JPH06204100A - Mask jig for forming external electrode of chip-shape circuit component - Google Patents

Abstract

PURPOSE:To form an external electrode on both ends of a chip-shape element with high precision and efficiency by sputtering. CONSTITUTION:A chip-shape element 4 has its middle part 41, both sides of which are held with middle part support grooves 12 and 32 of mask plates 1 and 3, and which is covered by their grooves. Both sides of the middle part 41 of the element 4 held by the middle part support grooves 12 and 32, namely, their ends 42 and 42 are exposed on the sides of through holes 11 and 31 of the mask plates 1 and 3. Further, as this element 4 is in the condition inserted in an element holding hole 21 of an element holding sheet 2, its movement is completely restricted. An assembled mask jig is mounted on a sputtering device, and by way of through holes 11, 11, 31, and 31, a metal is deposited on the ends 42 and 42 of the element 4 from both sides.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming external electrodes on both ends of a prismatic or cylindrical element body in manufacturing circuit parts such as capacitors, inductors, resistors or thermistors.

[0002]

2. Description of the Related Art Conventionally, for an external electrode such as a ceramic thermistor, a conductive paste containing Ag or the like as a conductor is applied to both ends of a porcelain body and baked, and then nickel or tin is sequentially plated. It was formed by. However, since the thickness of the external electrode formed by a so-called thick film method such as coating and baking of the conductive paste is as thick as about 20 to 30 μ, the chip-shaped circuit component is miniaturized year by year, and the width and the thickness are increased. When an extremely small chip-shaped circuit component having a length of 0.5 mm and a length of 1 mm is manufactured, there is a problem that it is difficult to reduce the size of the external electrode in terms of film thickness.

Further, in the electrode forming method having a plating step, in the case where the element body itself has conductivity such as a ceramic thermistor, the metal to be plated is deposited also in the intermediate portion of the element body. However, a so-called plating spread, which is an inconvenient phenomenon in terms of characteristics, occurs. Further, since the porcelain body contains components such as copper and iron which are weak in the plating solution, there is a problem that the porcelain body is easily corroded by the plating solution.

Therefore, as means for forming a thin external electrode, a means for forming an external electrode by forming a conductor film on the surface of an element body by sputtering has come to the attention. With this sputtering method, it is possible to form a conductor thin film having a film thickness of 2 to 3 μ, and the problem of the thick film method can be solved.

Conventionally, in the formation of the external electrodes by this sputtering method, masking is performed on portions other than the electrode forming portion of the element body so that the conductive thin film is formed only on the necessary portions of the element body.
It was performed by sputtering silver etc. on the surface. That is, using a metal mask or a quartz glass mask jig, a porcelain body is sputtered from one side thereof to deposit a conductor film on the end portion, and an electrode is formed there.

[0006]

However, since the porcelain body is separately sputtered from one side of the porcelain body, after the first sputtering, the mask jig is taken out from the sputtering device and disassembled to reverse the porcelain body. The mask jig had to be reoriented and mounted again, and it was necessary to attach it to the sputtering device and perform sputtering again. Therefore, it takes time to form the electrodes,
There was a problem of low productivity. Therefore, in view of the above-mentioned conventional problems, the present invention provides a mask jig for forming an external electrode of a chip-shaped circuit component capable of forming external electrodes at both ends of a chip-shaped element body with high accuracy and high efficiency by sputtering. The purpose is to provide.

[0007]

That is, according to the present invention,
In order to achieve the above object, a mask jig for forming an external electrode by depositing a conductor film on both end portions 42, 42 of the surface of the chip-shaped element body 4 by sputtering, and a predetermined position In relation to each other, there are a pair of mask plates 1 and 3 and an element holding sheet 2 inserted between these mask plates 1 and 3, and the mask plates 1 and 3 are
At the corresponding positions of the surfaces where they are overlapped, intermediate portion support grooves 12 and 32 each having a length shorter than the length of the chip-shaped element body 4 and corresponding to the shape of the semi-circular surface of the element body 4 are provided, and these intermediate portion support grooves 12 are provided. , 32 on both sides of the through holes 11, 31
And the element body holding sheet 2 has the mask plates 1, 3
External electrode formation of a chip-shaped circuit component, characterized in that it has element body holding holes 21 each having a size slightly larger than the length and width of the chip element body 4 at positions corresponding to the intermediate support grooves 12 and 32. Provide a mask jig for use.

[0008]

In the mask jig for forming the external electrodes of the chip-shaped circuit component, the mask plates 1 and 3 are overlapped with each other, and the intermediate portions of the chip-shaped element body 4 are sandwiched between the intermediate-portion supporting grooves 12 and 32 thereof. Let Then, the intermediate support groove 1
Since the through holes 11 and 31 are provided on both sides of the chips 2 and 32, it is possible to hold the intermediate portion of the chip-shaped element body 4 in a state where only both ends thereof are exposed to the through holes 11 and 31. Further, by fitting the element body 4 into the element body holding hole 21 of the element body holding sheet 2 inserted between the mask plates 1 and 3, the element body 4 is held at a predetermined position so as not to move. . In this state,
Through the through holes 11 and 31 of the mask plates 1 and 3, metal can be irradiated from both sides of the mask plates 1 and 3 superposed on each other to form a metal film on the end portion of the element body 4.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. As shown in FIG. 1, a mask jig for forming external electrodes of a chip-shaped circuit component according to an embodiment of the present invention includes mask plates 1 and 3 which are superposed on each other.
It has the element body holding sheet 2 inserted between them.
The mask plates 1 and 3 are made of, for example, quartz glass or metal, and the element body holding sheet 2 is made of metal, tetrafluoroethylene resin, polyimide resin, or the like.

The mask plate 1 has a V-shaped intermediate support groove 12 at the center of the surface on which the other mask plate 3 is superposed, and the support groove 12 is formed by sputtering at both end portions 42. , 42 are formed in conformity with the shape and size of the two adjacent side surfaces of the prismatic element body 4 on which electrodes are to be formed. That is, the crossing angle of the groove is a right angle,
The width of the inclined surfaces on both sides thereof is approximately the same as the width of the side surface of the element body 1. The length of the intermediate portion support groove 12 is shorter than the dimension of the element body 4, and more specifically, the intermediate portion 41 excluding the dimensions of both end portions 42, 42 of the element body 4 on which electrodes are to be formed. It is the size according to the size of.

Rectangular through holes 11, 11 are provided on both sides of the intermediate portion support groove 12, and the through holes 11,
The width of 11 is sufficiently wider than the size for forming electrodes on both ends 42, 42 of the element body 4. Pins 13, 13, ... For positioning with another mask plate 3 are projected from four corners of the mask plate 1.

The intermediate support groove 32 and the through holes 31, 31 of the other mask plate 3 are the intermediate support grooves 1 of the mask plate 1.
2 and the through holes 11 and 11 are provided in a completely symmetrical manner.
That is, when the mask plates 1 and 3 are overlapped with each other, their intermediate support grooves 12 and 32 and the through holes 11 and 1 are formed.
1, 31, 31 are symmetrically arranged on both sides of the superposed surfaces. From the four corners of the mask plate 3, through holes 34, 34 ... Into which the pins 13, 13 ... Are fitted are provided for positioning when overlapping with the mask plate 1.

The body holding sheet 2 is composed of the mask plates 1 and 3 described above.
Is a thin sheet having the same shape as, and has an element body holding hole 21 in the center thereof. The element body holding hole 21 has a length and a width dimension that are slightly larger than the length of the element body 4 and the diagonal length of the end face, and the center position of the element body holding hole 21 is the intermediate portion support groove 12 of the mask plates 1 and 3. It corresponds to the center position of 32. The pins 13, 13 are provided at the four corners of the element body holding sheet 2 for positioning when the sheet is inserted between the mask plates 1, 3.
Through holes 22, 22 ... into which ... are fitted are provided.

When this mask jig is used, first, as shown in FIG. 1, one of the long ridgelines of the element body 4 faces downward, and the intermediate portion thereof is fitted into the intermediate portion supporting groove 12 of the mask plate 1. Put in. Next, the element body holding sheet 2 is superposed on the mask plate 1, and the through holes 22, 22 ... Are fitted to the pins 13, 13. In this state, the element body 4 is fitted into the element body holding hole 21 of the element body holding sheet 2, and movement of the element body 4 in the longitudinal direction is restricted. Next, from above, the intermediate support groove 32
With the side facing downward, the other mask plate 3 is replaced with the mask plate 1 described above.
And the through hole 34, 3 overlaid on the body holding sheet 2.
4 are fitted to the pins 13, 13 ...

The mask jig thus assembled is shown in FIGS. 2 and 3. As shown in these figures, the element body 4 has its intermediate portion 41 clamped from both sides by the intermediate portion support grooves 12 and 32 of the mask plates 1 and 3 on both sides, and is covered by those groove surfaces. . Then, the intermediate support groove 12,
Both sides of the intermediate portion 41 of the element body 4 held by 32, that is, both ends 42, 42, are formed in the through holes 11 of the mask plates 1, 3.
It is exposed on the 31 side. Further, the movement of the element body 4 is completely restricted in a state of being fitted into the element body holding hole 21 of the element body holding sheet 2.

The mask jig thus assembled is attached to, for example, a sputtering apparatus as shown in FIG. That is, the mask jig is installed on the jig supporting portion which is installed in the vacuum chamber 9 and serves as an anode. Cathodes 7 and 7 with targets 5 and 5 attached to both sides of the mask jig
Are arranged, and the shutters 8, 8 are inserted between them.
The vacuum chamber 9 is evacuated to an appropriate atmospheric pressure, and argon gas or the like is introduced into the vacuum chamber 9 to cause glow discharge and metal is ejected from the targets 5 and 5. And the shutter 8,
8 is opened and the through holes 11, 11 of both mask plates 1 and 3 are
Metals fired from both targets 5 and 5 are deposited on both ends 42 and 42 of the element body 4 through 31 and 31. As a result, electrodes are formed on both ends 42, 42 of the element body 4.

FIG. 5 shows another embodiment of the present invention. That is, this embodiment is a mask jig for forming electrodes on both ends of the cylindrical element body 4. In this case, the intermediate support grooves 12 and 32 have a diameter slightly larger than the diameter of the element body. It is a circular groove. As described above, the intermediate support grooves 12 and 32 of the mask plates 1 and 3 are grooves having a semicircular shape of the element body 4 on which electrodes are to be formed.

[0018]

As described above, according to the mask jig of the present invention, the element holding sheet holds the element at a predetermined position by sputtering, and only the both ends of the element are simultaneously exposed from both sides. Since the metal can be deposited, the electrode can be formed with high precision by only one sputtering process. As a result, it is possible to improve the productivity of forming the electrodes of the element body and improve the quality by improving the accuracy of the electrode dimensions.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a mask jig for forming external electrodes of a chip-shaped circuit component according to an embodiment of the present invention.

FIG. 2 is a plan view of an assembled state showing a mask jig for forming external electrodes of a chip-shaped circuit component according to the embodiment.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a vertical cross-sectional side view showing a usage example of a mask jig for forming external electrodes of a chip-shaped circuit component according to the embodiment.

FIG. 5 is an exploded perspective view showing a mask jig for forming external electrodes of a chip-shaped circuit component according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mask plate 2 Element holding sheet 3 Mask plate 4 Chip-shaped element 11 Through hole of mask plate 12 Middle support groove of mask plate 21 Element holding hole of element holding sheet 31 Through hole of mask plate 32 Mask plate Middle part support groove 41 middle part of element body 42 both ends of element body

Claims (1)

[Reference number] 004087-01 [Claims] 1. A mask jig for forming an external electrode by depositing a conductor film on both ends (42), (42) of a surface of a chip-shaped element body (4) by sputtering. A pair of mask plates (1), (3) which are superposed on each other in a predetermined positional relationship, and these mask plates (1),
The element-body holding sheet (2) inserted between (3), and the mask plates (1) and (3) are chip-shaped element bodies at corresponding positions on the surfaces where they are superposed. The intermediate portion support grooves (12) and (32) each having a length shorter than the length of (4) and corresponding to the half circumferential surface shape of the allotrope (4) are provided, and both sides of these intermediate portion support grooves (12) and (32) are provided. An element holding sheet (2) having through holes (11) and (31), respectively.
Is an intermediate support groove (1) of the mask plates (1) and (3).
2) and (32) at positions corresponding to the element body holding holes (2) each slightly larger than the length and width of the chip body (4).
1) A mask jig for forming an external electrode of a chip-shaped circuit component, which has 1).