JP2011121227A - Thermal print head and thermal printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress peeling of a heat diffusion part or a second protective layer. <P>SOLUTION: A heat generating body plate 30 of the thermal print head 1 has insulation base plate 34, 36, a heat generation resistance part 40, conductive parts 44, 46, a first protective layer 50, the heat diffusion part 52, and the second protective layer 56. The heat generation resistance part 40 is laminated on the insulation base plate 34, 36 and extended in the sub-scanning direction 92 in which a recording medium runs. The conductive parts 44, 46 are electrically connected to an end of the heat generation resistance part 40 and apply voltage to the sub-scanning direction 92 of the heat generation resistance part 40. The first protective layer 50 consists of an insulation material, and laminated on the heat generation resistance part 40 to cover the same. The heat diffusion part 52 has a plurality of through-holes 54 laminated on the first protective layer 50 and formed to communicate the front with the rear side. The second protective layer 56 is laminated on the heat diffusion part 52 and bonded to the first protective layer 50 via the plurality of through-holes 54. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a thermal print head and a thermal printer using the same.

  The thermal print head is an output device that generates heat from a plurality of heating resistors arranged in a heat generating area and forms images such as letters and figures on a heat-sensitive recording medium such as heat-sensitive recording paper. This thermal print head is widely used in recording devices such as a barcode printer, a digital plate making machine, a photo printer, an imager, and a seal printer.

  A conventional thermal print head will be described with reference to FIG. FIG. 7 is a view for explaining a conventional thermal print head, and is a partial cross-sectional view of a heating element plate.

  The thermal print head includes a heat radiating plate, and a heat generating plate 130 and a circuit board disposed on the same surface of the heat radiating plate. The heating element plate 130 includes a support substrate 134, a glaze layer 136, a resistor layer, a conductor layer, a first protective layer 150, a heat diffusion portion 152, and a second heat diffusion layer 156.

  The resistor layer is formed on the glaze layer 136 and has a plurality of heating resistor portions 140. The plurality of heating resistor portions 140 each extend in the sub-scanning direction 92 and are arranged at intervals in the main scanning direction 91. Electrodes (conductive portions) 144 and 146 are formed at both ends of each heating resistor portion 140, and the electrodes 144 and 146 are connected to the driving IC. Each heat generating resistor 140 serves as a heat generating element, and a belt-like region in which a plurality of heat generating resistors 140 are arranged becomes a heat generating region 132.

  The first protective layer 150 is laminated so as to cover the heat generating resistor part 140 and the conductive parts 144 and 146, and serves to insulate the heat generating resistor part 140 and the like from a heat diffusion part 152 described later. The thermal diffusion unit 152 is formed on the first protective layer 150 and above each of the heat generating resistor units 140, and plays a role of uniformizing the surface temperature distribution of the second protective layer 156 in the heat generating region 132. . Further, the second protective layer 156 is laminated so as to cover the heat diffusing portion 152, and plays a role of protecting the heat generating resistor portion 140 and the like from friction with the thermal recording medium when the thermal printer is used.

  On the other hand, an electrical component such as a driving IC serving as a driving circuit for supplying power to the heating resistor 140 is mounted on the circuit board.

  A thermal printer using such a thermal print head generally includes a platen roller. The platen roller is arranged so that its side surface is in contact with the heat generating region 132 with the main scanning direction 91 as an axis, and is provided to be rotatable around the axis. The thermal printer rotates the platen roller to move the thermal recording medium in the sub-scanning direction 92 while pressing the thermal recording medium inserted between the platen roller and the heat generating area 132 against the heat generating area 132. In addition, a desired image is formed on the thermal recording medium by changing the heat generation pattern of the heat generation region 132 as the thermal recording medium moves (see, for example, Patent Document 1).

JP 2006-205520 A

  At the time of manufacturing the thermal print head, the thermal print head is heated in order to seal the driving IC and the bonding wire with resin. Further, when the thermal print head is used, the heat generating plate 130 becomes high temperature. Then, since the thermal expansion coefficient and the thermal contraction ratio of the first protective layer 150 and the thermal diffusion unit 152 are different from each other, the thermal diffusion unit 152 may be separated from the first protective layer 150.

  Further, when there is a height difference between the resistor layer and the conductor layer, the second protective layer is formed at the boundary between the heat generating resistor portion 140 and the conductive portions 144 and 146 (the boundary between the heat generating region 132 and the region that does not generate heat). A crack 95 may occur in 156 and the second protective layer 156 may peel off. In particular, since friction is generated on the surface of the second protective layer 156 due to the movement of the thermal recording medium, such a situation is likely to occur.

  Then, this invention is made | formed in order to solve the above-mentioned subject, and it aims at suppressing peeling of a thermal-diffusion part or a 2nd protective layer.

  In order to achieve the above object, a thermal print head according to the present invention includes an insulating substrate, a heating resistor portion stacked on the insulating substrate and extending in a sub-scanning direction in which a recording medium travels, and the heating resistor portion. A conductive portion that is electrically connected to an end of the heating resistor and applies a voltage in the sub-scanning direction of the heating resistor, and an insulating material that is stacked on the heating resistor so as to cover at least the heating resistor. 1 protective layer, a thermal diffusion part laminated on the first protective layer to form a plurality of through holes, and the first protective layer laminated on the thermal diffusion part via the plurality of through holes And a second protective layer adhered to the substrate.

  In order to achieve the above object, a thermal printer according to the present invention includes an insulating substrate, a heating resistor layer stacked on the insulating substrate and extending in a sub-scanning direction in which a recording medium travels, and the heating resistor. A conductive portion that is electrically connected to an end of the portion and applies a voltage in the sub-scanning direction of the heating resistor portion, and an insulating material laminated on the heating resistor portion so as to cover at least the heating resistor portion A first protective layer; a heat diffusion portion formed on the first protective layer and formed with a plurality of through holes; and the first protection layer stacked on the heat diffusion portion and the plurality of through holes. A thermal print head having a second protective layer bonded to the layer is provided.

  According to the present invention, an object is to suppress peeling of the thermal diffusion portion or the second protective layer.

1 is a perspective view of a thermal print head according to a first embodiment of the present invention. 1 is a partial cross-sectional view of a thermal printer according to a first embodiment of the present invention. It is a figure for demonstrating the thermal print head which concerns on the 1st Embodiment of this invention, Comprising: It is a partial top view of the heat generating body board which abbreviate | omitted the 1st protective layer and the 2nd protective layer. FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 3. It is a figure for demonstrating the thermal print head concerning the 2nd Embodiment of this invention, Comprising: It is the partial top view of the heat generating body board which abbreviate | omitted the 1st protective layer and the 2nd protective layer. It is a figure for demonstrating the thermal print head which concerns on the 3rd Embodiment of this invention, Comprising: It is the partial top view of the heat generating body board which abbreviate | omitted the 1st protective layer and the 2nd protective layer. It is a figure for demonstrating the conventional thermal print head, Comprising: It is a fragmentary sectional view of a heat generating body board.

[First Embodiment]
A thermal print head and a thermal printer according to a first embodiment of the present invention will be described.

  First, an outline of the thermal print head 10 and the thermal printer according to the first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view of a thermal print head according to the present embodiment. FIG. 2 is a partial cross-sectional view of the thermal printer according to the present embodiment.

  The thermal print head 10 includes a heat radiating plate 20, a heating element plate 30, and a circuit board 60. The heat generating plate 30 and the circuit board 60 are placed on the same surface of the heat radiating plate 20.

  The heat sink 20 is made of a metal such as aluminum and extends in the main scanning direction 91.

  The heat generating plate 30 is placed on the heat radiating plate 20 and extends in the main scanning direction 91. A heat generating region 32 extending in the main scanning direction 91 is formed on the heat generating plate 30.

  The circuit board 60 is placed on the heat radiating plate 20 and extends in the main scanning direction 91 in parallel with the heating element plate 30. A driving IC 62 and connectors 64 and 65 are mounted on the circuit board 60. The driving IC 62 serves as a driving circuit that generates heat in the heat generating region 32. A control signal and driving power for forming a predetermined heat generation pattern in the heat generation region 32 are input via the connectors 64 and 65.

  The heating element plate 30 and the driving IC 62 are electrically connected by, for example, a bonding wire 66. Further, the driving IC 62 and the wiring pattern formed on the circuit board 60 are electrically connected by, for example, bonding wires 67. The driving IC 62 and the bonding wires 66 and 67 are sealed with a resin 68.

  The thermal printer has a platen roller 70 made of a material having a predetermined elasticity and formed in a cylindrical shape. The platen roller 70 is provided so as to be rotatable about the shaft 72 with the main scanning direction 91 as a shaft 72. The platen roller 70 is disposed such that the side surface 74 is in contact with the heat generating region 32.

  When the thermal printer is used, a thermal recording medium 76 is inserted between the platen roller 70 and the heat generating area 32. The thermal recording medium 76 is, for example, thermal paper, and develops color when heated to a temperature higher than the thermal printing temperature. The thermal printer rotates the platen roller 70 to move the thermal recording medium 76 in the sub-scanning direction 92 perpendicular to the main scanning direction 91 while pressing the thermal recording medium 76 against the heat generating area 32. In addition, the thermal printer changes the heat generation pattern of the heat generating area 32 as the heat sensitive recording medium 76 moves, thereby forming a desired image on the heat sensitive recording medium 76.

  Next, details of the heating element plate 30 of the thermal print head 10 according to the present embodiment will be described with reference to FIGS. 3 and 4. FIG. 3 is a view for explaining the thermal print head according to the present embodiment, and is a partial top view of the heating element plate from which the first protective layer and the second protective layer are omitted. 4 is a cross-sectional view taken along the line IV-IV in FIG.

  The heating element plate 30 includes an insulating substrate, a resistor layer, a conductor layer, a first protective layer 50, a heat diffusion portion 52, and a second protective layer 56. The insulating substrate has a glaze layer 36 formed on the surface of a support substrate 34 made of an insulator such as alumina.

  A resistor layer is formed on the surface of the glaze layer 36 of the insulating substrate. The resistor layer has a plurality of heating resistor portions 40. The plurality of heating resistor portions 40 each extend linearly with a certain width in the sub-scanning direction 92 and are arranged at intervals in the main scanning direction 91. The heat generating region 32 refers to a band-shaped region in which a plurality of heat generating resistor portions 40 are arranged.

  An individual electrode (conductive portion) 44 is formed and electrically connected to the upstream end portion 40a of each heating resistor portion 40 in the sub-scanning direction 92. Further, end portions 40 b on the downstream side in the sub-scanning direction 92 of a pair of heating resistor portions 40 adjacent to each other are electrically connected by a folded electrode (conductive portion) 46. The individual electrode 44 and the folded electrode 46 are made of, for example, aluminum. As described above, the individual electrode 44 is connected to the driving IC 62 via the bonding wire 66, for example. The individual electrode 44 and the folded electrode 46 are formed with a thickness of 1.0 μm, for example.

  Each of the heating resistor portions 40 serves as a heating element, and the pair of heating resistor portions 40 connected by the folded electrode 46 simultaneously generate heat due to the voltage applied between the individual electrodes 44, and the thermal recording medium 76. 1 dot is output to (1 pixel 2 element type).

The first protective layer 50 covers the exposed surfaces of the plurality of heating resistor portions 40, the conductive portions 44 and 46, and the glaze layer 36. The first protective layer 50 is made of, for example, a material mainly composed of SiO ₂ , SiAlON, or SiON, and serves to insulate the heating resistor portion 40 and the conductive portions 44 and 46 from a heat diffusion portion 52 described later. Fulfill. Further, the first protective layer 50 also serves to protect the heat generating resistor portion 40 and the conductive portions 44 and 46 from friction with the thermal recording medium 76 when the thermal printer is used. The first protective layer 50 is formed with a thickness of 3.0 μm, for example.

  The thermal diffusion portion 52 is disposed on the first protective layer 50 so as to cover the set of heating resistor portions 40 connected by the folded electrode 46 so as to spread above the set of heating resistor portions 40. Is formed. That is, in the heat generating region 32, a plurality of heat diffusing portions 52 are arranged for each dot (for each set of heat generating resistor portions 40) along the main scanning direction 91. The heat diffusing unit 52 is made of a highly heat conductive material such as metal (Al, Cu, etc.) or an alloy, for example, and one heat diffusing unit 52 diffuses heat generated from a set of heat generating resistor units 40 that print one pixel. To play a role. In addition, the thermal diffusion part 52 is formed in thickness of 1.0 micrometer, for example.

  A plurality of through-holes 54 communicating with the front and back sides are formed in the thermal diffusion part 52. In the present embodiment, nine through holes 54 have a circular shape with a diameter of about 15 μm, and nine are formed in one heat diffusion portion 52.

The second protective layer 56 covers the exposed surfaces of the thermal diffusion part 52 and the first protective layer 50. The second protective layer 56 is made of, for example, a wear-resistant material such as SiAlON or Ta ₂ O _5, and due to friction with the heat-sensitive recording medium 76 when the thermal printer is used, the heating resistor portion 40 and the conductive portions 44 and 46. And serves to protect the thermal diffusion part 52. The second protective layer 56 is formed with a thickness of 5.0 μm, for example.

  The second protective layer 56 enters the plurality of through holes 54 formed in the thermal diffusion part 52 and adheres to the first protective layer 50. When the first protective layer 50 and the second protective layer 56 are made of the same material, the adhesiveness is high, which is preferable. For example, the first protective layer 50 and the second protective layer 56 are preferably made of a material mainly composed of SiON having both insulating properties and wear resistance.

  Next, an example of a method for forming the heating element plate 30 will be described.

  First, a support substrate 34 made of ceramic is formed, and a glaze layer 36 made of glass is fused to the surface thereof.

  Next, a resistor layer and a conductor layer are sequentially laminated on the entire surface of the glaze layer 36 by a thin film forming apparatus such as a sputtering apparatus. Then, after the conductor layer is formed in the shape of the conductive portions 44 and 46 by the photoengraving process, the resistor layer is formed in the shape of the heating resistor portion 40.

  Next, a first protective layer 50 that covers the exposed surfaces of the plurality of heating resistor portions 40, the conductive portions 44 and 46, and the glaze layer 36 is formed. And after laminating | stacking a thermal-diffusion layer with a thin film formation apparatus, a thermal-diffusion layer is formed in the shape of the thermal-diffusion part 52 by the photo-engraving process, and the predetermined through-hole 54 is formed. Then, the 2nd protective layer 56 which covers the thermal diffusion part 52 and the exposed surface of the 1st protective layer 50 is formed.

  Further, an opening is formed on the surface of the portion of the individual electrode 44 that is connected to the bonding wire 66 by a photoengraving process.

  The effects of the thermal print head 10 and the thermal printer 1 according to the present embodiment will be described.

  If the thermal diffusion portion 52 is not provided, the surface temperature distribution of the second protective layer 56 is maximized at the center in the sub-scanning direction 92 of the heat generating region 32, which causes printing medium burn-in and the like. In the present embodiment, since the thermal diffusion portion 52 is provided, the surface temperature distribution of the second protective layer 56 in the sub-scanning direction 92 of the heat generating region 32 can be made uniform.

  In addition, a slit 42 is formed between two adjacent heating resistor portions 40 that output one dot, and the slit 42 does not generate heat. Therefore, if the heat diffusing part 52 is not provided, the surface temperature above the slit 42 becomes lower than the surface temperature above the heating resistor part 40, and is formed by two adjacent heating resistor parts 40. Dots are divided and the image quality is degraded. In the present embodiment, since the thermal diffusion portion 52 is disposed above the two adjacent heating resistor portions 40 and the slits 42, the surface temperature distribution of the second protective layer 56 in the main scanning direction 91 of the heating region 32 is determined. Uniformity can be achieved and degradation of image quality can be suppressed.

  Furthermore, since the through hole 54 is formed in the thermal diffusion part 52, the second protective layer 56 enters the through hole 54 and is bonded to the first protective layer 50. Therefore, the adhesive force between the first protective layer 50 and the second protective layer 56 is increased. As a result, the adhesion between the first protective layer 50, the thermal diffusion portion 52, and the second protective layer 56 can be improved, and the thermal diffusion portion 52 is peeled off from the first protective layer 50, and the first It can suppress that 2 protective layer 56 peels from the 1st protective layer 50. FIG. In addition, when the 1st protective layer 50 and the 2nd protective layer 56 are comprised with the same material, since the adhesive force of the 1st protective layer 50 and the 2nd protective layer 56 improves, it is more effective.

[Second Embodiment]
A thermal print head according to a second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a diagram for explaining the thermal print head according to the present embodiment, and is a partial top view of the heating element plate from which the first protective layer and the second protective layer are omitted. In addition, this embodiment is a modification of 1st Embodiment, Comprising: The same code | symbol is attached | subjected to the same part or similar part as 1st Embodiment, and duplication description is abbreviate | omitted.

  In the present embodiment, the through hole 54 of the thermal diffusion part 52 is formed in a square shape having a side of about 15 μm. Also according to this embodiment, the same effect as that of the first embodiment can be obtained. Thus, the present invention is not limited by the shape of the through hole 54.

  In the present embodiment, the plurality of through holes 54 have the same shape and size, but different shapes and sizes can be combined. Furthermore, arbitrary thermal diffusion characteristics can be set by changing the size and position of the through hole 54.

[Third Embodiment]
A thermal print head according to a third embodiment of the present invention will be described with reference to FIG. FIG. 6 is a diagram for explaining the thermal print head according to the present embodiment, and is a partial top view of the heating element plate from which the first protective layer and the second protective layer are omitted. In addition, this embodiment is a modification of 1st Embodiment, Comprising: The same code | symbol is attached | subjected to the same part or similar part as 1st Embodiment, and duplication description is abbreviate | omitted.

  In the present embodiment, an individual electrode (conductive portion) 44 is formed and electrically connected to the upstream end portion 40a of each heating resistor portion 40 in the sub-scanning direction 92. A common electrode (conductive portion) 48 is formed and electrically connected to the downstream end 40 b in the sub-scanning direction 92. Each heating resistor section 40 generates heat by a voltage applied between the individual electrode 44 and the common electrode 48, and outputs one dot to the thermal recording medium 76 (one pixel one element type).

  In the present embodiment, the thermal diffusion part 52 is formed on the first protective layer 50 so as to spread above the heating resistor parts 40. Also according to this embodiment, the same effect as that of the first embodiment can be obtained.

[Other Embodiments]
In the first to third embodiments, the flat glaze layer 36 is employed, but a convex glaze layer that rises along the heat generating region 32 may be employed.

DESCRIPTION OF SYMBOLS 10 ... Thermal print head, 20 ... Heat sink, 30 ... Heat generating board, 32 ... Heat generating area, 34 ... Supporting substrate, 36 ... Glaze layer, 40 ... Heat generating resistor part, 40a ... Upstream side of sub-scanning direction of heat generating resistor part , 40b... Downstream end of the heating resistor in the sub-scanning direction, 42... Slit, 44. Individual electrode (conductive part), 46. Folded electrode (conductive part), 48. Common electrode (conductive part) , 50 ... 1st protective layer, 52 ... Thermal diffusion part, 54 ... Through hole of thermal diffusion part, 56 ... 2nd protective layer, 60 ... Circuit board, 62 ... Driving IC, 64, 65 ... Connector, 66, 67 ... bonding wire, 68 ... resin, 70 ... platen roller, 72 ... platen roller shaft, 74 ... side surface of platen roller, 76 ... thermal recording medium, 91 ... main scanning direction, 92 ... sub-scanning direction, 95 ... crack

Claims (5)

An insulating substrate;
A heating resistor layer stacked on the insulating substrate and extending in the sub-scanning direction in which the recording medium travels;
A conductive part that is electrically connected to an end of the heating resistor and applies a voltage in a sub-scanning direction of the heating resistor;
A first protective layer made of an insulating material laminated on the heating resistor portion so as to cover at least the heating resistor portion;
A thermal diffusion part formed on the first protective layer and formed with a plurality of through holes;
A second protective layer laminated on the thermal diffusion part and bonded to the first protective layer through the plurality of through holes;
A thermal print head comprising:   The thermal print head according to claim 1, wherein the first protective layer and the second protective layer are made of the same material.   The thermal print head according to claim 2, wherein the first protective layer and the second protective layer are made of a material mainly composed of SiON.   The thermal print head according to claim 1, wherein the thermal diffusion portion is made of a metal material.   An insulating substrate; a heating resistor layer stacked on the insulating substrate and extending in a sub-scanning direction in which a recording medium travels; and a sub-scanning direction of the heating resistor unit electrically connected to an end of the heating resistor unit A conductive portion for applying a voltage to the first protective layer; a first protective layer made of an insulating material stacked on the heat generating resistor portion so as to cover at least the heat generating resistor portion; and a plurality of through holes stacked on the first protective layer. A thermal print head comprising: a heat diffusion part in which a hole is formed; and a second protective layer laminated on the heat diffusion part and bonded to the first protective layer through the plurality of through holes. A thermal printer characterized by that.

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