JPS63239068A - Thermal head - Google Patents

Abstract

PURPOSE:To dispense with a heat sink required heretofore and to facilitate the mounting of a thermal head, by constituting a thermal head so that a large number of heat generating resistor elements connected to indivisual electrodes on one side thereof and connected to a common electrode on the other side thereof on the vitreous layer fused to the upper surface of a metal plate. CONSTITUTION:A thermal head 31 is constituted by a method wherein a vitreous layer 33 whose upper surface is exposed at the right and left end parts thereof is fused to the upper surface of a metal plate 32 composed of Fe, Cu, stainless steel or Al and a large number of heat generating resistor elements 8 and electrodes 9 for external connection are formed on the vitreous layer 33 and a driving IC 7 is mounted thereon. The metal plate 32 becomes a common electrode. The heat generating resistor elements 8 are a part of an electric resistance layer 10 exposed between the opposed conductor layers 11, 12 when the conductor layers 11, 12 are formed on the electric resistance layer 10 in a pair and covered with a protective film 15. The conductor layers 11 are connected and formed to the exposed part at the left end part of the upper surface of the metal plate (common electrode) 32, and the conductor layers 12 being indivisual electrodes and the electrodes 9 for external connection are electrically connected to the driving IC 7 by bonding wires 13.

Description

[Detailed Description of the Invention] [Summary] In a thermal head formed with a large number of heat-generating resistive elements, the heat-generating resistive elements are formed on a hollow substrate with a glass layer fused to the top surface of a metal plate, and By using the metal plate as a common electrode, the present invention provides a thermal head with a new configuration that is inexpensive and does not require a heat sink.

[Industrial application field]

The present invention provides a thermal head that prints characters, symbols, etc. by forming a large number of heating resistance elements on a substrate, one of which is connected to an individual electrode and the other of which is connected to a common electrode, and selectively generates heat from the elements. Regarding improvements.

Thermal heads, which are characterized by being noiseless and maintenance-free, have come to be widely used as output devices for various office automation equipment, and there has been a strong demand for further lower prices and easier installation. Ta.

[Conventional technology]

FIG. 2 is a side view showing a schematic configuration of a conventional thermal head mounted on a metal fitting. The thermal head 1 is mounted on a metal fitting 3 via a heat sink 2 that absorbs excess heat.

The thermal head 1 includes a common electrode 5 formed by thick film means on the upper surface of an alumina ceramic substrate 4 having electrical insulation properties.
A glass glaze NG is formed to ensure a smooth surface and provide heat insulation, and on the glaze layer 6 on which the driving integrated circuit (IC) 7 is mounted, a large number of heat generating resistive elements 8 and driving elements are formed by thin film means. The electrode 9 for external connection of the IC 7 is formed.

The heating resistance element 8 is a part of the resistance layer 10 that is exposed between the opposing conductors 11 and 12 when a pair of conductor layers 11 and 12 are formed on the electrical resistance layer 10, and is covered by the protective film 15. I will be lost. The conductor N11 is connected to the common electrode 5, and the conductor layer 12 serving as an individual electrode and the external connection electrode 9 are electrically connected to the driving IC 1 by a bonding wire 13, and the resistance layer 10 is connected to the conductor layer 10 through the conductor layers 11 and 12. When a given current is applied to
The heating resistance element 8 generates heat.

Note that the external connection electrode 9, the resistance layer 10, and the conductor layer 11.
12 is formed by laminating a four-body thin film on a resistive thin film and removing unnecessary parts thereof. Therefore, the external connection electrode 9 is laminated on the resistance layer 14 which is a part of the resistance thin film, and the heating resistance element 8
The bonding wire 13 and the like are covered with an insulation protection resin 23.

The thermal head 1 configured in this way and attached to the metal fitting 3 with a plurality of machine screws 22 is attached to the flexible cable 1.
It is electrically connected to the outside via G.

That is, the middle part of the flexible cable I6, which has a large number of conductor patterns connected to a large number of electrodes 9 and has a connector 17 connected to its right end, is connected to a spacer 19 attached to the upper surface of the right end of the heat sink 2 with machine screws 18 and a protective cover. The left end of the flexible cable 16, which is fixed between the electrodes 20 and has a large number of conductor patterns facing the large number of electrodes 9, is connected to the electrode 9 at a predetermined position by an elastic body 21 made of rubber and pressed against the protective cover 20. Contact with pressure.

FIG. 3 is a circuit diagram of the thermal head 1, in which a conductor Nll connected to one end of the heat generating resistor element 8 is connected to the common electrode 5, and a driving IC 7 connected to the other end of the heat generating resistor element 8 through a conductor layer 12 is connected to the common electrode 5. , are connected to the external connection electrode 9.

[Problem that the invention seeks to solve]

As explained above, conventional thermal heads in which heat-generating resistive elements are formed on insulating substrates such as alumina ceramics require patterning of the common electrode, and also use metal to absorb excess thermal energy of the thermal head. required a heat sink.

[Means for solving problems]

The thermal head of the present invention, which aims to eliminate the above-mentioned problems, is characterized by forming a large number of heating resistive elements 8 connected to a metal plate 3232, according to the embodiment shown in FIG.

[Effect]

According to the above means, a substrate in which a glassy layer is fused to a metal plate is used, and a heating resistor element is formed on the glassy layer, which makes it possible to use a substrate that is cheaper than alumina ceramic. In addition to eliminating the need for a heat sink, using the metal plate as a common electrode eliminates the need to form a common electrode pattern, making it possible to provide the thermal head at a low cost and to easily mount it.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS A thermal head according to an embodiment of the present invention will be explained below using the drawings.

FIG. 1 is a side view showing a schematic structure in which a thermal head according to an embodiment of the present invention is mounted on a metal fitting.

In FIG. 1, in which the same reference numerals are used for parts common to those in FIG. 2, the thermal head 31 is attached to the upper surface of the metal fitting 3 using a plurality of machine screws 22.

The thermal head 11 fuses a glassy layer 33 whose right and left ends are exposed on the upper surface of a metal plate 32 made of Fel CL11 stainless steel, A1, etc., and
A large number of heating resistive elements 8 and external connection electrodes 9 are formed on a glassy layer 33, and a driving IC 7 is mounted.
The metal plate 32 itself is a common electrode.

The heating resistance element 8 is a part of the resistance layer 10 that appears between the opposing conductor layers 11 and 12 when a pair of conductor layers 11 and 12 are formed on the electrical resistance N10, and is covered with a protective film 15. It becomes. However, the conductor Jiill is connected to the exposed part of the upper left end of the metal plate (common electrode) 32, and the conductor layer 12, which is an individual electrode, and the electrode 9 for external connection are driven by the bonding wire 13. It is electrically connected to the IC7.

Note that the external connection electrode 9, the resistance layer 10, and the conductor layer LL1
2 is made by laminating a conductive thin film on a resistive thin film and removing unnecessary parts thereof. Therefore, the external connection electrode 9 is laminated on the resistor JiJ 14, which is a part of the resistor thin film, and the heating resistor element 8, bonding wire 13, etc. are covered with the protective resin 23.

↓ The external connection electrode 9 of the thermal head 31 configured as above and attached to the metal fitting 3 with a plurality of machine screws 22 is electrically connected to the outside via the flexible cable 16.

That is, the middle part of the flexible cable 16, which has a large number of conductor patterns connected to a large number of electrodes 9 and has a connector 17 connected to its right end, is connected to a spacer 35 attached to the upper surface of the right end of the metal plate 32 with a small screw 34. The left end portion of the flexible cable 16, which is fixed between the protective covers 20 and has a large number of conductor patterns facing the large number of electrodes 9, is held by an elastic body 21 made of rubber and pressed against the protective cover 20.
It contacts the electrode 9 with a predetermined pressure.

In the thermal spatula t'31 configured in this manner, when a predetermined current is passed through the resistance layer 10 through the conductor layers 11 and 12, the heating resistance element 8 generates heat.

In the above embodiment, the thermal head 31 directly uses the metal plate 32 as the common electrode, but the present invention is not limited to this embodiment, and the common electrode may be patterned and used on the glassy layer 33. Alternatively, it should be noted that some of the effects of the present invention can be achieved by patterning and using a common electrode made of noble metal on the exposed portion of the metal plate 32.

〔Effect of the invention〕

As explained above, according to the present invention, glass is fused to a metal plate that has excellent absorption of excess heat, and the metal plate itself is used as a common electrode. This has the effect of reducing the cost, eliminating the need for a conventionally required heat sink, and making it easier to attach the thermal head.

[Brief explanation of the drawing]

Fig. 1 is a schematic side view of a thermal head according to an embodiment of the present invention mounted on a metal fitting, Fig. 2 is a schematic side view of a conventional thermal head mounted on a metal fitting, and Fig. 3 is a schematic side view of a thermal head mounted on a metal fitting. In the circuit diagram, 8 is a heating resistive element, 9 is an electrode for external connection, 10 is a resistance layer, 11, 12 is a conductor layer, 31 is a thermal head, 32 is a metal plate, and 33 is a glass layer. Boo Nagute no L, / Cao tno) 1D stone is fake nj casting 3 figure

Claims (2)

[Claims] (1) On a glassy layer (33) fused to the top surface of a metal plate (32), a large number of heating resistive elements (8) are formed, one connected to an individual electrode and the other connected to a common electrode. A thermal head characterized by: (2) the common electrode is the metal plate (32) itself;
The metal plate (3) which does not fuse the glassy layer (33)
2) The thermal head according to claim 1, characterized in that the other of the heating resistive elements (8) is connected to the upper surface.