JP2001118703A - Chip resistor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chip resistor in which resistor paste does ooze out nor sags after the paste is screen-printed on an insulating substrate at the time of manufacturing the resistor. SOLUTION: At the time of manufacturing a chip resistor which is constituted in such a way that at least a pair of counter electrode sections is formed on an insulating substrate and a resistance body is formed between the electrodes by printing and sintering resistance body paste 5, a pair of parallel guide walls 3 is formed on the resistance body arranging surface of the substrate after the electrode sections are formed and the paste 5 is printed between the walls 3. After the electrode sections are formed, alternatively, a rectangular frame-like guide wall 3' is formed on the resistance body arranging surface and the paste 5 is printed in the area surrounded by the wall 3'. In addition, the guide walls 3 and 3' are formed by screen-printing and sintering glass paste.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip type resistor formed on an insulating substrate such as a ceramic substrate, and more particularly to a chip type resistor in which a resistor paste is prevented from sagging and bleeding to prevent occurrence of a defect. It relates to a chip type resistor.

[0002]

2. Description of the Related Art Heretofore, there has been a chip type resistor formed by applying a resistor paste containing ruthenium or the like on an insulating substrate made of a ceramics substrate and firing the resistor paste. The chip resistor is manufactured by the following procedure.

[0003] First, a first break groove 11 and a second break groove 12 are engraved in a lattice shape on a ceramic sheet before firing, and fired to obtain an aggregated ceramic substrate 10 as shown in FIG. a)).

An upper electrode 13 and a lower electrode (not shown) are printed and fired on the same ceramic substrate 10 with an electrode paste (FIG. 4B), and a resistor paste is provided between the upper electrodes 13 and 13. Is printed in a substantially rectangular shape and fired to form a resistor 14
(FIG. 4C). Next, a protective glass 15 for protecting the resistor 14 is printed and fired (FIG. 4).
(D)).

Then, the resistor is trimmed by laser trimming.
14 was adjusted (FIG. 4E) to fill the trimming grooves 16 generated by the trimming and to form a coating glass layer.
The intermediate glass layer 17 serving as a base for 18 is printed (FIG. 4)
(F)) Then, the coated glass layer 18 is printed (FIG. 4)
(G)), baking of the intermediate glass layer 17 and the coating glass layer 18 is performed.

Next, the aggregated ceramic substrate 10 is divided along the first break groove 11 to form a bar-shaped substrate 19, and the longitudinal direction of the bar-shaped substrate 19 is set so as to electrically connect the upper electrode 13 and the lower electrode. An electrode paste is applied to both sides parallel to the direction, and the electrode paste is sintered to form side electrodes 20 (FIG. 4 (h)).

[0007] Thereafter, the chip is divided at the second break groove 12 to obtain a single chip resistor, and the electrode portion of the chip resistor is plated with solder to obtain a completed product.

[0008] In recent years, as the demand for miniaturization and price reduction of products has increased, the number of single chip resistors formed from one collective ceramic substrate has tended to increase. The need to print body paste has arisen.

In order to enable reliable printing of the resistor paste at a fine pitch, a resistor paste having a lower viscosity has been used.

[0010]

However, when the viscosity of the resistor paste 14 'is reduced, as shown in FIG. 5 (a), when printing on the ceramic substrate 10', the side edges of the resistor paste 14 'are formed. There is a problem that bleeding 21 easily occurs and sag 22 easily occurs in the printed resistor paste 14 '.

FIG. 5B is a cross-sectional view taken along the line II-II of FIG. 5A. In particular, in a portion where the upper electrode 13 and the resistor paste 14 ′ overlap, the base rises by the thickness of the upper electrode 13. Therefore, it is easy to cause sagging 22 and bleeding 21 during printing, and the portion where sagging 22 and bleeding 21 occur tends to cause cracking or chipping of the resistor after firing, and also deteriorates withstand voltage characteristics. Was.

Furthermore, since the thickness of the resistor is non-uniform, the variation in the adjustment of the resistance value by trimming becomes large, and also causes noise during mounting and use.

[0013]

According to the present invention, at least one pair of opposing electrode portions is formed on an insulating substrate, and a resistor paste is printed between the electrode portions to fire the same. In a chip-type resistor that forms a resistor by tying, after forming an electrode portion, a pair of mutually parallel guide walls is protruded from a surface on which the resistor is provided, and a resistor paste is printed between the guide walls. The present invention is to provide a chip-type resistor characterized by the following.

After forming the electrode portion, a substantially rectangular frame-shaped guide wall is protruded from the surface on which the resistor is provided, and a resistor paste is printed in a frame surrounded by the guide wall. It is not intended to provide a type resistor.

Particularly, the guide wall is characterized in that it is formed by screen-printing and sintering a glass paste.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A chip-type resistor according to the present invention has a pair of parallel resistors on a surface on which a resistor is provided before printing a resistor paste between electrode portions formed on an insulating substrate such as a ceramic substrate. A guide wall is projected, and a resistor paste is printed and sintered between the guide walls to form a resistor.

The guide wall may be formed by using an insulating material, and may be formed by screen-printing an appropriate resin and drying and solidifying it, or by screen-printing and sintering a glass paste. May be formed.

In particular, by using a protective glass which is screen-printed on the upper surface of the resistor after sintering the resistor, or the same glass paste as the glass paste of the intermediate glass layer or the coating glass layer, the resistor is made of glass. You may comprise so that sealing may be performed reliably.

By forming the guide wall, it is possible to prevent bleeding or sagging of the side edge portion of the printed resistor paste, and to use the guide wall as the starting point of the laser trimming, so that the starting point can be obtained. Can be easily positioned, so that the time required for trimming can be reduced.

Instead of forming parallel guide walls, a guide frame having a substantially rectangular frame shape may be formed, and the resistor paste may be printed in a frame surrounded by the guide walls. By forming a frame in which the resistor is provided by the guide wall, the resistor paste printed in the frame can be maintained in a substantially rectangular shape. A substantially rectangular resistor can be formed by sintering without causing bleeding or sagging.

Therefore, it is possible to prevent the resistance value of the same resistor from varying, to facilitate adjustment to a predetermined resistance value by trimming, and to make the thickness of the resistor uniform. And withstand voltage characteristics can be improved.

As described above, the resistor formed by sintering is:
After printing and firing the protective glass, trimming is performed,
As described in the section of “Prior Art”, the intermediate glass layer and the coated glass layer are printed and fired, divided into bar-shaped substrates, and after forming the side electrodes, divided into a single chip type resistor to form an electrode portion. It is finished by plating.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0024]

FIG. 1 is a plan view showing a chip type resistor A1 according to a first embodiment. Actually, the chip-type resistor A1 is manufactured in a state of a collective substrate in which a plurality of the resistors are assembled as described in the section of the “prior art”. Only the following will be described.

Alumina ceramic is used for the insulating substrate. After printing and firing the upper electrodes 2, 2 and the lower electrode (not shown) on the ceramic substrate 1, the upper electrodes 2, 2 are formed.
The glass paste is screen-printed in a narrow band shape on the surface on which the resistor is provided, and is fired to form the ridged guide walls 3,3.

At both ends of the guide walls 3, 3, upper electrodes 2,
Auxiliary guide walls 4, 4 protruding to the side 2 are formed, respectively, and when a resistor paste 5 is printed as described later, a resistor is formed between the upper electrodes 2, 2 and the guide walls 3, 3. The auxiliary guide walls 4, 4 prevent the paste 5 from bleeding or dripping.

Incidentally, since the resistor paste 5 printed on the upper surfaces of the upper electrodes 2, 2 has a property that it does not easily spread along the upper surfaces of the upper electrodes 2, 2, the first embodiment uses the upper electrode 2, 2, 2 No guide wall 3 was formed on the upper surface.

The insulating substrate is not limited to alumina ceramics, and any substrate having an insulating property may be used.

The same glass paste as that of the protective glass that is screen-printed so as to cover the upper surface of the resistor after sintering the resistor paste 5 to form a resistor is used as the glass paste. The glass paste is not limited to the same as the glass paste of the protective glass, and a glass paste of a different composition may be used. A wall may be formed.

However, in particular, by using the same glass paste as the protective glass, the familiarity and adhesion between the guide wall and the protective glass can be improved, and the resistor can be reliably shielded. And moisture resistance can be improved.

As shown in FIG. 2A, the guide walls 3, 3 are formed on the left edge 5a of the resistor paste 5 to be screen-printed.
And at positions corresponding to the right side edge 5b, respectively.

By forming the guide walls 3, 3, it is possible to prevent the resistor paste 5 screen-printed from bleeding or sagging in the left-right direction as shown in FIG. 2B. Accordingly, the thickness of the resistor paste 5 can be kept uniform as a whole. Accordingly, it is possible to improve the withstand voltage characteristics when the resistor is fired.

In the subsequent laser trimming, the starting point of the trimming is adjusted to the guide wall 3 so that the resistor side edge portion, that is, the left edge 5a can be easily formed.
Alternatively, the starting point can be located on the right side edge 5b, and the trimming can be reliably performed by the minimum required laser irradiation, so that the time required for the trimming can be reduced, and the working efficiency can be improved. .

Furthermore, since the shape of the resistor, particularly the cross-sectional shape, can be made substantially constant, it is possible to suppress the variation of the resistance value during the adjustment of the resistance value by trimming, thereby suppressing the variation of the product itself. Thus, a more homogeneous product can be manufactured.

In this embodiment, the chip type resistor A1 in which one resistor is formed on one chip substrate has been described. However, the present invention is not limited to this chip type resistor A1, and is not limited to this chip type resistor A1. The guide wall 3 may be similarly formed for a multiple chip resistor in which a plurality of resistors are formed.

<Second Embodiment> FIG. 3 is a perspective view of a chip resistor A2 according to a second embodiment. The only difference between the chip resistor A2 of the second embodiment and the chip resistor A1 of the first embodiment is the shape of the guide wall, and the other points are the same as those of the chip resistor A1 of the first embodiment. Therefore, description of the same components will be omitted. Hereinafter, only the differences from the first embodiment will be described.

In the chip type resistor A2 of the second embodiment, after the upper electrodes 2, 2 and the lower electrodes 2 ', 2' are printed and fired on the ceramic substrate 1, the resistor provided with the upper electrodes 2, 2 is provided. A glass paste is screen-printed in a substantially rectangular frame shape on the disposition surface, and is baked to form a guide wall 3 'having a substantially rectangular frame shape.

The space 6 inside the frame surrounded by the guide wall 3 '
By printing the resistor paste 5 on the substrate 1, the outer peripheral shape of the resistor paste 5 can be maintained in a substantially rectangular shape. In the present embodiment, the space 6 in the frame is formed by the guide wall 3 ′ having a predetermined width.
Screen printing of glass paste on all other parts,
The guide wall 3 'may be formed by firing.

By forming the in-frame space 6 by the guide wall 3 ′ having a substantially rectangular frame, even if the viscosity of the resistor paste 5 printed in the in-frame space 6 is further reduced,
The predetermined amount of the resistor paste 5 can be reliably printed, and the variation in the printed amount of the resistor paste 5 printed on each resistor portion can be suppressed. Therefore, since the volume of the resistor can be stabilized, the resistance value before the adjustment of the resistance value by trimming can be brought close to the resistance value after the adjustment in advance, and the time required for the trimming operation can be reduced.

Further, since the bleeding and sagging of the resistor paste 5 can be prevented by the guide walls 3 ', a thinned portion is less likely to occur in the fired resistor, and the withstand voltage characteristics can be improved. it can.

In the chip-type resistor A2 of the second embodiment, similarly to the chip-type resistor A1 of the first embodiment, since the cross-sectional shape of the sintered resistor can be made substantially constant, trimming is performed. Can suppress the variation of the resistance value adjustment, and can manufacture a more uniform product.Furthermore, by setting the starting point of the trimming to the guide wall 3 ', the starting point can be easily positioned. it can.

Further, similarly to the first embodiment, the guide wall 3 'of this embodiment may be configured to be used for a multiple chip type resistor.

[0043]

According to the first aspect of the present invention, after the formation of the electrode portion, a pair of mutually parallel guide walls is projected from the surface on which the resistor is provided, and the resistor paste is applied between the guide walls. By printing, it is possible to prevent bleeding or sagging of the printed resistor paste, and to prevent the fired resistor from having a thin portion. Therefore, it is possible to prevent the resistor from cracking or chipping,
Further, the withstand voltage characteristics can be improved.

In particular, since the left and right sides of the resistor paste are regulated by the guide walls, when the resistance value is adjusted by laser trimming, the starting point of laser trimming may be adjusted to the guide wall portion. The start point position can be easily adjusted, and the time required for laser trimming can be reduced.

Furthermore, since the shape of the resistor obtained by sintering the resistor paste, particularly the cross-sectional shape, can be made substantially constant, it is possible to suppress the variation in the resistance value when adjusting the resistance value by trimming. In addition, it is possible to manufacture a more uniform product while suppressing variations in the product itself.

According to the second aspect of the present invention, after the electrode portion is formed, a substantially rectangular frame-like guide wall is protruded from the surface on which the resistor is provided, and the resistor paste is placed in a frame surrounded by the guide wall. By printing the resistor paste, a resistor paste having a lower viscosity can be used, and the printed amount of the resistor paste on each resistor portion can be made uniform. Therefore, since the volume of the resistor can be stabilized, the variation in the resistance value can be suppressed, and the resistance value before the resistance value adjustment by trimming can be brought close to the resistance value after the adjustment in advance. In addition, the time required for the trimming operation can be reduced.

According to the third aspect of the present invention, the guide wall is formed by screen-printing and sintering the glass paste, so that the protective glass is printed and fired after the sintering of the resistor. Or an intermediate glass layer,
Alternatively, since the adaptation and the close contact between the coating glass layer and the guide wall can be reliably performed, the resistor can be reliably shielded, and the moisture resistance can be improved.

[Brief description of the drawings]

FIG. 1 is a plan view of a chip-type resistor according to a first embodiment after a guide wall is formed.

FIG. 2A is a plan view of the chip-type resistor according to the first embodiment after printing a resistor paste, and FIG. 2B is a cross-sectional view taken along line II of FIG.

FIG. 3 is a perspective view of a chip-type resistor according to a second embodiment after a guide wall is formed.

FIG. 4 is an explanatory view illustrating a method for manufacturing a conventional chip resistor.

FIG. 5A is a plan view of a conventional chip resistor after printing a resistor paste, and FIG. 5B is a cross-sectional view taken along the line II-II of FIG.

[Explanation of symbols]

 A1, A2 Chip resistor 1 Ceramic substrate 2 Upper electrode 3,3 'Guide wall 4 Auxiliary guide wall 5 Resistor paste 5a Left edge 5b Right edge 6 Space in frame

Claims (3)

[Claims] 1. A chip type resistor in which at least one pair of opposing electrode portions is formed on an insulating substrate, and a resistor paste is printed and sintered between the electrode portions to form a resistor. A pair of mutually parallel guide walls protruding from the surface on which the resistor is provided, and printing a resistor paste between the guide walls. 2. A chip type resistor in which at least one pair of opposing electrode portions is formed on an insulating substrate, and a resistor paste is printed and sintered between the electrode portions to form a resistor. A chip-shaped resistor, wherein a substantially rectangular frame-shaped guide wall is protruded from a surface on which the resistor is provided, and a resistor paste is printed in a frame surrounded by the guide wall. 3. The chip-type resistor according to claim 1, wherein the guide wall is formed by screen printing and sintering a glass paste.