JPS59198701A - Semifixed 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] Technical field The present invention relates to a chip-shaped semi-fixed resistor.

Backpack technology With the trend toward miniaturization of electronic devices, the electronic components used in these electronic devices are also becoming smaller, and semi-fixed resistors 1. There were 511 shots of chips 1).

Fig. 1 is a plane view of a conventional chip-shaped semi-fixed resistor, and Fig. A2 is a sectional view taken from the direction of the arrow pointing to the II-II string in Fig. 1; is -F blood stain 1. In the figure, 2. is made of 96% alumina, etc. Hani4Ii
It is a 10-ramic board with a through hole 2 in its center and an arc-shaped notch 3 at one end (lower end in the figure). 4,5
are both sides of the notch 3 at the one end of the ceramic ivy substrate 1 (111
i Table 44 Ag-Pd consecutively and spaced apart from each other
The first electrode 7 is formed by applying a sealing conductive paste and the implantation @3 is made. 6 is the ceramic substrate 1
Around the through hole 2, it is shaped like a horseshoe with a part missing, and R is formed so that both ends thereof overlap with the first and third electric ladders 7, 4°5.
This is a resistance layer formed by applying and baking a resistance paste such as uQ2. Reference numeral 7 denotes a slider made of nickel silver or the like, which has two concentric arc-shaped slits 8°9, arc-shaped parts 10 and 11 divided by these slits 8 and 9, and each arc-shaped part 1.
A contact 12.1 is formed by bending the central part of 0.11 mm toward the ceramic substrate 1 side and moves ()1 on the resistance layer 6.
3, and a notch @14 into which a jig such as a driver for rotating the slider 7 is inserted. Reference numeral 15 denotes an eyelet metal fitting which is electrically connected to the slider 7 and rotatably supports the slider 7 on the ceramic substrate l.
It integrally has a second electric persimmon, 16 extending to the back surface and end surface of the.

In the above semi-fixed resistor, 8r31. Third electrode4.
5, the total resistance value of the resistance j so 6 is obtained, and the second electrode 16
and the first electrode 4 i+j'! or the third electrode 5, the rotation angle of the slider 7, that is, the contact points 12, 1.3
Any resistance value within the range of the total loss UL value can be obtained depending on the VC.

By the way, the above-mentioned semi-fixed resistor has ml, 3rd,'1i2i1Q4,'1i2i1Q4,5 of the back side ij+i of the ceramic substrate 1.
, 16 are used by soldering them to a conductive layer such as a printed circuit board or a hybrid integrated circuit board. When applying this solder, there is a method of supplying solder to the conductive layer of the board, and a method of applying preliminary solder to the semi-fixed resistor restraints 1. button, 3. 2nd electrical installation J4, 5.16. However, in both methods, soldering requires supplying solder to the planned locations one by one, which is complicated.Therefore, the entire semi-fixed resistor is immersed in molten solder. : It is possible to add preliminary solder to z, but since the solder also adheres to the slider 7, it becomes impossible to change the resistance value by operating the slider 7 after soldering. 1. If the slider 7 is made of stainless steel without any solder, preliminary solder is applied only to each electrode, and no solder adheres to the slider 7, but the slider 7 can be rotated. In this case, there was a problem that the contact resistance between the resistance layer 6 and the contacts "12 and 13" was not stable, and the contact resistance variation characteristic (CRV) was poor.

DISCLOSURE OF THE INVENTION Therefore, the present invention provides a method for pre-preparing each ■℃ rod by the dipping method.
The object of the present invention is to provide a semi-fixed resistor that can be soldered under the same conditions as No. 11 and has a good CRV.

In summary, the present invention is characterized in that the main body of the slider is made of a good 8-electroconductor material such as nickel silver, to which solder easily adheres, and its surface is coated with a conductive film that prevents solder from adhering. be.

In other words, with the above configuration, the surface of the slider body is covered with a conductive film to which solder does not adhere, so that solder will not adhere to the slider even if it is immersed in molten solder. The slider body can be made of a good conductor, and the conductive film on its surface is extremely thin, making it possible to apply pre-soldering to each electrode of a large number of solder constant resistors at once. The contact resistance between the contact and the contact point is stable, and the ORV is excellent.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

Since the structure as a whole may be the same as that shown in FIGS. 1 to 3, FIG. 4 shows an enlarged sectional view of the contact 12 (13), which is the main part of the slider 70, which is a feature.

That is, the slider 70 of the present invention has a main body 71 made of a good conductor such as nickel silver, etc., which has a thickness of 0.1, and is made of, for example, Or, to which solder does not adhere. -0.
It is covered with a paddle electric cavity 72 of about 3 μm.

This conductive film 72 can be easily formed all at once on the multi-throw/f slider main body 71 before assembly by meshing.

This slider 70 is assembled on the ceramic substrate 1 to form a semi-fixed resistor 1. After the vessel is completed, the whole body is immersed in molten solder. No. 34 @, preliminary soldering is applied only to the 2nd electrode 4°5.16, and the conductive film 72 on the surface of the slider 70 is applied.
By the way, Handa's clothes are so hot.

In the past, when this semi-fixed resistor was placed in a predetermined position on a Brit-1It board or a hybrid circuit board, and the whole was heated to a humidity higher than the solder il point, each ηL(il・
4゜5.16, some of the spare solder is reflowed,
A semi-fixed resistor is soldered to the board. After that, when a jig such as a screwdriver is inserted into the notch 14 of the slider 70 and the slider 70 is rotated, the main body 71 is formed of a good conductor such as nickel silver, and is a conductor. Since the a coating film 72 is thin, the contact resistance between the resistance layer 6 and the contacts 12 and 13 is stable compared to when the entire slider is made of stainless steel, etc., and the ORV can be used for stopping. .

In addition, in the embodiment described in -, a slit and an arcuate portion are used.

Ml' for the one that has two contacts each and has high reliability '1-! , but one of each may be removed.

Mag ζ, 2nd wire 4ifi+', 16 is shown together with the eyelet fitting 15, but the 1st wire at one end of the ceramic base &J
It can also be formed by applying a conductive paste between the third electrodes 4 and 5.

1: A simple explanation of ir+i FIG. 1 is a plan view of a chip-shaped semi-fixed resistor.

FIG. 2 is a side view of the semi-fixed resistor shown in FIG. 1 taken along line II-II and viewed from the direction of the arrow.

FIG. 3 is a diagram of the semi-fixed resistor of FIG. 1;

FIG. 4 is an enlarged sectional view of a main part of a slider, which is the main structure and element of this invention.

l... Ceramic substrate, 2...Through hole, 4...1st train (1b:, 5...3rd Electric Toga... 6...Resistance layer, 12, U3... contact, 15... J-Li metal fittings, 16... Second space (>Il+,.

70...Suri 4...child, 71... Main body, 72. Conductive film.

Permit applicant: Shin Nippon Katori Co., Ltd. Part] 1 figure 3rd L.] ko　　　　　　　　　]6 Figure 2 ]

Claims (1)

[Scope of Claims] A first paralytic turtle 3 is formed at one end of a ceramic substrate having a through hole in the center thereof, continuous from front to back and immediately spaced from each other.
a resistor formed around the through hole on the surface of the ceramic substrate by connecting both ends to the first and third electric wires, and a contact that slides above the resistor J. I
ζ, which is equipped with an eyelet metal fitting that is electrically connected to the slider 1jj and the slider and supports the slider so that the slider can rotate freely. In the I' fixed resistor, the main body of the haJ slider is made of a good conductor, and
A semi-fixed resistor characterized in that its surface is corrugated with a conductive film that does not have half 1 or 11 layers attached.