JPH0629102A - Chip resistor and its manufacturing method - Google Patents

Abstract

PURPOSE:To obtain a chip resistor not requiring its position check a when automatically mounted on a printed board. CONSTITUTION:A longitudinal dimension h1 of a resistance substrate 20 of a chip resistor D is almost the same as a width dimension w1 thereof, and an electrode Ea of a surface 21, an electrode Eb of a rear surface 22, an electrode Ec of an end 23, and an electrode Ed of a chamfered part 24b of a side 24 are formed at its both ends, and also a resistor R ranging between the electrodes Ea and Ea is formed on the surface 21. As the longitudinal h1 is almost the same as the width dimension w1, it can be treated in the same manner as a chip part having a column shape. Also, if the side is mounted on a printed board, as the electrode Ed is formed in this side 24, the chip part D is stably soldered by this electrode Ed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip resistor and a manufacturing method for manufacturing the chip resistor.

[0002]

2. Description of the Related Art FIG. 8 is a perspective view showing a conventional chip resistor A, and FIG. 9 is a sectional view thereof. The resistance substrate 1 of the chip resistor A is made of a hard ceramic material or the like. The resistance substrate 1 of the conventional chip resistor A has a flat plate shape 6
It is a face body and has a rectangular front surface 1a and back surface 1b, a pair of end surfaces 1c, 1c continuous with the short sides of the front and back surfaces, and a pair of side surfaces 1d, 1d continuous with the long sides of the front and back surfaces.
In this resistance substrate 1, the width dimension w between both side surfaces is larger than the vertical dimension h between both front and back surfaces.

Electrode portions 3 are formed on both ends of the resistance substrate 1 in the longitudinal direction. The electrode portions 3, 3 are formed so as to straddle the front surface 1a, the back surface 1b, and both end surfaces 1c, 1c of the resistance substrate 1. A resistor 2 is formed on the surface 1a of the resistor substrate 1 so as to be electrically connected to the electrode portions 3 and 3. Further, as shown in FIG. 9, an overcoat 4 made of a glass material is formed on the surface 1 a of the resistance substrate 1 to cover the resistor 2 and the electrode portions 3 and 3.

16 to 18 show steps of manufacturing the conventional chip resistor A. As shown in FIG. In FIG. 16, B is a flat plate material for forming each resistance substrate 1. Separation lines 5, 5 ... And 6, 6 ... For dividing each resistance substrate 1 are formed on the flat plate material B by crossing a plurality of lines. In the manufacturing process of the flat plate material B, a slurry in which ceramic powder and a binder resin are mixed is first spread in a plate shape to form a sheet material called a green sheet. When the green sheet is formed, the separation grooves 5, 5 ...
And 6 and 6 are press-molded. Then, the flat plate material B made of hard ceramic is formed by firing this. The separation lines 5 and 6 are extremely shallow grooves that facilitate separation of the individual resistance substrates 1 later.

As shown in FIG. 17, on both front and back surfaces of the flat plate material B, the electrodes 3 are arranged in a direction crossing the separation lines 5, 5, ....
a is formed by screen printing. Flat plate material B
A resistor 2 is formed by printing between the electrodes 3a and 3a on the surface of, and an overcoat 4 is formed to cover the resistor 2 and the electrodes 3a, 3a.

After the resistor 2, the electrodes 3a, 3a and the overcoat 4 are formed, the flat plate material B is divided by the separating line 5, so that the ceramic dividing plate Ba shown in FIG.
Is obtained. FIG. 18A is a perspective view of the ceramic division plate Ba viewed from the front surface side, and FIG. 18B is a perspective view showing the ceramic division plate Ba from the back surface side. As shown in these figures, the electrodes 3 are formed on the surface of the ceramic division plate Ba.
a, the resistor 2 and the overcoat 4 are formed, and the electrode 3b formed by the process shown in FIG. 17 is also formed on the back surface. Next, electrodes are printed on both side surfaces (a) of the ceramic division plate Ba. This electrode is designated by reference numeral 3c in FIGS. After the electrode 3c is formed,
The ceramic dividing plate Ba is separated by separating lines 6, 6, ...
The individual chip resistors A shown in FIGS. 8 and 9 are formed.
Nickel plating and solder plating are applied to the electrode parts 3 and 3 of the chip resistor A which are individually separated.

Here, as a method of automatically mounting various chip parts such as a chip resistor and a chip type capacitor on a printed circuit board of an electronic device, there is a so-called one-by-one method of automatically transferring one by one to the board, and various and many types. There is a so-called multi-mount method in which chip components are simultaneously mounted on a printed circuit board. In the one-by-one method, the chip component I is stored in the recess 7a of the chip storage tape 7 shown in FIG. 11, and the chip storage tape 7 is automatically fed. In the automatic mounter for a printed circuit board, the electronic components housed in the recesses 7a of the chip housing tape 7 are adsorbed by the suction arm and taken out, and supplied one by one to the surface of the printed circuit board.

Further, in the multi-mount system, as shown in FIG. 12, a large number of one type of chip components are supplied to a predetermined aligning and supplying device 8. A plurality of the aligning and supplying device 8 are provided for each of a plurality of types of chip components. The individual chip components are dropped into the tube 9 by the aligning and feeding device 8, and the dropped chip components I are sent to the template 11.

FIG. 13 shows the internal structure of the aligning and feeding device 8. In this alignment supply device 8, when the same type of chip components I are supplied to the hopper 8a, they are agitated by the agitation roll 8b and aligned vertically in the alignment passage 8c. The aligned chip components I are sequentially held by the shutter 8d from the bottom, and the chip 8 is dropped one by one by the movement of the shutter 8d to the right in the figure.
Sent in. The chip component I is supplied to the template 11 by the tube 9 continuing to the drop passage 8e.

The template 11 is formed with a plurality of storage recesses 11a corresponding to the component mounting positions of the printed circuit board on which the chip components are mounted, and the plurality of types of chip components are aligned by the alignment supply device 8. , The tube 9 is slid down, and the tubes are supplied one by one into the respective storage recesses 11a. At this time, the air pressure P1 ejected from the alignment supply device 8 or the storage recess 1 of the template 11
Air suction pressure V1 from suction hole 11b communicating with 1a
As a result, the chip component I is surely dropped in the tube 9 and stored in the storage recess 11a.

Next, a plurality of suction nozzles 13 provided on the component transfer member 12 enter the respective storage recesses 11a,
Each chip component I is attracted and lifted by the air suction pressure V2. The solder paste H is applied to the conductive pattern 14 on the surface of the printed circuit board 15, and the chip component I sucked and conveyed by the suction nozzle 13 is mounted on the solder paste H as it is. Chip part I
Are temporarily fixed by the adhesive force of the cream solder H, the air suction pressure V2 of the suction nozzle 13 is stopped at this time, the vacuum in the suction nozzle 13 is broken, and each chip component I is temporarily fixed to the printed circuit board 15. . Multiple suction nozzles 1
The printed circuit board 15 on which a plurality of chip parts are simultaneously mounted by means of 3 is sent to the reflow furnace and the cream solder H
Are melted by heating, and each chip component I is soldered.

[0012]

Here, the resistance substrate 1 of the chip resistor A manufactured by the above-described process is shown in FIGS.
As shown in FIG. 3, the electrodes 3a, 3b and 3c have a flat plate shape having a width dimension w larger than the vertical dimension h, and only the front surface 1a, the back surface 1b and the end surfaces 1c and 1c of the resistance substrate 1 are formed, and both side surfaces 1d , 1d are not formed. Therefore, if the chip resistor A is applied to the component mounting work of each of the one-by-one system and the multi-mount system, the following problems occur.

(A) First, when the chip resistors A are randomly supplied onto the printed circuit board 15, the chip resistors A are provided on the surface 1a of the resistance substrate 1 as shown in FIG. 10 (a).
Is an upward posture, the back surface 1b shown in the same figure (b) is an upward posture, and the side surface 1d shown in the same figure (c) is an upward posture. Here, when the mounting is performed in the postures shown in FIGS. 10A and 10B, the stability is good in a state of being installed on the cream solder H, and therefore, the chip resistor A before the transfer to the reflow furnace. Don't worry about falling. However, if it is mounted in the posture shown in FIG. 10C, it becomes unstable in a state where it is installed on the cream solder H, and there is a risk that it will fall down before shifting to the reflow furnace.

(B) FIGS. 14 and 15 show the function when the chip resistor A is soldered on the printed board 15. FIG. 14 shows a case where the back surface 1b of the resistance board 1 is mounted so as to face the printed board 15. When heated in the reflow furnace, the cream solder H melts and spreads, but the solder that spreads in the next cooling step contracts and solidifies. At this time, as shown in FIG.
If there is the electrode 3b on the surface facing the printed circuit board 5, the electrode 3b is forced by the contraction of the solder by the forces F1 and F2.
Be attracted to. Further, due to the contracting force of the solder attached to the electrodes 3c, 3c formed on both end surfaces of the resistance substrate 1, F3
And the force indicated by F4 acts. F3 and F4 are chip parts A
, But the force for stabilizing the chip resistor A by F1 and F2 largely acts, so that the chip resistor A is stably soldered.
This is the same when the chip resistor A is mounted in the posture shown in FIG. On the other hand, as shown in FIG. 15, assuming that the side surface 1d of the resistance substrate 1 is mounted on the cream solder H with the posture facing the printed board 15 and sent to the reflow furnace as it is, the side surface 1d of the resistance substrate 1 is assumed. Since no electrodes are formed on the F1 and F2 shown in FIG.
The force of 2 does not act, and only the forces indicated by F3 and F4 act by the solder attached to the electrodes 3c, 3c on the end faces. This F3
When the force balance between F4 and F4 is lost, the chip resistor A rises as shown by the broken line in FIG.

(C) As described above, in the conventional chip resistor A shown in FIGS. 8 and 9, there are restrictions on the mounting posture on the printed circuit board. Therefore, in the case of automatically mounting on the printed circuit board by the one-by-one method, when the chip resistor A is supplied into the concave portion 7a of the chip housing tape 7 shown in FIG. 11, the attitude of the chip resistor A is determined, Since the front surface 1a or the back surface 1b of the resistance substrate 1 must be housed in the recess 7a so that it faces upward, extra work for discrimination is required. Moreover, in the conventional chip resistor A shown in FIGS. 8 and 9, since the resistance substrate 1 is a rectangular parallelepiped, burrs are easily formed at the upper and lower edges of the side surface 1d during the dividing step. Therefore, when the chip resistor A is taken out from the chip housing tape 7 shown in FIG. 11, burrs may be caught on the paper tape and the chip resistor A may be taken out incorrectly.

(D) Further, in the multi-mount system shown in FIGS. 12 and 13, the chip feeding parts 8 are merely vertically aligned and dropped in the aligning and feeding device 8, and the front and back surfaces and side surfaces of the chip parts are dropped. It has no function to discriminate or regulate the direction of these surfaces. Therefore, when the conventional chip resistor A shown in FIGS. 8 and 9 is used in this multi-mount method, when the chip resistor A falls into the recess 11a of the template 11 of FIG. 12A, the surface 1a, It is unknown whether the back surface 1b or the side surface 1d faces downward. Therefore, the chip resistor A is often mounted on the printed circuit board 15 in the lateral orientation shown in FIG. 15, and the above-mentioned problem occurs. Also, burrs remaining on the edge of the resistance substrate 1 are recessed portions 11
There is a possibility of being caught by "a", which may cause an error in taking out the component by the suction nozzle 13.

Therefore, at present, the chip resistor A using the hexahedron resistance substrate 1 shown in FIGS. 8 and 9 cannot be applied to the multi-mount system, and in the actual multi-mount system, the direction of the posture direction is different. Only cylindrical chip parts that did not require identification were used. This multi-mount method is extremely efficient because it allows multiple types of chip components to be mounted on a printed circuit board at the same time.
Only the columnar chip parts can be applied to this method, and the resistor A of each type shown in FIG. 8 and the like must rely on the mounting work of the one-by-one method. Since this one-by-one method of automatic mounting must be performed for each part in order, the total number of steps for mounting parts on a printed circuit board is extremely large, which causes a reduction in work efficiency.

The present invention solves the above-mentioned conventional problems, and eliminates the need to discriminate the mounting posture, and enables stable soldering regardless of the mounting posture, and a method of manufacturing the same. Is intended to provide.

[0019]

A chip resistor according to the present invention comprises a resistance substrate, a front surface and a back surface, a pair of end portions continuous with short sides of the front surface and the back surface, and a length of each of the front surface and the back surface. A pair of side portions continuous to the side is formed, and a resistor extending along the long side of this surface is formed on the front surface of the resistance substrate, and the front surface and the back surface of the resistance substrate and both end portions and both side portions are formed. Each of them is characterized in that an electrode is formed which is electrically connected to the end of the resistor. Further, it is preferable that the dimension between the front surface and the back surface of the resistance substrate and the dimension between both side portions are substantially equal.

Next, in the method for manufacturing the chip resistor according to the present invention, the first separation groove forming the short side of the resistor and the second separation groove forming the long side intersect each other on the front and back surfaces. A flat plate material having a plurality of strips is used, and the following steps are performed.

(1) On both the front and back surfaces of the flat plate material, electrodes are formed in strip-shaped regions including the first separation grooves, and at this time, the first and second separation trenches in the strip-shaped regions are formed. A first electrode forming step in which electrodes are simultaneously formed in the groove,

(2) Before or after the first electrode forming step, a step of forming a resistor electrically connected to the electrode on the surface of the flat plate material surrounded by the separation groove,

(3) Separation step of separating the flat plate material on which the electrode and the resistor are formed by the first separation groove,

(4) A second electrode forming step of forming electrodes on the separation surface separated by the first separation groove,

(5) A dividing step of dividing each chip resistor from the second separation groove after the second electrode forming step.

[0026]

In the above chip resistor, electrodes are formed not only on the front and back surfaces of the resistor substrate and on the side portions, but also on the side portions. Therefore, no matter which direction the resistor board is mounted, the electrodes are directed to the printed board. Therefore, the electrodes directed to the printed circuit board are pulled by the contraction force of the solder, and the solder is stably soldered in any posture. Therefore, it can be applied to automatic mounting of the multi-mount method. Further, by making the dimension between the front and back surfaces of the resistor substrate substantially the same as the dimension between the side portions, it is possible to stably and temporarily fix the resistor substrate, no matter which posture it is mounted on.

Further, in the above-mentioned manufacturing method, the separation groove of the flat plate material is deeper than the conventional one, and the electrodes are simultaneously formed in the separation groove when the electrodes are formed on the front surface and the back surface of the resistance substrate. The electrodes can be formed also on the side portions of the resistance substrate. Therefore, it becomes possible to manufacture the chip resistor having the electrodes on the side parts by substantially the same number of steps as the manufacturing steps of the conventional resistance substrate.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 shows an example of the chip resistor of the present invention.
1A is a perspective view showing the chip resistor with its front surface facing upward, and FIG. 1B is a perspective view showing its back surface facing upward. The resistance substrate 20 of this chip resistor D has a surface 2
1 and the back surface 22, a pair of end portions 23, 23 continuous with the respective short sides of the front surface 21 and the back surface 22, and a pair of side portions 23, 2 continuous with the respective long sides of the front surface 21 and the back surface 22.
3 and 3. Each of the end portions 23 has an end surface 23a which is a part of the total area of the end portion 23, and chamfered portions 23b, 23b formed on the upper and lower portions of the end surface 23a.
Are formed. Further, the side portion 24 is formed with a side surface 24a which is a part of the entire area thereof and a chamfered portion 24b formed on the upper and lower portions thereof.

A chamfer 23b is formed at each end 23,
As a result of forming the chamfered portion 24 b on each side portion 24, the resistance substrate 20 has a tetrahedral shape. The vertical dimension h1 between the front surface 21 and the back surface 22 of the resistance substrate 20 and the width dimension w1 between the side surfaces 24a, 24a are substantially equal.

Electrode portions E are formed on both ends of the resistance substrate 20 in the longitudinal direction. In each of the electrode portions E, the electrode Ea is first formed on the front surface 21 of the resistance substrate 20, and the electrode Eb is formed on the back surface 22. Also the end 2
3, the electrode Ec is formed between the end surface 23a and the chamfered portion 23b, and the side portion 24 has the electrode Ed formed on the chamfered portions 24b and 24b. These electrodes Ea, E
b, Ec, and Ed are continuous and electrically connected to each other.

On the surface 21 of the resistance substrate 20, a resistor R is formed across the electrodes Ea. Further, as in the conventional example shown in FIG. 9, the electrode Ea and the resistor R are covered with the overcoat 4 made of a glass material.
Etc., the illustration of this overcoat is omitted.

Next, a method for manufacturing the chip resistor D will be described. 4 to 6 show a method of manufacturing the chip resistor D for each step. First, as in the conventional case, a slurry containing ceramic powder as a main component and containing a binder resin is spread into a thin plate to form a green sheet. In the state of this green sheet, a plurality of grooves are formed on both the front and back sides by press working, and this is fired to form a hard ceramic flat plate material 30 shown in FIG.

A plurality of first separation grooves 3 are formed on the front and back surfaces of the flat plate material 30 by press molding with the green sheet.
The first and second separation grooves 32 are formed. The first separation groove 31 and the second separation groove 32 have a V-shaped cross section. In the conventional manufacturing process of the chip resistor A, the separation lines 5 and 6 formed on the flat plate material B shown in FIG. 16 are very shallow, but in the flat plate material 30 shown in FIG. 4, the first separation groove 31 is formed. And the second separation groove 32 are both deep, and are large in both width a1 and depth b1.

Depth b1 of the separation grooves 31 and 32 on the front and back sides
Relates to the area ratio between the side surface 24a and the chamfered portion 24b shown in FIG. 1, and therefore also relates to the area of the electrode Ed. The chip resistor D in this embodiment has a side portion 24.
One of the purposes is to fix the electrode Ed portion to the printed circuit board with sufficient force by soldering when is mounted on the printed circuit board. The area of the electrode Ed can be widened to some extent. is necessary. Therefore, the depth b1 of the separation grooves 31 and 32 is preferably 1/4 or more of the thickness dimension h1 of the flat plate material 30, and more preferably, the depth b1 is 1/3 or more of the thickness dimension h1. is there. However, the depth dimension b1 is not limited to ¼ or more of h1, and the depth dimension b1 is not limited as long as it is within a range in which the solder attached to the electrode Ed of the side portion 24 can be attracted to the printed board with sufficient strength. The height b1 may be 1/4 or less of h1. Further, the width dimension a1 of the opening ends of the separation grooves 31 and 32 needs to be a size that allows the electrode layer to sufficiently penetrate into the inside of the groove in the first electrode forming step shown in FIG.

FIG. 5 shows the first electrode forming step.
In this first electrode forming step, the surface 30a of the flat plate material 30 is formed.
And the strip-shaped electrode layer Eo is formed on the back surface 30b. The electrode layer Eo is formed by printing an electrode material such as a gold alloy by screen printing or the like. The electrode layer Eo is formed on the front surface 30a and the back surface 30b of the flat plate member 30 in a band-shaped region having a predetermined width including the first separation groove 31. The electrode layer Eo permeates not only the front surface 30a and the back surface 30b of the flat plate material 30 but also the inner surfaces of the first separation groove 31 and the second separation groove 32 in the strip-shaped region to separate them. Groove 3
It is formed on the entire V-shaped surfaces 1 and 32. The portion surrounded by the first separation groove 31 and the second separation groove 32 in the flat plate material 30 is later divided to become the resistance substrate 20, and by forming the electrode layer Eo, it is shown in FIG. The electrodes Ea and Eb on the front surface and the back surface, the electrode Ec1 on the chamfered portion 23b of the end electrodes Ec, and the electrodes Ed and Ed on the chamfered portion 24b on the side portion 24 are formed on the resistance substrate 20, respectively.

Next, the resistor R is formed after or before the first electrode forming step. The resistor R is formed by a printing process using a resistance material mainly composed of carbon or the like. Although the resistor R is not shown in FIG. 5, the resistor R extends over the electrodes Ea and Ea in the surface region surrounded by the separation grooves 31 and 32 as shown in FIG. It is formed. Further, although not shown, the electrode E
Part of a and the resistor R are covered with an overcoat of glass material (the same as reference numeral 4 in FIG. 9).

The above electrodes, resistors and overcoat are shown in FIG.
The flat plate material 30 is formed on the flat plate material 30 shown in (1), but after these are formed, the flat plate material 30 is divided by the first separation groove 31. The divided ceramic division plate 30-1 is shown in FIG. On the division surface of the division plate 30-1, the electrode Ec1 is formed only on the V-shaped surface (chamfered portion) of the first division groove 31.
Is formed, and no electrode is formed on the separated side surface 23a-1. Therefore, in the second electrode forming step, electrodes are further printed and formed on the ceramic division plate 30-1 from both sides shown by (B) in FIG. By this second electrode forming step, electrodes are formed on the entire divided surface including the electrode Ec1. This is the electrode E at the end 23 shown in FIG.
c. After the electrode formation step, the second dividing groove 32 is formed.
By further separating the ceramic division plate 30-1 by the above, the individual chip resistors D shown in FIG. 1 are divided.

Next, in the chip resistor D, the electrodes Ed are formed on the chamfered portions 24b of the both side portions 24 as described above, and the vertical dimension h1 and the width dimension w1 are substantially the same. It is not necessary to determine the posture direction as in the case of automatically mounting the chip resistor A described in the conventional example.

First, as described above, the vertical dimension h1 and the width dimension w.
1 is almost the same, the posture when the chip resistor D is mounted on the printed circuit board 15 is as shown in FIG. 2B even if the surface 21 is upward as shown in FIG. As shown, even when the surface 21 is oriented sideways, the stability when placed is almost the same, and the conventional unnatural posture as shown in FIG. 10C does not occur.

Further, as shown in FIG. 3, even when the side portion 24 of the resistance substrate 20 is placed on the cream solder H on the printed circuit board 15 in a downward posture, the soldering is stably performed. That is, the chip resistor D is placed on the printed circuit board 15.
After mounting, the cream solder H is heated and melted by the reflow furnace, the solder once spreads, and the solder tries to contract due to cooling, but at this time, the electrode Ed formed on the side portion 24 adheres to the solder H. Therefore, due to the contraction of the solder, this electrode Ed causes a force F1 toward the printed board 15.
And attracted by F2. Therefore, even if the electrode Ec at the end portion is pulled in the left-right direction by the solder as indicated by F3 and F4, the forces of F1 and F2 act, and the chip resistor rises as indicated by the broken line in FIG. Such a phenomenon does not occur. This is the same even when the front surface 21 and the back surface 22 of the resistance substrate 20 are mounted so as to face the printed circuit board 15.

Since the chip resistor D in this embodiment may be mounted in either orientation,
In the mounting work, it is not necessary to determine the posture direction as in the conventional example shown in FIG. Therefore, for example, in the one-by-one automatic mounting described in FIG. 11, when the chip resistor D is stored in the recess 7a of the chip storage tape 7,
The posture direction can be set arbitrarily, and the setup work can be simplified because the determination work is unnecessary.

Further, the chip resistor D of the above embodiment can be applied to automatic mounting by the multi-mount method shown in FIGS. 12 and 13. As shown in FIG. 1, this chip resistor D
Since the vertical dimension h1 and the width dimension w1 are substantially the same, when the chip resistors D thrown into the alignment supply device 8 are aligned and supplied, they can be treated almost the same as a columnar chip component. Further, since it is not necessary to discriminate the posture direction, the posture after dropping from the tube 9 into the storage recess 11a of the template 11 may be any direction,
The suction nozzle 13 may be taken out as it is and mounted on the printed circuit board 15.

Further, as shown in FIG. 1, since the resistance substrate 20 has chamfered portions 23b and 24b, the surface 2
No burrs appear at the edges of the first and rear surfaces 22 when the substrate is divided. Therefore, when the chip resistor D is taken out from the chip housing tape 7 shown in FIG. 11 or the template 11 shown in FIG. Incidentally, in the above-mentioned embodiment, as shown in FIG.
As shown in FIG.
2 was formed, but as shown in FIG. 7, the dividing grooves 31 and 3 were formed.
The inner surface of 2 may be curved.

[0044]

As described above, according to the invention of claim 1,
Since the electrodes are formed not only on the front and back surfaces and the ends of the resistance substrate but also on the sides, stable soldering can be performed even when the sides are mounted toward the printed circuit board.

According to the second aspect of the present invention, since the dimension between the front and back surfaces of the resistance substrate and the dimension between the side portions are substantially the same, the temporary fixing is stable regardless of the posture when mounted on the printed circuit board. To be done. Further, even in the multi-mount type automatic mounting work, it can be handled in the same manner as a cylindrical chip component.

According to the third aspect of the invention, when the electrodes are formed in the strip-shaped region, the electrodes are permeated into the dividing grooves to form the side electrodes of the resistance substrate. Therefore, the front surface and the back surface of the resistance substrate are formed. It becomes possible to form the electrodes on the side portions at the same time in the electrode forming work.

[Brief description of drawings]

FIG. 1A is a perspective view showing a chip resistor according to the present invention with its front surface facing upward, and FIG. 1B is a perspective view showing its back surface facing upward.

2A and 2B are perspective views showing a posture when a chip resistor is installed on a printed circuit board,

FIG. 3 is a cross-sectional view showing a soldering function when the chip resistor according to the present invention is installed on a printed circuit board in a horizontal posture.

FIG. 4 is a perspective view of a flat plate material showing a manufacturing process of a chip resistor according to the present invention;

FIG. 5 is a perspective view showing a first electrode forming step for the flat plate material,

FIG. 6 is a perspective view showing a ceramic division plate divided by a first division groove;

FIG. 7 is a side view showing another shape of the dividing groove,

FIG. 8 is a perspective view showing a conventional chip resistor,

FIG. 9 is a cross-sectional view of a conventional chip resistor,

10 (a), (b) and (c) are perspective views showing postures when a conventional chip resistor is installed on a printed circuit board,

FIG. 11 is a cross-sectional view showing a chip storage tape when chip components are automatically mounted by a one-by-one method.

12 (a), (b) and (c) are process explanatory views showing a mounting work of a chip component by a multi-mount method,

FIG. 13 is a cross-sectional view showing the internal structure of an alignment and supply device used in the multi-mount method.

FIG. 14 is a cross-sectional view showing a soldering operation when a conventional chip resistor is mounted in a normal posture,

FIG. 15 is a cross-sectional view showing a soldering operation when a conventional chip resistor is mounted in an abnormal posture.

FIG. 16 is a perspective view of a flat plate material showing a manufacturing process of a conventional chip resistor;

FIG. 17 is a perspective view showing a step of forming electrodes and resistors on the flat plate material;

FIG. 18 (a) is a perspective view showing a ceramic division plate divided from a conventional flat plate material with its front surface facing upward, and FIG. 18 (b) is a perspective view showing the same rear surface upward.

[Explanation of symbols]

 D Chip resistor E Electrode part Ea, Eb, Ec, Ed electrode R Resistor 20 Resistive substrate 21 Front surface 22 Back surface 23 End 23a End face 23b Chamfer 24 Side 24a Side 24b Chamfer 30 Flat plate 30-1 Ceramic division plate 31 first separation groove 32 second separation groove

Claims (3)

[Claims] 1. A resistance substrate is formed with a front surface and a back surface, a pair of end portions continuous with respective short sides of the front surface and the back surface, and a pair of side portions continuous with respective long sides of the front surface and the back surface. A resistor body is formed on the surface of the resistor substrate, the resistor body extending along the long side of the face, and the resistor substrate is electrically connected to the front and back surfaces, both ends and both sides of the resistor substrate. A chip resistor having an electrode formed thereon. 2. The chip resistor according to claim 1, wherein a dimension between the front surface and the back surface of the resistance substrate and a dimension between both side portions are formed to be substantially equal to each other. 3. A flat plate material having a plurality of strips formed by intersecting a first separation groove forming a short side of a resistor and a second separation groove forming a long side of the resistor on both front and back surfaces. , A method of manufacturing a chip resistor by the following steps. (1) On both front and back surfaces of the flat plate material, electrodes are formed in strip-shaped regions including the first separation groove, and inside the first separation groove and the second separation groove in the strip-shaped region at this time. A second electrode forming step of simultaneously forming electrodes, (2) before or after the first electrode forming step,
A step of forming a resistor which is electrically connected to the electrode on the surface of the flat plate material surrounded by the separation groove, and (3) a separation step of separating the flat plate material having the electrode and the resistor formed therein by the first separation groove. (4) A second electrode forming step of forming electrodes on the separation surface separated by the first separating groove, (5) After the second electrode forming step, individual chip resistors are formed from the second separating groove. A dividing step for dividing the.