JPH07192857A - Resistor heater - Google Patents

Abstract

PURPOSE:To provide a resistor heater with no breakage of a resistant heating element, low cost, and high reliability. CONSTITUTION:A resistor heater 16 consists of an insulating film 18 made of polyimide resin and the like, and an electrode 19, a power supply part 20 formed so as to cover the electrode 21 connected to the power supply part 20, and a protecting layer 22. The power supply part 20 and the resistant heating element 21 are integratively formed by screen printing. Although heat is generated in the resistant heating element 21 by applying voltage to the electrode 19, since current density in the power supplying part 20 is low and heat generation is slight, variation in stress in a crooked part 25 is small, and generation of cracks and breakage is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resistor heater for heating by a ladder-shaped resistance heating element.

[0002]

2. Description of the Related Art Ink jet printers that perform printing by applying pressure by a piezoelectric element or the like and ejecting ink from thin nozzles are used as inexpensive and low noise printers. However, there is a problem in that the ink that has solidified while not in use causes clogging of the nozzles and printing cannot be performed.

On the other hand, an ink jet printer which uses an ink in which a pigment or the like is mixed with a wax which is solid at room temperature, heats and melts the ink during printing and ejects it from a nozzle. That is, the nozzle or the like is at room temperature when not in use, and the ink in the nozzle is solidified, but the head is heated in advance to heat and melt the ink in the nozzle or the like during use. Therefore, nozzle clogging does not occur, and highly reliable printing is possible.

Conventionally, in order to heat the print head 100 of such an ink jet printer, a resistor heater 112 as shown in FIG. 8 has been used. That is, the ink ejecting section 1 that ejects ink from the nozzle by the piezoelectric element
The resistor heater 112 is bonded to the heat equalizing plate 103 for uniformly heating 01. The resistor heater 112 includes an insulating film 105, an electrode 107, a power feeding portion 108, a resistance heating element 109, and a protective layer 110.

The power supply section 108 and the resistance heating element 109 are integrally made of the same material by screen printing.
As shown in FIG. 5, the power feeding portion 108 is formed in parallel with the electrodes 107, and the resistance heating element 109 is formed in a ladder shape between the electrodes 107. The power feeding portion 108 is formed with a width that is almost the same as or slightly narrower than the electrode 107, and serves to efficiently supply current to the resistance heating element 109. When a voltage is applied to the electrode 107, a current flows through the resistance heating element 109 to generate heat.

[0006]

However, the resistance heating element 109 has a bent portion 120 due to a gap between the electrode 107 and the insulating film 105, and a large change in stress occurs due to the heat generation of the resistance heating element 109. Occurs. For this reason, the resistance heating element 109 is used for a long time or by repeating heat generation and cooling by frequently turning the voltage on and off.
As shown in FIG. 10, cracks and disconnections occur near the bent portion 120, and normal heating cannot be performed.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an inexpensive and highly reliable resistor heater in which the resistance heating element is not disconnected. It is in.

[0008]

In order to achieve this object, a resistor heater according to the present invention comprises an insulating substrate, a plurality of electrodes provided on the insulating substrate, and a power feeding portion formed along the electrodes. A resistance heating element arranged in a ladder shape is provided between the power feeding sections, and the coupling section between the power feeding section and the resistance heating element is located in a region sandwiched by two adjacent electrodes. Further, the power supply unit and the resistance heating element may be manufactured by printing.

[0009]

In the resistor heater of the present invention having the above structure, the connecting portion between the power feeding portion and the resistance heating element is located in the region sandwiched by the two adjacent electrodes. Therefore, the bent portion caused by the gap between the electrode and the insulating substrate is in the power feeding portion, and the resistance heating element does not have the bent portion. Here, since the power feeding portion hardly generates heat and a large stress change does not occur, the wire breakage does not occur in the bent portion. Further, the power supply unit and the resistance heating element can be manufactured by printing resistance paste at the same time.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

A resistor heater 16 to which the present invention is preferably applied for heating the ink jet printer head 10.
1 is bonded to a heat equalizing plate 14 made of Invar alloy or the like for uniformly heating the ink ejecting portion 12 that ejects ink from the nozzle by the piezoelectric element as shown in FIG.
The resistor heater 16 includes an insulating film 18 such as a polyimide resin used as an insulating substrate and an electrode 19 made of copper or the like.
And a power supply unit 20, a resistance heating element 21, and a protective layer 22.

The power supply section 20 and the resistance heating element 21 are made of the same material, that is, a resistance paste in which carbon is dispersed in a binder made of phenol resin, epoxy resin, or the like, and as shown in FIG. It is made in one. The power feeding portion 20 is formed in parallel with the electrodes 19, and the resistance heating element 21 is formed in a ladder shape between the electrodes 19. Since the power feeding portion 20 is formed to have a width wider than that of the electrode 19, the bent portion 25 is formed in the power feeding portion 20 due to the gap between the electrode 19 and the insulating film 18. At this time, the connecting portion 26 between the power feeding portion 20 and the resistance heating element 21 is 2
It is located on the insulating film 18 sandwiched between the two electrodes 19.

When a voltage is applied to the electrode 19, a current flows from the electrode 19 through the power feeding portion 20 to the resistance heating element 21 having a narrow width, and the resistance heating element 21 has a high current density to generate heat. At this time, since the power supply portion 20 has a low current density and generates little heat, the change in stress in the bent portion 25 is small, and cracks and disconnections do not occur.

A method of manufacturing the resistor heater 10 will be described with reference to FIG. The electrode 19 is manufactured by a method similar to that of a well-known printed wiring board. That is, as shown in FIG. 3A, an electrode pattern is formed by the etching resistant material 33 on the copper foil 31 which is previously rolled and pressure-bonded to the insulating film 18 such as polyimide. As the etching resistant material 33, a photoresist, a masking film, or the like is used. Next, the copper foil 31 is melted with an etching solution such as ferric chloride and the etching resistant material 33 is removed, whereby the electrode 19 is produced as shown in FIG.

A resistor paste is applied to the electrodes 19 and the insulating film 18 by a well-known screen printing method.
Print on top and heat and bake. The plate used for screen printing has a power supply unit 20 and a resistance heating element 21 in advance.
Since the pattern is provided, the power feeding portion 20 and the resistance heating element 21 are formed as shown in FIG. 7C by printing once, and therefore, in the present embodiment, they can be manufactured at low cost. Furthermore, a protective layer 22 of epoxy resin or the like is further formed thereon.
Is applied by screen printing or the like to manufacture the resistor heater 16.

Although one embodiment of the present invention has been described in detail above with reference to FIGS. 1 to 3, the present invention is not limited to the embodiment described above in detail and does not depart from the spirit of the invention. Various changes can be made.

A connecting portion 2 between the power feeding portion 20 and the resistance heating element 21.
If 6 is located on the insulating film 18 sandwiched between the two electrodes 19, the power feeding section 20 does not need to be formed with a width wider than that of the electrode 19. For example, as shown in FIG. 4, the power feeding part 20 may be narrower than the width of the electrode 19, or the power feeding part 20 may be formed so as to extend over a part of the upper surface of the electrode 19 and a part of the insulating film 18. . Also in this case, the electrode 19
The bent portion 25 due to the difference between the insulating film 18 and the insulating film 18 is generated in the power feeding portion 20, and the occurrence of cracks and disconnection in the bent portion 25 can be prevented.

Further, regarding the number, width, pitch, length and shape of the resistance heating elements 21 or the width and length shape of the power feeding portion 20, the connecting portion 26 between the power feeding portion 20 and the resistance heating element 21 has two electrodes. It is not particularly limited as long as it is located on the insulating film 18 sandwiched between 19. For example, as shown in FIG. 5, the width of the power feeding unit 60 may be changed. Further, the electrodes 19 do not have to be parallel to each other, and the intervals may be changed as shown in FIG. 6, for example. At this time, the length, width, etc. of the resistance heating element 21 may be changed for each one.

The material of the resistance paste used as the material of the resistance heating element 21 is not particularly limited.
For example, a polyimide resin or the like having high heat resistance may be used as the resin binder. Also, the concentration of carbon dispersed in the resin binder can be changed according to the required resistance value. Also, the electrode material is not particularly limited. The material of the insulating substrate 18 is not particularly limited as long as it is an insulating material. Moreover, you may use the insulator formed on the conductor.

The number of electrodes is not limited to two. For example, as shown in FIG. 7, three electrodes 49a, 49b, 49c are provided, and the power feeding parts 50a, 50b, 50c and the resistance heating element 51 are provided.
You may form a, 51b. This facilitates control of the temperature distribution.

[0021]

As is apparent from the above description, in the resistor heater of the present invention, the connecting portion between the power feeding portion and the resistance heating element is located in the region sandwiched by the two adjacent electrodes. Therefore, the bent portion caused by the gap between the electrode and the insulating substrate is in the power feeding portion, and the resistance heating element does not have the bent portion. here,
Since the power feeding portion hardly generates heat and a large stress change does not occur, cracks and disconnections do not occur at the bent portion, and reliability is improved. Furthermore, if the power supply portion and the resistance heating element are simultaneously manufactured by printing the resistance paste, the cost is lower than that of a manufacturing method in which thin film formation by sputtering or the like and pattern formation by photolithography are combined.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing an embodiment of a resistor heater according to the present invention.

FIG. 2 is a plan view of an essential part showing one embodiment of the resistor heater of the present invention.

FIG. 3 is a cross-sectional view of an essential part showing the method for manufacturing the resistor heater of the present invention.

FIG. 4 is a main part plan view showing another embodiment of the resistor heater according to the present invention.

FIG. 5 is a main part plan view showing another embodiment of the resistor heater of the present invention.

FIG. 6 is a main part plan view showing another embodiment of the resistor heater of the present invention.

FIG. 7 is a main part plan view showing another embodiment of the resistor heater of the present invention.

FIG. 8 is a cross-sectional view of essential parts showing a conventional resistor heater.

FIG. 9 is a plan view of an essential part showing a conventional resistor heater.

FIG. 10 is a main part plan view showing a conventional resistor heater.

[Explanation of symbols]

 16 Resistor Heater 18 Insulating Substrate 19 Electrode 20 Power Feeding Section 21 Resistance Heating Body 26 Coupling Section of Power Feeding Section and Resistance Heating Body

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hamaguchi ▲ Taku ▼ ya 15-1 Naeshiro-cho, Mizuho-ku, Nagoya-shi Brother Industrial Co., Ltd.

Claims (4)

[Claims] 1. An insulating substrate, a plurality of electrodes provided on the insulating substrate, a power feeding portion formed along the electrodes, and a resistance heating element arranged in a ladder shape between the power feeding portions. The resistor heater is characterized in that the coupling portion between the power feeding portion and the resistance heating element is located in a region sandwiched by two adjacent electrodes. 2. The resistor heater according to claim 1, wherein
A resistor heater, wherein the power feeding portion and the resistance heating element are manufactured by printing. 3. The resistor heater according to claim 1, wherein
The resistor heater is formed at least along the region side of the electrode. 4. The resistor heater according to claim 1,
The resistor heater, wherein the power feeding portion is formed to have a width wider than that of the electrode.