JP2013043430A - Thermal head, printer and marking method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent quality in strength from being degraded by an identification mark.SOLUTION: A thermal head 10 includes a laminated substrate 13 made of a glass material, a heat element formed on one surface of the laminated substrate 13, and an electrode unit connected across the heat element to supply power to the heat element. The identification mark 30 constituted of a character or a sign indicating peculiar identification information on the laminated substrate 13, and the identification mark 30 is configured by arraying a plurality of molten marks formed by melting and then curing parts of the laminated substrate 13 into almost elliptical shapes by being intermittently irradiated with carbon dioxide laser at intervals.

Description

  The present invention relates to a thermal head, a printer, and a marking method.

  Conventionally, a thermal head used in a thermal printer is known (for example, see Patent Document 1). In the thermal head described in Patent Document 1, a plurality of heating resistors are formed on a laminated substrate of a support substrate made of a glass material and an upper substrate, and power is supplied to a pair of electrode portions connected to the heating resistors. Is provided so that the heating resistor can generate heat and can be printed on a thermal recording medium or the like.

In such a thermal head, when a plurality of thermal heads are manufactured simultaneously with a large-sized glass substrate, the position of each thermal head on the large-sized glass substrate is grasped, or the history of the manufacturing process is traced back (that is, To ensure traceability), or to identify the flow status and inventory status of the process in the middle of manufacturing, etc. For the purpose of process control and manufacturing control, it is necessary to mark the identification mark on the substrate surface for each thermal head is there.
As a method of marking an identification mark on a glass substrate, a method using a carbon dioxide laser that is inexpensive and has a high marking speed is known (for example, see Patent Document 2).

JP 2009-119850 A JP 2003-136259 A

  However, in the conventional marking method using a carbon dioxide laser, processing is performed at a temperature higher than the temperature at which the surface of the glass substrate is melted. Therefore, if the glass substrate is rapidly heated and melted and then rapidly cooled and solidified, the molten portion of the glass substrate is heated. Shrinkage and cracks may occur in areas that cannot withstand the heat shrinking force. Then, if a crack occurs in one place of one character, the crack may propagate to the entire character.

  When a crack propagates to the entire character, cracks originating from the crack are caused throughout the thermal head substrate due to thermal expansion and contraction due to heat treatment during the thermal head manufacturing process, film stress due to the sputtered film, corrosion due to etching chemicals, etc. When it propagates or is incorporated into a printer as a thermal head, cracks originating from the cracks are caused on the entire thermal head substrate due to mechanical impact from the outside or expansion and contraction of the glass substrate due to heat storage during printing ON / OFF. It will propagate. Therefore, the conventional marking method using a carbon dioxide laser has a problem that the strength quality of the thermal head is remarkably lowered.

  Even if no cracks occur on the substrate, the marked characters tend to shrink due to thermal shrinkage, and the marked surface of the glass substrate may warp in a concave shape (on the side opposite to the marked surface). The surface warps convexly.) As a result, there is a problem in that the platen roller or paper hits the thermal head at the marking portion and the printing quality as a printer deteriorates.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a thermal head and a printer on which an identification mark is formed without reducing strength quality. It is another object of the present invention to provide a marking method capable of forming an identification mark on a thermal head while preventing cracks from propagating throughout the substrate or warping of the substrate.

In order to achieve the above object, the present invention provides the following means.
The present invention comprises a substrate made of a glass material, a heating resistor formed on one surface of the substrate, and electrode portions connected to both ends of the heating resistor to supply power to the heating resistor, An identification mark consisting of characters or symbols indicating identification information unique to the substrate is formed, and the identification mark is cured by intermittently irradiating a carbon dioxide gas laser to melt a part of the substrate into a substantially oval shape. There is provided a thermal head configured by arranging a plurality of melt marks at intervals.

  According to the present invention, it is possible to distinguish from other thermal heads by the identification mark formed on the substrate. This identification mark is formed by arranging a plurality of substantially oval melting marks formed by intermittently irradiating a substrate made of a glass material with a carbon dioxide laser so that the carbon dioxide laser is continuously provided. Compared to the case where the identification mark is formed by a continuous line-shaped melt mark formed by irradiation, the area for each irradiation region of the carbon dioxide laser is small, and cracks are unlikely to occur.

Also, since the carbon dioxide laser irradiation area is closed for each oval melting mark, even if a crack occurs in any melting mark, it is difficult for the crack to propagate to other adjacent melting marks, and the entire substrate The impact on the environment is small. Furthermore, compared with the case where the identification mark is formed by a continuous line, the thermal contraction force in the carbon dioxide laser irradiation region is halved, and the periphery of the identification mark on the substrate is unlikely to warp in a concave shape.
Therefore, it is possible to prevent a decrease in strength quality due to the identification mark.

  In the above invention, the identification mark may be formed in a region other than a region facing the heating resistor on the other surface of the substrate.

  When the other side of the board is fixed to the heat sink and the heat generated in the heating resistor and absorbed by the board is released from the other side of the board to the heat sink, in the area facing the heating resistor on the other side of the board If an identification mark is formed on the surface, the portion does not come into contact with the heat radiating plate, so that heat is hardly dissipated. Since the identification mark is formed in a region other than the region facing the heating resistor on the other surface of the substrate, the region facing the heating resistor on the other surface of the substrate is brought into contact with the heat radiating plate, so that heat is efficiently generated. Can be dissipated. Thereby, when mounted on a printer, it is possible to prevent the print quality of the printer from being impaired.

  In the above invention, the melt mark has a line width of 0.03 mm or more and 0.5 mm or less, has a line width of 0.1 mm or more and 1 mm or less between the melt marks, The length of the blank portion may be 2 mm or less.

  By configuring in this way, the size of each melt mark relative to the size of the substrate is made minute, and even if a crack occurs in any of the melt marks, it is possible to suppress the significant influence on the strength quality of the substrate. Can do. Further, the identification mark can be sufficiently recognized visually from the relationship between the size of the melt mark and the size of the blank portion between the adjacent melt marks.

In the above invention, the substrate may be made of alkali-free glass.
While the thermal expansion coefficient of alkali-free glass is 3.8 × 10 ⁻⁶ / ° C., the thermal expansion coefficient of soda glass is 8.6 × 10 ⁻⁶ / ° C. In comparison, the coefficient of thermal expansion is as small as about half. Therefore, by using a substrate made of alkali-free glass, cracks are hardly generated even when rapidly heated and melted by a carbon dioxide laser and then rapidly cooled and solidified. Further, it is inexpensive and excellent in workability as compared with a substrate made of Pyrex (registered trademark). Further, when a driver IC is mounted on a substrate, IC contamination due to an alkali component contained in glass can be prevented.

  In the above invention, the substrate is formed by laminating a flat support substrate member and a flat upper substrate member on which the heating resistor is formed, and the support substrate member It is good also as having a cavity part in the area | region facing the said heating resistor in a junction part with an upper board substrate member.

  By comprising in this way, the upper-plate board | substrate member arrange | positioned directly under the heating resistor functions as a heat storage layer which accumulates heat. Moreover, the cavity part formed in the area | region which opposes a heating resistor functions as a hollow heat insulation layer which insulates heat. This hollow portion can reduce the amount of heat transmitted to the support substrate member through the upper substrate member out of the heat generated in the heating resistor. Therefore, it is possible to improve the heat generation efficiency while improving the convenience of process management and manufacturing management by the identification mark.

The present invention provides a printer comprising the above-described thermal head and a pressurizing mechanism for feeding the thermal recording medium while pressing it against the heating resistor of the thermal head.
According to the present invention, the reliability can be improved by the thermal head on which the identification mark is formed without deteriorating the strength quality.

  The present invention includes a melting step of intermittently irradiating a substrate made of a glass material while scanning with a carbon dioxide laser to partially melt the substrate into a substantially oval shape, and cooling a plurality of melting portions melted by the melting step. And a cooling step of forming an identification mark composed of characters or symbols indicating unique identification information constituted by a plurality of melt marks arranged at intervals.

  According to the present invention, as compared with the case of forming an identification mark constituted by a continuous line-shaped melting mark by continuously irradiating a substrate made of a glass material with a carbon dioxide laser, for each irradiation region of the carbon dioxide laser. It is possible to reduce the area of the substrate and make it difficult to generate cracks. In addition, by closing the irradiation area of the carbon dioxide laser for each oval melting mark, even if a crack occurs in any melting mark, it is difficult for the crack to propagate to other adjacent melting marks, The influence can also be suppressed.

In addition, compared with the case where an identification mark composed of continuous line-shaped melt marks is formed, the thermal contraction force in the irradiation area of the carbon dioxide laser is halved and the periphery of the identification mark on the substrate is prevented from warping in a concave shape. be able to.
Therefore, it is possible to form an identification mark on the thermal head while suppressing crack propagation to the entire substrate or warping of the substrate.

In the above invention, the identification mark may be formed by irradiating a carbon dioxide laser to a region other than the region where the heating resistor and the electrode on the surface of the substrate where the heating resistor and the electrode are formed. Good.
By comprising in this way, a fusion | melting process and a cooling process can be implemented regardless of before and after the process of forming a heating resistor and an electrode on one surface of the substrate.

  In the above invention, before forming the heating resistor and the electrode on the substrate, the carbon dioxide laser is irradiated on the other surface of the substrate opposite to the surface on which the heating resistor and the electrode are formed, and the identification is performed. A mark may be formed.

  Since the substrate made of glass material is a transparent body, when the identification mark is formed on the other side of the substrate opposite to the one side on which the heating resistor and electrode are formed, marking is performed before the heating resistor and electrode are formed. By doing so, it is possible to prevent the carbon dioxide laser that has been transmitted without being absorbed by the substrate from being irradiated to the heating resistor and the electrodes, and these can be prevented from being altered or burned out. Therefore, the identification mark can be formed on the other surface of the substrate without affecting the heating resistors and the electrodes formed on the one surface of the substrate.

  In the above invention, the identification mark is formed by irradiating a carbon dioxide laser to a region on the other side of the substrate opposite to the surface on which the heating resistor is formed, other than the region facing the heating resistor. It is good to do.

  With this configuration, even if the identification mark is formed on the other surface of the substrate, the region facing the heating resistor and the electrode on the other surface of the substrate can be brought into contact with the heat radiating plate. Therefore, the heat generated in the heating resistor and absorbed by the substrate can be efficiently dissipated through the heat sink.

  According to the thermal head and the printer of the present invention, it is possible to prevent the strength quality from being deteriorated due to the identification mark. In addition, according to the marking method of the present invention, it is possible to suppress the propagation of cracks over the entire substrate or the occurrence of warping of the substrate and to form the identification mark on the thermal head.

1 is a schematic configuration diagram of a thermal printer according to an embodiment of the present invention. It is the top view which looked at the thermal head of FIG. 1 from the protective film side in the lamination direction. FIG. 3 is an α-α longitudinal sectional view of the thermal head of FIG. 2. It is a top view which shows the identification mark formed in the thermal head of FIG. It is an enlarged view of the identification mark of FIG. 3 is a flowchart showing a method for manufacturing the thermal head of FIG. 2. (A) shows a recess forming step, (b) shows a joining step, (c) shows a thinning step, (d) shows a resistor forming step, and (e) shows an individual electrode forming step. (F) shows a common electrode forming step, and (g) is a longitudinal sectional view showing a protective film forming step. It is a schematic block diagram of the laser apparatus used for the marking method which concerns on one Embodiment of this invention. It is a figure which shows the font data used as the basis of the identification mark formed by the marking method which concerns on one Embodiment of this invention.

Hereinafter, a thermal head, a printer, and a marking method according to an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, a thermal printer (printer) 100 according to the present embodiment includes a main body frame 2, a horizontally disposed platen roller 4, and a thermal head 10 disposed to face the outer peripheral surface of the platen roller 4, A paper feed mechanism 6 that feeds a printing object such as a thermal paper (thermal recording medium) 3 between the platen roller 4 and the thermal head 10, and a pressure that presses the thermal head 10 against the thermal paper 3 with a predetermined pressing force. And a mechanism 8.

  The thermal paper 3 and the thermal head 10 are pressed against the platen roller 4 by the operation of the pressure mechanism 8. As a result, the load of the platen roller 4 is applied to the thermal head 10 via the thermal paper 3. The heat-sensitive paper 3 is colored and printed by pressing the heat generation area of the thermal head 10 against the heat-sensitive paper 3.

  As shown in FIGS. 2 and 3, the thermal head 10 is formed in a substantially flat plate shape. The thermal head 10 includes a laminated substrate (substrate) 13 made of a glass material, a plurality of heating resistors 15 formed on the laminated substrate 13, and electrodes provided on the laminated substrate 13 in contact with the heating resistors 15. And a protective film 19 that covers the heating resistors 15 and the electrode portions 17A and 17B and protects them from wear and corrosion. An arrow Y indicates the feeding direction of the thermal paper 3 by the platen roller 4.

  The laminated substrate 13 is fixed to a heat radiating plate (not shown) of a plate member made of a metal such as aluminum, resin, ceramics, or glass, and can radiate heat through the heat radiating plate. The laminated substrate 13 is formed by laminating a flat support substrate (support substrate member) 12 fixed to the heat sink and a flat upper substrate (upper substrate member) 14 on which the heating resistor 15 is formed. It is joined and configured.

  The support substrate 12 is made of, for example, a rectangular non-alkali glass having a thickness of about 300 μm to 1 mm. The support substrate 12 is formed with a recess 21 that opens in a rectangular shape on the joint surface with the upper substrate 14. The recess 21 extends along the longitudinal direction of the support substrate 12 and has a width dimension of, for example, 50 to 500 μm.

  The upper substrate 14 is made of, for example, a rectangular non-alkali glass having a thickness of about 5 to 100 μm. The upper substrate 14 is laminated on the bonding surface of the support substrate 12 so as to close the recess 21. The upper substrate 14 has a heating resistor 15 formed on one surface opposite to the bonding surface with the support substrate 12, and functions as a heat storage layer that stores a part of the heat generated in the heating resistor 15. It has become.

  The heating resistor 15 is made of, for example, a Ta-based or silicide-based material, and is formed in a rectangular shape. Further, the heating resistor 15 has a dimension in which the length in the longitudinal direction is larger than the width dimension of the recess 21 of the support substrate 12. Each heating resistor 15 is arranged with its longitudinal direction facing the width direction of the upper substrate 14, and with a predetermined interval along the longitudinal direction of the upper substrate 14 (longitudinal direction of the recess 21 of the support substrate 12). It is arranged.

  The electrode portions 17A and 17B are individually connected to the individual electrodes 17A individually connected to both ends in the longitudinal direction of the heating resistor 15, and the common electrodes 17B which are respectively connected to the individual electrodes 17A arranged on one side. It is comprised by. By connecting two independent individual electrodes 17A to one heating resistor 15 and connecting the common electrode 17B over one individual electrode 17A, the wiring resistance value of the common electrode 17B can be reduced. Can do. For example, aluminum is used as the material of the electrode portions 17A and 17B.

  These electrode portions 17A and 17B can supply electric power from an external power source (not shown) to the heating resistor 15 so that the heating resistor 15 can generate heat. A region between the individual electrodes 17 </ b> A in the heating resistor 15, that is, a region located almost directly above the recess 21 of the support substrate 12 in the heating resistor 15 is a heating region.

  In the thermal head 10 configured as described above, the opening of the concave portion 21 of the support substrate 12 is closed by the upper substrate 14, so that a cavity portion 23 is formed immediately below the heat generating portion 15 a of the heat generating resistor 15. The cavity 23 has a communication structure that faces all the heating resistors 15. The cavity 23 functions as a hollow heat insulating layer that suppresses heat generated in the heat generating region of the heat generating resistor 15 from being transmitted from the upper substrate 14 to the support substrate 12 side.

  Further, the other surface of the laminated substrate 13 opposite to the surface on which the heating resistor 15 is formed, that is, the other surface of the support substrate 12 opposite to the bonding surface with the upper substrate 14 is shown in FIG. As shown, an identification mark 30 composed of characters or symbols indicating unique identification information is formed. In the present embodiment, “T-126CS” composed of alphabets and numbers is formed as the identification mark 30.

  The identification mark 30 is disposed in a region other than the region facing the heating resistor 15 on the other surface of the support substrate 12, for example, in any one of the four corner spaces. Further, as shown in FIG. 5, the identification mark 30 is a melt mark 31 (hereinafter referred to as “drawing line”) in which carbon dioxide laser is intermittently irradiated to melt a part of the support substrate 12 into a substantially oval shape and then cured. 31 ”) are arranged at intervals.

  The melt mark 31 has a line width of 0.03 mm or more and 0.5 mm or less, a length of line width of 0.1 mm or more and 1 mm or less, and a length of a blank portion between the melt marks 31 is 2 mm or less. It is desirable. In the present embodiment, the identification mark 30 has a character size of 1.5 mm both vertically and horizontally, a line width of the drawing line 31 of 0.08 mm, a length of 0.1 mm to 0.3 mm, and a space between the drawing lines 31. The length of the part is 0.3 mm.

Next, a manufacturing method of the thermal head 10 configured as described above will be described with reference to the flowchart of FIG.
In the manufacturing method of the thermal head 10 according to the present embodiment, the first step of forming the laminated substrate 13 and marking the identification mark 30, the heating resistor 15, the electrode portions 17 </ b> A and 17 </ b> B, and the protective film 19 are provided on the laminated substrate 13. A second step of forming and a third step of mounting an IC (Integrated Circuit) and an FPC (Flexible Printed Circuits) on the multilayer substrate 13 are included.

  The first step is a recess forming step SA1 for forming the recess 21 on one surface of the support substrate 12, a joining step SA2 for bonding the support substrate 12 and the upper substrate 14, and a thinning step for thinning the upper substrate 14. SA3 and a marking step SA4 for marking the identification mark 30 on the laminated substrate 12 are included.

  In the recess forming step SA1, as shown in FIG. 7A, a recess 21 is formed in a region where the heating resistor 15 is opposed on one surface of the support substrate 12. The recess 21 is formed, for example, by subjecting one surface of the support substrate 12 to sandblasting, dry etching, wet etching, laser processing, or the like.

  In the joining step SA2, as shown in FIG. 7B, a thin glass (upper substrate 14) made of non-alkali glass having a thickness of, for example, 100 μm or more is formed on one surface of the support substrate 12 in which the recesses 21 are formed. Are joined in a laminated state. By covering the opening of the recess 21 with the upper substrate 14, a cavity 23 is formed between the support substrate 12 and the upper substrate 14. Since the thickness of the cavity 23 is determined by the depth of the recess 21, the thickness of the cavity 23 as a hollow heat insulating layer can be easily controlled.

  As a method for joining the support substrate 12 and the upper substrate 14, for example, direct joining by thermal fusion can be mentioned. After the support substrate 12 and the upper substrate 14 are bonded together at room temperature, they are heat-sealed at a high temperature. Thereby, it can join with sufficient intensity | strength. In order to prevent the deformation of the upper substrate 14, it is desirable to bond at a softening point or less.

  In the thinning step SA3, as shown in FIG. 7C, the upper substrate 14 is thinned to a desired thickness by etching or polishing. Thin glass with a thickness of 100 μm or less as the upper substrate 14 is difficult to manufacture and handle, and is expensive. Therefore, instead of joining the thin glass sheet with a small thickness to the support substrate 12, a thin glass sheet with a thickness that is easy to manufacture and handle is joined to the support substrate 12. After that, by thinning the thin glass, the very thin upper substrate 14 can be easily and inexpensively formed on the surface of the support substrate 12. Thereby, the laminated substrate 13 composed of the support substrate 12 and the upper substrate 14 is formed.

While the thermal expansion coefficient of alkali-free glass is 3.8 × 10 ⁻⁶ / ° C., the thermal expansion coefficient of soda glass is 8.6 × 10 ⁻⁶ / ° C. In comparison, the coefficient of thermal expansion is as small as about half. Therefore, by forming the laminated substrate 13 with the support substrate 12 and the upper substrate 14 made of alkali-free glass, cracks are hardly generated even when rapidly heated and melted by a carbon dioxide gas laser and then rapidly cooled and solidified. Further, it is inexpensive and excellent in workability as compared with a substrate made of Pyrex (registered trademark). Further, when a driver IC is mounted on a substrate, IC contamination due to an alkali component contained in glass can be prevented.

Next, the marking step SA4 is performed using a laser apparatus 40 as shown in FIG. 8 by the marking method according to the present embodiment.
In the marking method according to this embodiment, the laser device 40 intermittently irradiates the other surface opposite to the surface on which the heating resistor 15 and the like of the multilayer substrate 13 are formed while scanning the laser beam. A melting step SA4-1 in which the substrate 13 is partially melted into a substantially oval shape and a plurality of melted portions melted in the melting step SA4-1 are cooled and solidified, and drawing lines 31 that are melting marks 31 are spaced apart. And a cooling step SA4-2 for forming identification marks 30 that are arranged in a plurality.

  The laser device 40 controls a stage 41 on which the multilayer substrate 13 is placed, a laser light source 43 that emits laser light, a galvano scanner 45 that scans the laser light from the laser light source 43, and the laser light source 43 and the galvano scanner 45. And a controller 47.

  In order to enable printing on the glass, the laser light source 43 is, for example, an infrared laser having a wavelength of 4.8 μm or more that does not transmit through the glass (specifically, a carbon dioxide gas laser having a wavelength of 10.6 μm in consideration of economy, etc.) Hereinafter, it is simply referred to as “laser light”). In the present embodiment, for example, a carbon dioxide laser having an output of 25 W, a drawing speed of 600 mm / s, and a wavelength of 10.6 μm is used.

  The galvano scanner 45 changes the direction of the laser light emitted from the laser light source 43 and irradiates the other surface of the multilayer substrate 13. The galvano scanner 45 includes a pair of galvanometer mirrors 51A and 51B, drive units 53A and 53B for driving the galvanometer mirrors 51A and 51B, and a converging lens 55.

  One galvanometer mirror 51A is swung by the drive unit 53A, and can change the reflection angle of the laser beam in the X-axis direction. The other galvanometer mirror 51B is swung by the drive unit 53B, and the reflection angle of the laser beam can be shifted in the Y-axis direction.

  The converging lens 55 is composed of, for example, an fθ lens, and converges the laser light reflected by the galvanometer mirrors 51A and 51B so as to focus on the other surface of the multilayer substrate 13. Thereby, the laser light emitted from the laser light source 43 is adjusted in the direction of the XY axes orthogonal to each other by the galvano mirrors 51A and 51B, and then converged by the converging lens 55 to be two-dimensionally on the laminated substrate 13. Are to be scanned.

  The controller 47 controls the drive units 53A and 53B of the galvano scanner 45 to drive the galvanometer mirrors 51A and 51B. The controller 47 includes a memory (not shown) that stores line segment data (font data) constituting characters, symbols, graphics, and the like, and a CPU (central processing unit). In addition, a console (not shown) is connected to the controller 47.

  When the controller 47 sets a desired character, symbol, figure, or the like that the user wants to mark on the console, the operation position of the CPU determines the irradiation position of the laser beam on the laminated substrate 13 based on the font data stored in the memory. Coordinate data to be determined is generated, D / A converted, and the coordinate data is given to each drive unit 53A, 53B of the galvano scanner 45.

  The font data that is the basis of the coordinate data may be created one character at a time so that it becomes intermittent drawing lines 31 with reference to continuous drawing line characters. The font data shown in FIG. 9 is an example when the character size is 1.5 mm both vertically and horizontally.

  It is desirable that the drawing lines 31 are arranged with a certain amount of white space so that the intermittent drawing lines 31 do not overlap when marked. When the character size is set to 1.5 mm both vertically and horizontally, for example, the length of the drawing line 31 is set to 0.1 mm or more and 0.3 mm or less, and the length of the blank portion between the drawing lines 31 is set to 0.3 mm or less. It is sufficient to create font data.

  By arranging the drawing lines 31 so as not to overlap each other, even if a crack occurs in any of the drawing lines 31, the crack is prevented from propagating to the adjacent drawing line 31, and the crack is spread over the entire character. Can be prevented. Further, by dividing the drawing line 31 by intermittent laser light irradiation, it is possible to prevent the heat shrinkage force of each drawing line 31 from being combined and become a large force, and warping of the laminated substrate 13 can be prevented. Can be prevented.

  Next, the second step is a resistor forming step SA5 for forming the heating resistor 15 on the multilayer substrate 13, an individual electrode forming step SA6 for forming the individual electrode 17A, and a common electrode forming step SA7 for forming the common electrode 17B. And a protective film forming step SA8 for forming the protective film 19.

  In the resistor forming step SA5, a heating resistor material is formed on the upper substrate 14 of the laminated substrate 13 by a thin film forming method such as sputtering, CVD (chemical vapor deposition) or vapor deposition, as shown in FIG. A thin film is formed. Then, a thin film of the heating resistor material is formed by a lift-off method, an etching method, or the like.

  In the individual electrode forming step SA6, as shown in FIG. 7E, a wiring material such as Al, Al-Si, Au, Ag, Cu, Pg or the like is sputtered or deposited on the upper substrate 14 of the multilayer substrate 13. Then, the film is formed using a lift-off method, an etching method, or the like, or the wiring material is screen-printed and fired to form the individual electrode 17A having a desired shape. .

  In the common electrode forming step SA7, as shown in FIG. 7 (f), a paste obtained by mixing a conductive material such as silver and a resin binder is printed in a desired shape and then baked at a temperature of 500 ° C. or higher to reduce the resistance. The common electrode 17B is formed.

  In the protective film forming step SA8, as shown in FIG. 7G, the protective film 19 is formed so as to cover the heating resistor 15 and the electrode portions 17A and 17B formed on the upper substrate 14. Yes. The protective film 19 is formed by depositing a protective film material such as SiO 2, Ta 2 O 5, SiAlON, Si 3 N 4, and diamond-like carbon on the upper substrate 14 by sputtering, ion plating, CVD, or the like.

Next, the third process includes an IC mounting process SA9 and an FPC mounting process SA10.
In the IC mounting step SA9, a driver IC (not shown) that controls printing of the thermal head 10 is mounted on the laminated substrate 13. The connection between the electrode terminal and the IC is made through a wire bond or a solder bump, and then the IC is covered and protected by a resin. The mounting location of the IC is not limited to the upper substrate 14 of the multilayer substrate 13, but may be mounted on an FPC, which will be described later, or on the circuit substrate of the printer 100.

  In the FPC mounting process SA10, a power cable, a drive signal, and a control signal from a printer control unit terminal (not shown) are mounted on the laminated substrate 13 to transmit a control cable to the thermal head 10 and the IC. It has become. This wiring cable is connected to electrode terminals on the laminated substrate 13. As a connection method, connection via solder, ACF (anisotropic conductive film), or the like is performed. As long as it has means for transmitting power and signals, it is not limited to FPC.

  Through the above-described steps, a glass substrate thermal mountable on the printer 100 in which the identification mark 30 is attached to the other surface of the laminated substrate 13 having the cavity 23 at the joint between the support substrate 12 and the upper substrate 14. The head 10 is completed. The order of the resistor forming step SA5, the individual electrode forming step SA6, the common electrode forming step SA7, and the protective film forming step SA8 may be arbitrary.

  As described above, according to the thermal head 10 according to the present embodiment, it can be distinguished from other thermal heads by the identification mark 30 formed on the other surface of the multilayer substrate 13. The identification mark 30 is formed by arranging a plurality of substantially oval melting marks 31 formed by intermittently irradiating the laminated substrate 13 with a carbon dioxide gas laser so that the carbon dioxide laser is continuously provided. Compared to the case where the identification mark is formed by a continuous line-shaped melt mark formed by irradiation, the area for each irradiation region of the carbon dioxide laser is small, and cracks are unlikely to occur.

Further, since the irradiation area of the carbon dioxide gas laser is closed for each oval melting mark 31, even if a crack occurs in any one of the melting marks 31, it is difficult for the crack to propagate to other adjacent melting marks 31. The influence on the entire laminated substrate 13 is also small. Furthermore, compared with the case where the identification mark 30 is formed by a continuous line, the thermal contraction force in the carbon dioxide laser irradiation region is halved and the periphery of the identification mark 30 of the laminated substrate 13 is unlikely to warp in a concave shape.
Accordingly, it is possible to prevent a reduction in strength quality due to the identification mark 30.

  Further, according to the thermal printer 100 according to the present embodiment, the reliability can be improved by the thermal head on which the identification mark 30 is formed without reducing the strength quality. Further, according to the marking method according to the present embodiment, it is possible to suppress the propagation of cracks in the entire laminated substrate 13 or the occurrence of warpage in the laminated substrate 13 and form the identification mark 30 on the thermal head 10. it can.

  In the present embodiment, the laser light output 25 W, the drawing speed 600 mm / s, the line width 0.08 mm of the drawing line 31 and the like have been described as examples. These values may be determined in consideration of the content, the size of characters, the time until all markings are completed, the visual recognition, the difficulty of cracking, the material of the laminated substrate 13, and the like.

  For example, if the output of the laser beam is lowered, the amount of melting of the laminated substrate 13 is reduced, the unevenness of the melted trace 31 is reduced, and it becomes difficult to visually recognize the identification mark 30. Even if the drawing speed is increased, the same result is obtained. On the contrary, if the output of the laser beam is increased, the amount of melting of the laminated substrate 13 is increased and the unevenness of the melt mark 31 is increased, so that the identification mark 30 can be easily recognized visually, but cracks are also easily formed. Even if the drawing speed is reduced, the same result is obtained. Further, if the output of the laser beam and the drawing speed are kept constant and the line width of the drawing line 31 is increased, the laser energy per unit area is reduced, so that the amount of melting of the laminated substrate 13 is reduced and the melting mark 31 is reduced. Unevenness is reduced, making it difficult to visually recognize the identification mark 30. On the contrary, if the output of the laser beam and the drawing speed are made constant and the line width of the drawing line 31 is reduced, the amount of melting of the laminated substrate 13 increases and the unevenness of the melted trace 31 increases, but cracks are likely to occur. Become. Therefore, it is desirable to set an appropriate drawing condition.

  In this embodiment, the length of the drawing line 31 is 0.1 mm or more and 0.3 mm or less and the length of the blank portion between the drawing lines 31 is 0.3 mm or less. Each length may be changed according to the above. However, if the length of the drawing line 31 is 1 mm or more, a large crack is likely to occur in the thermal head 10 made of a glass substrate, and the strength quality is likely to deteriorate. Even if a crack does not occur, a large warp due to thermal shrinkage occurs, which affects printing, but is high. Therefore, the drawing line 31 is desirably 1 mm or less.

  Further, when the length of the blank portion between the drawing lines 31 is 2 mm or more, it may be difficult to visually recognize the identification mark 30 because it is confused with the drawing lines 31 of adjacently arranged characters. There is sex. Therefore, the length of the blank portion is desirably 2 mm or less. In order to make it possible to clearly recognize the marked character visually, the length of the relationship between the drawing line 31 and the blank portion may be adjusted according to the character to be marked. The lengths of the drawing lines 31 may all be the same or different. Further, the lengths of the blank portions of the drawing line 31 may all be the same or different.

  In the present embodiment, the marking step SA4 is performed after the thinning step SA3. Instead, the marking step SA4 may be performed between the joining step SA2 and the thinning step SA3. Moreover, it is good also as performing marking process SA4 between recessed part formation process SA1 and joining process SA2, or before recessed part formation process SA1.

  In the present embodiment, the thermal head manufacturing method includes the thinning step SA3. Instead, for example, the upper substrate having a desired thickness with respect to the support substrate 12 from the beginning. 14 may be bonded together. As a result, the thinning step SA3 can be omitted.

  Further, in the present embodiment, the laminated substrate 13 having the cavity portion 23 is exemplified and described as the substrate, but instead of this, a substrate having no cavity portion may be adopted. In this case, as a substrate, two substrate members are not joined in a laminated state, but a single substrate member may be employed. A thermal head provided with a glass substrate that does not have a hollow portion can also exhibit the same effect against cracks.

  In the present embodiment, the manufacturing method for individually manufacturing the thermal heads 10 has been described as an example. However, a plurality of thermal heads 10 may be manufactured collectively using a substrate member made of a large glass material. Good. In this case, the identification mark 30 may be marked for each region of the thermal head 10 in the large glass substrate member by the marking method according to the present embodiment in a state where the substrates of the thermal heads 10 are connected to each other.

  In the present embodiment, the identification mark 30 is formed on the other surface of the multilayer substrate 13, but the region other than the region where the heating resistor 15 and the electrode portions 17 </ b> A and 17 </ b> B are formed on the one surface of the multilayer substrate 13. When there is a sufficient space, the identification mark 30 may be formed in the space on one surface of the laminated substrate 13. In this case, in the marking method according to the present embodiment, the marking step SA4 may be performed before or after the resistor forming step SA5, the individual electrode forming step SA6, and the common electrode forming step SA7.

8 Pressurizing mechanism 10 Thermal head 12 Support substrate (support substrate member)
13 Multilayer substrate (substrate)
14 Upper substrate (Upper substrate member)
DESCRIPTION OF SYMBOLS 15 Heating resistor 17A, 17B Electrode part 23 Cavity part 30 Identification mark 31 Melting trace, Drawing line 100 Thermal printer (printer)
SA4-1 Melting process SA4-2 Cooling process

Claims (10)

A substrate made of a glass material;
A heating resistor formed on one surface of the substrate;
An electrode portion connected to both ends of the heating resistor and supplying power to the heating resistor;
An identification mark made of characters or symbols indicating identification information unique to the substrate is formed, and the identification mark is cured after intermittently irradiating a carbon dioxide laser to melt a part of the substrate into a substantially oval shape. A thermal head constructed by arranging a plurality of molten traces at intervals.   The thermal head according to claim 1, wherein the identification mark is formed in a region other than a region facing the heating resistor on the other surface of the substrate.   The melt mark has a line width of 0.03 mm or more and 0.5 mm or less, the line width is 0.1 mm or more and 1 mm or less, and the length of the blank portion between the melt marks is 2 mm. The thermal head according to claim 1 or 2, wherein:   The thermal head according to claim 1, wherein the substrate is made of alkali-free glass.   The substrate is formed by laminating a flat support substrate member and a flat upper plate member on which the heating resistor is formed, and joining the support substrate member and the upper substrate member. The thermal head according to any one of claims 1 to 4, further comprising a hollow portion in a region of the portion facing the heating resistor. The thermal head according to any one of claims 1 to 5,
A printer comprising: a pressurizing mechanism that sends out a thermal recording medium while pressing the thermal recording medium against the heating resistor of the thermal head. A melting step of intermittently irradiating a substrate made of a glass material while scanning with a carbon dioxide laser, and partially melting the substrate into a substantially oval shape;
A cooling step of cooling and solidifying a plurality of melted portions melted by the melting step, and forming an identification mark composed of characters or symbols indicating unique identification information configured by arranging a plurality of melting marks at intervals. And marking method including.   The marking method according to claim 7, wherein the identification mark is formed by irradiating a carbon dioxide laser to a region other than the region where the heating resistor and the electrode are formed on one surface of the substrate on which the heating resistor and the electrode are formed. .   8. Before forming the heating resistor and the electrode on the substrate, the carbon dioxide laser is irradiated on the other surface of the substrate opposite to the surface on which the heating resistor and the electrode are formed to form the identification mark. Marking method as described in. 8. The identification mark is formed by irradiating a carbon dioxide laser to a region other than a region facing the heat generating resistor on the other surface of the substrate opposite to the surface on which the heat generating resistor is formed. 9. The marking method according to 9.

Images