JPS6233281Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a chip resistor, and its purpose is that even if the resistor and its supporting substrate are made of inexpensive materials, it will not cause soldering heat during soldering, similar to conventional expensive chip resistors. The goal is to avoid being influenced.

Conventional chip resistors use an expensive metal-grace resistor with excellent heat resistance as the resistor so that it is not affected by the soldering heat during soldering, and the supporting substrate is made of alumina that can withstand high temperatures. Expensive materials such as To explain this in more detail, the structure of a conventional chip resistor is as shown in FIGS. The resistor 3 is bridged between the electrodes 2b and 2d, and a protective film 4 is formed on the resistor 3 to protect it.
A lead electrode 8 is formed of three-layer electrodes 5b to 7b. Moreover, the materials of each of the above-mentioned constituent parts are alumina for the substrate 1 and internal electrodes 2a.
~2d is silver palladium, resistor 3 is metal glaze, protective film 4 is glass, electrode 5a,
Silver palladium, nickel, and solder are used for 5b, 6a, 6b, 7a, and 7b, respectively. To assemble it, first, internal electrodes 2a to 2d are printed on an alumina substrate 1 using a silver-palladium conductive paste using glass frit as a binder, and then fired at a temperature of about 800°C. Next, a metal glaze paste of the resistor material is applied by screen printing and fired at a temperature of about 800° C. to form the resistor 3. Glass is applied thereon and the protective film 4 is fired. Finally, silver palladium is coated on the end face of the substrate 1 and fired to form the electrodes 5a and 5b, and the internal electrodes 2a to 2d and the end face electrodes 5a to 5b are successively nickel plated and solder plated to form lead electrodes.

In such conventional chip resistors, the resistor is simply covered with a glass film, so expensive metal gray is used as the resistor so that it will not be affected by the soldering heat applied during soldering. In order to withstand the high firing temperature during firing of this metal glaze, an expensive material with excellent heat resistance, such as alumina, must be used as the substrate.

Therefore, the present invention is intended to eliminate such conventional drawbacks, and the third embodiment of the invention will be described below.
This will be explained with reference to FIG.

First, the structure of the chip resistor of this embodiment has internal electrodes 11a and 11b on both ends of the upper and lower surfaces of a resistor support substrate 10 having through holes 9 near both ends, which are electrically connected at the upper and lower sides through the through holes 9. A printed resistor 12 is formed on the upper surface of the substrate 10 along with the internal electrode 11.
In order to bridge between a and 11b and protect this printed resistor 12, a protective plate 13 of approximately the same size as the substrate 10 is attached to the resistor arrangement side of the substrate 10 using an adhesive 1.
4 was fixed with adhesive, and lead electrodes 18 having a three-layer electrode structure of 15a to 17a and 15b to 17b were formed at both ends of the laminated structure in which the resistor was sandwiched between the substrate and the protective plate thus obtained. It is something. Next, the materials of each of the above components are the substrate 10 and the protection plate 13.
As glass epoxy, polyester etc. substrate,
Silver palladium material using resin as a binder for internal electrodes 11a, 11b, carbon resin material for resistor 12, 15a, 15b, 16
Silver palladium, nickel, and solder are used for a, 16b, 17a, and 17b, respectively.

Next, the assembly is performed by first printing and firing internal electrodes 11a and 11b using a silver-palladium conductive paste on the substrate 10, and then printing a carbon resin material on the substrate 10 and firing it at about 150°C to form the resistor 12. do. Then, a protective plate 1 is placed on the resistor arrangement surface of the substrate 10.
Finally, silver-palladium paste is applied to the end face of the laminated structure and fired to form 15a and 15b, and nickel and solder are plated thereon to form lead electrodes.

According to the chip resistor structure of this embodiment, the resistor 12 is sandwiched between the substrate 10 and the protection plate 13, which are approximately the same size, so that when the chip resistor is soldered to a printed wiring board, etc. It is difficult for soldering heat to be applied to the resistor 12, so that an inexpensive material such as carbon resin that can be fired at a low temperature can be used as the resistor 12. As a result, the substrate 10, the protection plate 13
Glass epoxy, similar to traditional printed wiring boards,
An inexpensive polyester material can be used. In this way, a chip resistor that is not affected by soldering heat like conventional chip resistors can be provided at low cost.

Further, since the through hole 9 of the substrate 10 is provided and the internal electrodes that are electrically connected through the hole 9 are provided on the upper and lower surfaces of the substrate 10, the internal electrode and the lead electrode can be reliably connected.

As explained above, the chip resistor of the present invention has a structure in which the resistor is sandwiched between a substrate and a protective plate that is approximately the same size as the substrate, so the effect of soldering heat during soldering is small and the resistance of the resistor is The material is a carbon range-based inexpensive material, and the resistor support substrate,
The protective plate can also be made of an inexpensive material such as glass epoxy, and can provide inexpensive chip resistance. In addition, a through hole is provided in the substrate, and the electrode that conducts through the hole is an internal electrode provided not only on the surface where the resistor is placed but also on the back surface of the substrate, and this internal electrode is made of a printed resistor, a substrate, and a protective plate. Since the lead electrodes of the three-layer electrode structure are connected so as to span the end faces and end planes of the laminated structure, it is synergistic that the protective plate is fixed to the substrate with adhesive across the printed resistor. This has the advantage that the connection between the internal electrode and the lead electrode becomes more reliable.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a conventional chip resistor, FIG. 2 is a sectional view taken along the line A-A' in FIG. 1, FIG. 3 is a perspective view of a chip resistor according to an embodiment of the present invention, and FIG. FIG. 3 is a sectional view taken along line BB' in FIG. 3; 9...Through hole, 10...Substrate, 11a, 11b
... Internal electrode, 12 ... Printed resistor, 13 ... Protective plate, 18 ... Lead electrode.

Claims (1)

[Scope of utility model registration request] A board on which a printed resistor is provided, and a laminated structure that is fixed to the resistor arrangement side of this board via an adhesive and has a laminated structure with the printed resistor sandwiched between the board and the board, which is approximately the same size as the above board. internal electrodes made of conductive paint that are arranged on the upper and lower surfaces of the substrate through through holes provided at both ends of the substrate and electrically connected to the printed resistor; An inner layer electrode made of conductive paint, provided continuously on both end surfaces of a laminated structure consisting of a resistor and a protection plate, and on both end planes of the protection plate, and electrically connected to the internal electrode, the internal electrode and the inner layer electrode. A chip resistor equipped with lead electrodes in a three-layer electrode configuration consisting of a nickel plating layer and a solder plating layer formed on top in sequence.