 1 made of alumina or the like.
1, on the surface of this mask 11, a plurality of recesses 12 having a rectangular cross section are arranged in an orderly manner laterally.

The insulating element 1 is, for example, a raw sheet of alumina, which is punched into a chip shape using a mold, then fired, and if necessary, a large number of the sheets are placed in a barrel and vibrated to take the corners off. It is.

A large number of such insulating elements 1 are placed in each recess 1 of the mask 11.
2 as shown in Figures 4 and 5.

Next, the resistive film 2 and its lead electrode (not shown) are formed on the surface of the mask 11 by screen printing or thermal transfer.

Then, the mask 11 is fired while being placed in the mask 11. Thereafter, the resistor W12 is trimmed.

FIG. 6 shows a second mask 14 made of alumina or the like similarly to the first mask, and this mask 14 has recesses 15 having a triangular cross section at positions facing each recess 12 of the first mask 11. It is a provision.

When this second mask 14 is placed over the first mask 11 and turned over while being overlapped, each insulating element 1 is tilted at 45 degrees in the recess 15 as shown in FIG. 7 when the mask 14 is turned down. It can be moved with 2. Furthermore, as shown in FIG. 8, the mask is transferred to a third mask 17 having the same triangular recess 16 as the second mask 14.

Next, as shown in FIG. 9, a transfer sheet 1 having an insulating film 3 is
8 is stacked on the resistive film 2 of the insulating element 1 and on the adjacent surface and pressed by a heated pressing member 19 to thermally transfer the insulating lI3.

Furthermore, as shown in FIG.
The transfer sheets 20 placed adjacent to each other at 2 m5 locations are stacked,
The display 5 is thermally transferred onto two adjacent surfaces by pressing with the heated pressing section @21.

Thereafter, the treated insulating element 1 is taken out from the mask 17, and external electrodes 4 are provided by applying a silver base, etc. to both ends thereof and baking, as shown in FIGS. 1 and 2. A resistor is obtained.

Furthermore, if necessary, a lead wire can be connected to the external electrode to form a lead wire type resistor.

Effects> Since the resistor of the present invention has the above configuration, it has the following effects.

The cross section is rectangular and the width and thickness are almost equal, and if necessary, by barreling, the corners are rounded and the shape is rounded, making it easy to handle with automatic mounting machines for printed circuit boards. Reliability of 99,9999% or more can be obtained.

Since the two adjacent sides are marked, there is no need to select the direction when mounting.

Therefore, there is no need to use an automatic mounting machine to determine the front and back sides of printed circuit boards. Therefore, the machine can be simplified and costs can be reduced, and chip clogging is less likely to occur, resulting in high reliability.

Furthermore, since external electrodes are formed on each unit, directional electrodes can be formed, and when soldering to a printed circuit board as a chip, the tensile force due to melting of the solder is dispersed, making it difficult for chips to stand up.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the resistor of the present invention, and FIG.
The figure is an enlarged cross-sectional front view of the same as above, Figures 3 to 10 show the @# manufacturing process of the same as above, Figure 3 is a partially cutaway perspective view of the first mask, and Figure 4 is a cross-sectional view of the first mask. FIG. 5 is an enlarged sectional view of a portion of the same as above, FIG. 6 is a partially cutaway perspective view of the second mask, and FIG. 7 is a partial cutaway perspective view of the second mask. 8 is an enlarged sectional view of a portion showing the transfer from the second mask to the third mask, and FIGS. 9 and 10 are the transfer state, respectively. FIG. 1... Insulating element 2... Resistive film 3...
Insulating film 4...External electrode 5...Display Applicant's agent Patent attorney Kazu 1) Showa 1

Claims (1)

[Claims] A resistor characterized in that a resistive film is formed on at least one surface of an insulating element body having approximately the same width and thickness, the surface is covered with an insulating film, external electrodes are provided at both ends, and the same marking is applied to two adjacent surfaces. vessel.