JP2004071930A - Electric component and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric component which can adequately be mounted and is reducible in probability of cracking while suppressing a rise in manufacturing cost. <P>SOLUTION: The electric component has a plurality of glass layers 4 to 6 which are stacked on a conductor 3 provided on a substrate 1 to cover the conductor 3 and also has a glass-made mark 7 formed on the top surface of the top glass layer 6; and a recessed part 51 is formed on the top surface of the glass layer 5 which is at least the 2nd layer from the top in the area right below the mark 7 and the top glass layer 6 sinks in the recessed part 51. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electric component having a structure in which a conductor is covered with a plurality of glass layers, such as a chip resistor, and a method for manufacturing the same.
[0002]
[Prior art]
FIG. 9 shows a chip resistor which is an example of a conventional electric component. Many electric components have been replaced with such chip-type devices for the purpose of improving the mounting density on a circuit board and improving the electrical characteristics.
[0003]
The illustrated chip type resistor 100 has a configuration in which a resistive film 103 that is electrically connected to a pair of electrodes 102 is provided on a substrate 101. An undercoat glass layer 104, a middle coat glass layer 105, and an overcoat glass layer 106 are stacked on the resistance coating 103, and a glass mark 107 is formed on the surface of the overcoat glass layer 106. Is formed.
[0004]
The above-described three glass layers 104 to 106 and the mark 107 are formed by printing and baking a glass paste, and the mark 107 formed last protrudes from the surface of the overcoat glass layer 106. I have.
[0005]
[Problems to be solved by the invention]
The above-mentioned conventional electric components have the following problems.
[0006]
That is, conventionally, as described above, since the mark 107 protrudes from the surface of the overcoat glass layer 106, when the chip type resistor 100 is mounted on a circuit board using, for example, a suction collet, the mark In some cases, the mark 107 hinders the suction, making it difficult to suck the chip-type resistor 100, or the chip-type resistor 100 may be sucked in an inclined posture. Further, when the suction collet is adsorbed on the upper surface of the chip type resistor 100, the suction collet easily comes into contact with the mark 107, and cracks occur in the mark 107, the overcoat glass layer 106, and the like due to this contact. In some cases, they entered.
[0007]
As described above, in the related art, there has been a problem in that the suction by the suction collet becomes difficult, which hinders the mounting operation and that cracks are easily generated. As a means for solving such a problem, it is conceivable to form a clear glass layer on the mark 107 and the overcoat glass layer 106. However, such a means causes a problem that the manufacturing cost is high because the number of working steps is increased.
[0008]
The present invention has been conceived under such circumstances, and it is possible to appropriately perform a mounting operation while suppressing an increase in manufacturing cost, and to reduce the risk of occurrence of cracks. The task is to provide possible electrical components. Another object of the present invention is to provide a method for manufacturing an electric component capable of suitably manufacturing such an electric component.
[0009]
DISCLOSURE OF THE INVENTION
In order to solve the above problems, the present invention takes the following technical measures.
[0010]
The electric component provided by the first aspect of the present invention has a plurality of glass layers formed on the conductor so as to cover the conductor provided on the substrate, and An electrical component having a glass mark formed on the surface of the glass layer of (1), and a concave portion is formed on at least the surface of the second glass layer from above in a region directly below the mark. The feature is that the uppermost glass layer sinks into the recess.
[0011]
According to such a configuration, in the region immediately below the mark, the uppermost glass layer sinks into the recess, so that the amount of protrusion of the mark from the surface of the uppermost glass layer is smaller than that of the related art. And the top surface of the electrical component is smoother than in the prior art. Therefore, for example, when a mounting operation is performed on a circuit board using a suction collet, the electric component can be appropriately suction-held by the suction collet, and an accurate mounting operation can be performed. In addition, since the amount of protrusion of the mark is small, it is difficult for the suction collet and the mark to come into contact with each other, and it is possible to reduce the possibility that the mark or the uppermost glass layer is cracked.
[0012]
In a preferred embodiment of the present invention, among the plurality of glass layers, in the glass layers other than the uppermost glass layer, the softening point of at least one glass layer is lower than the softening point of the uppermost glass layer. Have been.
[0013]
According to such a configuration, in the process of manufacturing the electric component, when the uppermost glass layer and the mark are heated to be fired, and before the firing and solidification is performed, the uppermost glass layer and the mark are heated. Although the mark softens, the glass layer having a lower softening point softens further than those, and becomes fluid. In the area immediately below the mark, the force due to the weight of the mark is applied downward, so that the glass layer softened so as to have fluidity is depressed by such a force, and a concave portion is formed on the surface thereof. Form. Then, the glass layer above the concave portion gradually sinks. As a result, the mark is sunk into the concave portion formed on the surface of the uppermost glass layer, and the structure of the electric component intended by the present invention is obtained.
[0014]
The method for manufacturing an electric component provided by the second aspect of the present invention includes a step of stacking and forming a plurality of glass layers on a conductor so as to cover the conductor provided on the substrate; A method for manufacturing an electric component, comprising: forming a glass mark on the surface of a glass layer; and firing the plurality of glass layers and the mark, wherein the plurality of glass layers are stacked. Is characterized by having a step of forming at least one glass layer below the uppermost glass layer using glass having a softening point lower than that of the uppermost glass layer.
[0015]
According to such a manufacturing method, the electric component provided by the first aspect of the present invention is appropriately and without increasing the number of steps as compared with the related art, that is, while suppressing an increase in manufacturing cost. It can be easily manufactured.
[0016]
Other features and advantages of the present invention will become more apparent from the following description of embodiments of the present invention.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.
[0018]
FIG. 1 shows an example of an electric component according to the present invention. In the present embodiment, the present invention is applied to a chip-type resistor X. As shown in the drawing, an electrode coating 2 and a resistance coating 3 which are electrically connected to each other are formed on a ceramic substrate 1, and an undercoat glass layer 4 and a middle coating 4 are formed so as to cover the resistance coating 3. The coat glass layer 5 and the overcoat glass layer 6 are sequentially laminated. A mark 7 made of glass is formed on the surface of the overcoat glass layer 6 so as to be embedded. On the side edge surface of the substrate 1 or on the back surface near the side edge surface, an electrode portion 8 that is electrically connected to the electrode coating 2 is formed.
[0019]
The undercoat glass layer 4 protects the resistive film 3 and helps to properly perform laser trimming in the process of manufacturing the chip resistor X. In other words, when laser trimming is performed on the resistive coating 3, the undercoat glass layer 4 suppresses the re-adhesion of the resistive coating material scattered by the heat of the laser light to the trimmed portion, and the target resistance value can be easily reduced. You can get to. In the present embodiment, most of the back surface of the undercoat glass layer 4 is in contact with the surface of the resistance coating 3, and the surface of the undercoat glass layer 4 has a concave portion 41 in a region directly below the mark 7. The other parts are substantially smooth.
[0020]
The middle coat glass layer 5 and the overcoat glass layer 6 are provided for appropriately protecting the resistance coating 3. In a region directly below the mark 7, the back surface portion of the middle coat glass layer 5 enters the recess 41, and a recess 51 is formed on the surface of the middle coat glass layer 5. The surface of the middle coat glass layer 5 excluding the concave portion 51 is substantially smooth. The same applies to the overcoat glass layer 6 as to the middle coat glass layer 5, and the back surface portion of the overcoat glass layer 6 enters the recess 51. The surface of the overcoat glass layer 6 has a concave portion 61 and a flat portion 62. The mark 7 indicates the serial number of the chip-type resistor X and the like, and is in a state of being embedded in the concave portion 61, and the surface thereof has substantially the same height as the flat portion 62. I have. The operation of forming the concave portions 41, 51, 61 will be described later.
[0021]
Next, an example of a method of manufacturing the above-described chip resistor X will be described.
[0022]
In manufacturing the chip-type resistor X, a ceramic collective substrate 10 as shown in FIG. 2 is used. A plurality of horizontal slits 10a and vertical slits 10b each having an appropriate width and depth are formed at regular intervals on the surface of the collective substrate 10. A rectangular area surrounded by the horizontal slits 10a and the vertical slits 10b is a unit area A serving as the substrate 1 of one chip-type resistor X.
[0023]
First, a plurality of electrode coatings 2 are formed on such a collective substrate 10 as shown in FIG. Each electrode coating 2 is formed by printing a paste-like electrode material on both end portions of each unit area A, and then firing the same. Subsequently, a plurality of resistance coatings 3 are formed between each electrode coating 2. Each of the resistance coatings 3 is formed by printing a paste-like resistance material and then firing the same, like the electrode coatings 2.
[0024]
Next, as shown in FIG. 4, a plurality of undercoat glass layers 4 are formed so as to cover the respective resistive films 3. The softening point of the undercoat glass layer 4 is lower than that of the middle coat glass layer 5, the overcoat glass layer 6, and the mark 7, for example, by increasing the blending amount of lead. In the present embodiment, the softening point of the undercoat glass layer 4 is about 400 ° C. Each undercoat glass layer 4 is formed by printing such a glass paste on each of the resistance coatings 3 so that the surface thereof is substantially smooth, and thereafter firing the glass paste.
[0025]
Next, for example, laser trimming is performed on each resistance film 3. A laser beam is applied to each resistance coating 3 from above each undercoat glass layer 4 while a resistance value is measured by applying a measuring probe to each electrode coating 2, and a groove (not shown) is formed in each resistance coating 3. As a result, a target resistance value can be obtained.
[0026]
Next, as shown in FIGS. 5 and 6, a plurality of unfired middle coat glass layers 5 and overcoat glass layers 6 are formed on each undercoat glass layer 4. As described above, these materials have a softening point higher than that of the undercoat glass layer 4, and for example, each of them has a softening point of about 480 ° C. The formation of the glass layers 5 and 6 is performed by printing a glass paste and then drying the paste. The above-mentioned drying is performed, for example, at about 150 to 200 ° C.
[0027]
As described above, when the middle coat glass layer 5 and the overcoat glass layer 6 are laminated on the undercoat glass layer 4, the case where only the overcoat glass layer 6 is laminated on the undercoat glass layer 4 will be described below. In comparison, the surface of the overcoat glass layer 6 can be formed to be smooth. That is, the chip-type resistor X needs to be sufficiently protected by a glass coat. Therefore, a glass layer having a necessary and sufficient thickness must be formed on the resistance film 3. However, if a large amount of glass paste is printed at once, the surface of the glass tends to be convex due to surface tension. On the other hand, if the two layers of the middle coat glass layer 5 and the overcoat glass layer 6 are laminated on the undercoat glass layer 4 as in this embodiment, each glass layer is printed in a thin shape. The surface can be made smooth and a sufficient thickness can be secured as a whole.
[0028]
Next, as shown in FIG. 7, a plurality of unfired marks 7 are formed on the surface of each overcoat glass layer 6. Each mark 7 is made of glass containing a pigment, and has a softening point of, for example, about 480 ° C., similar to each middle coat glass layer 5 and each overcoat glass layer 6.
[0029]
Next, the collective substrate 10 is divided along each vertical slit 10b, and a plurality of unfired electrode portions 8 are formed as shown in FIG. Each electrode portion 8 is formed by printing a paste-like electrode material on each substrate bar-shaped piece 10 ′ obtained by division and then drying the paste.
[0030]
Next, each middle coat glass layer 5, each overcoat glass layer 6, and each mark 7 are fired. At this time, each electrode section 8 is also fired at the same time. The firing is performed, for example, at about 600 ° C. Thereby, each undercoat glass layer 4 whose softening point is set to about 400 ° C. is softened and has fluidity, and each middle coat glass layer 5 whose softening point is set to about 480 ° C. The overcoat glass layer 6 and each mark 7 are softened to the extent that they do not lose their shape. Then, in the region immediately below each mark 7, since the force due to the weight of each mark 7 is applied downward, each undercoat glass layer 4 is depressed by this force. Due to this depression, concave portions 41 are formed on the surface of each undercoat glass layer 4 like the chip type resistor X shown in FIG. 1, and each middle coat glass layer 5 sinks in each concave portion 41. . Thereafter, each overcoat glass layer 6 and each mark 7 gradually sink down.
[0031]
More specifically, when each middle coat glass layer 5 sinks into each recess 41, a recess 51 is also formed on the surface of each middle coat glass layer 5. At the same time as each recess 51 is formed, each overcoat glass layer 6 sinks into each recess 51, and a recess 61 is formed on the surface thereof. As a result, each mark 7 is embedded in each recess 61. That is, the surface of each mark 7 has substantially the same height as the surface of each overcoat glass layer 6. In such a state, each middle coat glass layer 5, each overcoat glass layer 6, and each mark 7 are solidified.
[0032]
Finally, each substrate bar 10 'is divided along each horizontal slit 10a. Through such a series of operations, the manufacture of the chip resistor X as shown in FIG. 1 can be completed.
[0033]
According to the above-described manufacturing method, the mark 7 can be sunk downward together with the glass layer in the region immediately below the mark. Therefore, in the chip type resistor X manufactured by this manufacturing method, the mark 7 has a smaller amount of protrusion of the overcoat glass layer 6 from the plane portion 62 than in the conventional technology. That is, the upper surface of the chip resistor X is smoother than in the related art. Therefore, for example, when the chip type resistor X is mounted on the circuit board using the suction collet, the suction collet is prevented from contacting the mark 7 to prevent the mark 7 and the overcoat glass layer 6 from being damaged. It is possible to reduce the incidence of defective products. Further, since the suction property of the suction collet with respect to the upper surface of the chip-type resistor X is improved, the above-described mounting operation can be appropriately performed. Since such a chip-type resistor X is manufactured through substantially the same process as the conventional technology, the above-described effects can be obtained while suppressing the manufacturing cost to the same level as that of the conventional technology.
[0034]
The present invention is not limited to the contents of the above-described embodiment. For example, the glass layer that protects the resistive film is not limited to being composed of three layers of an undercoat glass layer, a middle coat glass layer, and an overcoat glass layer, and the overcoat glass layer is formed on the undercoat glass layer. A stacked two-layer structure may be used. Further, the glass layer whose softening point is lower than that of the overcoat glass layer is not limited to the undercoat glass layer, and may be both an undercoat glass layer and a middle coat glass layer. Instead of the undercoat glass layer, only the softening point of the middle coat glass layer may be lower than the softening point of the overcoat glass layer. Even with these configurations, the projecting amount of the mark can be made smaller than in the related art, and the same effect as in the above-described embodiment can be expected.
[0035]
The softening point, firing temperature, and the like of the glass layer and the mark are not limited to the above values, and may be set so that the mark sinks into the concave portion of the uppermost glass layer.
[0036]
The firing of the electrode portion is not limited to being performed simultaneously with the glass layer and the mark. After firing the glass layer and the mark, a paste-like electrode material may be printed on the substrate and then fired. Even with such a manufacturing method, a chip-type resistor similar to the above-described embodiment can be manufactured. Further, the present invention is not limited to the chip type resistor, but can be applied to various electric components having a glass layer having a mark on the surface. In addition, the specific configuration of each part of the electric component according to the present invention can be variously changed in design. Similarly, the specific configuration of each operation step in the method for manufacturing an electric component according to the present invention can be variously changed.
[Brief description of the drawings]
FIG. 1 is a sectional view showing an example of an electric component according to the present invention.
FIG. 2 is a plan view of a collective board used for manufacturing the electric component shown in FIG.
FIG. 3 is a plan view showing steps of a method for manufacturing the electric component shown in FIG.
FIG. 4 is a cross-sectional view showing a step of the method for manufacturing the electric component shown in FIG.
FIG. 5 is a cross-sectional view showing a step of the method for manufacturing the electric component shown in FIG.
FIG. 6 is a cross-sectional view showing a step of the method for manufacturing the electric component shown in FIG.
FIG. 7 is a cross-sectional view showing a step of the method for manufacturing the electric component shown in FIG.
FIG. 8 is a cross-sectional view showing a step of the method for manufacturing the electric component shown in FIG.
FIG. 9 is a cross-sectional view illustrating an example of a conventional electric component.
[Explanation of symbols]
1 substrate 3 resistive film (conductor)
4 Undercoat glass layer 5 Middle coat glass layer (second glass layer from the top)
6 Overcoat glass layer (top glass layer)
7 Marks 41, 51, 61 recess

Claims (3)

It has a plurality of glass layers formed by stacking on the conductor so as to cover the conductor provided on the substrate, and a glass mark is formed on the surface of the uppermost glass layer. Electrical components,
An electric component, characterized in that a recess is formed at least in the surface of the second glass layer from above in a region immediately below the mark, and the uppermost glass layer sinks into the recess. 2. The glass layer according to claim 1, wherein, in the glass layers other than the uppermost glass layer, the softening point of at least one glass layer is lower than the softening point of the uppermost glass layer. Electrical component. A step of stacking and forming a plurality of glass layers on the conductor so as to cover the conductor provided on the substrate,
Forming a glass mark on the surface of the uppermost glass layer;
Firing the plurality of glass layers and the mark;
A method for manufacturing an electric component having
In the step of stacking the plurality of glass layers, at least one glass layer below the uppermost glass layer is formed using a glass having a softening point lower than the uppermost glass layer, Manufacturing method of electrical parts.

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