JP2002056953A - Connection method of lead member and heat generating element having lead member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connection method of a lead member and a heat generating element having the lead member. SOLUTION: This connection method of the lead member concerns a heat generating element 9 which comprises a stainless substrate 1, an insulating layer 2 formed on the stainless substrate, and a resistor pattern 3 formed on the insulating layer. The lead member 7 (lead wire L, shaped plate terminal, etc.), which is installed on the terminal 4 of the resistor 4 is adhered by a conductive paste (silver paste or the like) and then fixed by an inorganic adhesive (adhesive made of alumina, calcium carbonate and water glass, or the like). The heat generating element having this lead member does not bring about connection failure due to deformation by heat or separation of the lead member or the like by the operation of the heat generating element and can control the temperature precisely.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for connecting a lead member and a heating element with a lead member, and more particularly, to a method for connecting a lead member to a terminal on a resistor pattern of a heating element having a stainless steel substrate as a substrate. And a heating element using the same. The heating element using the lead member connection method of the present invention is used for irons, electronic jars, hot water heaters for shower toilets, thermal heads for copiers and laser printers, and the like.

[0002]

2. Description of the Related Art Conventionally, 25
A lead member attached to a terminal on a resistor pattern, which is a heating element at 0 to 500 ° C., has been directly soldered to the terminal or connected in the form of a connector in which a connection component with the lead member is housed in a plastic mold. Was. But,
Solder has a low safe use temperature of 250 ° C., and connector has plastic deformation or damage at 200 ° C. or higher. Therefore, there is a demand for a connection method that does not damage the lead member and the terminal in order to maintain the followability, reproducibility, and stability to the set temperature.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and eliminates a connection failure when connecting a terminal on a resistor pattern of a heating element having a stainless steel substrate to a lead member. It is an object of the present invention to provide a lead member connection method which can be performed and has a good electrical connection state, and a heating element using the same.

[0004]

Means for Solving the Problems The present inventors can eliminate poor connection and electrically connect a terminal on a resistor pattern of a heating element made of stainless steel as a substrate and a lead member. The present inventors have completed the present invention as a result of examining a lead member connection method in a good state and a heating element using the same. The lead member connecting method according to the first aspect of the present invention provides a method of connecting a heating element, comprising: a stainless steel substrate; an insulating layer formed on the stainless steel substrate; and a resistor pattern formed on the insulating layer. The lead member provided on the terminal on the body pattern is fixed with a conductive paste and then fixed with an inorganic adhesive.

[0005] A heating element with a lead member according to the eleventh aspect of the present invention comprises a stainless steel substrate, an insulating layer formed on the stainless steel substrate, a resistor pattern formed on the insulating layer, A lead member provided on a terminal on the pattern, a conductive layer for fixing the lead member, and an inorganic adhesive portion for further covering the lead member, wherein the lead member is a terminal on the resistor pattern. Characterized in that it is fixed to

[0006] The "stainless steel" constituting the stainless steel substrate is not particularly limited, but heat resistant ferritic steel is preferably used.
US444 is preferably used. The shape of the substrate is not particularly limited, and may be a plate, a cylinder, or a partially bent or curved surface. The size can be variously selected depending on the purpose and application.

As the "insulating layer", glass such as semi-crystalline glass is preferably used in consideration of the thermal expansion balance with the stainless steel substrate. The “resistor pattern” is usually printed in a circuit shape in accordance with the purpose and the shape of the substrate using a resistor paste containing no lead, cadmium or nickel, and is formed by a baking process.

The "lead member" is not particularly limited in its shape, and may be, for example, a lead wire (see the second and twelfth inventions) or a plate-like material. This lead wire is usually a single wire or a stranded wire made of a thin wire such as copper and covered with a polyvinyl chloride resin or the like. The shape of the plate-like material is not particularly limited, and may be a flat plate-like material or an L-shaped plate-like material having a substantially L-shaped vertical section (see the fifth and fifteenth inventions). The length ratio between the bottom portion and the standing portion of the L-shaped plate-like material can be variously selected, and the bottom shape of the bottom portion only needs to correspond to the surface shape of the substrate to be fixed. ,
In the case of a flat substrate having a smooth surface, it has a smooth bottom surface shape, and in the case of a tubular substrate, it has a curved bottom surface shape corresponding to the curved surface surface. The material of the plate-like material is not particularly limited, but may be, for example, Kovar (iron-nickel-cobalt alloy).

When the above-mentioned L-shaped plate is used,
As shown in the eighth and eighteenth aspects of the invention, at least the upright portions are conductive and are not oxidized (they are hardly oxidized,
(It is not oxidized by a heat treatment in a later step). As a result, surface oxidation during heat curing can be prevented, and conductivity can be maintained. Examples of the “conductive / non-oxidizing material” include, but are not particularly limited to, silver, silver-palladium, and the like, and when covering the standing portion, or the entire standing portion and the bottom portion, include these fine particles. Pastes or other paints can be used.

[0010] As described in the third and thirteenth aspects of the present invention, the lead wire can be embedded in a terminal on the resistor pattern with a conductive paste. Further, as described in the sixth and sixteenth aspects of the present invention, the L-shaped plate-like material has the bottom surface of the L-shaped plate-like material joined to the surface of the terminal on the resistor pattern by a conductive paste. be able to.

The conductive paste used to form the “conductive paste” and the “conductive layer” is not particularly limited as long as it is a conductive paste so that the electrical resistance of the resistor pattern does not fluctuate greatly. Instead, for example, a mixture of fine particles of carbon, copper, silver, silver-palladium or the like mixed with a highly viscous binder resin or the like may be used. Among them, a silver paste containing silver is preferable as shown in the ninth and nineteenth inventions. The conductive paste can be cured at 200 ° C. or lower, preferably at 100 to 200 ° C., and more preferably at 120 to 18 ° C., as shown in the fourth and fourteenth inventions.
It is preferred to cure at 0 ° C. This method is preferable when the lead member such as a lead wire is covered (buried) as shown in the third invention. In addition, the conductive paste is
It can be baked at a temperature of 00 ° C. or more. In particular, Book 10
As described in the twentieth aspect, the present invention is suitable for a case where only the bottom surface is joined without covering the L-shaped plate-like material, that is, the conductive paste is 800 ° C. or more (preferably 820 ° C. or more, more preferably (850 ° C. or higher, usually 870 ° C. or lower). Thereby, stronger adhesive fixation can be performed without covering the whole.

The "inorganic adhesive" and the "inorganic adhesive" constituting the "inorganic adhesive portion" are not particularly limited as long as they include an inorganic filler and have an adhesive property. The main components of the inorganic adhesive are an inorganic filler, a water-soluble binder and a coagulant, and these can be used as an adhesive in combination.

Examples of the inorganic filler include silica, alumina, zirconia, magnesia, boron nitride, aluminum nitride, silicon nitride, silicon carbide, etc., and they can be used alone or in combination of two or more. It is preferable to use a material having a composition close to the expansion coefficient of the material of the lead wire. The inorganic filler is preferably in the form of fine particles, and is easily dispersed uniformly in a water-soluble binder, and enables strong adhesion. As this inorganic filler, as shown in the eighth and eighteenth inventions, alumina can be used. Examples of the water-soluble binder include water glass, phosphate, colloidal silica, and the like, and water glass can be used as described in the tenth and twentieth inventions. Further, as a coagulant, sodium aluminate, sodium carbonate, calcium carbonate,
Examples thereof include calcium sulfoaluminate. As shown in the tenth and twentieth aspects, calcium carbonate can be used.

The inorganic adhesive and the inorganic adhesive part are preferably cured at a temperature of 200 ° C. or lower, more preferably 100 to 2 as described in the fourth and fourteenth inventions.
It is preferable to cure at 00 ° C, more preferably at 120 to 180 ° C. This case is suitable for embedding the lead wire with a conductive paste and curing the conductive paste at 200 ° C. or lower (see the fourth and fourteenth inventions). When using the above-mentioned inorganic adhesive, it is preferable to use as large an area as possible in order to reduce the mechanical stress applied to the fixing surface of the lead wire, and furthermore, to make the fixing portion have the thickness of the inorganic adhesive as much as possible. preferable.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
This will be described in more detail. Embodiment 1 The present embodiment relates to a heating element in which a lead wire is used as a lead member, and FIG. 1 is an explanatory sectional view thereof. After smoothing the surface of the SUS430 plate-like substrate 1 having a thickness of 2 mm, the semi-crystalline glass is fired to a thickness of 100 μm.
m, and the baking treatment was repeated twice to form an insulating layer 2. Thereafter, a predetermined circuit-shaped resistor pattern 3 is printed using a resistor paste (trade name “3615”, manufactured by DuPont) containing no lead, cadmium or nickel (line width 1.5 mm, line thickness 10 μm, overall length 750 mm) )
And fired. Terminals 4 at both ends of resistor pattern 3
A silver paste was printed at a size of 5 mm in length and 5 mm in width, and portions other than the terminals were coated as protective glass 8 with semi-crystalline glass containing no lead, cadmium or nickel to produce a heating element.

Next, in order to connect the lead wire 7 to the terminal 4, a stranded wire (a single wire diameter of 0.18 mm
And an outer diameter of 1.5 mm), and coated so as to cover with a silver paste for a terminal (trade name “3660”, manufactured by DuPont).
The mixture was heated at 50 ° C. for 1 hour, allowed to cool naturally, and the silver paste was cured. Further, an inorganic adhesive 6 consisting of 65 parts by weight of alumina, 35 parts by weight of calcium carbonate, and 20 parts by weight of water glass is applied to the protective glass 8 so as to cover the protective glass 8, and allowed to stand at room temperature for 12 hours. 2 hours at 150 ° C
Heating for natural time, cooling naturally, heating element 9 with lead wire
Was manufactured.

As shown in FIG. 1, the heating element with leads is formed by laminating an insulating layer 2 of semicrystalline glass, a resistor pattern 3 and terminals 4 in this order on a SUS430 substrate 1. In order to connect the terminal 4 and the lead wire 7, the lead wire 7 is embedded on the terminal 4 with a conductive paste 5, and further fixed so as to cover the protective glass 8 with an inorganic adhesive 6.

After connecting and fixing the lead wires, the SUS43
The tensile strength was measured by the method shown in FIG. As a result, it was 3 kgf. After performing an operation test of the heating element [repeated “room temperature → 500 ° C. (holding for 5 minutes) → room temperature” 500 times), the tensile strength was measured under the same conditions and found to be 3 kgf. Also,
The electric resistance value of the heating element before and after the operation test was 12.19.
Ω → 12.30Ω, almost no change was observed.

Example 2 The tensile strength was measured in the same manner as in Example 1 except that the bonding area of the inorganic adhesive for covering the lead wires and fixing the terminals was doubled. The weight was 6 kgf before the test and 6 kgf after the operation test.
The electric resistance value of the heating element before and after the operation test is 1
2.10Ω → 12.20Ω, almost no change was observed.

Embodiment 3 This embodiment relates to a heating element when an L-shaped plate material is used as a lead member. FIG. 3 is a cross-sectional view for explaining the heating element and FIG. . SUS430 cylindrical substrate 1 having an outer diameter of 17 mm, a thickness of 1 mm, and a length of 120 mm
a after smoothing the semi-crystalline glass
The coating was performed so as to have a thickness of 0 μm, and the baking treatment was repeated twice to form an insulating layer 2a. Thereafter, a resistor paste containing no lead, cadmium or nickel (trade name “3615”,
Predetermined circuit-shaped resistor pattern 3 using
Print a (line width 6 mm, line thickness 10 μm, total length 280 m
m), and baked. A silver paste is printed on both ends of the resistor pattern 3a as terminals 4a in a size of 6 mm long × 7 mm wide, and portions other than the terminals are coated with semi-crystalline glass containing no lead, cadmium or nickel as protective glass 8a. Thus, a heating element was manufactured.

Next, the terminal 4a has an L-shaped plate-like terminal (bottom part 71; 5 mm long × 6 mm wide, upright part 72) having a curved bottom surface (curved surface equal to the surface of the cylindrical substrate 1a). In order to connect 7a (height 6mm x width 6mm) 7a, first, Kovar L-shaped plate-shaped terminal 71 bent perpendicularly to the substrate
Of the silver paste for terminals (trade name “366”)
0 "(manufactured by DuPont), heated at 150 ° C for 15 minutes, and cooled naturally. And the coating layer 7 on this standing portion
The terminal silver paste 5a is applied to the bottom surface portion 71 of the L-shaped plate-like terminal 7a provided with the terminal 3 and static pressure is applied on the terminal 4a so that the terminal silver paste 5a protrudes (see FIGS. 4 and 3).
In FIG. 4, the protective glass 8a is omitted. ). This was heated at 150 ° C. for 15 minutes, and further baked at 850 ° C. for 10 minutes. After drying, an inorganic adhesive 6a consisting of 65 parts by weight of alumina, 35 parts by weight of calcium carbonate, and 20 parts by weight of water glass was applied to the protective glass 8a so as to cover the protective glass 8a, and allowed to stand at room temperature for 12 hours.
The heating element was heated at 150 ° C. for 2 hours and cooled naturally to produce a heating element 9 a with an L-shaped plate terminal.

After connecting and fixing the L-shaped plate terminal 7a,
The standing portion 72 of the L-shaped lead terminal was fixed using the US430 substrate as a support, and the tensile strength was measured. As a result, 1
It was 8 kgf. After performing an operation test of the heating element [repeated "room temperature → 500 ° C. (holding for 5 minutes) → room temperature” 500 times), the tensile strength was measured under the same conditions and found to be 18 kgf. The electric resistance value of the heating element before and after the operation test was 7.20Ω → 7.25Ω.
There was almost no change.

Effects of Embodiments In the first and second embodiments, the lead wires are prevented from coming off without breaking the core of the lead wires, damaging the substrate and the terminals, and sufficiently using the area of the terminals. Was able to connect. No deformation or damage due to heat was observed on the substrate and the terminals even after the operation test of the heating element, and it was confirmed that the manufactured heating element accurately reached the target resistance value and further reached the temperature. Further, in the third embodiment, the bonding portion of the bottom surface of the L-shaped plate-shaped terminal is baked with a silver paste, so that the plate-shaped terminal can be firmly fixed without being covered with the silver paste. Even after the test, there was no deformation or damage to the substrate and the terminals due to heat, and it was confirmed that the manufactured heating element accurately reached the target resistance value and the target temperature. Further, since the upright portions of the L-shaped plate-shaped terminals were previously coated with a non- (difficult) oxidizable silver paste, the surface was not oxidized at the time of baking, and no contact failure was caused.

The present invention is not limited to the above embodiment, but may be variously modified within the scope of the present invention in accordance with the purpose and application. For example,
In order to further improve heat resistance and adhesiveness, an inorganic fiber or cloth such as silica-alumina fiber, alumina fiber, or zirconia fiber may be blended with the inorganic adhesive.

When a lead wire is used as a lead member, a soft lead wire (a wire material such as aluminum, copper, annealed nickel, etc.) or a stranded wire is used to disperse the mechanical stress applied to the lead wire during fixing. Is preferred. Further, the L-shaped plate-shaped material may not be perpendicular to the substrate but may be acute or obtuse.

[0026]

According to the lead member mounting method of the present invention, the connection failure between the terminal on the resistor pattern and the lead member is eliminated, and the lead member does not come off even when the heating element operates. Further, by curing the conductive paste and the inorganic adhesive at a temperature of 200 ° C. or lower, it is possible to prevent the coagulant in the inorganic adhesive from foaming. Further, by baking the conductive paste at 800 ° C. or more,
Bonding with excellent tensile strength was achieved. In particular,
When the L-shaped plate material was used as the lead member, a considerably large tensile strength was shown as compared with the case where the lead wire was used. Further, according to the heating element with a lead member of the present invention, even if the heating element operates, it does not cause deformation due to heat or disconnection such as detachment of the lead member, and can follow or reproduce the set temperature as a heating element. And stability can be maintained.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view when a lead wire is connected to a terminal formed on a resistor pattern on a heating element using a plate-like substrate in Examples 1 and 2.

FIG. 2 is an explanatory sectional view of a tensile test after connecting lead wires used in Examples 1 and 2.

FIG. 3 is an explanatory longitudinal sectional view when an L-shaped plate-shaped terminal is connected to a terminal formed on a resistor pattern on a heating element using a cylindrical substrate in a third embodiment.

FIG. 4 is a partial explanatory perspective view when a bottom surface of an L-shaped plate-shaped terminal is fixed on the terminal by static pressure and a silver paste for a terminal in a third embodiment.

[Explanation of symbols]

1, 1a; stainless steel substrate, 2, 2a; insulating layer, 3,
3a; resistor pattern, 4, 4a; terminal, 5, 5a; conductive paste, 6, 6a; inorganic adhesive, 7;
7a; L-shaped plate-shaped terminal, 71; bottom surface of L-shaped plate-shaped terminal, 7
2; standing portion of L-shaped plate terminal; 73; silver paste coating layer;
8, 8a; protective glass, 9, 9a; heating element.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) H05B 3/48 H05B 3/48 (72) Inventor Tadashi Kamiya 969 Komatsu, Komaki City, Aichi Prefecture Misuzu Corporation F-term in industry (reference) QC46 QC56 QC58 RA02 RD03 RD27 RF03 RF09 RF17 RF22 VV31 VV35

Claims (20)

[Claims] 1. A heating element comprising a stainless steel substrate, an insulating layer formed on the stainless steel substrate, and a resistor pattern formed on the insulating layer, a terminal on the resistor pattern. A lead wire connecting method, wherein a lead member to be provided is fixed with a conductive paste and then fixed with an inorganic adhesive. 2. The method according to claim 1, wherein the lead member is a lead wire. 3. The lead member connecting method according to claim 2, wherein said lead wire is embedded with a conductive paste. 4. The method according to claim 1, wherein the conductive paste and the inorganic adhesive are
The method for connecting a lead member according to claim 1, wherein the lead member is cured at a temperature of 00 ° C. or lower. 5. The method according to claim 1, wherein the lead member is an L-shaped plate. 6. The lead member connecting method according to claim 5, wherein the bottom surface of the L-shaped plate is joined to the surface of the terminal on the resistor pattern by a conductive paste. 7. The method according to claim 6, wherein the conductive paste is further baked at 800 ° C. or higher. 8. The lead member connecting method according to claim 5, wherein an upright portion of the L-shaped plate is covered with a conductive and non-oxidizing material. 9. The method according to claim 1, wherein the conductive paste is a silver paste. 10. The method according to claim 1, wherein the inorganic adhesive includes alumina, calcium carbonate, and water glass. 11. A stainless steel substrate, an insulating layer formed on the stainless steel substrate, a resistor pattern formed on the insulating layer, and a lead member disposed on a terminal on the resistor pattern. And a conductive layer for fixing the lead member,
Further, an inorganic adhesive portion covering the lead member,
A heating element with a lead member, wherein the lead member is fixed to a terminal on the resistor pattern. 12. The heating element with a lead member according to claim 11, wherein said lead member is a lead wire. 13. The heating element with a lead member according to claim 12, wherein said lead wire is embedded with a conductive paste. 14. The conductive layer and the inorganic adhesive part having a thickness of 200
The heating element with a lead member according to any one of claims 11 to 13, wherein the heating element is formed by curing at a temperature of not more than ° C. 15. The heating element with a lead member according to claim 11, wherein the lead member is an L-shaped plate. 16. The heating element with a lead member according to claim 15, wherein a bottom surface of said L-shaped plate is joined to a surface of a terminal on said resistor pattern by a conductive paste. 17. The heating element with a lead member according to claim 16, wherein said conductive layer is further formed by baking at 800 ° C. or higher. 18. The heating element with a lead member according to claim 15, wherein an upright portion of the L-shaped plate is covered with a conductive and non-oxidizing material. 19. The heating element with a lead member according to claim 11, wherein said conductive layer and said conductive paste contain silver. 20. The method according to claim 11, wherein the inorganic adhesive portion is made of alumina, calcium carbonate and water glass.
10. The heating element with a lead member according to any one of items 9.