JP5373912B2 - Low resistance chip resistor and manufacturing method thereof - Google Patents

Description

  The present invention relates to a chip resistor, and more particularly to a low resistor chip resistor and a method of manufacturing the same.

  Recently, in order to protect an overcurrent entering a multifunctional portable device or the like, a chip resistor having a low resistance value for current detection is frequently used. Therefore, there is a demand for an increase in the rated power so that the resistor has the same size and resistance value and can detect a larger current value. Thus, the requirement increases self-heating of the resistor. And the malfunction which damages the protective film of the resistor, the printed wiring board after mounting of the resistor, etc. occurs.

  Therefore, Patent Document 1 reinforces the mechanical strength of a component by bonding a resistor 2 directly on a ceramic substrate 1 by thermal diffusion.

  Patent Document 2 also discloses a method in which a resistor is integrally bonded to a ceramic substrate by an activated metal method using silver solder or the like.

  Further, Patent Document 3 proposes a resistor to which a technique of applying a resistance foil to a ceramic substrate with an inorganic adhesive containing silica is applied.

JP 2006-313763 A Japanese Patent Laid-Open No. 11-97203 JP-A-9-320802

  However, in Patent Document 1, when a resistance metal plate or foil is bonded to a ceramic substrate, bonding by thermal diffusion in an atmosphere of a high temperature of 960 to 980 ° C. and an oxygen concentration of 50 ppm or less becomes large-scale as a mass production facility. A problem is assumed. Further, since the cutting width is adjusted within the allowable range of the resistor width for adjusting the resistance value, it is difficult to mechanically easily cut the resistance metal plate and the ceramic. In addition, the electrical characteristics of the resistive metal plate may be deteriorated by the high temperature treatment.

Patent Document 2 applies an activated metal method using silver braze or the like when a resistance metal plate or foil is bonded to a ceramic substrate. In this case as well, there is no description of specific conditions such as temperature as in Patent Document 1, but it is assumed that the temperature is exposed to about 800 ° C. Thereby, there is a problem similar to that of Patent Document 1.
Further, in Patent Document 3, a resistance foil is provided from an upper surface to a side surface of a substrate via an inorganic adhesive mainly composed of silica. It is described that the resistance value is adjusted by forming an opening by laser trimming or the like. However, in that aspect, it is assumed that when an opening is formed in the resistance foil by adjusting the resistance value, current concentration occurs in that portion, leading to a decrease in the life characteristics of the resistor.

  Therefore, the present invention has been made to solve the above-described problems, and the problem is that a higher current can be detected, and a high electrical durability and a low self-supporting mechanical strength are improved. The present invention provides a resistor chip resistor. Here, giving the chip resistor the above self-supporting property means that the chip resistor has sufficient mechanical strength to be mounted by a mounting machine, and also has high electrical durability. This means that it can be applied to a large current. Therefore, even when a large current is applied, a substrate or a resistance film that reduces the surface temperature of the resistor, and a low-resistance chip-type resistor with a resistance layer structure that has a self-supporting property while reducing the volume further To be able to get.

  Another object of the present invention is to enhance the electrical durability of the resistor by using an end face electrode or a belt-like one provided with a protective film if necessary, which is a laminate of a substrate and a resistance layer. Therefore, without providing the current concentration portion due to the trimming trace in the resistance layer, instead of adjusting the cutting width in the longitudinal direction of the band and cutting with a preset width according to the resistance value, it is easy and quick This method makes it possible to manufacture a highly accurate resistor.

The low-resistance chip-type resistor according to the present invention is a solution to the above-mentioned problem, and the gist thereof is that a resistance layer is formed on both the front and back surfaces of the substrate, and a protective film is formed on the center of both the front and back surfaces. The front and back electrodes are disposed on both sides of the protective film on the resistance layer, and end electrodes are formed on both ends of the substrate, the resistance film, and the front and back electrodes. It is made of an insulating resin or rubber dispersed in the metal, and the resistance layer is either a metal plate or a metal foil.
Here, as the metal plate or metal foil of the resistance layer, there are manganin, nichrome, iron / chromium / aluminum, or an alloy thereof. Among them, the metal plate is 0.1 mm or more and the metal foil is less than 0.1 mm. It is set by the volume resistivity specified by the kind of the low resistance metal plate and its thickness depending on the desired resistance value. Therefore, various plates and foils are conceivable depending on the thickness of the resistance film. In addition to acrylic resin, insulating resin or rubber with ceramic powder dispersed inside is epoxy resin, chloroprene rubber, butyl rubber, urethane rubber, nitrile-butadiene rubber, styrene-butadiene rubber, One or more selected from polyester resins, polyvinyl chloride resins, polyurethane resins, silicone resins, phenol resins, amide resins, imide resins, cellulose resins, and ABS resins. Further, the resistance layer is made of manganin, nichrome, iron / chromium / aluminum, or an alloy thereof. In addition, an epoxy resin, a polyimide resin, a silicone resin, etc. can be considered as a raw material of the protective film, and the surface electrode is formed from a copper, nickel, tin plating film on the resistance layer in order from the bottom, for example, by electroplating. The end face electrode is made of, for example, a copper, nickel, or tin plating film by electroplating on a nichrome film by sputtering or a film by conductive resin paste from below.

According to a third aspect of the present invention, there is provided a method for manufacturing a low-resistance chip-type resistor. And a protective film is formed in the longitudinal center of both sides of the laminated belt-like front and back, and a front electrode and a back electrode are formed on the resistance layer on both sides of the protective film, and the substrate, the resistance film, and the front and back are formed. After end face electrodes are formed on both ends of the electrode, it may be obtained by crossing in the longitudinal direction of the belt and cutting to a predetermined width.
The present invention is a method of manufacturing a low resistance chip resistor according to claim 1, characterized in that a resistance layer and a protective film are formed on both front and back sides of a belt-like substrate, and front and back electrodes and end electrodes are formed on both sides thereof. It is characterized by applying a technique in which the formed belt-like material is crossed in the longitudinal direction and cut into a length (predetermined width) designed in advance.

According to another aspect of the present invention, there is provided a method for laminating the resistance layer on the strip-shaped insulating resin or rubber substrate according to the third aspect, wherein the resistance layer of either the metal plate or the metal foil is used. Heating and sticking to the substrate, and the both ends of the laminated strip in the longitudinal direction are laminated by rolling that presses more than the central part where the protective film formed in the subsequent process is located. .
According to the present invention, both end portions in the longitudinal direction of the laminated body are pressed more greatly than the center portion so that they are integrated in the inner direction from both end sides of the laminated body.

According to a fifth aspect of the present invention, the method for laminating the resistive layer on the strip-shaped insulating resin or rubber substrate according to the third aspect is characterized in that the resistive layer of either the metal plate or the metal foil is used. Heating and sticking to the substrate, and laminating the central portion in the longitudinal direction where the protective film formed in the post-process of the laminated strip is positioned by rolling that presses more than both ends.
In the present invention, the laminated central portion in the longitudinal direction is pressed more greatly than both end portions, and both end sides are sufficiently integrated from the central portion of the laminate.

According to a second aspect of the present invention, a substrate is formed in the center of both front and back surfaces of the resistance layer, and front and back electrodes are disposed on the resistance layer on both sides of the substrate, and the resistance layer and the substrate There is one in which end electrodes are formed on both sides, the substrate is made of an insulating resin or rubber in which ceramic powder is dispersed, and the resistance layer is either a metal plate or a metal foil.
The invention of claim 2 is a simplified structure than that of claim 1 in which the substrate of claim 1 and the resistance layer are reversed and the substrate also has a protective film function.

As a low resistance chip-shaped manufacturing method according to the present invention of claim 2, the resistance layer is heated at the center in the longitudinal direction on both the front and back sides of the belt-like resistance layer of either a metal plate or a metal foil, and the ceramic An insulating resin or rubber substrate in which powder is dispersed is bonded to form a front electrode and a back electrode on the resistance layer on both sides of the substrate, and end electrodes are formed on both ends of the resistance layer and the substrate. Thereafter, it is obtained by crossing the strip in the longitudinal direction and cutting it to a predetermined width.
The sixth aspect of the present invention is a method for manufacturing the low resistance chip resistor of the second aspect.

  The feature of the present invention is that it can detect even larger currents, improves the mechanical strength of high electrical durability and self-sustainedness, and further protects the surface of the low-resistance chip resistor when the current is applied or the surface on the substrate Reduced temperature. In order to achieve the effect, an insulating resin in which ceramic powder is dispersed or a rubber insulating resin is applied to the substrate of the present invention. In addition, the current resistance between the trimming grooves in the conventional resistance layer, which is a cause of lowering the electrical durability of the low resistance chip resistors to which the insulating resin is applied, is manufactured in a quick and easy manner. can do.

(A) And (b) is the one part strip | belt-shaped schematic perspective view which manufactures the low resistance chip-type resistor of this invention, and its cross-sectional view. (A) And (b) is the one part strip | belt-shaped schematic perspective view and cross-sectional view which manufacture the chip resistor of the low resistance which is an Example different from FIG. (A) -1-4 and (b) -1-4 are explanatory drawings which show the manufacture procedure of the low resistance chip-type resistor of FIG. (A) -1-4 and (b) -1-4 are explanatory drawings which show a manufacturing procedure different from FIG. (A) -1-4 and (b) -1-4 are explanatory drawings which show the manufacture procedure of the low resistance chip-type resistor different from FIG.3 and FIG.4. (A) -1 to 3 and (b) -1 to 4 are explanatory views showing a manufacturing procedure of the low-resistance chip resistor of FIG. It is the graph which compared the surface temperature of the resistor using the insulated substrate of this invention, and the conventional insulated substrate.

DESCRIPTION OF SYMBOLS 1 Insulation board | substrate 2 Resistance layer 3 Protective film 4-1 Front electrode 4-2 End surface electrode 4-3 Back electrode

Assuming that the low-resistance chip-type resistor is a thin, small and low-resistance resistor, it is possible to improve durability by increasing the mechanical strength by giving it self-independence.
Further, in the method of the present invention, a belt-like substrate and a resistance layer are stretched, and a protective film, front and back electrodes and end face electrodes, or a resistance layer and a substrate provided with front and back electrodes and end face electrodes, It is manufactured by cutting in a predetermined width by crossing in the direction.

The configuration of the low resistance chip resistor according to the present invention will be described below.
1 (a) and 1 (b) are a perspective view of a long object of an insulating substrate in which alumina powder, which is a kind of ceramic powder, is dispersed in an epoxy resin in a volume ratio of 7 to 3, and a cross section thereof. FIG. In these figures, both the front and back surfaces of a strip-shaped substrate 1 having a thickness of 0.3 mm and a width of 4.3 mm have a length of approximately several meters of a strip-shaped substrate having a thickness of 0.05 mm and a width of 6.3 mm. A metal plate made of iron, chrome, and aluminum alloy is laminated as the resistance layer 2. In the longitudinal direction of the central part of the upper and lower sides of the resistance film, an epoxy resin protective film 3 is formed by a screen printing method to a thickness of about 10 μm, and the substrate is placed on the resistive layer 2 on both sides of the upper and lower protective films 3. The front and back electrodes 4-1 and 4-3 are polymerized through end face electrodes 4-2 provided at the end portions of 1 and the resistance layer 2, respectively.
Note that the above-mentioned long layered objects are cut every 3.2 mm shown in FIG. 1A to complete the low-resistance chip resistor of the present invention.
As shown in the graph of FIG. 7, the resistance of the resistor generated when a current corresponding to 0.5 W, 1 W, 1.5 W, 2 W is applied to the low resistance chip resistor of the present invention. The surface temperature of the protective film depends on the insulating resin or rubber insulating resin substrate in which the ceramic powder is dispersed (A), and the insulating resin or rubber insulating material in which the ceramic powder is not dispersed in the conventional product. It shows that there is a difference between the resin substrate (B). As a result, the surface temperature of the protective film when a current corresponding to each of the electric powers is applied is mixed with ceramic powder dispersed in the substrate of the present invention rather than the conventional ceramic substrate, and the heat release effect is more effective. It turns out that there is.

Next, the manufacturing method of the low resistance chip resistor of the present invention will be described below.
(Example 1-1)

FIGS. 3A and 3B are a partial perspective view and a transverse cross-sectional view showing a manufacturing procedure of the low-resistance chip resistor of FIG.
FIGS. 1 (a) -1 and (b) -1 are insulating plates 1 in which alumina powder is dispersed and mixed in an epoxy resin. In FIGS. An iron / chrome / aluminum alloy metal plate is stretched, heated at 150 ° C. to 200 ° C., pressed and rolled in the range of 2 hPa to 3 hPa, and in (a) -3 and (b) -3, the upper and lower centers The above-mentioned epoxy resin is screen-printed on the part and baked at a temperature of 150 ° C. to 250 ° C., and both ends are sequentially immersed in a chromium / nickel solution in (a) -4 and (b) -4. Finally, as shown in (a) -4, it is crossed in the longitudinal direction and cut into a predetermined resistance value, for example, every 3.0 mm to 3.3 mm, and finished.
(Example 1-2)

The embodiment shown in FIG. 4 is a modification of the above-described (Example 1-1).
This embodiment differs from (Example 1-1) in that when the resistance film 2 is heated and rolled on the insulating substrate 1, both ends are stronger than the center in the width direction, that is, the center is 1.5 hPa. And both sides are to press and roll at 3 hPa.
(Example 1-3)

The embodiment shown in FIG. 5 shows another modified example different from the above-mentioned (Example 1-1) and (Example 1-2).
When this example is different from (Example 1-1) and (Example 1-2), the resistance layer 2 is heated and rolled on the insulating substrate, which is opposite to the above (Example 1-2). The center part is pressed at 3 hPa at both end parts 1.5 hPa in the width direction and rolled.

FIGS. 2A and 2B are resistors different from those in the above embodiment. In FIG. 2, the resistive layer 2 is a strip-shaped layer having a thickness of 0.1 mm and a width of 6.3 mm, which is about several meters in size. An insulating substrate 1 in which ceramic powder is dispersed in epoxy resin is laminated at the upper and lower central portions of a metal plate made of iron, chrome, and aluminum alloy.
Note that there are upper and lower electrodes on both upper and lower sides of the upper and lower substrates via end face electrodes 4-2 at both ends of the resistance layer 2.
(Example 2-1)

The embodiment shown in FIG. 6 is the manufacturing method of Embodiment 2 described above.
Insulating substrate 1 in which alumina powder is dispersed and mixed in an epoxy resin at a volume ratio of 7: 3 is heated at 150 ° C. to 200 ° C. at the center of the front and back sides of resistance layer 2 of a metal plate made of iron, chrome, and aluminum alloy. , Rolled and laminated, screen-printed front and back electrodes 4-1 and 4-3 on the upper and lower sides of the resistance layer on both sides of the substrate, heated at 150 to 250 ° C. Baking is carried out by sequentially dipping in a solution made of chromium / nickel, and finally it is cut to a width of 3.0 mm to 3.3 mm as shown in FIG.

  Used as a low-resistance chip resistor.

Claims (6)

  A resistance layer is formed on both the front and back surfaces of the substrate, a protective film is formed on the center portion of the front and back surfaces, and a front electrode and a back electrode are disposed on both sides of the protective film on the resistance layer, and the substrate, the resistance film, And an end face electrode formed on both ends of the front and back electrodes, the substrate is made of insulating resin or rubber in which ceramic powder is dispersed, and the resistance layer is either a metal plate or a metal foil. A low-resistance chip resistor characterized by being.   A substrate is formed at the center of both front and back surfaces of the resistance layer, front and back electrodes are arranged on the resistance layer on both sides of the substrate, and end electrodes are formed at both ends of the resistance layer and the front and back electrodes. A low resistance chip resistor characterized in that the substrate is made of insulating resin or rubber in which ceramic powder is dispersed, and the resistance layer is made of either a metal plate or a metal foil. .   A resistive layer made of a metal plate or metal foil is laminated on both the front and back sides of a strip-shaped insulating resin or rubber substrate with ceramic powder dispersed inside, and a protective film is formed at the center in the longitudinal direction on both sides of the laminated strip-shaped front and back surfaces. The front and back electrodes are formed on the resistance layer on both sides of the protective film, and end electrodes are formed on both ends of the substrate, the resistance film, and the front and back electrodes, and then crossed in the longitudinal direction of the strip. A method of manufacturing a low-resistance chip resistor, which is obtained by cutting to a predetermined width.   The method of laminating the resistance layer on the band-shaped insulating resin or rubber substrate according to claim 3 is to heat and paste the resistance layer of either the metal plate or the metal foil to the substrate. In addition, a method of manufacturing a low-resistance chip resistor, characterized in that the laminated strip-like longitudinal ends are laminated by rolling that presses larger than the central portion where a protective film formed in a later step is located.   The method of laminating the resistance layer on the band-shaped insulating resin or rubber substrate according to claim 3 is to heat and paste the resistance layer of either the metal plate or the metal foil to the substrate. And the manufacturing method of the chip resistor of low resistance characterized by laminating | stacking the center part of the longitudinal direction in which the protective film made in the laminated | stacked strip | belt-shaped post-process was located more greatly than the both ends.   The resistance layer is heated and the insulating resin or rubber substrate in which the ceramic powder is dispersed is bonded to the longitudinal center portions of the front and back surfaces of the belt-shaped resistance layer of either the metal plate or the metal foil, and the substrate A front electrode and a back electrode are formed on the resistance layers on both sides of the substrate, and end electrodes are formed on both ends of the resistance layer and the substrate, and then crossed in the longitudinal direction of the strip and cut to a predetermined width. A method for manufacturing a chip resistor having a low resistance.

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