JP4360602B2 - Thermal head, manufacturing method thereof, and thermal printer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is a thermal head and a manufacturing method thereof, for use as a recording device such as a facsimile or a video printer relates thermal printer each time if,.
[0002]
[Prior art]
Conventionally, thermal heads have been used as recording devices such as facsimiles and video printers.
[0003]
Such conventional thermal head, for example as shown in FIG. 5, together with depositing the glaze layer 22 on the entire upper surface of the to substrate 21, such an elongated, a plurality of heating elements 23 on to the glaze layer 22, heat generating has a structure including a connection pad 25 are electrically connected to the element 23, heat-sensitive paper or an ink ribbon with a platen roller which is disposed on the thermal head, heat-sensitive paper or recording paper of the recording medium The heat generating element 23 is conveyed to the recording medium on the heat generating element 23 while selectively heating the plurality of heat generating elements 23 based on the print signal from the outside. on paper or recording paper it is forming a predetermined print.
[0004]
The connection pad 25 is covered with a conductive material 26 such as solder or bonding wire on its upper surface, and is electrically connected to an external wiring board 28 such as a flexible printed wiring board via the conductive material 26. The connection pads 25 are arranged near the end of the substrate 21 (positions separated from the other long side of the substrate 21 by 300 μm to 600 μm) in order to reduce the area of the thermal head as much as possible.
[0005]
However, in the conventional thermal head described above, the glaze layer 22 underlying the connection pads 25 are relatively brittle, thermal and dividing the substrate 21 having the above-described glaze layer 22, heating element 23, and connection pads 25 when manufacturing the head, often cracks during the glaze layer 22 than cutting portion (see Patent Document 1).
[0006]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 11-277780
[Problems to be solved by the invention]
When such a crack grows and reaches the surface of the glaze layer 22, the adhesion strength between the connection pad 25 and the glaze layer 22 disposed in the vicinity of the arrival point is lowered, and the connection pad 25 may be peeled off. There was a problem that the yield of the thermal head decreased (see FIG. 6).
[0008]
In order to solve such a problem, it is conceivable to dispose the connection pad 25 far away from the end of the substrate 21. However, according to such a configuration, it is difficult to reduce the size of the thermal head. Trigger a new.
[0009]
The present invention has been devised in view of the above problems, while maintaining a high yield of the thermal head, the thermal head manufacturing method of the patron Oyo thermal head capable of downsizing, if the beauty It is to provide a thermal printer.
[0010]
[Means for Solving the Problems]
A thermal head of the present invention includes: a rectangular substrate, and a glaze layer provided on the substrate, a plurality of heating elements provided on the glaze layer, with is provided on the glaze layer the arrayed along one of the one side in the vicinity of the side of the substrate, and includes a plurality of connection pads Ru electrically connected to Tei to said plurality of heating elements, the substrate to the connection pad it is characterized in that the slit extending substantially parallel to said one side of the is provided.
[0011]
The thermal head of the present invention, the plurality of connection pads are arranged along one of the one long side to long side near the substrate, the end portion of the slit is the one long side It is preferable to be provided .
[0012]
In addition, the thermal head of the present invention, the glaze layer is preferably exposed from the inside of the slit.
[0013]
Also further, the thermal head of the present invention, the connection pads, it is preferably divided in a plane into a plurality of regions through the slit.
[0014]
Also further, the thermal head of the present invention, the slit is provided more on one of the connection pads, the spacing of the slit that separates the single connection pads to a plurality one side of the substrate it is preferably larger as it between RiHanare.
[0015]
Also further, thermal head of the present invention, before Kise' connection pad is preferably provided in 100μm~300μm position spaced from said one side of said substrate.
[0016]
Also further, manufacturing method for a thermal head of the present invention includes a first step of forming a glaze layer on the substrate body, after the first step, compartment for multiple-up on the glaze layer A connection pad that is electrically connected to the plurality of heat generating elements along the boundary, and a slit that extends substantially parallel to the boundary of the partition is formed in the connection pad. And a third step of dividing the substrate body and the glaze layer along the section after the second step .
[0017]
Also further, manufacturing method for a thermal head of the present invention, in the second step, Rukoto to form said slits so as to divide the connection pad in plan view a plurality of regions are preferred.
[0018]
Also further, manufacturing method for a thermal head of the present invention, in the second step, when forming the slit to the connection pads, the spacing of the slits is spaced apart from the boundary of the section of the substrate body It is preferable to form a plurality of the slits in one connection pad so as to increase with time .
[0019]
Also further, manufacturing method for a thermal head of the present invention, in the second step, it is preferable that to form the connecting pad 100μm~300μm position spaced from the boundary of the section of the substrate body.
[0020]
Also further, manufacturing method for a thermal head of the present invention, prior to the first step, together with a fourth step of forming a groove along the boundary of the compartment to the lower surface of the substrate body, wherein in the third step, it is preferable intends rows by breaking method for dividing the cross-sectional said substrate body and the glaze layer along the groove.
[0021]
The thermal printer of the present invention is characterized by comprising a thermal head described above, and driving means for driving the thermal head.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
[0023]
Figure 1 is a sectional view of a thermal head according to an embodiment of the present invention, FIG. 2 is a plan view of the thermal head of FIG. 1 (protective film 7 not shown), a thermal head shows in the figure, the substrate heating element 3 on the glaze layer 2 provided on the 1, has a structure with a circuit conductor 4, connection pads 5, and the protective film 7.
[0024]
The substrate 1, alumina ceramics or single crystal silicon are formed on Suyo such a rectangular shape by a variety of materials such as Fe-Ni alloy, the glaze layer 2 is deposited on the upper surface thereof, further heating element 3, circuit conductor 4, and the connection pads 5, and the like Ru is deposited. That is, it functions as a support base material that supports the glaze layer 2 , the heating element 3, the circuit conductor 4, the connection pad 5, and the like.
[0025]
A glass glaze layer 2 is deposited on the upper surface of the substrate 1.
[0026]
The glaze layer 2 partially includes a projecting portion 2a having an arcuate cross section disposed in a strip shape along one long side of the substrate 1 on a base portion 2b that is deposited with a substantially uniform thickness over the entire upper surface of the substrate 1. has the formed structure, the thickness of the base portion 2b in 50Myuemu～250myuemu, the thickness of the top portion of the protruding portion 2a is set to the 20Myuemu～80myuemu.
[0027]
The glaze layer 2 is made of, for example, glass having a thermal conductivity of 0.7 W / m · K to 1.0 W / m · K, and thus stores a part of the heat of the heating element 3 therein. Thus, the thermal responsiveness of the thermal head is maintained satisfactorily. Specifically, the thermal head functions as a heat storage layer that raises the temperature of the heating element 3 to a predetermined temperature required for printing in a short time.
[0028]
In addition, a plurality of heating elements 3 are deposited in near the top of the projecting portion 2a of the glaze layer 2.
[0029]
The heating element 3, for example, 600dpi are arranged linearly at a density of (dot per inch), each TaSiO-based, TiSiO-based, or for being Tsu Do from the electrical resistance material TiCSiO system such as at both ends When the power from the connected external through the circuit conductor 4 Ru Tei is supplied cause Joule heat, or to form a printing on thermal paper, or temperature required or to melt the ink of the ink ribbon, For example, it generates heat at a temperature of 150 ° C to 400 ° C.
[0030]
Further, the Tei Ru circuit conductor 4 is connected to both ends of the heating elements 3, which functions as a power supply wiring for supplying a predetermined power to the heating element 3, aluminum (Al), copper (Cu) or the like of metal are formed in a predetermined pattern on the material, with one end thereof to Do the connection pad 5 a conductor output section by derivation to the vicinity of the other long side of the substrate 1 (100 m to 300 m a location spaced from the end portion of the substrate 1) Yes.
[0031]
The connection pads 5 are of order to be electrically connected to the wiring conductor 9 of the external wiring board 8 via the (solder in this embodiment) conductive material 6, such as a solder or a bonding wire on its upper surface, A plurality are arranged along the other long side of the substrate 1.
[0032]
Such a connection pad 5, the underlying has the lead portion of the circuit conductor 4, for example a Ni layer and Au layer were successively deposited structure, the other substrate 1 to each of the connection pads 5 One or more slits 5a substantially parallel to the long side (three in the present embodiment) are provided.
[0033]
For example, each of the slits 5a (width in a direction orthogonal to the slit 5a) is set to 5 μm to 150 μm and the depth is set to 2.5 μm to 5.0 μm. exposed connection pads 5 planes separated into a plurality of regions, are divided.
[0034]
For this reason, when the thermal head is manufactured, even if the crack generated in the glaze layer 2 extends upward when the substrate 1 is divided and the connection pad 5 is peeled off, the peeling is satisfactorily stopped at the slit 5a. . Therefore, even if the connection pad 5 is arranged near the end of the substrate 1 and the thermal head is miniaturized, the yield of the thermal head can be maintained high, and the productivity of the thermal printer is improved.
[0035]
Further, the slit 5a, the interval between the slits 5a is set to be larger as apart from the end portion of the head substrate 1, which among the areas of the divided connection pad 5 by the end of the substrate 1 The area of the region located in the immediate vicinity of the part is smaller than the other regions. For this reason, the peeling region of the connection pad 5 can be kept small, the area of the connection pad 5 is kept wide to increase the bonding strength between the head substrate 1 and the external wiring board 8, and the electric resistance at the bonding portion is reduced. Can be maintained.
[0036]
Meanwhile, the coercive Mamorumaku 7 on the upper surface of the heating element 3 and circuit conductor 4 are deposited, the heating elements 3 and circuit conductor 4 by the protective film 7 are commonly coated.
[0037]
The protective film 7, silicon nitride _{(Si 3} N 4), silicon oxide _(SiO 2), and sialon (Si-Al-O-N ) Ri Do from excellent inorganic material abrasion resistance, such as heating elements 3 and the circuit conductor 4 are protected from wear due to sliding contact of the recording medium and corrosion due to contact with moisture contained in the atmosphere.
[0038]
The thermal printer thermal head as described above is incorporated, as shown in FIG. 3, provided with a drive means C for driving the thermal head T, transports the recording medium on the heating element 3 of the thermal head T the platen roller 10 and the conveying roller 11a as conveying means, 11b, 11c, 11d or the like is disposed Ru Empire.
[0039]
The driving means C includes a driver IC in which a shift register, a latch, a switching transistor, and the like are integrated at a high density, a control circuit that supplies a control signal such as a strobe signal and a latch signal to the driver IC, and the like. by switching on and off of the switching transistor in a driver IC based, it is Gyoshi control the heating of the heating element 3.
[0040]
On the other hand, the platen roller 10 as the conveying means is a cylindrical member which is wound butadiene rubber or the like to a thickness of about 3mm~15mm the outer periphery of the axial core of a metal such as SUS ing, heating elements of the thermal head T The recording medium is conveyed in a direction orthogonal to the arrangement of the heating elements 3 (in the direction of the arrow in the figure) while pressing the recording medium against the heating elements 3.
[0041]
Further, the transport rollers 11a, 11b, 11c, 11d, the outer peripheral portion is formed of metal or rubber, is disposed separated in the conveyance direction upstream side and downstream side of the recording medium relative to a thermal head T, These transport rollers 11a , 11b , 11c , and 11d and the platen roller 10 described above support the running of the recording medium.
[0042]
At the same time, a large number of heat generating elements 3 are selectively joule-heated as the driving means C is driven, and a predetermined print is formed by conducting these heats to the recording medium.
[0043]
Next, the manufacturing method of the thermal head of this embodiment described above will be described in detail with reference to FIG.
[0044]
(1) First, a substrate element A for preparing a plurality of thermal heads is prepared, the substrate element A is divided into a plurality of sections, and the lower surface of the substrate element A located at the boundary of the sections ( A groove 9 is formed on the surface opposite to the surface on which the glaze layer 2 and the heat generating element 3 are formed (FIG. 4A).
[0045]
The substrate body A, when the alumina ceramics ing, for example, alumina, silica, ceramic raw material powder in a suitable organic solvent magnesia, addition of a solvent, with eggplant mud漿状mixed, this well-known doctor to obtain a ceramic green sheet by adopting a blade method or calendar roll method or the like, thereafter, after having punched ceramic green sheets in a rectangular shape, are manufacturing by firing at high temperatures.
[0046]
Further , the groove 9 provided in the substrate body A is for easily dividing the substrate body A into sections when a plurality of thermal heads are taken from the substrate body A. It is formed to a depth of 33% to 67% of the thickness of the substrate body A by a laser.
[0047]
(2) Next, the glaze layer 2 is formed in each section of the substrate body A (FIG . 4B) .
The glaze layer 2 is obtained by printing and applying a predetermined glass paste obtained by adding and mixing a suitable organic solvent to glass powder on the entire upper surface of the substrate body A by conventional screen printing or the like. It is formed by processing into a predetermined pattern by a known etching method or sand blasting method and baking at a high temperature (850 ° C. to 950 ° C.).
[0048]
(3) Subsequently, the heating element 3 , the circuit conductor 4 , and the connection pad 5 are formed in each section of the substrate body A (FIG. 4C).
[0049]
The heating element 3 and circuit conductor 4, conventionally known thin film forming technique, for example, TaSiO-based, such as sequential predetermined thickness (resistive film by the resistance film and conventionally known sputtering or vapor deposition of metal film such as Al of 0.015Myuemu～0.02Myuemu, with laminated on the metal film 0.9μm~1.2μm), by processing in a predetermined pattern by employing a conventionally well-known photolithography technique and etching technique the laminate It is formed. Further, the connection pad 5, for example with sequentially laminated Ni layer and Au layer by employing a conventionally known electroless plating method on a predetermined region of the circuit conductor 4, the resistor film and metal film It is formed by providing the slit 5a by employing a conventionally well-known photolithography technique and etching technique to laminate comprising.
[0050]
(4) and with dividing the substrate element A per section (FIG. 4 (d)), to obtain a plurality of thermal heads by Rukoto to deposit a protective film on each substrate that is the divided.
[0051]
The substrate element A is divided by a chocolate break method in which the substrate element A is divided into a plurality of parts starting from the grooves 9 provided at the boundaries of each section by applying mechanical stress to the substrate element A. Is called.
[0052]
At this time, even if a crack is generated in the glaze layer 2 due to the mechanical stress generated when the substrate body A is divided, and the crack extends upward and the connection pad 5 is peeled off, the peeling is performed at the slit 5a. Can stop well. Therefore, even if the connection pad 5 is arranged near the end of the substrate 1 and the thermal head is miniaturized, the yield of the thermal head can be maintained high, and the productivity of the thermal printer is improved.
[0053]
Further , since the area of each region of the connection pad 5 divided by the slit 5a is small in the region located in the immediate vicinity of the end portion of the substrate 1 as described above, the separation region of the connection pad 5 is obtained. Therefore, it is possible to keep the area of the connection pad 5 wide, increase the bonding strength between the head substrate 1 and the external wiring board 8, and keep the electric resistance at the bonding portion low. Become.
[0054]
The protective film 7 employs a conventionally well-known thin film formation technique, such as a CVD ( Chemical Vapor Deposition ) method, sputtering, etc., and silicon nitride (Si ₃ N ₄ ), silicon oxide (SiO ₂ ), sialon (Si— It is formed by depositing an inorganic material such as Al—O—N) on the upper surface of the heating element 3 and the circuit conductor 4 to a thickness of 5 μm to 10 μm.
[0055]
The present invention is not limited to the above-described embodiment, and various modifications and improvements can be made without departing from the scope of the present invention.
[0056]
For example, in the above-described embodiment, although the slits 5a formed in the long sides substantially parallel straight substrate 1, have a shape which can effectively prevent the peeling of the connection pad 5, a combination of slits cross Various shapes such as a shape , a triangular shape, and a quadrangular shape may be configured.
[0057]
In the above-described embodiment, the substrate body A in which the grooves 9 are formed is divided. However, the substrate body A may be divided without forming the grooves. You may make it divide by dicing with a diamond cutter etc., without forming a slot in element A.
[0058]
Furthermore , in the above-described embodiment, when a thermal head is manufactured, a plurality of thermal heads are obtained simultaneously from one substrate element A. Instead, a single substrate element A is used as a single unit. Even if one thermal head is obtained, the present invention is applicable.
[0059]
Furthermore , in the above-described embodiment, the protective film 7 is formed after the substrate element A is divided. Instead, the protective film 7 is formed before the substrate element A is divided. It doesn't matter.
[0060]
Furthermore, in the above-described embodiment, good slit 5a, but the glaze layer 2 from the inner portion is formed to a depth to expose, if the depth of the slits 5a is the degree at least resistor film is exposed Even in such a case, peeling of the connection pad 5 can be prevented to some extent.
[0061]
Furthermore , in the above-described embodiment, the connection pad 5 is separated into a plurality of regions by the slits 5a, but the plurality of regions are completely separated from each other as long as the connection pad 5 can be effectively prevented from being peeled off. It does not need to be separated and may be partially connected.
[0062]
【The invention's effect】
According to the present invention, on the glaze layer deposited on the substrate body so as to follow the boundary of the section of the substrate body, the connection pads for electrically connecting to the plurality of heating elements, the connection pad Since a slit extending substantially parallel to the boundary is formed in the vicinity of the boundary of the partition, when the substrate is divided, even if a crack generated in the glaze layer extends upward and peeling occurs in the connection pad Peeling can be satisfactorily stopped at the slit. Therefore, even if the connection pads are arranged near the edge of the substrate and the thermal head is miniaturized, the yield of the thermal head can be maintained high, and the productivity of the thermal printer is improved.
[0063]
Since cracks in the glaze layer are particularly likely to occur when the substrate is divided by a break method or a dicing method, the present invention is particularly useful when the substrate is divided by such a method.
[0064]
Further, according to the present invention, a rectangular substrate, and a glaze layer provided on the substrate, a plurality of heating elements provided on the glaze layer, is provided on the glaze layer together, they are arranged along the one side in the vicinity of one side of the substrate, and are electrically connected to the plurality of heating elements and a plurality of connection pads Ru Tei, one of the substrate connection pads since the slit extending substantially parallel to the side is provided, in dividing the substrate, elongation crack that occurs in the glaze layer is upward, even peeling occurs in the connection pad, it is applied peeling Ru well be stemmed in part of the slits.
[Brief description of the drawings]
1 is a cross-sectional view of the engagement Ru thermal head to an embodiment of the present invention.
FIG. 2 is a plan view of the thermal head of FIG. 1 (protective film not shown).
FIG. 3 is a schematic diagram of a thermal printer configured by incorporating the thermal head of FIG. 1;
4A to 4D are cross-sectional views of steps for explaining a method of manufacturing the thermal head of FIG.
FIG. 5 is a cross-sectional view of a conventional thermal head.
FIG. 6 is a sectional view of the conventional thermal head during the manufacturing process.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Board | substrate 2 ... Glaze layer 3 ... Heat generating element 4 ... Circuit conductor 5 ... Connection pad 5a ... Slit 6 ... Conductive material 7 ... Protective film 8 ... External wiring board 9 ... groove 10 ... platen roller 11a, 11b, 11c, 11d ... conveying roller A ... substrate body

Claims (12)

A rectangular substrate, and a glaze layer provided on the substrate, a plurality of heating elements provided on the glaze layer, with is provided on the glaze layer, one side of the substrate are arranged along the one side in the vicinity of, and provided with a plurality of connection pads Ru electrically connected to Tei to said plurality of heating elements,
A thermal head, wherein a slit extending substantially parallel to said one side of the substrate to the connection pads are provided. The plurality of connection pads are arranged along one long side in the vicinity of one long side of the substrate, and the slit is provided at an end of the one long side. The thermal head according to claim 1. The thermal head according to claim 1 , wherein the glaze layer is exposed from the inside of the slit. 4. The thermal head according to claim 1, wherein the connection pad is divided into a plurality of regions in a plane via the slit. 5. A plurality of the slits are provided in one connection pad ,
5. The thermal head according to claim 4 , wherein an interval between the slits dividing the one connection pad into a plurality increases as the distance from the one side of the substrate increases . The connection pad, a thermal head according to any one of claims 1 to 5, characterized in that is provided, et al is in said one side than 100μm~300μm spaced locations of the substrate. A first step of forming a glaze layer on the substrate body ;
After the first step, along the border in the vicinity of the boundary of the compartment for several up to the glaze layer, and the connection pad you electrically connected to the plurality of heating elements, the connection A second step of forming a slit in the pad extending substantially parallel to the boundary of the section ;
After the second step, the manufacturing method for a thermal head and a third step of dividing the substrate body and the glaze layer along the compartment. Wherein in the second step, manufacturing method for a thermal head according to claim 7, characterized that you form the slits so as to divide the connection pad in plan view a plurality of regions. In the second step, when the slits are formed in the connection pad, a plurality of the connection pads are provided on one connection pad such that the interval between the slits increases as the distance from the boundary of the section of the substrate body increases. The method of manufacturing a thermal head according to claim 8 , wherein a slit is formed . Wherein in the second step, manufacturing method for a thermal head according to any one of claims 7 to 9, characterized that you form the connection pad 100μm~300μm position spaced from the boundary of the partition. Before the first step, including a fourth step of forming a groove along the boundary of the section on the lower surface of the substrate body,
Wherein in the third step, manufacturing method for a thermal head according to any one of claims 7 to 10, characterized in the partial sectional to Turkey the substrate body and the glaze layer along the groove. A thermal printer comprising the thermal head according to any one of claims 1 to 6 and driving means for driving the thermal head.

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