JP3231370B2 - Manufacturing method of square chip resistor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a rectangular chip resistor which is used in a high-density wiring circuit and which is mounted on a packaged mounting device for cylindrical chip resistors in place of a cylindrical chip resistor.

[0002]

2. Description of the Related Art In recent years, as the demand for lighter, thinner and smaller electronic devices is increasing, very small rectangular chip resistors are often used as resistor elements in order to increase the wiring density of circuit boards. It has become Further, it has to speed up implementation rate in more recent years, so that collective mount to mount many chip components simultaneously performed.

[0003] One conventional thick film type cylindrical chip resistor
FIG. 5 shows an example of the structure of a square chip resistor mounted by the batch mounting machine .

A rectangular chip resistor mounted by a conventional packaged mounting device for cylindrical chip resistors has a rectangular plate-like insulation whose length in the thickness direction is 80% to 120% of the length in the width direction. 96 alumina substrate 20, an upper electrode layer 21 composed of a pair of thick film electrodes formed on the main surface of the 96 alumina substrate 20, and a ruthenium-based thick film formed so as to be connected to the upper electrode layer 21 Resistance layer 22 by resistance and resistance
The first glass layer 24 covering the layer 22 and having a softening point of 550 ° C. to 580 ° C., and the back electrode layer 27 on the back surface of the 96-alumina substrate 20 and a softening point overlapping with a part of the back electrode layer 27 of 55
The second glass layer 28 at 0 ° C. to 580 ° C. and the upper electrode layer 21
And an end face electrode layer 23 overlapping with a part of the Ni electrode. A Ni plating layer 25 and a solder plating layer 26 are formed on the exposed electrode surface by electrolytic plating in order to secure solderability.

Further, the method of manufacturing this square chip resistor has been performed according to the flow shown in FIG.

[0006]

However, in the conventional square chip resistor, when the above-described batch mounting is performed, when the components are mounted, the square chip resistor 30 as shown in FIG.
May be mounted not on the main surface of the substrate but on the side surface. In such a case, the area of the electrode portion 29 in contact with the printed circuit board is small, and the area to be soldered is reduced. There was a drawback that strength could not be obtained.

In the conventional square chip resistor, the first protective layer and the second protective layer have the same softening point (550 ° C. to 580 ° C.).
(° C.), the product 52 is placed on a jig 53 and lifted off the conveyor belt 51 of the firing furnace as shown in FIG. 7 when firing the glass and as shown in FIG. 8 when firing the end face electrodes. As a result, the manufacturing process of the rectangular chip resistor becomes complicated as shown in FIG. 9 (especially, the man-hour is required for the set of the strip-shaped products 52 in FIG. 8), and the production is performed. There was a problem that costs increased.

SUMMARY OF THE INVENTION The present invention solves such a problem at a time. Even if a rectangular chip resistor is mounted on a side surface, a sufficient fixing strength can be obtained, and a rectangular chip resistor can be manufactured in a simple manufacturing process. The aim is to provide a method.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a dividing method for dividing into strips and individual pieces.
A step of forming a pair of upper electrode layers and a pair of back electrode layers on the grooved alumina substrate; and a softening point of 630 ° C. to 850 ° C. so as to partially overlap the pair of back electrode layers .
Print the glass paste, at a temperature of 700-950 ° C
Forming a second glass layer by firing, and forming a resistive layer so as to overlap a portion of the pair of upper surface electrode layers, Garasupe to completely cover the resistive layer
Print and bake at a temperature of 550 ° C to 620 ° C.
Forming a first glass layer by a, the alumina
Divided grooves for dividing the substrate into strips
Providing a strip-shaped alumina substrate by dividing the plate into strips, and applying a conductive paste to an end surface of the strip-shaped alumina substrate.
One of the pair of upper electrode layers and the pair of back electrode layers
At the same time as the conductive paste
Is formed on the alumina substrate, and the alumina substrate is individually
Soak into the dividing groove to divide it into pieces
It is fired at a temperature of 550 ℃ ~660 ℃ below the softening point of the scan layer
Provided with a pair of end faces the electrode layer by Rukoto, the pair of upper surface electrode layers, the pair of backside electrode layer and the one
On a side surface on which the pair of end surface electrode layers are not formed, two pairs of first side surface electrode layers for electrically connecting the pair of upper surface electrode layers and the pair of end surface electrode layers, and the pair of back surface electrode layers, Two pairs of second electrodes electrically connecting the pair of end face electrode layers
Providing each of the side electrode layers;
To divide the formed strip alumina substrate into individual pieces
Divided into individual pieces by the dividing grooves of
And an obtaining step .

[0010]

According to the present invention, the first side electrode layer and the second side electrode layer provided on the side portion even if the rectangular chip resistor is mounted on the side surface .
Since it is soldered to the side electrode layer, the area of the electrode portion in contact with the printed circuit board is increased, and sufficient fixing strength can be obtained without complicating the manufacturing process.

Further, when forming the end face electrode layer, a conductive paste is impregnated into the dividing grooves to form the first side face electrode layer and the second side face electrode layer.
Since the side electrode layer is provided, the manufacturing process can be simplified.

Further, the first glass layer, the end face electrode layer,
Since the side surface electrode layer and the second side surface electrode layer are fired after the second glass layer and the firing temperature is lower than that of the second glass layer, the first glass layer, the end surface electrode layer, the first side surface electrode layer, and the second side surface When the electrode layer is fired, the second glass layer does not melt, so that the first glass layer, the end face electrode layer, and the second glass layer can be directly placed on the conveyor belt of the firing furnace with the second glass layer facing down. When the first side electrode layer and the second side electrode layer are fired, there is no need to float the square chip resistor from the conveyor belt of the firing furnace, so that the manufacturing process can be further simplified.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a square chip resistor according to an embodiment of the present invention;

FIGS. 1A and 1B show an embodiment of the present invention.
It is the perspective view and sectional drawing of the square chip resistor shown . In FIG. 1, the rectangular chip resistor according to one embodiment of the present invention has a length in the thickness direction of 80% to 120% of the length in the width direction.
% Insulated alumina substrate 1, a pair of upper electrode layers 2 of a silver-based thick film on one main surface of the alumina substrate 1, and the other main surface of the alumina substrate 1 An upper back electrode layer 3, a ruthenium-based thick resistive layer 4 overlapping a part of the upper electrode layer 2, and a first glass layer 5 having a softening point of 560 ± 5 ° C. completely covering the resistive layer 4. The back electrode layer 3
The second glass layer 6 having a softening point of 680 ± 5 ° C. overlapping a part of
An end surface electrode layer 7 of a silver-based thick film overlapping a part of the upper surface electrode layer 2 and the back surface electrode layer 3; a first side surface electrode layer 10 connected to the upper surface electrode layer 2 and the end surface electrode layer 7; It is composed of an electrode layer 3 and a second side electrode layer 11 connected to the end face electrode layer 7. In addition, the Ni plating layer 8 and the Sn—Pb plating layer 9 are applied to the exposed electrode surface by electrolytic plating in order to improve the solderability.

Next, in one embodiment of the present invention shown in FIG.
A method of manufacturing a square chip resistor to be manufactured will be described with reference to FIG. First, an alumina substrate 1 having excellent heat resistance and insulation properties is received. The alumina substrate 1 is formed with a dividing groove (molding at the time of a green sheet) for dividing into a strip shape and an individual piece shape (the thickness of the substrate is 0.635 mm).
The division grooves for division are formed at a pitch of 1.5 mm and 0.8 mm. ). Next, the alumina substrate 1
Is screen-printed and dried with a thick-film silver paste on the surface of the substrate, and is further screen-printed and dried with a thick-film silver paste on the back surface of the alumina substrate 1.
At a temperature of 0 ° C., a peak time of 6 minutes and an IN-OUT time of 45 minutes
The upper surface electrode layer 2 and the back surface electrode layer 3 are formed at the same time by sintering according to a minute profile. Next, the back electrode layer 3
A borosilicate lead glass paste (white) is screen-printed and dried so as to partially overlap with a part thereof, and a peak is obtained at a temperature of 850 ° C. by a belt-type continuous firing furnace (so that the upper electrode layer 2 is in contact with the transport belt). Time 6 minutes, IN-OU
The second glass layer 6 is formed by firing according to a firing profile of T50. Next, a thick-film resistance paste containing RuO ₂ as a main component is screen-printed and dried so as to partially overlap the upper electrode layer 2, and is heated at 850 ° C. in a belt-type continuous firing furnace (to be floated from a transport belt). The resist layer 4 is formed by sintering at a temperature of 6 hours with a profile of a peak time of 6 minutes and an IN-OUT time of 45 minutes. Next, in order to equalize the resistance value of the resistance layer 4 between the upper surface electrode layers 2, a part of the resistance layer 4 is broken by laser light and the resistance value is corrected (L cut, 100 mm / sec, 12 kHz, 5 W )I do. Subsequently, a lead borosilicate glass paste (black) is screen-printed and dried so as to completely cover the resistance layer 4, and a belt-type continuous firing furnace (the second glass layer 6 is brought into contact with the transport belt). At a temperature of 590 ° C. according to a firing profile of IN-OUT 50 minutes for a peak time of 6 minutes to form the first glass layer 5. Next, as a preparation process for forming the end face electrodes, the alumina substrate 1 is divided into strips in order to expose the end face electrodes (1.
By dividing the pitch side of 5 mm), a strip-shaped alumina substrate is obtained. A thick-film silver paste is applied to the end surface of the strip-shaped alumina substrate by a roller so as to overlap a part of the upper electrode layer 2 and a part of the rear electrode layer 3, and a belt-type continuous baking furnace (conveying the second glass layer 6). Make contact with the belt)
At a temperature of 600 ° C. with a peak time of 6 minutes, IN-O
The end electrode layer 7 is formed by firing according to a firing profile of UT 45 minutes (at this time, when the strip-shaped alumina substrate is viewed from the end electrode layer 7 side, it is represented as shown in FIG. The paste soaks (FIG. 4).
Therefore, simultaneously with the end face electrode layer 7, the first side face electrode layer 10 and the second side face electrode layer 11 are formed on the side face on which the upper face electrode layer 2, the back face electrode layer 3, and the end face electrode layer 7 are not formed. ).

Next, as a preparation step for electrode plating, the strip-shaped alumina substrate on which the end face electrode layer 7 has been formed is divided into individual pieces (0.8 mm pitch side is divided) to obtain an individual-piece alumina substrate. . And finally, the exposed upper electrode layer 2,
In order to prevent electrode erosion during soldering of the back electrode layer 3, the end face electrode layer 7, the first side electrode layer 10, and the second side electrode layer 11 and to secure the reliability of soldering, a Ni plating layer is formed by electrolytic plating. 8 and a Sn—Pb plating layer 9 are formed.

According to the above steps, an embodiment of the present invention is provided.
And prototype takes Chip resistor (dimensions of the finished product, is 1.6 mm, 0.8 mm in width length, next thickness 0.74 mm, 92.5% in the thickness direction dimension is a width dimension It became.)

A rectangular chip resistor according to one embodiment of the present invention is mounted on the side surface of an alumina substrate 1 as shown in FIG. 5, similarly to a rectangular chip resistor mounted by a conventional cylindrical chip resistor package mounting machine. Since the first side surface electrode layer 10 and the second side surface electrode layer 11 are formed on the side surface even when the bonding is performed, the fixing strength (the limit weight of the rectangular chip resistor from the direction parallel to the printed circuit board) is reduced. (In this case, about 8 kg for side mounting, about 10 kg for surface mounting, and about 3 kg for conventional side mounting).

Further, when the end face electrode layer 7 is formed, the first side face electrode layer 10 and the second side face electrode layer 11 are provided by impregnating the paste into the dividing grooves, so that the manufacturing process is simplified. It has an excellent effect of being able to be made.

Further, the first glass layer 5, the end face electrode layer 7,
The first side surface electrode layer 10 and the second side surface electrode layer 11
Since it is fired after the glass layer 6 and the firing temperature is lower than that of the second glass layer 6, the first glass layer 5, the end face electrode layer 7,
When the first side electrode layer 10 and the second side electrode layer 11 are fired, the second glass layer 6 does not melt, so that the second glass layer 6 is placed directly on the conveyor belt of the firing furnace with the second glass layer 6 facing down. Then, when firing the first glass layer 5, the end face electrode layer 7, the first side face electrode layer 10, and the second side face electrode layer 11, it is not necessary to float the square chip resistor from the conveyor belt of the firing furnace. This has an excellent effect that the manufacturing process can be simplified (especially, it is not necessary to float the strip-shaped ceramic substrate from the conveyor belt of the firing furnace before firing the end face electrode layer 7).

In the embodiment of the present invention, glass having a softening point of 560 ± 5 ° C. is used for the first glass layer 5, and glass having a softening point of 680 ± 5 ° C. is used for the second glass layer 6. ,
These have a softening point of 520 ° C. to 580 ° C. and 630 ° C., respectively.
It is needless to say that the same effect can be exerted if the glass temperature is between 850 ° C. and 850 ° C. (However, in this case ,
Since the softening point of an embodiment is most stable in a glass composition, resistance performance of Chip resistor becomes the best. ). The firing temperature of each glass layer is 550.
The temperature may be appropriately selected in the range of from ℃ to 620 ℃ and from 700 ℃ to 950 ℃. The firing temperature of the end face electrode layer 7 is selected in a range lower than the softening point of the second glass layer 6.

[0022]

As described above, according to the present invention, the strip shape
And alumina with dividing grooves for dividing into individual pieces
Forming a pair of upper electrode layers and a pair of back electrode layers on the substrate , and printing a glass paste having a softening point of 630 ° C. to 850 ° C. so as to partially overlap the pair of back electrode layers;
And firing at a temperature of 700 ° C. to 950 ° C.
(2) a step of forming a glass layer, a step of forming a resistance layer so as to partially overlap the pair of upper electrode layers, and printing a glass paste so as to completely cover the resistance layer.
The first glass layer is fired at a temperature of
And dividing the alumina substrate into strips.
A step of dividing the alumina substrate into strips by dividing grooves for providing a strip-shaped alumina substrate, and applying an electrically conductive paste to the pair of upper electrode layers and the pair of end faces on the end surface of the strip-shaped alumina substrate . Apply so that it overlaps part of the back electrode layer
At the same time, the conductive paste is applied to the alumina substrate.
Formed and for dividing the alumina substrate into individual pieces
5 that is below the softening point of the second glass layer
Provided with a pair of end <br/> surface electrode layer by baking at a temperature of 50 ℃ ~660 ℃, the pair of upper surface electrode layers, before
The serial not formed a pair of back electrode layer and the pair of end faces electrode layer side, the said pair of upper surface electrode layer pair
Two pairs second side of connecting the end surface electrode layer first side electrode layer of the two pairs of electrically connecting the and the pair of backside electrode layer and said pair of end face electrodes layer <br/> electrically Providing each of the electrode layers; and forming a strip-shaped aluminum having the end face electrode layer formed thereon.
Divide the mina substrate into individual pieces by dividing grooves
According to this manufacturing method, when forming the end face electrode layer, the paste is impregnated into the dividing grooves to form the first alumina substrate . Since the side electrode layer and the second side electrode layer are provided, there is an excellent effect that the manufacturing process can be simplified. In addition, the first glass layer, the end face electrode layer, the first side face electrode layer, and the second side face electrode layer are fired after the second glass layer, and the firing temperature is lower than that of the second glass layer. When firing the layer, the end face electrode layer, the first side face electrode layer and the second side face electrode layer, the second glass layer
Not but be melted, by which, if Nosere the second glass layer directly on the conveyor belt of the baking furnace in the lower, first glass layer, the end surface electrode layer, a first side electrode layer and a second side electrode layer This eliminates the need to float the square chip resistor from the conveyor belt of the firing furnace during firing, and thus has an excellent effect of further simplifying the manufacturing process.

[Brief description of the drawings]

FIGS. 1A and 1B are a perspective view and a sectional view showing the structure of a rectangular chip resistor according to an embodiment of the present invention.

FIG. 2 is an explanatory view showing an example of a method of manufacturing a square chip resistor in one embodiment of the present invention.

FIG. 3 is an explanatory view of a strip-shaped alumina substrate in the process of manufacturing a square chip resistor according to one embodiment of the present invention.

FIG. 4 shows a square chip resistor according to an embodiment of the present invention.
Explanatory drawing of the end electrode layer and side electrode layer application state

FIG. 5 is a sectional view showing the manufacture of a conventional square chip resistor.

FIG. 6 is an explanatory view showing a state in which a conventional square chip resistor is mounted on a side surface.

FIG. 7 is an explanatory view of a glass firing jig of a conventional square chip resistor.

FIG. 8 is an explanatory view of a conventional jig for firing an end face electrode of a square chip resistor.

FIG. 9 is an explanatory view showing an example of a method of manufacturing a conventional square chip resistor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Alumina substrate 2 Top electrode layer 3 Back electrode layer 4 Resistance layer 5 First glass layer 6 Second glass layer 7 Edge electrode layer 10 First side electrode layer 11 Second side electrode layer

Claims (1)

(57) [Claims] An apparatus for dividing into strips and individual pieces.
A step of forming a pair of upper electrode layers and a pair of back electrode layers on an alumina substrate having a split groove, and a softening point of 630 ° C. to 850 ° C. so as to partially overlap the pair of back electrode layers.
Print the glass paste of the temperature of 700 ℃ ~ 950 ℃
Forming a second glass layer by firing in
Forming a resistive layer so as to partially overlap the pair of upper electrode layers, and a glass pen so as to completely cover the resistive layer.
Print and bake at a temperature of 550 ° C to 620 ° C
Forming a first glass layer by the aluminum
Divided grooves for dividing the substrate into strips
Providing a strip-shaped alumina substrate by dividing the substrate into strips; and providing a conductive paste on an end surface of the strip-shaped alumina substrate.
Of the pair of upper electrode layers and the pair of back electrode layers
At the same time, the conductive paste
Is formed on the alumina substrate, and the alumina substrate is
Infiltrate into the dividing groove for dividing into individual pieces
Calcined at a temperature of 550 ℃ ~660 ℃ below the softening point of the lath layer
Provided with a pair of end-face electrodes layer by the pair of upper surface electrode layers, said pair of back electrode layer and the
On a side surface on which the pair of end surface electrode layers are not formed, two pairs of first side surface electrode layers electrically connecting the pair of upper surface electrode layers and the pair of end surface electrode layers and the pair of back surface electrode layers, a step of providing a pair of the end surface electrode layer electrically connected to the second side electrode layer of the two pairs of respectively, the end surface electrode layer
Is used to divide the strip-shaped alumina substrate on which
Alumina substrate divided into individual pieces by dividing grooves
Obtaining a square chip resistor.