JPS5939001A - 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 (al) Technical Field of the Invention The present invention relates to a chip resistor, and in particular to a chip resistor that can be easily connected to printed wiring on a printed circuit board by soldering and that can be manufactured at low cost. Concerning the structure of the vessel.

(1)) Background of the technology In response to the trend of electronic devices becoming smaller and smaller, electronic components suitable for high-density mounting and automatic insertion into printed circuit boards are being developed and put into practical use. On the other hand, some of the conventional discrete resistors are being replaced by dip resistors.

(C1 Prior Art and Problems The general structure of a conventional chip resistor is shown in the perspective view of Fig. 1. Terminals 2 and resistor 3 are formed on the surface of a ceramic substrate l by a thick film printing method. .

For the sake of the following explanation, the manufacturing method will be briefly described with reference to the plan view of FIG. Thickness 0.63~0.30m
A pattern of terminals 2 for a certain number of chip resistors is screen printed on the surface of a ceramic motherboard 4 having a diameter of about m with conductive ink such as silver-palladium, and then ruthenium oxide is applied in the same manner. After printing the pattern of the resistor 3 with the ink of the main resistor material, it is heated and fired in a firing furnace. Thereafter, the ceramic motherboard 4 is cut using the slits 5 previously formed on the surface thereof to separate the individual chip resistors.

As a natural result of the manufacturing process of the chip resistor described above, it is possible to place the chip resistor on the ceramic substrate l and connect it to the wiring from the printed circuit board 1 by soldering. It's extremely difficult because it gets in the way.

In some rare models, the chip resistor is mounted by sinking so that the printed circuit board wiring and the terminal 2 of the chip resistor are on the same plane, but this increases the cost.

Therefore, as a countermeasure on the chip resistor side, as shown in the perspective view of FIG. 3, a conductive film 2a is formed on the side surface la of the ceramic substrate 1 that is in contact with the terminals 2 so as to extend the terminals 2. things are being done.

However, when forming the conductive film 2a, individual chip resistors 1 are handled, so the number of chip resistors 1 is large, and the efficiency of the process is inevitably low. In addition, when forming the conductive film 2a, the ink of the conductive material is applied manually with a brush to the side surface 1a of the ceramic substrate 1, or the side surface 1a of a certain number of chip resistors l being processed is coated in one plane. A hatching method has been adopted in which the conductive material is stacked and pressed against a sponge or the like impregnated with conductive material ink, but the work efficiency cannot be said to be high.

In particular, as conceptually shown in the plan view of FIG.

A so-called resistor array consisting of a plurality of resistors, their terminals, and some necessary wiring has many terminals as shown in FIG.
Manually forming a plurality of conductive films 28 requires a large number of man-hours. In particular, when using the hatch processing method described above, it is necessary to apply patterns corresponding to the plurality of terminals in order to impregnate the sponge with the conductive material ink, and it becomes necessary to apply a pattern corresponding to the plurality of terminals, which makes the chip resistor as a single chip resistor. This requires a more complicated process than in the case of conventional methods.

fdl OBJECTS OF THE INVENTION The present invention has been made in view of the above-mentioned points, and improves the structure of a ceramic substrate l of a one-chip resistor.

When forming the terminals 2 on the surface of the ceramic substrate 1 by screen printing, the conductive film 2a is simultaneously applied to the side surface 1a.
It is intended to form a

(e) Structure of the Invention The object of the above invention is to provide a chip resistor comprising a resistor and a terminal formed by screen printing on the surface of a ceramic substrate, the edge of the ceramic substrate in contact with the terminal. This can be easily achieved by using a chip resistor characterized in that the chip resistor has a recess corresponding to each of the terminals, and the recess is covered with a conductive film connected to the terminal.

(fl Embodiments of the Invention) Embodiments of the invention will now be described with reference to the drawings. The perspective view of FIG. 5 shows an embodiment of the structural improvement of a chip resistor based on the invention.

Reference numeral 6 denotes a recess provided in the side surface 1a in contact with the terminal 2, and is semicircular in this example. A new improvement is that the above-mentioned conductive film 2a is formed on the measured surface 1b of the ceramic substrate 1 in the recess 6. The forming force method is as follows.

As shown in the plan view of FIG. 6, the ceramic motherboard 7 includes:
A certain number of patterns are printed on the 14 elements 2 and the resistor 3 by screen printing using respective inks. At this time, the aforementioned recess 6 forms a hole 8 in line with the recess 6 of the ceramic substrate I of the adjacent chip resistor. This hole group 8 is formed in advance when the ceramic motherboard 7 is formed.

In the process of printing the pattern of the terminal 2, the conductive material ink is fluid and drips onto the inner surface of the hole 8 to form a film, so no special process is required. Furthermore, during the screen printing process described above, as conceptually shown in the cross-sectional view of FIG. 7, the back surface of the ceramic motherboard 7 is lightly evacuated with an air pump using the exhaust jig 9 to reduce the pressure.

It becomes easier to attract the conductive material ink to the inner surface of the holes 8.

The subsequent firing process for the conductive film and the resistive film is the same as the conventional method.

The slit 5 may be formed in advance on the surface of the ceramic motherboard 7 as in the prior art, or may be formed later with a laser beam, but as shown in Figure 2, the slit 5 crosses the hole 8. Even if the chip resistor 7 is cut and separated into individual chip resistors 1 using the slit 5, the inner surface 1b of the recess 6 is still covered with a conductive film.

Through the above steps, a chip resistor having a structure based on the present invention is completed.

In the explanation so far, the recess 6 is semicircular.

Therefore, although it has been assumed that the hole 8 is circular, there are various variations as shown in the plan view of FIG. It is obvious that the shape of the recess 6 may be rectangular as shown in Fig. a1, triangular as shown in Fig. fb1, or any other shape. It is sufficient that the holes 8 formed do not obstruct the inflow of the conductive material ink (for example, thin slit-like holes).1 Also, if the dimensions of the hole group 8 arranged in the ceramic motherboard 7 are too large, It is sufficient as long as the strength of the ceramic motherboard 7 is not so low that it is inconvenient to handle.

Furthermore, the recess 6 is located on the side surface 1a of the board 1 connected to the terminal 2, but even if the recess 6 is located at the center of one side of the board 1 to be connected, it may be located on one side as shown in Fig. fC1 of Fig. 8. It doesn't matter if you are biased.

Especially as shown in the plan view of FIG.

In a resistor array having multiple resistors.

Although it has many terminals, the structure of the present invention can be easily applied as shown in FIG. 9, and the number of manufacturing steps can be greatly reduced.

(gl) Effects of the Invention As is clear from the above explanation, in the chip resistor having the structure based on the present invention, it is possible to
This has the effect of forming a terminal structure that can be easily connected to the wiring on the printed board by soldering.

This effect is particularly remarkable in a resistor array having a plurality of resistors.

[Brief explanation of drawings]

Figure 1 is a perspective view showing the structure of a conventional depth resistor;
The figure is a plan view showing a pattern-printed ceramic motherboard, Figure 3 is a perspective view showing the structure of a conventional chip resistor in which a conductive film is formed on the side surface of the ceramic substrate on the terminal side, and Figure 4 is a conventional chip resistor. FIG. 5 is a plan view conceptually showing a resistor array, and FIG. 5 is a perspective view showing the structure of an improved chip resistor based on the present invention. Fig. 6 is a plan view showing a ceramic motherboard printed with a round pattern for manufacturing a chip resistor having a structure based on the present invention, and Fig. 7 is a 2 to 30 example of variations in the structure of a resistor on a ceramic motherboard. FIG. 9 is a conceptual plan view showing a resistor array using the structure based on the present invention. In the figure, ■ is a ceramic substrate, and 2 is a terminal. 3 is a resistor, 4 and 7 are ceramic motherboards, 5 is a slit, 6 is a recess, and 8 is a hole. Figure 1 Figure 5 Figure 4 Cabinet 7th Flash

Claims (1)

[Claims] A chip resistor comprising a resistor and a terminal formed by screen printing on the surface of a ceramic substrate, wherein a recess is formed in a peripheral portion of the ceramic substrate in contact with the terminal, corresponding to each of the terminals. and the recess is covered with a conductive film connected to the terminal.