JP2005149877A - Heating element and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heating element with excellent productivity, large current-carrying capacity, and excellent reliability. <P>SOLUTION: An electrode 2 and a terminal member 4 are joined electrically and physically through a conductive resin material 5, and at the same time, by way of a through-hole formed by hot-melting of a sheathing material 6, bonding metal 7 formed at the terminal member 4 and joining metal 8 formed at a lead wire 9 are welded by thermal fusion to join the terminal member 4 and the lead wire 9 electrically and physically. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a heating element that can be used as a heat source for heating, heating, drying, and the like, and a method for manufacturing the same.

  Conventionally, as this type of heating element, as shown in FIGS. 7 and 8, a pair of copper foil electrodes 15 is attached to an electrically insulating substrate 14 with a hot-melt adhesive 16, and this pair of copper A heating element material 17 is formed between the foil electrodes 15.

  The surfaces of the electrically insulating substrate 14, the copper foil electrode 15, and the heating element material 17 are covered with an electrically insulating film 18 with a hot melt adhesive. Solder 19 is formed in advance on the lead connection portion of the copper foil electrode 15, and thereafter, the electrical insulating film 18 is covered.

The lead wire 20 is connected by heating the solder 21 of the lead wire 20 with a soldering iron to form a through hole in the electrically insulating film 18 with a hot melt adhesive and joining the solder 19 and the solder 21 together. (For example, patent document 1).
Japanese Patent Laid-Open No. 57-202079

  However, even if a conventional heating element is used to form a complicated electrode pattern that is finely branched or curved, for example, it is difficult to process by attaching a metal foil material on a substrate with a hot melt adhesive. In practice, it was actually a simple parallel electrode pattern.

  Of course, it is possible to draw complex patterns using advanced processes such as etching, but usually the area where the electrodes are formed is very small, which removes most of the electrode material, In particular, in the case of a heating element with a large area, the situation was extremely poor in terms of resource saving and material cost.

  In addition, in an electrode made of a metal foil material, even if it is intended to form a heat generating body having elasticity and flexibility, there is a limit due to its strength being too strong, and durability when it is repeatedly expanded and bent is repeated. It was a big issue.

  On the other hand, when an electrode is formed by printing using a conductive paste in which silver powder is dispersed in an epoxy resin, it is easy to form a complicated electrode pattern with a curve, Although it can cope with flexibility, even if it is attempted to solder the terminal portion before coating as in the case of a conventional heating element, it cannot be formed because it is repelled by the resin component.

  Therefore, a configuration in which the lead wire is soldered through the coating cannot be realized. In this way, when using a material that cannot be soldered for the electrode, it is common to apply various measures to expose a part of the electrode after coating, and connect the lead wire to the part with a crimp terminal. It was the target.

  In order to expose a part of the electrode after coating, an extra pattern such as extending or meandering so that a part of the electrode comes out of the coating is necessary. In addition, a release paper is provided on a part of the electrode, and a hole is made in that part after coating, or a hole is made in the coating, and processing is performed by a method such that the hole comes to a predetermined position of the electrode. It was necessary to complete the process.

  Note that the terminal connection by crimping involves a decrease in the crimping force due to resin shrinkage, and therefore, a special measure that does not increase the contact resistance is required.

  Also, as a special case, it is not necessary to expose a part of the electrode, and a terminal with a terminal biting in from the outside of the coating has been devised, but there are restrictions on the current, so it can be used for applications where the current is large. There wasn't.

  As described above, the conventional heating element cannot be branched finely or form a complicated electrode pattern with a curve, and has poor flexibility and stretchability. It was possible to connect.

  On the other hand, in the case of an electrode made of a conductive paste that can be printed, it is easy to form a complicated electrode pattern that is finely branched or curved, and can handle flexibility and stretchability. The lead wire could not be connected with solder from outside. In addition, the alternative lead wire connection method has various problems such as a complicated configuration and process, a need for measures against contact resistance due to resin shrinkage, and inability to use with a large current.

  An object of the present invention is to solve such a conventional problem, and to provide a heating element that is excellent in productivity, has a large allowable current, and is excellent in reliability.

  In order to achieve the above object, the heating element of the present invention includes a pair of electrodes, a heat generating resistor formed between the electrodes, a terminal member formed on a power feeding portion of the electrode, A heat-meltable bonding metal formed on the terminal member, an exterior material that integrally covers the resistor, the electrode, the terminal member, and the bonding metal, and heat melting that can be melt-bonded to the bonding metal. A lead wire formed by welding a conductive bonding metal to the connection portion, and the electrode and the terminal member are electrically and physically joined via a conductive resin material, and the exterior material is melted by heat. The terminal metal and the lead wire are electrically and physically joined to each other by melting and joining the joining metal and the joining metal via a through hole formed by the above.

  In the heating element of the present invention, an electrode and a terminal member are electrically and physically joined via a conductive resin material, and a bonding metal is formed via a through hole formed by heat melting of an exterior material. The joining metal is melt-bonded, and the terminal member and the lead wire are electrically and physically joined. As a result, it is possible to form a highly reliable and highly productive power feeding portion with a large allowable current after the exterior is applied to the entire surface at an arbitrary position of the heating element. This configuration is extremely useful when a large amount of current is required because the power supply voltage is low, or when a heating element having a positive resistance temperature characteristic that requires a large inrush current to obtain rapid thermal performance is used. Useful.

  An embodiment of the present invention includes a pair of electrodes, a resistor capable of generating heat formed between the electrodes, a terminal member formed through a conductive resin material on a power feeding portion of the electrodes, A heat-meltable bonding metal formed on the surface of the terminal member, an exterior material that integrally covers the resistor, the electrode, the terminal member, and the bonding metal, and fusion bonding with the bonding metal are possible. A lead wire formed by welding a hot-melt bonding metal to the connection portion, and the electrode and the terminal member are electrically and physically bonded via a conductive resin material, and the exterior material The bonding metal and the bonding metal are melt-bonded via a through hole formed by thermal melting of the terminal member, and the terminal member and the lead wire are electrically and physically bonded.

  The terminal member formed in the electrode power feeding portion is joined to the electrode through a conductive resin material, and enables electrical and physical joining regardless of the material of the electrode.

  Since the conductive resin composition is usually formed into a thin surface, the resistance value of the joint is extremely low, and a large current can flow. In addition, sufficient strength can be ensured for joining in a planar shape.

  This bonding strength is further strengthened because the exterior material formed outside the terminal member supports the terminal member.

  The heat-meltable bonding metal formed on the terminal member and the heat-melting bonding metal welded to the connecting portion of the lead wire have through-holes due to heat melting of the exterior material in a heated state at a melting temperature or higher. Via, the bonding metal and the bonding metal are welded by being thermally melted together. This bond is a metal-to-metal bond, and the electrode and the lead wire can be firmly connected electrically and physically.

  Moreover, since the through-hole provided in the exterior material is filled with the bonding metal or the bonding metal, airtightness is obtained. This terminal member can be formed at an arbitrary position of the electrode, and the connection position of the lead wire can be easily changed.

  Since lead wires can be connected from the outside of the exterior material, the exterior material can be applied without being affected by the position where the terminal member is formed. As a result, it is possible to form a highly reliable and highly productive power feeding unit with a large allowable current at an arbitrary position of the heating element. This configuration is extremely useful when a large amount of current is required because the power supply voltage is low, or when a heating element having a positive resistance temperature characteristic that requires a large inrush current to obtain rapid thermal performance is used. It is effective.

  A conductive resin material is formed on the surface bonded to the electrode, and a terminal member formed with a heat-meltable bonding metal on the other surface is disposed in the power feeding portion of the electrode. In this configuration, in particular, a terminal member provided with a conductive resin material and a bonding metal is disposed at the electrode portion where it is desired to connect the lead wire, so that the conductive resin material side is in contact with the electrode, By simply forming the material, it is possible to obtain a configuration in which lead wires can be connected from the outside of the exterior material.

  There is no need to form the conductive resin material, the terminal member, and the joining metal individually in sequence, thereby improving the processing accuracy and greatly shortening the processing time.

  The electrode is formed from a conductive paste in which conductive metal powder is dispersed in a resin. In the case of an electrode in which conductive metal powder is dispersed in a resin, a complicated pattern can be drawn by a processing method such as printing, but the resin contained in the electrode has the property of repelling the metal melted by heat. Lead wires cannot be joined with a meltable joining metal.

  A terminal member is formed through a conductive resin material that can be electrically and physically bonded to such an electrode, and a hot-melt bonding metal is formed on the surface of the terminal member. And the bonding metal of the lead wire are welded to each other by thermal melting through the through hole by thermal melting of the outer packaging material, and the electrode and the lead wire can be firmly connected electrically and physically.

  The terminal member is a thin metal plate, and the joint surface with the conductive resin material is roughened. If it is this structure, the adhesive strength with an electrode can further be raised by the increase in the adhesive surface area between a metal thin plate and a conductive resin material, an anchor effect, etc. As a result, a highly reliable terminal connection with higher peel strength is possible.

  The terminal member is formed from an electrolytic metal foil. The electrolytic metal foil can be made of a foil having a uniform thickness and a high purity, and even when it is thin, sufficient conductivity can be obtained, so that a terminal member having excellent flexibility can be formed.

  The terminal member is formed from a rolled metal foil. Since the rolled metal foil does not easily break with respect to elongation, a terminal member having excellent bending resistance can be formed.

  The terminal member is formed of a thin metal plate having a surface plated with a different kind of metal. By plating different types of metal on the terminal member, the corrosion resistance can be improved or the contact resistance can be reduced. Moreover, the copper damage at the time of using copper foil for olefin resin can also be relieved. By these actions, the characteristics of the terminal portion can be improved and the reliability can be improved.

  The terminal member is formed with a plurality of openings. By forming a plurality of openings in the terminal member, the conductive resin material wraps around the side surface and the back surface of the terminal member, and voids due to the generation of bubbles are reduced, so that the adhesive strength between the electrode and the terminal member is increased. Can be improved. This is extremely effective when the strength of the terminal member is required.

  The terminal member has a fibrous shape. When the terminal member is fibrous, the conductive resin material can be firmly bonded to enter the fibrous portion of the terminal member. Further, since flexibility is imparted, durability against various stresses such as deformation and impact is improved.

  A conductive resin material and an adhesive material are juxtaposed on a terminal member on the surface joined to the electrode. The conductive resin material is responsible for the physical connection as well as the electrical connection with the electrode. However, the adhesive material reinforces this physical connection and has the effect of increasing the reliability as a terminal member.

  Further, since the terminal member can be easily temporarily fixed at a predetermined position by the adhesive force of the adhesive material, a configuration in which the terminal member is completely fixed by the exterior material is made possible.

  The conductive resin material is thermosetting and is in an uncured state when bonded to the electrode. When the conductive resin material is bonded to the electrode, it is in an uncured state, so that the resin retains the heat melting property and can be thermally bonded to the electrode. The original adhesive strength of the conductive resin material is exhibited by curing after thermally bonding to the electrode.

  The conductive resin material is thermosetting, contains a solvent for imparting fluidity, and is uncured when bonded to the electrode, and most of the solvent is removed. . In order to form the conductive resin material on the terminal member by a method such as printing, the conductive resin material is uncured and requires appropriate fluidity. For this purpose, it is effective to contain a solvent for imparting fluidity.

  However, when the terminal member is joined to the electrode using an uncured conductive resin material containing a solvent, the solvent causes a foaming phenomenon due to heating during curing, and sufficient adhesive strength cannot be obtained.

  When the conductive resin material is bonded to the electrode, it is uncured and most of the solvent is removed. Therefore, the resin retains the heat melting property, and foaming due to the residual solvent occurs. Thermal bonding in the absence is possible. As a result, the original adhesive strength of the conductive resin material is exhibited, and sufficient adhesive strength with the electrode is obtained.

  The conductive resin material contains a resin having a copolymer polyester as a main component and an isocyanate curing agent. Since the isocyanate is in an unreacted state when bonded to the electrode, the copolyester is heat-meltable and can be bonded to the electrode.

  Copolyester is a resin excellent in heat-weldability and at the same time is cured by isocyanate, but it is still flexible after curing, and the terminal member and the electrode are firmly bonded while maintaining flexibility.

  As a result, reliability under various stresses such as deformation and impact can be improved.

  The conductive resin material contains a curing agent whose reactivity is limited below a predetermined temperature. The process of forming the conductive resin material on the terminal member often requires some kind of heat treatment, but heat treatment is performed in an unreacted state by containing a curing agent with limited reactivity below a predetermined temperature. Is possible.

  By treating the curing agent in an unreacted state, when the conductive resin material is bonded to the electrode, it retains heat melting and can be thermally bonded to the electrode. After this thermal bonding, the original strong adhesive strength of the conductive resin material can be obtained by curing by heating to a temperature higher than the reaction temperature of the curing agent.

  In addition, by containing a curing agent whose reactivity is limited below a predetermined temperature, an uncured state can be maintained and managed for a long period of time. Can be lengthened.

  The conductive resin material contains a resin having a copolymer polyester as a main component and a block type isocyanate curing agent whose reactivity is limited below a predetermined temperature.

  Since the block type isocyanate is heat-treated in an unreacted state until it is bonded to the electrode, the copolyester retains the heat melting property and can be thermally bonded to the electrode.

  The thermal polymerization is carried out at a temperature higher than the temperature at which the block of the curing agent is released after the thermal bonding with the electrode, whereby the copolymerized polyester is cured, and the inherently strong adhesive strength of the thermally cured copolymerized polyester is obtained. In addition, the copolyester is flexible even after curing, and an adhesive strength strong against deformation can be obtained.

  Furthermore, the storage period of the terminal member on which the conductive resin material is formed in order to be able to maintain and manage the uncured state for a long period of time by using a block type isocyanate whose thermal reaction is suppressed below a predetermined temperature. Can be lengthened.

  The conductive resin material and the electrode contain the same type of resin. When both the electrode and the conductive resin material contain the same kind of resin, bonding by thermal fusion is facilitated, and at the same time, strong adhesive strength can be obtained after thermosetting.

  The electrode is thermosetting, and when the conductive resin material is bonded to the electrode, the electrode is thermoset. The electrode before thermosetting can be easily heat-sealed, but since the strength as an adherend is weakened, sufficient adhesive strength cannot be obtained with the terminal member. By bonding an uncured conductive resin material to the heat-cured electrode and thermally curing the conductive resin material, sufficient adhesive strength required for the terminal portion can be ensured.

  Also, a pair of electrodes or more, a heat generating resistor formed between the electrodes, a terminal member formed through a conductive resin material on the power feeding portion of the electrode, and a surface of the terminal member A heat-meltable bonding metal to be formed, an exterior material that integrally covers the resistor, the electrode, the terminal member, and the bonding metal, and a heat-meltable bond that can be melt-bonded to the bonding metal. After forming a conductive resin material on one surface of the terminal member and forming the bonding metal on the other surface, the conductive resin material is formed of a lead wire formed by welding a metal to a connection portion. It arrange | positions so that the said joining metal may appear on the surface of the said terminal member while contacting the electric power feeding part of an electrode, Then, the said exterior material is formed, and also after that, the said coupling metal on the surface of the said exterior material in which the said joining metal is located The above welded When the lead wire is brought close and heated, the bonding metal and the bonding metal are melt-bonded via a through hole formed by thermal melting of the exterior material, and the terminal member and the lead wire are electrically and physically connected It is formed by joining.

  Since the conductive resin material is formed on the surface of the terminal member to be bonded to the electrode in advance and the heat-meltable bonding metal is formed on the other surface, the terminal member is electrically connected to the electrode or the lead wire. And all the necessary configurations to achieve physical bonding. A terminal member is formed by forming an exterior material after arranging the surface of the conductive resin material in contact with the electrode at a portion of the electrode to which the terminal is connected.

  Since this terminal member is formed with a heat-meltable bonding metal, the bonding metal portion of the lead wire is brought close to the outer packaging material and the bonding metal and the bonding metal are heated by heating and pressurizing. A through hole is formed by melting, and at the same time, melt bonding is performed, and the terminal member and the lead wire are electrically and physically bonded.

  Since the connection by this manufacturing method is not via an exterior material but a bond between metals, the electrode and the lead wire can be connected electrically and physically firmly.

  Moreover, since the through-hole provided in the exterior material is filled with the bonding metal or the bonding metal, airtightness can be obtained. This terminal member can be joined to an arbitrary position of the electrode, and the connection position of the lead wire can be easily changed. In addition, the lead wire can be connected after the exterior material is applied to the entire surface regardless of the position of the terminal member. As a result, it is possible to form a highly reliable and highly productive power feeding unit with a large allowable current at an arbitrary position of the heating element.

  The conductive resin material of the terminal member is thermosetting, and after being heat-treated at a temperature lower than the thermosetting temperature, it is bonded to the electrode and is thermoset in the process of covering the exterior material.

  Although the conductive resin material is thermosetting, volatile components such as a solvent can be removed by heat treatment at a temperature lower than the thermosetting temperature. The uncured conductive resin material maintains heat melting property and can be thermally bonded to the electrode.

  The uncured conductive resin material thermally bonded to the electrode is cured and strongly bonded because it is exposed to a high temperature when forming the exterior material. In the process of thermosetting, since volatile components are removed, foaming does not occur, and the structure becomes dense and sufficient strength is obtained.

  The conductive resin material of the terminal member is thermosetting, is heat-treated at a temperature lower than the thermosetting temperature, is bonded to the electrode, and is thermoset in the process of bonding the lead wire. Although the conductive resin material is thermosetting, volatile components such as a solvent can be removed by heat treatment at a temperature lower than the thermosetting temperature.

  The uncured conductive resin material is thermally adhesive and can be thermally bonded to the electrode. The uncured conductive resin material thermally bonded to the electrode is cured and strongly bonded because it is exposed to a high temperature in the process of joining the lead wires.

  In the process of thermosetting, volatile components are removed, so foaming does not occur, a dense structure is obtained, and sufficient strength is obtained.

  Adhesive agent is juxtaposed on a part of the surface of the terminal member where the conductive resin material is formed, and the conductive resin material is disposed in contact with the electrode due to the adhesive property of the adhesive agent. The exterior material which covers the said electrode, the said terminal member, and the whole joining metal integrally is formed.

  The conductive resin material is responsible for the physical connection as well as the electrical connection with the electrode. However, the adhesive material reinforces this physical connection and has the effect of increasing the reliability as a terminal member. In addition, because the adhesive force of this adhesive material makes it easy to temporarily fix the terminal member in place, it is possible to perform a procedure of fixing it completely after the temporary fixing by the process after the exterior material. To.

  The terminal member is coated with cream solder on one side and then heated to form a bonding metal. On the other side, a thermosetting conductive resin paste is applied, and the solvent content is reduced below the curing temperature. The conductive resin material is formed by removing.

  Since the cream solder can be processed by printing or the like, it is easy to make the thickness and shape uniform, and air mixing due to unevenness and tearing of the exterior material can be eliminated by laminating work when forming the exterior material.

  In addition, although the conductive resin material is thermosetting, volatile components such as a solvent can be removed by heat treatment at a temperature lower than the thermosetting temperature. The uncured conductive resin material retains heat melting property and can be thermally bonded to the electrode.

  The uncured conductive resin material thermally bonded to the electrode is cured and firmly bonded to be exposed to a high temperature when forming an exterior material or joining a lead wire. In the process of thermosetting, since it does not contain volatile matter, it does not foam, has a dense structure, and a sufficient strength can be obtained.

  The terminal member is formed in a large plate shape in which a large number of terminal members are assembled, and is divided.

  Cream solder can form a large number of solders on a large plate surface by printing or the like. Also, the conductive resin material can be formed over a wide area by printing or the like. Therefore, the terminal member can be reasonably manufactured by forming a large plate shape in which a large number of terminal members are assembled and dividing the terminal member.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

(Example 1)
1, 2 and 3, 1 is a substrate using a 188 μm thick polyethylene terephthalate film, 2 is a pair of electrodes, which are formed on the substrate 1 by printing and drying a conductive silver paste. .

  The conductive silver paste is prepared by dispersing silver powder as a conductivity-imparting material in a copolyester resin and adding an appropriate amount of isocyanate as a curing agent.

  The electrode 2 is composed of a main electrode and a branch electrode branched from the main electrode, and the corresponding branch electrodes of the electrode 2 are arranged alternately.

  Reference numeral 3 denotes a resistor having a positive resistance temperature characteristic, which is formed by printing and drying the paste of an ethylene vinyl acetate copolymer and carbon black on the surface of the electrode 2.

  A terminal member 4 is formed at a power feeding portion of the electrode 2, and the electrode 2 and the terminal member 4 are electrically and physically joined by a conductive resin 5.

  The terminal member 4 is a 70 μm thick copper plate, the conductive resin 5 is a conductive paste prepared by dispersing silver powder as a conductivity-imparting material in a copolymerized polyester, and further adding an appropriate amount of isocyanate as a curing agent. I use it.

  The entire substrate 1 on which the electrodes 2 and the resistors 4 are formed is covered with an exterior material 6 in which a heat-meltable resin film having a thickness of 30 μm is laminated on a polyethylene terephthalate film having a thickness of 50 μm. The exterior material 6 is formed by heat fusion using a laminating roll set to be equal to or higher than the melting point of the heat-meltable resin film.

  The terminal member 4 is formed with a heat-melting bonding metal 7 made of solder, the lead wire is formed with a heat-melting bonding metal 8, and the bonding metal 7 and the bonding metal are formed in holes penetrating the exterior material 6. 8 of the molten phase is filled, and the terminal member 4 and the lead wire 9 are electrically and physically connected.

  Next, a method for manufacturing the heating element of Example 1 will be described. First, a conductive silver paste is printed on a substrate 1 made of a polyethylene terephthalate film and dried to form a pair of electrodes 2. The drying condition is 150 ° C. for 30 minutes so that the copolymer polyester resin constituting the electrode 2 is completely cured by the isocyanate.

  Next, the resistor paste is printed, and the resistor 3 is formed under dry conditions at 150 ° C. for 30 minutes. Thereafter, the conductive resin 5 is applied to the terminal connection portion of the electrode 2, and the terminal member 4 is placed on the conductive resin 5 and is crimped.

  Further, a hot-melt bonding metal 7 made of solder is formed in the center of the terminal member 4 by a soldering iron. By heating at the time of forming the bonding metal 7, a curing reaction of isocyanate contained in the conductive resin 5 is caused, and the terminal member 4 is fixed to the terminal connection portion of the electrode 2. Thereafter, the exterior material 6 is heat-sealed with a laminating roll having a surface temperature of 170 ° C. to complete the heating element main body. Next, the lead wire 9 is connected to the terminal member 4 to complete the heating element.

  A heat-meltable bonding metal 8 made of solder is welded to the tip of the lead wire 9, and the bonding metal 7 formed on the terminal member 4 is covered while the portion of the bonding metal 8 is heated with a soldering iron. Press against the surface of the exterior material 6 to be performed. At this time, the exterior material 6 is melted by the heat of the soldering iron, and at the same time, the bonding metal 7 formed on the surface of the terminal member 4 and the bonding metal 8 welded to the tip of the lead wire 9 are integrally melted.

  As a result, the bonding metal and the bonding metal are melted and bonded to each other to fill the melting hole of the outer packaging material 6 to form a molten phase, and the terminal member 4 and the lead wire 9 are electrically and physically connected. Is completed. As a result of measuring the breaking strength of the lead wire 9 for the heating element of Example 1, it was confirmed that it had a strength in the vicinity of 10 kgf and was sufficiently practical. Further, even when a continuous 5 A current was passed through the terminal portion, the temperature rise was 2K or less, and it was confirmed that there was no problem in practical use.

  Since the terminal member 4 formed in the power feeding portion of the electrode 2 is joined to the electrode 2 through the conductive resin material 5, the material of the electrode 2 is silver powder as a conductivity imparting material in the copolymerized polyester resin. Even a so-called resin-based conductive paste that is dispersed enables electrical and physical bonding. Naturally, even an electrode such as a metal thin plate can be electrically and physically joined, and the terminal member 4 can be joined without being restricted by the material of the electrode.

  In addition, since the conductive resin material 5 is interposed in the form of a thin wall, it is possible to set the resistance value of the joint portion to be extremely low, and it is possible to hardly generate heat even if a large current continues to flow. . In addition, sufficient strength can be ensured by securing the bonding area.

  Furthermore, since the exterior material 6 formed on the outer side of the terminal member 4 supports the terminal member 4, this bonding strength can be further strengthened. The heat-meltable bonding metal 7 formed on the terminal member and the heat-meltable bonding metal 8 welded to the connecting portion of the lead wire are penetrated by heat melting of the exterior material in a heated state at a melting temperature or higher. The bonding metal 7 and the bonding metal 8 are welded by being thermally melted with each other via the holes.

  This bond is a bond between metals, and the electrode 2 and the lead wire 9 can be connected electrically and physically firmly. The through holes provided in the exterior material are filled with the bonding metal 7 or the bonding metal 8 so that the airtightness is maintained. The terminal member 4 can be formed at an arbitrary position of the electrode 2 and the connection position of the lead wire 9 can be easily changed.

  In addition, the lead wire 9 can be connected after the exterior material 6 is applied regardless of where the terminal member 4 is formed.

  As a result, it is possible to form a highly reliable and highly productive power feeding unit with a large allowable current at an arbitrary position of the heating element.

  This configuration is extremely useful when a large amount of current is required because the power supply voltage is low, or when a heating element having a positive resistance temperature characteristic that requires a large inrush current to obtain rapid thermal performance is used. It is effective.

(Example 2)
FIG. 4 shows a heating element of Example 2. The difference between the second embodiment and the first embodiment is that the terminal member 4, the conductive resin 10, and the bonding metal 7 are integrally formed, and the composition of the conductive resin 10. The idea is added.

  A method for manufacturing the heating element of Example 2 will be described. First, a conductive silver paste is printed on a substrate 1 made of a polyethylene terephthalate film and dried to form a pair of electrodes 2.

  The conductive silver paste is prepared by dispersing silver powder as a conductivity-imparting material in a copolyester resin and adding an appropriate amount of isocyanate as a curing agent.

  The drying condition is 150 ° C. for 30 minutes so that the copolymer polyester resin constituting the electrode 2 is completely cured by the isocyanate.

  Next, the resistor paste is printed, and the resistor 3 is formed under dry conditions at 150 ° C. for 30 minutes. As shown in FIGS. 4A and 4B, the terminal member 4 is placed on the terminal connection portion of the electrode 2. The terminal member 4 is a copper plate having a thickness of 70 μm. A conductive resin 10 is formed on one side of the copper plate, and a bonding metal 7 made of solder is formed on the other side. The conductive resin 10 is formed. The surface is in contact with the electrode 2.

  The conductive resin 10 uses a conductive paste prepared by dispersing silver powder as a conductivity-imparting material in a copolyester and further adding an appropriate amount of isocyanate as a curing agent. Since the conductive resin 10 at this stage is dried at a low temperature so as not to cause a curing reaction due to isocyanate, it retains thermoplasticity. If it is pressurized at a temperature equal to or higher than the melting point, it is thermally fused to the electrode 2. Is in a state where it is possible.

  In this case, in particular, since the electrode 2 and the conductive resin 10 use the same kind of resin, the heat-fusibility is very good, and a sufficient heat-sealing strength can be obtained. Thereafter, as shown in FIG. 4C, the exterior material 6 is heat-sealed with a laminating roll having a surface temperature of 170 ° C. to complete the heating element main body. The conductive resin 10 is thermally fused to the electrode 2 by heating and pressurization with this laminate roll, and the curing reaction of the copolymerized polyester by the isocyanate that has been left unreacted proceeds so that the electrode 2 is firmly bonded. Is done.

  Next, the lead wire 9 is connected to the terminal member 4 to complete the heating element. As shown in FIG. 4D, a bonding metal 8 made of solder is welded to the tip of the lead wire 9, and the portion of the bonding metal 8 is formed on the terminal member 4 while being heated with a soldering iron. It presses against the surface of the exterior material 6 which coat | covers the joining metal 7 made.

  At this time, the exterior material 6 is melted by the heat of the soldering iron, and at the same time, the bonding metal 7 formed on the surface of the terminal member 4 and the bonding metal 8 welded to the tip of the lead wire 8 are integrally melted.

  As a result, the bonding metal and the bonding metal are melted and bonded to each other to fill the melting hole of the outer packaging material 6 to form a molten phase, and the terminal member 4 and the lead wire 9 are electrically and physically connected. Is completed.

  By this heating, the curing reaction of the copolyester with isocyanate proceeds further, and the bonding with the electrode 2 becomes stronger.

  In the heating element of Example 2, the conductive resin material 10 is formed in advance on the surface where the electrode member 2 is bonded to the terminal member 4, and the heat-meltable bonding metal 7 is formed on the other surface. If it is this structure, it is not necessary to form the conductive resin material 10, the terminal member 4, and the joining metal 7 separately in the site | part of the electrode 2 which wants to connect the lead wire 9, and especially a conductive resin material The terminal member 4 provided with the bonding metal 7 and the terminal member 4 can be provided with a very simple configuration in which the terminal member 4 is disposed at the connection portion of the lead wire 9.

Example 3
The heating element of Example 3 relates to a manufacturing method for rationally forming a terminal component in which a terminal member 11, a conductive resin 12, and a bonding metal 13 are integrated.

  5 and 6 show a structure before the structure in which the terminal member 11, the conductive resin 12, and the bonding metal 13 are integrated is divided.

  First, after solder cream was printed in a circular pattern with a diameter of 8 mm on the surface side of the terminal member 11 before splitting made of a 70 μm thick copper plate, the bonding metal 13 was formed by heating in an oven at 230 ° C.

  Cream solder not only excels in productivity, but also has features such as easy shape alignment and uniform thickness. Next, a conductive paste for forming the conductive resin 12 is applied to the entire surface by screen printing on the back surface of the terminal member 11 before the division, and dried at 100 ° C. for 30 minutes to remove the solvent. Conductive resin 12 was formed.

  The conductive paste for forming the conductive resin 12 contains a curing agent for curing the copolyester, but uses a block type isocyanate that hardly causes a curing reaction in a temperature range of about 130 ° C. or lower. doing.

  Therefore, although the solvent component of the conductive resin 12 at this stage is removed by drying, since the resin is uncured, it has thermoplasticity and can be thermally fused with the electrode material. Further, in the process of thermosetting, there is no foaming due to the solvent, and the structure becomes dense and the strength is greatly improved. The terminal member 11, the conductive resin 12 and the bonding metal 13 formed in this way are integrated at a broken line portion in FIG. 5 to obtain a component necessary for terminal connection.

  By such a procedure, the terminal component in which the terminal member 11, the conductive resin 12, and the bonding metal 13 are integrally formed can be manufactured with high accuracy and reasonably.

  In addition, a part of said Example 1, Example 2, and Example 3 can be substituted, and it can be set as the following structures, and a further effect | action and effect can be brought about.

  First, instead of using a simple metal thin plate such as a copper plate for the terminal member, the surface area of adhesion between the conductive resin material and the conductive resin material is replaced with a roughened metal plate. And the peel strength can be enhanced. Moreover, when roughening a copper plate, by making it the shape which the front-end | tip of a rough surface convex part spreads, an anchor effect can be provided and peeling strength can be raised further. As such a roughening method, surface polishing, plating by an electrical or chemical method, etching or the like is useful, and the electroplating can provide an anchor effect.

  In addition, instead of using a simple metal thin plate such as a copper plate for the terminal member, it is possible to produce a foil having a uniform thickness and high purity by replacing it with an electrolytic metal foil. Therefore, the terminal member excellent in flexibility can be formed.

  In addition, instead of using a simple metal thin plate such as a copper plate for the terminal member, by replacing with a rolled metal foil, a property that does not easily break with respect to elongation is given, and a terminal member having excellent bending resistance is provided. Can be formed.

  Further, instead of using a simple metal thin plate such as a copper plate for the terminal member, the contact resistance can be reduced or the increase in the resistance value due to oxidation degradation can be suppressed by plating a corrosion-resistant metal on the surface. Moreover, when using copper foil for olefin resin, copper damage can also be relieved. As the plating material, a metal that is resistant to oxidation and does not inhibit conductivity, such as nickel, tin, or solder, can be selected.

  In addition, instead of using a simple metal thin plate such as a copper plate for the terminal member, the conductive resin material of the terminal member opening is replaced by a material in which an opening such as a square hole or a round hole is formed. Adhesive strength can be greatly improved because it wraps around the edge or back. This is extremely effective when the strength of the terminal member is required, and the strength can be greatly improved by examining the shape, number and arrangement of the openings.

  In addition, instead of using a simple metal thin plate such as a copper plate for the terminal member, replacing it with a fibrous material allows the conductive resin material to enter the fibrous portion of the terminal member, greatly improving the adhesive strength. can do. Further, flexibility can be imparted, and a terminal member having excellent bending resistance can be formed.

  In addition to the conductive resin material, the adhesive material is placed on the terminal member on the surface to be joined to the electrode to reinforce the physical connection with the electrode by the conductive resin material, and the reliability as a terminal member Can be increased. Further, the terminal member can be easily temporarily fixed at a predetermined position by the adhesive force of the adhesive material. If it can be temporarily fixed, productivity increases and positional accuracy is improved. Since the temporarily fixed terminal member is completely fixed by the exterior material, a terminal member having excellent peel strength and reliability can be formed.

  Normally, the terminal forming portion is treated with a resin mold for the purpose of electrical insulation, sealing and reinforcement, but this configuration is also useful in the present invention and can improve the reliability of the terminal portion. Needless to say.

  In addition, the conductive resin material is not limited to the copolyester, and can be selected from many reactive resins such as epoxy, silicon, and acrylic. Further, the curing agent is not limited to isocyanate, and can be selected from various materials according to the resin.

  As mentioned above, although description was added based on the Example, this invention has the same effect | action and effect, without being limited to these Examples and the numerical value or material shown there.

  As described above, the heating element according to the present invention has a large allowable current and can form a highly reliable and highly productive power feeding portion at any position of the heating element and after the exterior is applied to the entire surface. This is extremely useful when a large amount of current is required due to a low power supply voltage, or when a heating element having a positive resistance temperature characteristic that requires a large inrush current to obtain rapid thermal performance is used. .

The top view which shows the structure of the heat generating body of Example 1 of this invention. A-A 'sectional view of FIG. Expanded sectional view of the main part Process drawing which shows the manufacture procedure of the heat generating body of Example 2 of this invention. The top view which shows the structure of the terminal component before the division | segmentation of Example 3 of this invention. Side view Plan view showing a conventional heating element Cross section

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 Electrode 3 Resistor 4, 11 Terminal member 5, 10, 12 Conductive resin 6 Exterior material 7, 13 Bonding metal 8 Bonding metal 9 Lead wire

Claims (23)

One or more pairs of electrodes, a heat-generating resistor formed between the electrodes, a terminal member formed on the power feeding portion of the electrode via a conductive resin material, and formed on the surface of the terminal member A heat-meltable bonding metal, an exterior material that integrally covers the resistor, the electrode, the terminal member, and the bonding metal, and a heat-meltable bonding metal that can be melt-bonded to the bonding metal. A lead wire welded to the connecting portion, and the electrode and the terminal member are electrically and physically joined via a conductive resin material, and the penetration formed by heat melting of the exterior material A heating element formed by melting and bonding the bonding metal and the bonding metal via holes and electrically and physically bonding the terminal member and the lead wire. The heating element according to claim 1, wherein a conductive resin material is formed on a surface to be bonded to the electrode, and a terminal member formed with a heat-meltable bonding metal is disposed on the other surface in the power feeding portion of the electrode. . The heating element according to claim 1 or 2, wherein the electrode is formed from a conductive paste in which conductive metal powder is dispersed in a resin. The heating element according to any one of claims 1 to 3, wherein the terminal member is a metal thin plate, and a joint surface with the conductive resin material is roughened. The heating element according to any one of claims 1 to 4, wherein the terminal member is an electrolytic metal foil. The heating element according to any one of claims 1 to 4, wherein the terminal member is a rolled metal foil. The heating element according to any one of claims 1 to 6, wherein the terminal member is a metal thin plate having a surface plated with a different kind of metal. The heating element according to any one of claims 1 to 7, wherein the terminal member has a plurality of openings. The heating element according to any one of claims 1 to 3, wherein the terminal member is fibrous. The heating element according to any one of claims 1 to 9, wherein a conductive resin material and an adhesive material are juxtaposed on a terminal member on a surface joined to the electrode. The heating element according to any one of claims 1 to 10, wherein the conductive resin material is thermosetting and is in an uncured state when bonded to an electrode. The conductive resin material is thermosetting and contains a solvent for imparting fluidity, and when bonded to the electrode, it is uncured and most of the solvent is removed. The heating element according to any one of 10. The heating element according to claim 11 or 12, wherein the conductive resin material contains a resin mainly composed of copolymerized polyester and a curing agent for isocyanate. The heating element according to any one of claims 11 to 13, wherein the conductive resin material contains a curing agent whose reactivity is limited below a predetermined temperature. The heating element according to claim 14, wherein the conductive resin material contains a resin having a copolymer polyester as a main component and a block type isocyanate curing agent whose reactivity is limited to a predetermined temperature or lower. The heating element according to any one of claims 11 to 15, wherein the conductive resin material and the electrode contain the same kind of resin. The heating element according to any one of 11 to 16, wherein the electrode is thermosetting and the electrode is thermoset when the conductive resin material is bonded to the electrode. One or more pairs of electrodes, a heat-generating resistor formed between the electrodes, a terminal member formed on the power feeding portion of the electrode via a conductive resin material, and formed on the surface of the terminal member A heat-meltable bonding metal, an exterior material that integrally covers the resistor, the electrode, the terminal member, and the bonding metal, and a heat-meltable bonding metal that can be melt-bonded to the bonding metal. After forming the conductive resin material on one surface of the terminal member and forming the bonding metal on the other surface, the conductive resin material is formed on the electrode. It arrange | positions so that the said joining metal may appear on the surface of the said terminal member while touching an electric power feeding part, Then, the said exterior material is formed, and also the said bonding metal is welded on the surface of the said exterior material in which the said joining metal is located after that The lead wire When heated close to each other, the bonding metal and the bonding metal are melt-bonded via a through hole formed by thermal melting of the exterior material, and the terminal member and the lead wire are electrically and physically bonded. A method for manufacturing a heating element. 19. The manufacturing of a heating element according to claim 18, wherein the conductive resin material of the terminal member is thermosetting, and is heat-treated at a temperature lower than or equal to the thermosetting temperature, bonded to the electrode, and thermoset in the process of covering the exterior material. Method. The heating element according to claim 18 or 19, wherein the conductive resin material of the terminal member is thermosetting, and is heat-treated at a temperature not higher than the thermosetting temperature, bonded to the electrode, and heat-cured in the process of bonding the lead wire. Manufacturing method. Adhesive agent is juxtaposed on a part of the surface of the terminal member where the conductive resin material is formed, and the conductive resin material is disposed in contact with the electrode due to the adhesive property of the adhesive agent. The manufacturing method of the heat generating body of any one of Claims 18-20 formed by forming the exterior material which coat | covers the said electrode, the said terminal member, and the whole joining metal integrally. The terminal member is coated with cream solder on one side and then heated to form a bonding metal. On the other side, a thermosetting conductive resin paste is applied, and the solvent content is reduced below the curing temperature. The manufacturing method of the heat generating body of any one of Claims 18-20 formed by removing and forming a conductive resin material. The method of manufacturing a heating element according to any one of claims 18 to 22, wherein the terminal member is formed in a large plate shape in which a large number of terminal members are gathered and divided.

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