WO2007132721A1 - Electronic component and method for manufacturing the same - Google Patents

Abstract

[PROBLEMS] To provide an electronic component, which can improve adhesion particularly between an electrode layer and a resistor layer and, at the same time, can improve the strength of the electrode layer and the resistor layer, and a method for manufacturing the same. [MEANS FOR SOLVING PROBLEMS] An electrode layer (22) comprises a composite powder comprising silver as a main component and bismuth oxide or carbon, or comprising silver as a main component and bismuth oxide and carbon. As compared with a silver powder, the composite powder is less likely to be melted at a firing temperature for curing a binder resin. Accordingly, as compared with the prior art technique, heat generation caused by the melting can be properly suppressed. As a result, decomposition of the binder resin and the like can be suppressed. Accordingly, the adhesion between the resistor layer and the electrode layer can be properly improved, and, at the same time, the strength of the resistor layer and the electrode layer can be improved, and when a transfer plate (30) is separated, the resistor layer is not separated together with the transfer plate (30) and, thus, a transfer-type substrate can be stably formed.

Description

 Specification

 Electronic component and method of manufacturing the same

 Technical field

 The present invention relates to an electronic component including a stacked electrode layer and a resistor layer, and a substrate supporting the electrode layer and the resistor layer.

 Background art

 Patent Documents 1 and 2 listed below disclose transfer type substrates formed by transferring a resistor layer to a substrate made of epoxy resin or the like. The transfer type substrate has a structure in which a resistor layer is provided in a predetermined pattern on the surface of a molded substrate, and electrode layers are formed under the both end portions of the resistor layer. A terminal electrically connected to each of the electrode layers is provided, and a slider is provided between the electrode layer and the electrode layer for sliding on the surface of the resistor layer. A change in voltage corresponding to the sliding position of the slider can be detected between the terminal and the terminal.

 [0003] First, the transfer type substrate is screen-printed on a transfer plate, for example, a paste-like resistor layer formed by mixing carbon black and a thermosetting binder resin in a solvent.

Next, a paste-like electrode layer in which a thermosetting binder resin and silver particles are mixed in a solvent is screen-printed on the resistor layer.

Then, the binder resin used in the resistor layer and the binder resin provided in the electrode layer are thermally cured by heating at a temperature of about 400 ° C.

Then, a transfer plate in which an electrode layer is superimposed on the resistor layer is mounted in a mold, an epoxy resin or the like is injected into the cavity of the mold, and the substrate is injection-molded and cooled. Later, the transfer plate is peeled off.

[0007] Thus, a resistor layer appears on the surface of the substrate, and in a state in which the electrode layer is superimposed on the inside of the resistor layer, the resistor layer and the electrode layer are supported in the substrate. Become.

 Patent Document 1: Patent Publication of Patent No. 3372636

Patent Document 2: Japanese Patent Application Laid-Open No. 2004-55900 Disclosure of the Invention Problem to be Solved by the Invention

 However, the transfer type substrate described above has the following problems.

 That is, at the time of firing for curing the binder resin, in particular, when the firing temperature is increased to accelerate crosslinking of the binder resin, or when the firing time is extended, the silver particles contained in the electrode layer are melted and Binder resin and carbon powder are decomposed by this heat to generate heat. It was not possible to obtain an electrode layer or a resistor layer having sufficient film strength due to the decomposition of such a resin or the like. In addition, a gap due to decomposition of the resin or the like is generated between the electrode layer and the resistor layer, and the electrode layer erodes the resistor layer, so that the resistor layer can not be sufficiently cured by heat curing. The adhesion between the resistor layer and the electrode layer was reduced. Therefore, when the above-mentioned transfer plate is peeled off, the problem that the resistor layer peels off from the substrate side together with the transfer plate occurred.

Also, even if the resistor layer does not separate from the substrate side together with the transfer plate, the film strength is low, and the sliding of the slider causes wear, so that it is used immediately and repeatedly. There is also a possibility that the resistor layer peels off the substrate. Thus, the sliding characteristics can not be improved, and a long-life resistive substrate can not be obtained.

 Further, the erosion of the electrode layer into the resistor layer leads to a reduction in the thickness of the resistor layer, leading to a decrease in migration resistance since the entire silver particles of the electrode layer approach the surface of the resistor layer. .

 [0011] In the inventions described in Patent Documents 1 and 2, as a matter of course, the above-mentioned problems are not recognized, and means for solving the problems are not presented.

Patent Document 2 deals with the point that silver powder leaches out to the surface of a resistor layer, but a decrease in film strength starting from the melting of silver powder, a decrease in adhesion between a resistor layer and an electrode layer, etc. There is no problem recognition. Moreover, although patent document 2 is invention which makes a thermosetting resin temperature a difference with the binder resin contained in the said electrode layer, and the binder resin contained in the said resistor layer, the melting of the silver particle by baking is appropriate. It is necessary to use different binder resins for the electrode layer and the resistor layer, and it is necessary to use a different binder resin. Basically, since the firing step for the electrode layer and the firing step for the resistor layer are performed in separate steps, there is a problem that the manufacturing step is likely to be complicated.

 Therefore, the present invention is intended to solve the above-mentioned conventional problems, and in particular, the adhesion between the electrode layer and the resistor layer can be improved, and the force of the electrode layer and the film of the resistor layer can be improved. It is an object of the present invention to provide an electronic component capable of improving strength and a method of manufacturing the same.

 The electronic component in the present invention is

 It comprises: a stacked electrode layer and a resistor layer; and a substrate for supporting the electrode layer and the resistor layer,

 The electrode layer has a thermosetting binder resin and conductive particles dispersed in the binder resin,

 The conductive particles are characterized in that they contain silver as a main component, bismuth oxide, carbon, or a composite powder comprising bismuth oxide and carbon.

 [0015] "Composite powder" is different from "mixed powder" or "alloy" in which a plurality of types of particles are simply mixed, and when one particle is taken out, silver and bismuth oxide or silver may be added to the particle. And carbon, or silver and bismuth oxide and carbon.

 [0016] The composite powder containing silver as a main component is harder to melt (or is insoluble) at a firing temperature for curing the binder resin than silver powder. Accordingly, heat generation due to the melting can be appropriately suppressed as compared with the conventional case, and as a result, decomposition of the binder resin and the like can be suppressed. Therefore, compared with the prior art, no gap due to decomposition occurs between the electrode layer and the resistor layer, and the electrode layer does not erode the resistor layer, so adhesion between the resistor layer and the electrode layer can be reduced. While improving appropriately, it is possible to improve the film strength of the resistor layer and the electrode layer.

In the present invention, preferably, the electrode layer and the resistor layer are carried in the substrate, and the surface of the resistor layer appears in the same plane as the surface of the substrate. Re ,. This is formed as a transfer type substrate, and the surface of the resistor layer can be formed into a mirror surface, which is preferable because sliding characteristics can be improved. Furthermore, the thickness of the resistor layer Because it can be maintained, the migration resistance can be improved.

 In the present invention, the binder resin preferably comprises an acetylene-terminated polyisoimide oligomer. Thereby, the glass transition temperature can be increased, and the heat resistance can be improved.

 The resistor layer preferably includes a thermosetting binder resin and carbon powder, and the binder resin of the resistor layer is preferably the same type as the binder resin contained in the electrode layer. It is possible to more appropriately improve the adhesion between the resistor layer and the electrode layer.

 The method of manufacturing an electronic component in the present invention is characterized by having the following steps.

 (A) forming a resistor layer on the transfer plate,

 (b) A paste-like electrode layer obtained by mixing, in a solvent, at least a thermosetting binder resin, silver as a main component and bismuth oxide, or carbon, or bismuth oxide and a composite powder containing carbon. Forming on the resistor layer;

 (c) heat treating the electrode layer to remove the solvent and thermally curing the binder resin;

 (d) A step of peeling off the transfer plate after forming a substrate for supporting the electrode layer and the resistor layer.

 In the present invention, when the heat treatment for thermally curing the binder resin of the paste-like electrode layer is performed in the step (c), the composite powder is more likely to melt than the silver powder. The decomposition of the binder resin can be appropriately suppressed. Therefore, it is possible to appropriately suppress the occurrence of a gap due to decomposition between the electrode layer and the resistor layer, and the phenomenon that the electrode layer erodes the resistor layer.

 Therefore, when the transfer plate is peeled in the step (d), the transfer plate can be properly peeled from the resistor layer, and the resistor layer is peeled together with the transfer plate as in the prior art. Problems can be suppressed. As described above, in the present invention, it is possible to stably manufacture a transfer substrate by a simple manufacturing method.

In the present invention, in the step (a), at least a thermosetting binder resin is contained in a solvent. A paste-like resistor layer formed by mixing with carbon powder is formed on the transfer plate, and the paste-like resistor layer is dried.

 It is preferable to thermally cure the binder resin of the resistor layer together with the binder resin of the electrode layer by the heat treatment in the step (C). In the present invention, even if the binder resin of the resistor layer and the binder resin of the electrode layer are thermally cured in the same firing step, the melting of the composite powder can be appropriately suppressed, and thus the resistor layer is thus obtained. By thermally curing the binder resin of and the binder resin of the electrode layer in the same firing step, the production process can be further facilitated.

 In the present invention, the use of a resin of the same type as the binder resin mixed in the electrode layer as a binder resin for the antibody layer improves the adhesion between the electrode layer and the resistor layer. While being possible, the manufacturing process can be simplified, which is preferable.

 Effect of the invention

 The electronic component in the present invention is configured to have a stacked electrode layer and resistor layer, and a substrate supporting the electrode layer and the resistor layer, and the electrode layer is thermally cured. Conductive particles dispersed in the binder resin, and the conductive particles contain silver as a main component and bismuth oxide, or carbon, or bismuth oxide, and carbon. It is characterized by including the following composite powder.

 [0027] The above composite powder is less likely to melt (or is insoluble) at a firing temperature for curing Noinda resin, as compared to silver powder. Therefore, the heat generation due to the melting can be appropriately suppressed as compared with the conventional case, and as a result, the decomposition of the binder resin and the like can be suppressed. Therefore, compared with the conventional case, no gap due to decomposition is generated between the electrode layer and the resistor layer, and the electrode layer does not erode the resistor layer, so that the adhesion between the resistor layer and the electrode layer is appropriate. It is possible to improve the resistance and to improve the film strength of the resistor layer and the electrode layer.

Therefore, when the electronic component in the present invention is a substrate on which the slider slides on the resistor layer, the electronic component is a long-life substrate with excellent sliding characteristics. Further, when the electronic component of the present invention is manufactured as a transfer type substrate, when the transfer plate is peeled off, the transfer type substrate can be stably manufactured without peeling off the resistor layer together with the transfer plate. BEST MODE FOR CARRYING OUT THE INVENTION

 FIG. 1 is a perspective view showing a resistive substrate (electronic component) used for a variable resistor according to the present embodiment, FIG. 2 is a plan view of the resistive substrate, and FIG. 3 is a III-III line of FIG. FIG.

 The resistor substrate 1 has an insulating molded substrate 2 formed of an epoxy resin or the like. A circular opening 2a to which a rotor is attached is formed at the center of the molded substrate 2. A common electrode pattern 3, a resistance detection pattern 4 and an electrode auxiliary pattern 5 are formed on the surface 2b of the molded substrate 2, and these main portions are ring-shaped patterns concentric with the center of the opening 2a. It is formed. The common electrode pattern 3 has a continuous lead-out pattern 3a which extends to the side edge 2c of the molded substrate 2, and the lead-out pattern 4a continuous with the resistance detection pattern 4 and the lead-out pattern 5a continuous with the auxiliary electrode pattern 5 Extend to the edge 2c.

 Terminals 6a, 6b and 6c made of a conductive metal material project from the side edge 2c of the molded substrate 2, and the terminal 6a is superimposed on the lead pattern 3a and made conductive, and the terminal 6b and 6b are formed. The terminals 6c are superimposed on the extraction patterns 4a and 5a and are conducted respectively.

 Further, the resistance detection pattern 4 and the electrode auxiliary pattern 5 are connected in series with each other in the connection pattern 5 b. The electrode auxiliary pattern 5 is a wire-wound reed that connects one end of the resistance detection pattern 4 to the terminal 6c. It is a turn.

 [0033] FIG. 3 shows a cross section taken along a line ΠΙ_ΠΙ in FIG.

 A part of 4 and its drawing pattern 4 a and a part of the electrode auxiliary pattern 5 appear. As shown in FIG. 3, each pattern has a region formed of only the resistor layer 21 and a region in which the electrode layer 22 is stacked on the substrate inward side of the resistor layer 21.

In FIG. 2, the region formed of only the resistor layer 21 is shown with dots, and the region where the resistor layer 21 and the electrode layer 22 are stacked is shown with hatching. ing. The resistor layer 21 and the electrode layer 22 are stacked over the entire area of the common electrode pattern 3 and the drawing pattern 3a thereof. In the resistance detection pattern 4, the range of the angle Θ is formed only by the resistor layer 21, and the resistor layer 21 and the electrode layer 22 are laminated on both ends and the lead pattern 4 a. The electrode auxiliary pattern 5 is formed by laminating the resistor layer 21 and the electrode layer 22 over the entire area including the lead pattern 5a and the connection pattern 5b. ing.

 That is, the range of the angle Θ of the resistance detection pattern 4 is a force S formed only by the resistor layer 21 in order to detect a change in resistance value according to the sliding position of the slider, The other patterns are formed by the electrode layer 22, and the electrode layer 22 is not exposed to the surface 2b, and is covered with the resistor layer 21 as shown in FIG.

 The terminals 6a, 6b, 6c are embedded in the molded substrate 2, and the electrode layer 22 formed on the inner side of the substrate by the pullouts, the turns 3a, 4a, 5a, Each of the terminals 6a, 6b, 6c is joined, for example, via an adhesive layer (not shown) of silver.

 A rotor (not shown) is attached to the opening 2a, and a conductive slider (not shown) attached to the rotor is a force of the surface of the common electrode pattern 3 and a resistance detection butter. Slide in a state where it is conducted to the surface of the run 4. As a result, a change in resistance corresponding to the sliding position of the slider can be detected between the terminals 6a and 6b and between the terminals 6a and 6c.

 In the present embodiment, the electrode layer 22 includes a thermosetting binder resin and conductive particles dispersed in the binder resin, and the conductive particles contain silver as a main component. A composite powder comprising bismuth oxide, carbon, or bismuth oxide and carbon is used. Here, “composite powder” is different from “mixed powder” in which silver powder and bismuth oxide powder are simply mixed and “alloy” in which a plurality of metals are dissolved, and when one particle is taken out, silver is added to the particles. And bismuth oxide, or silver and carbon, or silver and bismuth oxide and carbon.

 A composite powder consisting of silver and bismuth oxide or a composite powder consisting of silver and carbon may be used, but a composite powder containing all of silver, bismuth oxide and carbon is more preferable. For example, about 79 at% (atomic%) of Ag as a main component and about 16 at% of bismuth oxide (Bi 2 O 3)

 twenty three

 And carbon at about 5 at%.

The electrode layer 22 may contain conductive particles other than the composite powder together with the composite powder. The conductive particles are preferably contained in the electrode layer 22 in an amount of 5 to 50% by volume. If the content of the conductive particles is less than 5% by volume, the specific resistance of the electrode layer 22 becomes large, and the specific resistance can not be sufficiently lowered compared to the resistor layer 21. The When the conductive particles are more than 50% by volume, the volume ratio of the binder resin becomes too small, and the film strength is unfavorably lowered. Therefore, it is preferable that the conductive particles contain 5 to 50% by volume.

The binder resin is selected from thermosetting resins such as polyimide resin, bismaleimide resin, epoxy resin, phenol resin, and acrylic resin, and in particular, it is preferable that the glass contains an acetylene-terminated polyisoimide oligomer. It is preferable to increase the transition temperature (Tg) and improve the heat resistance.

 The electrode layer 22 is formed by screen printing a conductive paste obtained by mixing the binder resin, conductive particles and the like in a solvent in a predetermined pattern shape, and removing the solvent by a heat treatment step, and The binder resin is thermally cured.

 The resistor layer 21 is obtained by dispersing carbon powder as a conductive powder inside a thermosetting binder resin. The carbon powder is carbon black, graphite, carbon fiber, carbon beads, carbon nanotubes, etc., and is not particularly limited.

 The binder resin constituting the resistor layer 21 is, for example, a polyimide resin, a bismaleimide resin, an epoxy resin, a phenol resin, an acrylic resin, etc., similarly to the binder resin constituting the electrode layer 22. It is selected from thermosetting resins.

 The binder resin of the resistor layer 21 and the binder resin of the electrode layer 22 are the same type. This is preferable in order to improve the adhesion between the resistor layer 21 and the electrode layer 22. Here, "homogeneous" includes not only the case of the same resin but also derivatives of the resin. Further, as with the binder resin of the electrode layer 22, the binder resin of the resistor layer 21 preferably also contains an acetylene-terminated polyisoimide oligomer in order to increase the glass transition temperature (Tg) and improve the heat resistance.

 Further, the specific resistance of the resistor layer 21 is sufficiently larger than the specific resistance of the electrode layer 22.

 The resistor layer 21 is screen-printed in a predetermined pattern shape of a resistive paste formed by mixing the binder resin, carbon powder and the like in a solvent, and the solvent is removed by a heat treatment step, and The binder resin is thermally cured.

The conductive particles contained in the resistor layer 21 may be other than carbon powder, The carbon powder is preferable in that the resistor layer 21 having excellent electrical stability, resistance to corrosion and the like and excellent in environmental resistance can be formed.

 As shown in FIG. 3, the resistor layer 21 and the electrode layer 22 are embedded in the molded substrate 2, and the surface 21 a of the resistor layer 21 is the same as that of the molded substrate 2. It appears in the same plane as surface 2b. The resistor substrate 1 shown in FIG. 3 is a transfer-type resistor substrate which will be described later in the manufacturing method, and the surface 2 la of the resistor layer 21 is formed of a mirror surface. Thus, the resistance substrate 1 is excellent in sliding characteristics and can obtain a long life.

 In the present embodiment, the conductive particles contained in the electrode layer 22 are composite powders comprising silver as the main component, bismuth oxide or carbon, or bismuth oxide and carbon. is there. The composite powder is less soluble (or insoluble) at the baking temperature for curing the binder resin than silver powder.

 Therefore, the heat generation due to the melting can be appropriately suppressed, and as a result, it is possible to suppress the decomposition of the binder resin, the carbon powder and the like.

 Therefore, while the electrode layer 22 does not intrude into the resistor layer 21 as compared with the conventional case, the adhesion between the electrode layer 22 and the resistor layer 21 can be appropriately improved. The film strength of the electrode layer 22 and the resistor layer 21 can be improved as compared with the prior art.

 By the improvement of the adhesion, it is possible to appropriately prevent the resistance layer 21 from peeling off together with the transfer plate when the transfer plate is peeled off in the process of manufacturing the transfer type resistance substrate.

 Further, even if the slider is repeatedly slid on the resistor layer 21 of the resistor substrate 1 due to the improvement of the adhesion and the film strength, the slider layer is not easily worn and the resistor layer 21 is used at the time of use. The resistance substrate 1 has excellent sliding characteristics without being peeled off from the resistance substrate 1. The migration resistance can also be improved by suppressing the penetration of the electrode layer 22 into the resistor layer 21.

 Next, a method of manufacturing the resistance substrate 1 will be described. In this specification, the term "paste" refers to a binder resin that has been heat-cured to form a state.

First, the first binder resin is dissolved in a first solvent, and for example, carbon black and carbon fiber (ground powder of carbon fiber having an average particle diameter of 3 to 30 μm) are dissolved therein. ) To form a resistive paste. The first binder resin is about 30 to 95% by volume, and the carbon black and the carbon fiber are about 5 to 70% by volume in total (the total of the first binder resin excluding the solvent, carbon black, and carbon fiber Is 100% by volume).

 Prepare a transfer plate 30 (see FIG. 4) formed of, for example, a brass plate. The surface of the transfer plate 30 is mirror finished.

 A stainless steel mask for making the shape of the pattern of the resistor layer 21 (all patterns shown by both dots and hatching in FIG. 2) on the surface of the transfer plate 30 is used for the transfer plate 30; The paste-like resistor layer 21 is screen printed on the surface.

 After printing, the screen-printed paste-like resistor layer 21 is dried at 100 to 250 ° C. for 10 to 60 minutes using a drying oven to evaporate and remove the first solvent. . A part of this drying step (complete drying) may be performed in the same step as drying for the paste-like electrode layer 22 later.

 Next, a paste-like electrode layer 22 is pattern-formed on the resistor layer 21 by screen printing.

 [0061] The electrode paste is a conductive powder such as a second binder resin, silver as a main component, and a composite powder comprising silver as a main component, bismuth oxide, carbon, or bismuth oxide and carbon in a second solvent. It is a mixture of particles. The second binder resin is about 50 to 95% by volume, and the conductive particles are about 5 to 50% by volume (the second binder resin excluding the solvent, the total of the conductive particles is 100% by volume) .

 The transfer plate 30 and the resistor layer 21 are covered with a mask for making a pattern of a hatched area in FIG. 2, and a paste-like electrode layer 22 is formed on the surface of the resistor layer 21 which has been dried. Do.

 After printing, the screen-printed paste-like electrode layer 22 is dried at 100 to 260 ° C. for 10 to 60 minutes using a drying oven to evaporate and remove the second solvent.

Next, the first binder resin and the second binder resin are simultaneously thermally cured by heating in a firing furnace at a firing temperature of about 400 ° C. for 1 to 2 hours. As a result, the resistor layer 21 has a film structure in which carbon powder is dispersed in the thermally cured binder resin. The electrode layer 22 has a film structure in which the composite powder is dispersed in the thermally cured binder resin.

Here, as the first solvent and the second solvent, carbitol acetate, methyl carbitol, ethylolecanolebitone, butyl carbitol, monoglyme, diglyme, methyltriglyme and the like can be used.

 The first binder resin and the second binder resin may be the same type, and the curing temperature of the first binder resin and the second binder resin may be the same or close to each other, and the temperature may be the same. The binder resin of 1 and the second binder resin can be preferably thermally cured in the same baking step. If the curing temperature of the first binder resin and the second binder resin are largely separated, the firing temperature for the resistor layer 21 and the firing for the paste-like electrode layer 22 can be appropriately set in order to thermally cure both of them. It is necessary to control the temperature separately, which complicates the manufacturing process. Therefore, it is preferable to make the first binder resin and the second binder resin the same, and to thermally cure the first binder resin and the second Noinder resin in the same baking process. Further, by making the first binder resin and the second binder resin the same type, the adhesion can be improved. As the first binder resin and the second binder resin, thermosetting resins such as polyimide resin, bismaleimide resin, epoxy resin, phenol resin and acrylic resin can be selected, but are limited thereto Not It is preferable to include an acetylene-terminated polyisoimide oligomer in the binder resin in order to increase the glass transition temperature (Tg) and improve the heat resistance.

 The melting temperature of the composite powder comprising silver, bismuth oxide, carbon, or bismuth oxide and carbon contained in the electrode layer 22 is higher than the curing temperature of the binder resin. ing.

 The electrode paste of the composite powder in the present embodiment has a melting peak at around 440 ° C. as shown in the experimental results of the examples described later, so heat treatment at around 400 ° C. is preferable. It is also difficult to melt. Or it is insoluble. The curing temperature of the polyimide resin is 300 DEG C. to 380 DEG. C, the curing temperature of the bismaleimide resin is about 350 ° C, and the curing temperature of the acetylene-terminated polyisoimide oligomer is about 300 ° C to 400 ° C, so heat treatment is performed at the curing temperature of each thermosetting resin. Also, the melting of the composite powder can be appropriately suppressed.

The glass transition temperature Tg of the polyimide resin is 300. C degree, a glass of bismaleimide resin The glass transition temperature Tg is about 250 to 300 ° C., and the glass transition temperature Tg of the acetylene-terminated polyisoimide oligomer is about 300 ° C. to 350 ° C.

 Next, in the process of FIG. 4, a terminal adhesive layer (conductive adhesive layer) is formed on the surface of the electrode layer 22 in the portion of each lead pattern 3a, 4a, 5a.

 In this step, a paste-like terminal adhesive layer is formed on the surface of the electrode layer 22 by screen printing. For example, in the paste-like terminal adhesive layer, a solvent comprising carbitol acetate etc., 20% by volume of silver powder, 20% by volume of phenol resin and amine compound as a curing agent, 60% by volume of epoxy resin as a main agent (The total volume excluding solvent is 100% by volume). Then, it is dried in an oven at 80 ° C. for 10 minutes to evaporate and remove the solvent in the terminal adhesive layer.

 Next, as shown in FIG. 5, the upper surface of the transfer plate 30 is covered with a mold 40. At this time, the terminals 6a, 6b, 6c are placed on the surfaces of the electrode layers 22 of the lead patterns 3a, 4a, 5a via the paste-like terminal adhesive layers. Then, a molten epoxy resin molding material is injected into the cavity 41 of the mold 40.

 The temperature of the mold 40 is 160 to 200 ° C., and the heat of the mold thermally cures the phenol resin and amine compound, which are curing agents of the terminal adhesive layer, and the epoxy resin of the main agent, The terminals 6a, 6b, 6c are bonded to the electrode layer 22 through the terminal adhesive layer in the lead patterns 3a, 4a, 5a.

 Further, the epoxy resin molding material is cured to form a molded substrate 2. Then, the resistance plate 1 is completed by removing the transfer plate 30 from the molded substrate 2 by taking it out of the mold 40 and as shown in FIG.

According to the manufacturing method of the present embodiment, it is possible to stably manufacture a transfer substrate by a simple manufacturing method. That is, conventionally, the electrode layer 22 corrodes the resistive layer 21 in the firing step, whereby a gap is generated between the electrode layer 22 and the resistive layer 21 due to thermal decomposition, and the adhesion is improved. descend. Thus, when the transfer plate 30 shown in FIG. 6 is peeled off from the resistance substrate 1, the adhesion between the transfer plate 30 and the resistor layer 21, the adhesion between the electrode layer 22 and the resistor layer 21. Although the resistor layer 21 tends to peel off together with the transfer plate 30 in order to become stronger than the force, in the present embodiment, the electrode layer 2 Since it is possible to appropriately suppress the erosion phenomenon into the resistor layer 21 of the second embodiment, the adhesion between the resistor layer 21 and the electrode layer 22 is not reduced compared to the prior art. The adhesion between the resistor layers 21 can be made stronger than the adhesion between the transfer plate 30 and the resistor layers 21.

 Therefore, when the transfer plate 30 is peeled from the resistance substrate 1, only the transfer plate 30 can be appropriately peeled from the resistance substrate 1, and the resistor layer 21 is peeled together with the transfer plate 30. Can be properly prevented.

 Since the surface of the transfer plate 30 is mirror-finished, the surface (sliding surface) of the resistor layer 21 formed directly on the surface of the transfer plate 30 is also formed as a mirror surface. The resistance substrate 1 excellent in dynamic characteristics can be manufactured appropriately and easily.

 In the conventional erosion of the electrode layer, the thickness of the resistor layer is eroded, and the migration resistance performance is degraded when the electrode layer is exposed to the surface, or at least a locally thin portion is formed. However, in the embodiment, this corrosion phenomenon does not occur and the film thickness of the resistor layer does not change, so that the migration resistance is significantly improved.

 Further, in the present embodiment, since the binder resin forming the resistor layer 21 and the binder resin forming the electrode layer 22 can be simultaneously thermally cured in the same baking step, the manufacturing process can be facilitated. .

 As another embodiment, for example, it is possible to present a structure in which an electrode layer and a resistor layer are screen-printed and fired in a predetermined pattern shape on a flat surface of a substrate. In such a case, since the electrode layer and the resistor layer are not transferred to the substrate side, when the transfer plate is peeled off, the problem that the resistor layer is peeled together with the transfer plate may not occur. Since there is no gap due to thermal decomposition between the electrode layer and the resistor layer, it is possible to appropriately improve the adhesion and the film strength of the electrode layer and the resistor layer, as described above. Also in the other embodiments, it is possible to form a resistance substrate which is excellent in sliding characteristics, long in life, and excellent in migration resistance.

 Moreover, it does not exclude the structure by which a resistor layer and an electrode layer are laminated | stacked reversely.

The resistance substrate 1 of the present invention is used not only for the rotary variable resistor as shown in FIG. 1 and FIG. 2, but also for a sliding variable resistor that slides linearly, other resistance sensors, etc. It is possible to do S. Further, a comb tooth shaped code pattern formed by laminating a resistor layer as a protective layer (overcoat layer) on an electrode layer as a conductive layer may be supported on a substrate (insulating substrate). In this case, the present invention is applied to the encoder substrate.

 Example

 As shown in FIG. 7, a resistor layer is formed on a substrate (transfer plate), and an electrode layer is formed on the resistor layer and formed in each of the example and the comparative example. did.

 First, in the comparative example, the electrode layer is formed to have a binder resin and silver powder, and in the example, the electrode layer is formed of an inorganic resin, silver as main components, bismuth oxide, and carbon. To form a composite powder. The resistor layers in the examples and comparative examples are the same, and are formed of a binder resin and carbon powder.

 First, the binder resin used in the electrode layer of the comparative example is an acetylene-terminated polyisoimide oligomer, and the silver powder contains about 30% by volume and the binder resin about 70% by volume.

 On the other hand, similarly, the binder resin used in the electrode layer of the example is also an acetylene-terminated polyisoimide oligomer, and the composite powder contains about 30% by volume in the electrode layer and about 70% by volume of the non-under resin. ing.

 The composite powder contains about 79 at% (atomic%) of Ag as a main component, bismuth oxide (Bi 2 O 3)

 2 3 Force Sl 6at%, carbon 5at% is contained. In the present example, precious metal powder AG-522 manufactured by Shoei Chemical Industry Co., Ltd. was used as the composite powder.

For the examples and comparative examples, first, a resistor layer was formed by screen printing on a transfer plate, and drying was performed at 260 ° C. for 30 minutes to evaporate the solvent. Next, a paste-like electrode layer is formed by the same screen printing on the resistor layer, and after drying for 30 minutes at 260 ° C. for both the example and the comparative example, the solvent is evaporated. Baking was performed at 390 ° C. for 90 minutes to thermally cure the binder resin. Then, the film thickness of only the portion of the resistor layer and the film thickness of the portion where the electrode layer and the resistor layer overlap in the example and the comparative example were measured with a surface roughness meter. The experimental results are shown in Fig. 8 and Fig. 9. The horizontal axis is the dimension in the width direction of the resistor layer and the electrode layer, and the vertical axis is the film thickness. FIG. 8 shows the experimental results of the comparative example, and FIG. 9 shows the experimental results of the example. According to the experimental results of the comparative example shown in FIG. 8, there is a place where the film thickness of the portion where the electrode layer and the antibody layer are laminated is thinner than the film thickness of the portion of the resistor layer alone, From this, it can be seen that in the comparative example, the electrode layer erodes the resistor layer.

 On the other hand, in the example shown in FIG. 9, no erosion of the electrode layer on the resistor layer was observed. The adhesion between the resistor layer and the electrode layer is good when the adhesive tape peel test is carried out according to the cross-cut method CFIS k 5600-56 (in accordance with the cross-cut method for confirming adhesion of the coating film). I understood it. In this test, a cut (cross cut) is made longitudinally and horizontally at 1 mm intervals on the surface of the coating film, a cellophane tape is attached to the portion, the tape is rapidly pulled apart, and the adhesion of the coating film is confirmed. It is.

 Next, FIG. 10 is a SEM (scanning electron microscope) photograph of the vicinity of the boundary between the resistor layer and the electrode layer of the above-described comparative example (near the arrow shown in FIG. 7) as viewed from directly above.

 The light dark spots appearing on the left of FIG. 10 are the surface of the resistor layer, and the white spots appearing on the right are the surface of the electrode layer.

 As shown in FIG. 10, a large number of depressed portions are observed. In particular, near the boundary, the surface of the antibody layer is located on the front side (higher position) than the surface of the electrode layer. It can be seen that Also, it can be seen that the surface of the resistor layer appears in some places from the surface of the electrode layer on the right side, and the electrode layer does not completely cover the surface of the resistor layer.

Next, silver powder (comparative example), about 79 at% of Ag, and about 16 at% of bismuth oxide (Bi 2 O 3),

 twenty three

 The composite powder (Example) containing about 5 at% of carbon is fired at 390 ° C. for 2 hours, respectively, and the SEM photograph of the state after firing is shown in FIGS. FIG. 11 is a SEM photograph of a comparative example, and FIG. 12 is a SEM photograph of an example. Figures 11 and 12 are SEM photographs taken at the same magnification.

 In the comparative example shown in FIG. 11, it was found that a large number of lumps in which the melted silver powder was gathered were seen, and a large number of pores were also formed. On the other hand, in the example shown in FIG. 12, it was found that the composite powder was hardly melted and maintained in the form of fine particles.

Next, the substrate (transfer plate) shown in FIG. 7 used in the experiments of FIG. 8 and FIG. 9 is covered with the mold 40 shown in FIG. 5, and the cavity 41 of the mold 40 is melted with epoxy resin. Injection and molding substrate 2 was formed, and the substrate (transfer plate) was removed to manufacture a transfer type resistance substrate. The shape of the transfer type resistance substrate is the same as that shown in FIGS. 1 to 3.

The surface hardness of the resistor layer laminated on the electrode layer was measured in a pressure tucker test (PCT) in which heating and humidification were performed under high pressure using each transfer type resistance substrate of the example and the comparative example. . The conditions were atmospheric pressure of 0.2 MPa, temperature of 121 ° C., and humidity of 100%, for up to 270 hours.

 In the experiment, the dynamic hardness of the surface was measured under the measurement load of 80 gf and 120 gf. Here, with the dynamic hardness, when a diamond indenter is brought into contact with the sample surface and a very small force is applied to depress the indenter, the indentation load and the indentation depth of the indenter are measured, and the relationship force between the two is obtained. Is obtained by calculating The apparatus used for the measurement is DUH-201 manufactured by Shimadzu Corporation.

 FIG. 13 is a graph showing the relationship between elapsed time and dynamic hardness in Examples. On the other hand, FIG. 14 is a graph showing the relationship between the elapsed time and the dynamic hardness of the comparative example.

 [0099] In the example of FIG. 13, the dynamic hardness did not change much up to 270 hours. On the other hand, in the comparative example of FIG. 14, the dynamic hardness became low in 100 hours, and in particular, it was possible to obtain only small hardness and hardness as compared with the example.

 Next, the surface hardness of the resistor layer laminated on the electrode layer is measured in the heat shock test in which the low temperature state and the high temperature state are alternately repeated using each transfer type resistance substrate of the example and the comparative example. did. The conditions were one cycle of heating from 40 ° C. to 148 ° C. and cooling from 148 ° C. to 140 ° C., and this cycle was performed 164 times.

In the experiment, the surface hardness (dynamic hardness) was measured under the measurement load of 80 gf and 120 gf.

FIG. 15 is a graph showing the relationship between the number of cycles and the dynamic hardness in the example. On the other hand, FIG. 16 is a graph showing the relationship between the number of cycles and the dynamic hardness in the comparative example.

 As shown in FIG. 15 and FIG. 16, it was found that the embodiment was able to obtain higher hardness and dynamic hardness than the comparative example.

In the experimental results shown in FIGS. 13 to 16, in the embodiment, higher hardness can be obtained compared to the comparative example, because the penetration of the electrode layer into the resistor layer is suppressed as compared to the comparative example. Because It is considered to be.

 Next, a submersion migration test was performed using the transfer resistance substrate.

Test conditions, respectively the transfer type resistor substrates of Examples and Comparative Examples people, pure water soaked in (conductivity ^{0. 06 X 10- 4 S / m} ), between the terminal 6a and the terminal 6c between the terminal (Figure 2 An applied voltage of 5 V was applied to), and the insulation resistance at this time was measured. The results are shown in FIG.

 As shown in FIG. 17, in each of the example and the comparative example, the insulation resistance decreases with time, and in the comparative example, the insulation resistance significantly decreases in about 4 hours, whereas in the example, the insulation resistance decreases about 12 hours. It was found that high insulation resistance was maintained, and that the example was superior to the comparative example in migration resistance. This is considered to be because the penetration of the electrode layer into the resistor layer is suppressed in the example compared to the comparative example, and the film thickness of the resistor layer is maintained as a large film thickness.

 [0107] FIG. 18 shows the experimental results of TG-DTA (thermogravimetric differential thermal analysis) for the electrode pastes of Examples and Comparative Examples. As TG-DTA measuring instrument, TG / DTA6200 manufactured by SII Nano Technology Co., Ltd. was used.

 The electrode pastes of the examples and comparative examples used in the experiment are the same as those used in the experiments of FIGS.

 As shown in FIG. 18, the electrode paste of the silver powder of the comparative example had a DTA curve and a TG curve, and had a melting peak around about 380 ° C. and a weight loss was observed.

 Further, as shown in FIG. 18, the electrode paste of the composite powder of the example had a melting peak at around DTA curve and T G curve force of about 440 ° C. and a weight loss was observed.

 The melting peak shown in the experiment corresponds to the melting peak of the composite powder in the example and the melting peak of the silver powder in the comparative example.

 Therefore, it was found that the composite powder of the example was “or less soluble” even by heat treatment at around 400 ° C. Also, since the thermosetting temperature of the binder resin is at most about 400 ° C. (when an acetylene-terminated polyisoimide oligomer is used), the composite powder is appropriately melted even if heat treatment is performed at the curing temperature. It turned out that it can control.

 Brief description of the drawings

[FIG. 1] A perspective view showing a resistance substrate of the present embodiment, [FIG. 2] A plan view of the resistance substrate,

[Fig. 3] A sectional view taken along line III-III in Fig. 2,

4) shows a method of manufacturing a resistance substrate, and is a cross-sectional view of a state in which a resistance layer and an electrode layer are laminated on a transfer plate,

Garden 5] is a process diagram performed next to FIG. 4 and is a sectional view showing a process of forming a substrate, Garden 6] is a process diagram performed next to FIG. 5 and is a sectional view showing a process of peeling a transfer plate [Fig. 7] A sectional view showing the laminated state of the resistor layer and the electrode layer used in the experiment,

8) In the comparative example in which the electrode layer containing silver powder is formed on the resistor layer, the film thickness of only the resistor layer, the film thickness of the portion where the resistor layer and the electrode layer are laminated, and [FIG. 9] A graph showing [FIG. 9] In an embodiment in which an electrode layer containing composite powder consisting of silver, bismuth oxide and carbon is formed on a resistor layer, the film thickness of only the resistor layer and the Graph showing the film thickness of the portion where the body layer and the electrode layer are stacked,

 [FIG. 10] A SEM photograph of the vicinity of the boundary between the resistor layer and the electrode layer of the comparative example (near the arrow shown in FIG. 7) as viewed from directly above,

11) SEM photograph (comparative example) after firing showing a state in which silver powder is fired at 390 ° C. for 2 hours (comparative example), a state in which composite powder consisting of silver, bismuth oxide and carbon is fired at 390 ° C. for 2 hours SEM photograph after firing (example) shown

13) In the example used in the experiment of FIG. 9, the transfer type substrate is manufactured from the state shown in FIG. 7, and the elapsed time when the pressure tacker test (PCT) is performed under predetermined conditions, the resistance antibody layer Graph showing the relationship with the surface hardness (dynamic hardness) of

14) In the comparative example used in the experiment of FIG. 8, the transfer type substrate is manufactured from the state shown in FIG. 7, and the elapsed time when the pressure tacker test (PCT) is performed under predetermined conditions, the resistance antibody layer Graph showing the relationship with the surface hardness (dynamic hardness) of

15) In the example used in the experiment of FIG. 9, the number of cycles and the surface hardness of the resistor layer when the transfer type substrate is manufactured from the state shown in FIG. 7 and heat shock test is performed under predetermined conditions Graph showing the relationship with (dynamic hardness),

16) In the comparative example used in the experiment of FIG. 8, the transfer type substrate is manufactured from the state shown in FIG. 7, and the number of cycles and the surface of the resistor layer when heat shock test is performed under predetermined conditions. Graph showing the relationship with hardness (dynamic hardness),

 [FIG. 17] A graph showing the relationship between elapsed time and insulation resistance when a submersion migration test is performed using the transfer type substrate of the example and the comparative example.

 [FIG. 18] TG-DTA curves for electrode pastes of examples and comparative examples,

Explanation of sign

1 Resistor board (Electronic parts)

2 Molded substrate

2b surface

 3 common electrode pattern

 4 Resistance detection pattern

 5 electrode auxiliary pattern

 3a, 4a, 5a bows | Outbreak pattern

 5b connection pattern

oa, 6b, 6c

 21 Resistor layer

 21 a surface

 22 electrode layer

 30 transfer plate

Claims

The scope of the claims  [1] It comprises: a stacked electrode layer and a resistor layer; and a substrate for supporting the electrode layer and the resistor layer,  The electrode layer has a thermosetting binder resin and conductive particles dispersed in the binder resin,  The electronic component is characterized in that the conductive particles include composite powder comprising silver as a main component, bismuth oxide or carbon, or bismuth oxide and carbon.  [2] The electronic component according to claim 1, wherein the electrode layer and the resistor layer are embedded in the substrate, and the surface of the resistor layer appears in the same plane as the surface of the substrate. [3] The electronic component according to claim 1 or 2, wherein the binder resin comprises an acetylene-terminated polyisoimide oligomer. [4] The resistor layer has a thermosetting binder resin and carbon powder, and the binder resin of the resistor layer is the same type as the binder resin contained in the electrode layer. The electronic component described in 3 or any one of them. [5] A method of manufacturing an electronic component comprising the following steps.  (a) forming a resistor layer on the transfer plate,  (b) A paste-like electrode obtained by mixing, in a solvent, at least a thermosetting binder resin, silver as a main component, bismuth oxide, carbon, or composite powder having bismuth oxide and carbon. Forming a layer on the resistor layer,  (c) heat treating the electrode layer to remove the solvent and thermally curing the binder resin;  (d) A step of peeling off the transfer plate after forming a substrate for supporting the electrode layer and the resistor layer.  [6] In the step (a), a paste-like resistive layer formed by mixing at least a thermosetting binder resin and carbon powder in a solvent is formed on the transfer plate, and the paste-like Dry the resistor layer, The method of manufacturing an electronic component according to claim 5, wherein the binder resin of the resistor layer is thermally cured together with the nodder resin of the electrode layer by the heat treatment in the step (c). The manufacturing method of the electronic component of Claim 6 using resin of the same kind as the binder resin mixed with the said electrode layer as a binder resin of the said resistor layer.