JP2005259897A - Semiconductor element, method for manufacturing the same and coordinate inputting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an excellent and highly reliable semiconductor element which is simple in miniaturization and thin film even when it is exposed or stored in any severe environment. <P>SOLUTION: This semiconductor element is configured by successively laminating a substrate 11 and a first electrode 12, semiconductor layer 13 and second electrode 14 formed on the substrate 11. The semiconductor layer 13 is configured of bonding resin 16 containing semiconductor particles 15 and coupling agent. The top ends 15a of the semiconductor particles 15 are brought into contact or made to invade the first electrode 12 and the second electrode 14, and either of them forms shot key junction. The molecules of the bonding resin 16 are strongly connected to each other by the coupling agent so that mechanical characteristics under a high temperature environment can be improved, and that the stability of electric characteristics can be improved. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a semiconductor element, a method for manufacturing a semiconductor element, and a coordinate input device, and more particularly to a semiconductor element including a semiconductor layer made of semiconductor particles and a binder resin and a method for manufacturing the same.

  In recent years, with the spread and progress of portable information devices, mainly mobile phones, PHS, calculators, watches, GPS (Global Positioning System, Global Positioning Information System), bank ATM systems, mainly electronic notebooks and PDAs (Personal Digital Assistants) Such as vending machines and POS (Point Of Sales) systems, touch panels that can be used to input information by touching the screen with a pen or finger are used for data entry. Applications in the direction are spreading. In particular, downsizing in portable information terminals such as mobile phones, PDAs, and notebook personal computers is remarkable due to advances in semiconductor element and electronic circuit formation technology, and the volume ratio of these input devices or display devices in the terminal body is large. It has become to.

  The touch panel has a structure in which a conductive film and a resistor film are respectively provided on the surfaces of two rectangular resin sheets having a screen shape, for example, and are laminated with a space therebetween. For example, when a resin sheet is touched with a resistor film pen or the like, the conductive film and the resistor film come into contact with each other, and a voltage corresponding to the contacted portion is output. The voltage is distributed with linearity, for example, and coordinates on the screen correspond to the voltage.

  In order to form such a voltage distribution, point electrodes or rectifying elements are arranged on the four sides of the resistor film. In order to detect the coordinate position of the pressed part with high accuracy, the voltage has linearity according to the distance from one side between two opposing sides, and a direction orthogonal to the direction of the two sides Therefore, it is necessary to form a voltage distribution that is substantially constant, and it is necessary to arrange rectifying elements that are miniaturized and thinned at high density.

In order to reduce the size and thickness of the rectifying element, a rectifying element including a semiconductor layer made of semiconductor particles and a binder resin and electrodes sandwiching the semiconductor layer has been proposed (see, for example, Patent Documents 2 and 3). . These rectifying elements can be reduced in size and thinned, are formed by patterning by a simple method such as a printing method, and do not cause much thermal damage to the resin sheet.
Japanese Patent Laid-Open No. 6-187083 Japanese translation of PCT publication No. 2002-508849 (pages 16-18, FIG. 3B) JP 2002-1000075 A

  By the way, as described above, a mobile terminal such as a mobile phone using a touch panel is often exposed to various environments, for example, a high temperature and high humidity environment and a low temperature drying environment, and the environmental change also changes dramatically. There is a case. The above-described semiconductor layer composed of the semiconductor particles and the binder resin has a problem that the binder resin is liable to be softened particularly at a high temperature, resulting in poor contact between the semiconductor particles and the electrode, and deterioration of electrical characteristics.

  Therefore, the present invention has been made in view of the above-mentioned problems, and the object of the present invention is to facilitate downsizing and thinning, and to provide excellent operational reliability even when exposed to or stored in a high temperature and high humidity environment. A semiconductor device, a method for manufacturing the semiconductor device, and a coordinate input device are provided.

  According to one aspect of the present invention, there is provided a semiconductor element comprising a semiconductor layer made of semiconductor particles and a binder resin, and a first electrode and a second electrode sandwiching the semiconductor layer, wherein the binder resin includes Provided is a semiconductor device characterized in that a coupling agent is added.

  According to the present invention, since the molecules of the binder resin that fixes the semiconductor particles are firmly bonded to each other by the coupling agent, the semiconductor particles, the first electrode, and the second electrode are not softened under a high temperature environment. The contact state with the electrode is stable, and the Schottky junction or ohmic junction state is kept good. As a result, the stability of electrical characteristics such as current-voltage characteristics is improved, and a semiconductor element having excellent reliability can be realized.

  The tip of the semiconductor particles may penetrate into the first electrode or the second electrode at each interface between the semiconductor layer and the first electrode and the second electrode. When the tip of the semiconductor particles penetrates into the first electrode or the second electrode, the contact state is further stabilized and the amount of current during conduction can be increased.

  The binder resin may be a hot melt adhesive or an ultraviolet curable resin. Hot-melt adhesives or ultraviolet curable resins do not require the use of a solvent such as water or an organic solvent, and are easy to process. Therefore, a thin film can be easily formed in a state where semiconductor elements are uniformly dispersed.

  According to another aspect of the present invention, a first substrate having a first conductive film formed on one surface, a second conductive film formed on one surface, and the first conductive film and the first conductive film. A second substrate arranged so that the two conductive films face each other, a power source for applying a voltage to the first conductive film, and when the first substrate or the second substrate is pressurized A detection means for detecting a potential at a position where the first conductive film and the second conductive film are in contact with each other, and between the first conductive film and a power source, and any one of claims 1 to 3. There is provided a coordinate input device comprising: a rectifier that rectifies a current flowing in the first conductive film using the semiconductor element according to the item.

  According to the present invention, a highly reliable coordinate input device can be realized because the semiconductor element does not soften or deform even under a severe environment such as a high temperature and is excellent in environmental resistance.

  According to another aspect of the present invention, a step of dispersing semiconductor particles in a binder resin to form a mixture, a step of forming a sheet-like molded product from the mixture, and electrodes on both surfaces of the sheet-like molded product There is provided a method for manufacturing a semiconductor element, comprising: a step of forming; and a step of performing a heat treatment for reacting a coupling agent contained in the sheet-like molded product.

  According to the present invention, before the heat treatment for reacting the coupling agent, the binder resin is molded into a sheet in a fluid state, so that the film can be easily formed. Finally, the binder resin is cupped. By firmly bonding the molecules of the binder resin with the ring agent, it is possible to achieve both the ease of manufacturing and the reliability of the semiconductor element in a high temperature environment.

  According to the present invention, since the molecules of the binder resin for fixing the semiconductor particles are firmly bonded to each other by the coupling agent, the semiconductor having excellent operational reliability even when exposed to or stored in a high-temperature and high-humidity environment. An element can be realized.

  Embodiments will be described below with reference to the drawings.

(First embodiment)
FIG. 1A is a cross-sectional view of a semiconductor element according to the first embodiment of the present invention, and FIG. 1B is an enlarged cross-sectional view of a main part of the semiconductor element shown in FIG.

  Referring to FIGS. 1A and 1B, a semiconductor device 10 according to a first embodiment of the present invention includes a substrate 11, a first electrode 12 formed on the substrate 11, a semiconductor layer. 13 and the second electrode 14 are sequentially stacked. The semiconductor layer 13 is composed of semiconductor particles 15 and a binder resin 16 containing a coupling agent. The semiconductor particle 15 has a tip portion 15 a in contact with or penetrating the first electrode 12 and the second electrode 14. In the semiconductor element 10 of the present embodiment, either the first electrode 12 or the second electrode 14 forms a Schottky junction with the semiconductor element 10 and the other electrode forms an ohmic junction. The energization state between the first electrode 12 and the second electrode 14 varies depending on the direction of the voltage applied between the first electrode 12 and the second electrode 14. That is, current is passed between or interrupted between the first electrode 12 and the second electrode 14. Further, since the binding of the molecular chains of the binder resin 16 is reinforced by the coupling agent in the binder resin 16, mechanical properties such as a viscoelastic modulus in a high temperature environment are improved. Hereinafter, the semiconductor element 10 will be specifically described.

  The substrate 11 is not particularly limited, such as a glass substrate, a semiconductor substrate, a ceramic substrate, or an insulating resin substrate. As the resin substrate, polyethylene, polycarbonate, polyvinyl chloride, polypropylene, polyamide, polyimide, polyurethane, or the like can be used. The substrate 11 may or may not be present.

  The first electrode 12 and the second electrode 14 can use materials such as inorganic and organic metals, metal compounds, and metal oxide compounds. For example, a dry process such as a vacuum evaporation method or a sputtering method may be used. A coating method such as a spin coating method, a blade coating method, a dip coating method, a spray coating method, a die coating method, or a roll coating method may be used. When using the coating method, it is preferable to use a gold paste, silver paste, copper paste, carbon paste, or the like in which conductive fine particles are dispersed in a solvent, or a paint in which conductive particles and a binder are kneaded and dispersed as an electrode material. .

  As an electrode material in which the first electrode 12 or the second electrode 14 forms a Schottky junction with the n-type conductive semiconductor particles 15, the work function of the electrode material (energy difference from the vacuum level to the Fermi level) is a semiconductor. An electrode material larger than the electron affinity of the particles 15 is preferable. For example, when the semiconductor particles 15 are made of Si (electron affinity 4.01 eV), gold, platinum, iridium, palladium, ruthenium, nickel, copper, silver, chromium, And alloys thereof are preferred.

  In addition, as an electrode material in which the first electrode 12 or the second electrode 14 forms an ohmic junction with the n-type conductive semiconductor particles 15, the work function of the electrode material (energy difference from the vacuum level to the Fermi level) is used. An electrode material smaller than the electron affinity of the semiconductor particles 15 is preferable. For example, when the semiconductor particles 15 are made of Si, lithium, beryllium, magnesium, lead, titanium, and alloys thereof are preferable.

  When the conductivity type of the semiconductor particles 15 is p-type, the relationship between the work function of the electrode material and the electron affinity of the semiconductor particles may be reversed from that of the n-type conductivity type. That is, as an electrode material that forms a Schottky junction with the p-type conductivity type semiconductor particles 15, an electrode material whose work function of the electrode material is smaller than the electron affinity of the semiconductor particles 15 is preferable. As an electrode material that forms an ohmic junction, an electrode material having a work function of the electrode material larger than the electron affinity of the semiconductor particles 15 is preferable.

  As described above, the semiconductor layer 13 is composed of the semiconductor particles 15 and the binder resin 16 containing a coupling agent. As the semiconductor particles 15, for example, powder obtained by pulverizing a semiconductor material such as Si material or Ge material doped with conductive impurities can be used, and the specific resistance is preferably 100 Ω · cm or less, more preferably 5 Ω · cm to The range is set to 15 Ω · cm. The average particle diameter of the semiconductor particles 15 is set in a range of 1 to 500 μm, and is preferably 10 to 150 μm in terms of contact resistance due to contact between the semiconductor particles 15.

  The aspect ratio (length in the longitudinal direction / length in the width direction) of the semiconductor particles 15 is set in a range of 1 to 10. As shown in FIG. 1B, the aspect ratio is 3 to 10 in that both ends of the semiconductor particle 15 in the longitudinal direction, that is, the tip 15a penetrates into the first electrode 12 and the second electrode 14 to ensure contact. Preferably there is. The semiconductor particles 15 are preferably arranged so that the longitudinal direction of the semiconductor particles 15 is substantially parallel to the thickness direction of the semiconductor layer 13. As a result, the tip portion 15a penetrates into the first electrode 12 and the second electrode 14 to further ensure contact, and at the same time, the density of semiconductor particles contributing to conduction of the semiconductor element is increased, and the amount of current during conduction is increased. can do.

  In addition, the average particle diameter in this specification uses the method based on JISK0069-1992, and the numerical value of the opening of the sieve in which the integrated percentage of the particle diameter distribution obtained from the sieve residue is 50% is defined as the average particle diameter. did.

  A thermoplastic resin can be used as the binder resin 16, and a hot melt adhesive and an ultraviolet curable resin are particularly preferable. Since there is no need to use a solvent, the semiconductor layer 13 can be easily dried after being formed into a sheet shape, and non-uniformity in mechanical properties such as uneven hardness of the semiconductor layer 13 can be avoided.

  The hot melt adhesive used as the binder resin 16 includes a thermoplastic base polymer, a viscosity modifier, and a viscosity imparting component. As thermoplastic base polymers, acrylic, methacrylic, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, polyvinyl alcohol, polyacetal, polyvinyl butyral, polyacrylonitrile, polyphenylene oxide, polysulfone, ethylene-vinyl acetate Polyamide, polyester, polyolefin, styrene-elastomer, thermoplastic rubber, butyl rubber, polyurethane, epoxy, polycarbonate, polyvinyl ether, polybutadiene, cellulose, and the like. Styrene-isoprene block copolymers, styrene-diene block copolymers such as styrene-butadiene block copolymers, ethylene propylene rubber and butyl rubber are preferred because they are excellent in heat resistance and non-solvent properties. Block copolymers such as SEBS (styrene-ethylene-butylene-styrene) block copolymers and SEPS (styrene-ethylene-propylene-styrene) block copolymers are more preferable.

  As a viscosity modifier to be added to the hot melt adhesive, it is preferable to add a wax from the viewpoint of increasing fluidity and non-tackiness during heating and melting and improving cohesion at room temperature. Examples of such wax include paraffin wax, microwax, low molecular weight polyethylene, low molecular weight polypropylene, and amorphous polyalphaolefin, and any resin that can be bound while maintaining the conductivity of the semiconductor particles 15. However, it is not limited to these. As the viscosity-imparting component added to the hot melt adhesive, a rosin derivative or the like can be used, and it may not be added.

  The ultraviolet curable resin used as the binder resin 16 includes benzyl (meth) acrylate, butoxyethyl (meth) acrylate, ECH-modified butyl acrylate, t-butyl as monomers used as the photopolymerizable component of the ultraviolet curable adhesive. Aminoethyl methacrylate, 3-chloro-2-hydroxypropyl methacrylate, cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, 2,3-dibromopropyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclo Pentenyloxyethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, 2-ethoxyethyl methacrylate, 2 (2-ethoxyethoxy) ethyl acrylate, 2-ethylhexyl (meth) acryl Glycerol methacrylate, isobornyl (meth) acrylate, isodecyl (meth) acrylate, isooctyl acrylate, lauryl (meth) acrylate, methoxydiethylene glycol methacrylate, methoxytriethylene glycol (meth) acrylate, methoxydipropylene glycol acrylate, octyl acrylate, Phenoxyethyl (meth) acrylate, phenoxydiethylene glycol acrylate, tetrachloropropyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,3-butyl glycol (meth) acrylate, Diethylene glycol (meth) acrylate, glycerol (meth) acrylate, 1,6-hex Diol (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol triacrylate, triethylene glycol di (meth) acrylate, triethylene glycol divinyl ether, trimethylolpropane triacrylate, tripropylene glycol diacrylate, zinc diacrylate And zinc dimethacrylate.

  Photopolymerization initiators for curing ultraviolet curable resins include chloroacetophenone, diethoxyacetophenone, α-aminoacetophenone, benzophenones, benzoin alkyl ethers, benzyldimethyl ketal, methyl-0-benzoylbenzoate, thioxanthone, acylphosphine Oxide, glyoxyester, 3-ketocoumarin, 2-ethylanthraquinone, camphorquinone, benzyl, Michler's ketone, etc. can be used, and may be used alone or in admixture of two or more.

  The coupling agent is added as a reinforcing agent for the binder resin 16 described above. The coupling agent causes a cross-linking reaction with the binder resin 16 to form a covalent bond or the like, thereby improving the stability in an environment of high temperature and high humidity. Further, the coupling agent crosslinks the semiconductor particles and the binder resin molecules to increase the bonding force to fix the semiconductor particles, and to increase the bonding strength between the first electrode 12 and the second electrode 14 and the semiconductor layer 13. This improves the long-term reliability of the semiconductor element 10.

  As the coupling agent, a chromium complex, titanate or the like can be used, but a silane coupling agent is preferable. Examples of silane coupling agents include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4 epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-glycidoxy. Propylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane , 3-acryloxypropyltrimethoxysilane and the like. When an acrylic resin is used for the hot melt resin, the coupling agent is 3-aminopropyltriethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3- It is preferable to use chloropropyltrimethoxysilane. The present invention is not limited to this as long as it exhibits reactivity with the binder resin 16 described above.

  In the semiconductor element 10 of the present embodiment, since the thermoplastic binder resin 16 that fixes the semiconductor particles 15 is strongly bonded to each other by a coupling agent, the semiconductor element 10 does not soften in a high temperature environment. The contact between the particle 15 and the first electrode 12 and the second electrode 14 is stabilized, and the Schottky junction or ohmic junction state is kept good. As a result, the stability of electrical characteristics such as current-voltage characteristics is excellent.

  In the case where the binder resin 16 is a hot melt adhesive, the thermoplastic base polymer molecules are in an amorphous state. Therefore, the binder resin 16 has a feature that it can be easily processed by heating in the manufacturing process described later. On the other hand, the semiconductor element 10 is easily softened and fluidized in a high temperature environment, and the reliability of the semiconductor element 10 is lowered as it is. However, the semiconductor element 10 of the present embodiment strongly bonds molecules in an amorphous state with a coupling agent. By doing so, the electrical characteristics are stabilized.

  In the semiconductor element 10 of the present embodiment, by setting the aspect ratio of the semiconductor particles 15 to be in the range of 1 to 10 (preferably 3 to 10), the tip portion 15a of the semiconductor particles 15 is connected to the first electrode 12 and the first electrode 12. The ratio of the semiconductor particles 15 penetrating the two electrodes 14 is increased, a good ohmic or Schottky junction is formed, and the maximum current amount per unit electrode area of the semiconductor element 10 can be increased.

  Next, a method for manufacturing a semiconductor device according to the first embodiment will be described with reference to FIG.

  FIG. 2 is a flowchart showing manufacturing steps of the semiconductor element according to the first embodiment.

  First, semiconductor particles obtained by pulverizing a semiconductor material, for example, an Si substrate doped with an n-type impurity, and hot-melt adhesive powder are mixed and stirred to make uniform (S102). The average particle diameter of the hot melt adhesive powder is preferably smaller than the average particle diameter of the semiconductor particles in terms of uniform dispersibility when a solid is formed in the next step.

  The mixed powder thus obtained is heated and pressurized to a temperature equal to or higher than the softening point of the hot melt adhesive using a uniaxial pressure molding machine to form a pellet-like solid, and the solid A semiconductor particle-containing sheet (corresponding to the semiconductor layer 13 in FIG. 1) having a film thickness of 30 μm to 150 μm is formed by hot rolling (S104). The semiconductor particle-containing sheet is 50% to 150% in terms of forming good contact between the semiconductor particles, the first electrode, and the second electrode in the thermocompression bonding in a later step, based on the average particle diameter of the semiconductor particles. It is preferable to set it as a film thickness, and it is preferable to set it as 100%-120%. In the case of forming a chip-like semiconductor element, it may be cut into a desired shape or while being heated.

  Next, the semiconductor particle-containing sheet is dipped in the above-described coupling agent in a solution having a concentration of 0.2 wt% to 3 wt%, the semiconductor agent-containing sheet is impregnated with the coupling agent, and further dried (S106). Here, the solvent for dissolving the coupling agent is a solvent that swells the semiconductor particle-containing sheet. As such a solvent, methanol, ethanol, isopropyl alcohol, toluene, xylene and the like are preferable. The coupling agent solution may be applied to the surface of the semiconductor particle-containing sheet so that the entire semiconductor particle-containing sheet swells.

  Next, a paste or a resin solution in which conductive particles are dispersed is applied and dried to form the first electrode and the second electrode (S108). As described above, the conductive particle material of the first electrode and the second electrode is selected such that one forms a Schottky junction with the semiconductor element and the other forms an ohmic junction. The first electrode and the second electrode may be formed by direct application or printing at a position where the rectifying element is formed, or may be formed after being formed on a process substrate or the like and then peeled off.

  Next, the semiconductor particle-containing sheet from which the solvent has been removed is sandwiched between the first electrode and the second electrode, and a semiconductor element is formed by thermocompression using a uniaxial pressure molding machine (S110). Here, the heating temperature is set to a temperature higher than the softening point temperature of the hot melt adhesive of the semiconductor particle-containing sheet and equal to or higher than the reaction start temperature of the coupling agent. Moreover, the applied pressure is set to about 1 MPa, for example. The hot melt adhesive is softened by heating and pressurizing, the semiconductor particles enter the first electrode and the second electrode, and a good bond is formed between the semiconductor particles / first electrode and between the semiconductor particles / second electrode. Is done. Further, the coupling agent is dissociated by heating and reacts with molecules forming the hot melt adhesive to cure the hot melt adhesive. As a result, the thermoplasticity disappears or the softening point rises and it becomes difficult to soften.

  In the manufacturing method of the present embodiment, by using a hot melt adhesive for the binder resin, the hot melt adhesive softened by heating spreads in the lateral direction when pressed in the film thickness direction during thermocompression bonding. The semiconductor particles are easily exposed from the hot melt adhesive. Therefore, the exposed tips of the semiconductor particles easily enter the first electrode and the second electrode, and a good contact state between the semiconductor particles and the first electrode and the second electrode is formed.

  Furthermore, when the heating temperature rises, the coupling agent dissociates and reacts to solidify the hot melt. Therefore, by thermocompression bonding, the pressure bonding step between the semiconductor particle-containing sheet, the first electrode and the second electrode and the reaction step of the coupling agent can be performed simultaneously.

  Further, by using a hot melt adhesive for the binder resin, it is easy to mix and disperse the hot melt adhesive powder and the semiconductor particles from the non-solvent point of the hot melt adhesive.

  In S104, a pellet-shaped solid was formed using a uniaxial pressure molding machine, but it may be molded into a thick film sheet using an extrusion molding machine, and further using an applicator. You may apply | coat directly on a process board | substrate or after forming the 1st electrode.

  Moreover, you may apply | coat the said coupling agent solution previously to the surface of the 1st electrode and 2nd electrode which contact a semiconductor particle containing sheet | seat. Adhesion between the semiconductor particle-containing sheet and the first electrode and the second electrode is improved.

  In the manufacturing process described above, the semiconductor particle-containing sheet is impregnated with the coupling agent solution. Instead, a hot melt adhesive powder surface-treated with the coupling agent in S102 may be used. At this time, the average particle diameter of the hot melt adhesive powder is preferably in the range of 10 μm to 30 μm in terms of uniformity and homogeneity of the coupling reaction, and the concentration of the coupling agent in the surface treatment is 0.5 wt% to It is preferable to set in the range of 3 wt%. Further, the semiconductor particles may be surface-treated with a coupling agent in the same manner as the hot melt adhesive powder.

  FIG. 3 is a flowchart showing another example of the manufacturing process of the semiconductor element according to the first embodiment. The manufacturing process will be described with reference to FIG.

  First, a semiconductor material, for example, a semiconductor particle powder obtained by pulverizing a Si substrate doped with an n-type impurity, a monomer or oligomer of an ultraviolet curable resin, a photopolymerization initiator, and the above coupling agent are kneaded to obtain a kneaded product. (S122). The monomer or oligomer of the ultraviolet curable resin is appropriately selected in consideration of the viscosity and the like appropriate for the coating method in a later step. The coupling agent is appropriately selected from, for example, the silane coupling agents described above.

  Next, a first electrode having a thickness of, for example, 30 μm is selectively formed on a substrate such as a glass substrate by a printing method such as a screen method (S124). As the material for the first electrode, the above-described paste in which conductive particles are dispersed, a resin solution, or the like may be used, or a vacuum process such as a vacuum deposition method or a sputtering method may be used.

  Next, the kneaded material is applied onto the first electrode by using, for example, a screen method to form a semiconductor layer (S126). The film thickness of the semiconductor layer is set in the same range as the film thickness of the semiconductor particle-containing sheet in S104 of FIG.

  Next, the semiconductor layer is irradiated with ultraviolet rays to cure the ultraviolet curable resin (S128). For the ultraviolet irradiation, a known ultraviolet irradiation apparatus using a light source such as a high-pressure mercury lamp can be used.

  Next, a second electrode is formed on the semiconductor layer by the same method as the first electrode (S130).

  Next, the substrate / first electrode / semiconductor layer / second electrode are pressurized and heated by a uniaxial pressure molding machine or the like to bond the respective layers (S132). The heating temperature and the pressure to be applied are set in a range almost similar to the step S108 in FIG.

  In the manufacturing method of the present embodiment, since the semiconductor layer is formed by patterning by a screen method, it can be directly formed on an electronic device or an electronic substrate on which a semiconductor element is formed. Therefore, the manufacturing cost can be easily reduced.

  Moreover, since the coupling agent is added to the kneaded material to be the semiconductor layer in advance, the step of impregnating the coupling agent in the subsequent step can be omitted, and the step can be simplified.

  In addition, in the manufacturing method of this Embodiment, although the coupling agent was added to the kneaded material used as a semiconductor layer, you may apply | coat a coupling agent solution with a coating method after ultraviolet irradiation.

  Next, Examples 1-4 according to the present embodiment and comparative examples not according to the present invention will be described.

[Example 1]
25 parts by weight of n-type Si powder having a specific resistance of 7.5 to 12.5 Ω · cm pulverized to an average particle size of 50 μm and a polyester hot melt resin pulverized to an average particle size of 45 μm or less (trade name Clan manufactured by Kurashiki Spinning Co., Ltd. Better, 100 parts by weight of a ball and ring measurement according to JIS K6863-1994 (with a softening temperature of 40 ° C.) was stirred using a planetary mill to obtain a mixture.

0.15 g of the mixture thus obtained was taken, and pellets were formed at a pressure of about 2500 kg / cm ² using a commercially available uniaxial pressure molding machine. Next, the pellet was stretched at a temperature of 160 ° C. and a pressure of 5 MPa using a heat and pressure press to obtain a semiconductor particle-containing sheet having a sheet thickness of 65 μm.

  The semiconductor particle sheet thus obtained was cut into a rectangular shape with a size of 4 mm in length and 4 mm in width, and placed in an ethanol solution of 3-isocyanatepropyltriethoxysilane (reaction (starting temperature: 130 ° C.) with a concentration of 2 wt% for 30 seconds. Immersion and silane coupling treatment were performed, followed by drying to remove ethanol. These operations were performed in a glove box substituted with nitrogen.

Subsequently, an Ag electrode (film thickness 20 μm), a semiconductor particle-containing sheet, a W electrode (film thickness 30 μm), and an Ag electrode (film thickness 20 μm) are stacked in order from the bottom, heating temperature 160 ° C., pressure 0.55 kgf / mm ² , The thermocompression bonding was carried out for 10 seconds and a coupling reaction was caused. As described above, a rectifying element in which the Ag electrode and the n-type Si powder of the semiconductor particle-containing sheet form a Schottky junction was formed.

  Here, as the Ag electrode, a bar coater was used to apply and dry an Ag paste to a thickness of 20 μm. The W electrode is obtained by dispersing 50 parts by weight of W metal powder (average particle size: 10 μm) in 100 parts by weight of a liquid epoxy resin, applying it to a film thickness of 30 μm with a bar coater, and curing it by heating.

  The rectifying characteristics of the rectifying element thus formed were measured before and after storage for 1000 hours in a 60 ° C., 95% RH environment.

  FIG. 4 is a diagram illustrating current-voltage characteristics of the rectifying element according to the first embodiment before and after storage. Referring to FIG. 4, it can be seen that the rectifying device according to Example 1 exhibits good rectifying characteristics both before and after storage, and the minimum voltage at which current begins to flow before and after storage hardly changes. From this, it can be seen that the reliability of the rectifying element according to Example 1 is high even when stored under severe high temperature and high humidity such as 60 ° C. and 95% RH environment.

[Example 2]
A rectifying element was formed in the same manner as in Example 1 except that n-type Si powder having an average particle size of 25 μm was used.

[Example 3]
Except for mixing 175 parts by weight of clanbetter (supra) with 25 parts by weight of n-type Si powder and using an ethanol solution of 3-isocyanatepropyltriethoxysilane having a concentration of 3 wt%, the same as in Example 1. A rectifying element was formed.

[Example 4]
A rectifying device was formed in the same manner as in Example 3 except that an ethanol solution of 3-isocyanatepropyltriethoxysilane having a concentration of 1 wt% was used.

  The rectifying elements of Examples 2 to 4 were measured in the same manner as in Example 1 in a 60 ° C., 95% RH environment before and after storage for 1000 hours. Although illustration is omitted, the rectifying elements of Examples 2 to 4 show good rectifying characteristics before and after storage as in Example 1, and the minimum voltage at which current begins to flow before and after storage changes almost. There wasn't. From this, it can be seen that the reliability of the rectifying elements according to Examples 2 to 4 is high even when the rectifying elements of Examples 2 to 4 are stored under high temperature and high humidity.

[Comparative example]
A rectifying element was formed in the same manner as in Example 1 except that the silane coupling treatment was not performed.

  The comparative rectifying element thus formed was measured in the same manner as in Example 1 in a 60 ° C., 95% RH environment before and after storage for 1000 hours.

  FIG. 5 is a diagram showing current-voltage characteristics before and after storage of the rectifying element according to the comparative example.

  Referring to FIG. 5, the rectifying device of the comparative example showed good rectifying characteristics before storage, but after storage, the saturation current value in the forward direction decreased and the current began to flow before and after storage. The voltage has changed. From this, it can be seen that the contact between the semiconductor particles and the first electrode or the second electrode deteriorated due to storage under high temperature and high humidity. On the other hand, the rectifying device according to Example 1 shown in FIG. 4 clearly has better characteristics after storage than the comparative example shown in FIG. 5, which is coupled to the binder resin of the semiconductor layer. It shows that the resistance to storage under high temperature and high humidity is remarkably improved by adding and reacting the agent. Therefore, it can be seen that the rectifying elements of Examples 1 to 4 are particularly suitable for electronic devices used outdoors such as portable terminals.

(Second Embodiment)
FIG. 6 is a configuration diagram of a coordinate input device according to the second embodiment of the present invention, and FIG. 7 is a cross-sectional view of a principal part of the coordinate input device according to the second embodiment. FIG. 7 shows an enlarged thickness direction for convenience of explanation. In the figure, portions corresponding to the portions described above are denoted by the same reference numerals, and description thereof is omitted.

  Referring to FIGS. 6 and 7, the coordinate input device 20 is roughly arranged with a substrate 21 such as a glass substrate having a resistance film 23 formed on the surface thereof, a substrate 21 and the like, and a detection electrode film 26. Is a flexible substrate 22 such as PET formed on the back surface, a direct current power source 28 for applying a voltage to the resistance film 23, and a pressing position coordinate when the flexible substrate 22 is partially pressed. It comprises a voltmeter 29 for detection.

  The resistance film 23 is made of a transparent resistor such as a solid ITO film, and a dotted electrode 24 electrically connected to the resistance film 23 is provided on the periphery of the resistance film 23 (in the vicinity of each side of the square). Many are formed at intervals. A diode 25 is connected to each dot electrode 24, and the diode 25 is connected to the dot electrode 24 in a predetermined direction in order to form a substantially linear potential distribution in the X-axis direction shown in the figure, for example. That is, the cathode of the diode 25 is connected to the dotted electrode 24 disposed on one side (+ X side) perpendicular to the X-axis direction, and the anode of the diode 25 is connected to the positive electrode ( The anode of a diode 25 is connected to the dotted electrode 24 arranged on the opposite side (−X side), and the cathode of the diode 25 is connected to the switch SW1 via the switch SW1. And connected to the negative electrode of the DC power supply 28 (when the switch SW1 contacts the A contact). In this way, a potential distribution in which the potential decreases in the −X direction is formed in the X axis direction of the resistance film 23.

  Similarly, the electrode 24 and the diode 25 are arranged and connected to the side perpendicular to the Y-axis direction as in the X-axis direction, and the potential decreases in the + Y direction by bringing the switches SW1 and SW2 into contact with the B contact. A distribution is formed.

  The detection electrode film 26 is formed in the form of a solid film on the back surface of the flexible substrate 22, is disposed opposite to the resistance film 23 via a spacer 31 made of an insulating material, and is connected to a voltmeter 29. The detection electrode film 26 is made of, for example, a thin metal electrode or a transparent electrode material such as ITO.

  Next, the operation of the coordinate input device 20 will be briefly described. By pressing the flexible substrate 22 with a pen or the like, the detection electrode film 26 comes into contact with the resistance film 23. When the switches SW1 and SW2 are in contact with the A contact, since the potential distribution is formed in the resistance film 23 in the X-axis direction, the potential corresponding to the X coordinate of the pressurization position is detected by the voltmeter 29. . When the switches SW1 and SW2 are switched to the B contact, a potential distribution is formed in the Y-axis direction in the resistance film 23, and therefore the potential corresponding to the Y coordinate of the pressurization position is detected by the voltmeter 29. Since the switches SW1 and SW2 are automatically switched in a short time with respect to the pressurization time by the pen, both the X coordinate and the Y coordinate of the pressurization position can be detected.

  The coordinate input device 20 according to the present embodiment is characterized by a diode 25. The diode 25 is the semiconductor element according to the first embodiment described above. As shown in FIG. 7, the diode 25 is formed around the first electrode 12 / semiconductor layer 13 / second on the periphery of the flexible substrate 22. The electrode 14 is formed by laminating, the first electrode is connected to the switch SW1 or SW2 shown in FIG. 6 (connection lines are not shown), and the second electrode is dotted by a conductive line 32 such as a wire or FPC. It is connected to the electrode 24. Since the diode 25 is excellent in environmental resistance such that the binder resin of the semiconductor layer is not softened and deformed in a high temperature environment, a highly reliable coordinate input device can be realized. Further, the diode 25 can be easily formed because it can be formed by a coating method, particularly a printing method, and has a thickness of about several hundred μm or less, so that it is 1/10 of the thickness of the conventional rectifier element of about 2 mm. It is thinned to the extent. Therefore, by using it as an input device such as a portable terminal, it is possible to promote thinning and miniaturization of the main body. Further, since the shape of the diode 25 can be easily patterned, the surface density of the diode 25 can be improved, the mounting area of the diode 25 can be reduced, and the input range can be expanded.

  In the second embodiment, the example in which the resistance film 23 and the dotted electrode 24 are formed on the surface of the substrate 21 and the detection electrode film 26 is provided on the back surface of the flexible substrate 22 has been described. May be formed on the surface of the substrate 21, and the resistance film 23 and the dotted electrode 24 may be formed on the back surface of the flexible substrate 22.

  In this embodiment, the coordinate input device is described as an example. However, the present invention is not particularly limited to the coordinate input device, and the semiconductor element of the first embodiment can be applied to other electronic devices such as a liquid crystal display device. it can.

  The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific embodiments, and various modifications and changes can be made within the scope of the present invention described in the claims. It can be changed.

In addition, the following additional notes are disclosed regarding the above description.
(Appendix 1) a semiconductor layer composed of semiconductor particles and a binder resin;
A semiconductor element comprising a first electrode and a second electrode sandwiching the semiconductor layer,
A semiconductor element, wherein a coupling agent is added to the binder resin.
(Supplementary note 2) The semiconductor element according to supplementary note 1, wherein the semiconductor particles are doped with impurity ions.
(Additional remark 3) The semiconductor element of Additional remark 1 or 2 characterized by the average particle diameter being set to the range of 1-500 micrometers.
(Supplementary Note 4) The semiconductor element according to any one of Supplementary Notes 1 to 3, wherein the semiconductor particles have an aspect ratio set in a range of 1 to 10.
(Supplementary Note 5) The semiconductor element according to any one of Supplementary Notes 1 to 4, wherein the semiconductor particles are arranged such that a longitudinal direction thereof is substantially parallel to a thickness direction of the semiconductor layer.
(Additional remark 6) The front-end | tip part of the said semiconductor particle penetrate | invades into a 1st electrode or a 2nd electrode in each interface of the said semiconductor layer, a 1st electrode, and a 2nd electrode, It is characterized by the above-mentioned. The semiconductor element according to any one of Supplementary Notes 1 to 5.
(Additional remark 7) The said coupling agent is a silane coupling agent, The semiconductor element as described in any one among Additional remarks 1-6 characterized by the above-mentioned.
(Additional remark 8) The said binder resin is a hot-melt-adhesive or an ultraviolet curable resin, The semiconductor element as described in any one of Additional remarks 1-7 characterized by the above-mentioned.
(Additional remark 9) The 1st board | substrate with which the 1st electrically conductive film was formed in one surface,
A second substrate in which a second conductive film is formed on one surface, and the first conductive film and the second conductive film are arranged to face each other;
A power supply for applying a voltage to the first conductive film;
Detecting means for detecting a potential at a position where the first conductive film and the second conductive film are in contact with each other when the first substrate or the second substrate is pressurized;
And a rectifier that rectifies current flowing in the first conductive film between the first conductive film and the power source using the semiconductor element according to any one of appendices 1 to 8. Coordinate input device.
(Supplementary Note 10) A step of dispersing semiconductor particles in a binder resin to form a mixture;
Forming a sheet-like molded product from the mixture;
Forming electrodes on both surfaces of the sheet-like molded product;
And a step of performing a heat treatment for reacting the coupling agent contained in the sheet-like molded product.
(Additional remark 11) Between the process of forming the said sheet-like molding, and the process of forming an electrode,
The method for manufacturing a semiconductor element according to appendix 10, further comprising a step of performing a coupling process of impregnating the sheet-like molded product with a solution containing a coupling agent.
(Additional remark 12) The said binder resin contains a coupling agent, The manufacturing method of the semiconductor element of Additional remark 10 characterized by the above-mentioned.
(Additional remark 13) The process of forming the said electrode apply | coats a coupling agent to one surface of an electrode, and laminate | stacks an electrode and a sheet-like molding so that the applied surface may become the sheet-like molding side. 14. The method for manufacturing a semiconductor element according to any one of Supplementary notes 10 to 12, which is characterized by the following.
(Supplementary note 14) The semiconductor element according to any one of supplementary notes 10 to 13, further comprising a step of pressure-bonding the sheet-like molded product and the electrode while heating after the step of forming the electrode. Manufacturing method.
(Additional remark 15) The manufacturing method of the semiconductor element of Additional remark 14 characterized by performing the heat processing which makes the said coupling agent react in the said crimping | compression-bonding process.
(Additional remark 16) The manufacturing method of the semiconductor element as described in any one of additional marks 10-15 characterized by the softening temperature of the said binder resin being lower than the reaction temperature of a coupling agent.
(Supplementary Note 17) A step of kneading semiconductor particles, an ultraviolet curable resin, and a coupling agent to form a mixture;
Applying the mixture on an electrode to form a semiconductor layer;
Curing the semiconductor layer by irradiating the semiconductor layer with ultraviolet rays; forming another electrode on the semiconductor layer;
And a step of performing a heat treatment for reacting the coupling agent.
(Additional remark 18) The manufacturing method of the semiconductor element of Additional remark 17 characterized by further comprising the process of crimping | bonding the said semiconductor layer and an electrode after heating after the process of forming said another electrode.

(A) is sectional drawing of the semiconductor element which concerns on the 1st Embodiment of this invention, (B) is principal part sectional drawing to which the semiconductor element shown to (A) was expanded. It is a flowchart which shows the manufacturing process of the semiconductor element which concerns on 1st Embodiment. It is a flowchart which shows the other example of the manufacturing process of the semiconductor element which concerns on 1st Embodiment. It is a figure which shows the current-voltage characteristic before and behind the preservation | save of the rectifier which concerns on Example 1. FIG. It is a figure which shows the current-voltage characteristic before and behind the preservation | save of the rectifier which concerns on a comparative example. It is a block diagram of the coordinate input device which concerns on the 2nd Embodiment of this invention. It is principal part sectional drawing of the coordinate input device which concerns on 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Semiconductor element 11 Board | substrate 12 1st electrode 13 Semiconductor layer 14 2nd electrode 15 Semiconductor particle 15a The front-end | tip part of a semiconductor particle 16 Binder resin 20 Coordinate input device 21 Board | substrate 22 Flexible board | substrate 23 Resistance film 24 Point-like electrode 25 Diode 26 Detection electrode film 28 DC power supply 29 Voltmeter 31 Spacer 32 Conductive wire

Claims (5)

A semiconductor layer comprising semiconductor particles and a binder resin;
A semiconductor element comprising a first electrode and a second electrode sandwiching the semiconductor layer,
A semiconductor element, wherein a coupling agent is added to the binder resin.   2. The tip of the semiconductor particle penetrates into the first electrode or the second electrode at each interface between the semiconductor layer and the first electrode and the second electrode. Semiconductor element.   3. The semiconductor element according to claim 1, wherein the binder resin is a hot melt adhesive or an ultraviolet curable resin. A first substrate having a first conductive film formed on one surface;
A second substrate in which a second conductive film is formed on one surface, and the first conductive film and the second conductive film are arranged to face each other;
A power supply for applying a voltage to the first conductive film;
Detecting means for detecting a potential at a position where the first conductive film and the second conductive film are in contact with each other when the first substrate or the second substrate is pressurized;
Rectifying means between the first conductive film and a power source and rectifying a current flowing in the first conductive film using the semiconductor element according to claim 1. A coordinate input device provided. A step of dispersing semiconductor particles in a binder resin to form a mixture;
Forming a sheet-like molded product from the mixture;
Forming electrodes on both surfaces of the sheet-like molded product;
And a step of performing a heat treatment for reacting the coupling agent contained in the sheet-like molded product.

Images