JP3121108B2 - Manufacturing method of thermal print head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a thermal print head used for a facsimile or a printer.

[0002]

2. Description of the Related Art Conventionally, a thermal print head of this type has been disclosed in, for example, Japanese Patent Application Laid-Open No. 56-126180 or Japanese Patent Application Laid-Open No. 57-24272.
It is well known that a ceramic head substrate having a heating resistor is bonded to a heat radiating plate made of aluminum or the like with an adhesive. A so-called heat-curable adhesive that is cured by heating as an adhesive for bonding
Or using a so-called room-temperature curing type adhesive that was cured at room temperature by mixing a curing agent, and after applying these adhesives to one or both of the head substrate and the heat sink, the head substrate and The heatsink is attached to it.

[0003]

However, when the former heat-curable adhesive is used as an adhesive for bonding the head substrate to the heat sink, the head substrate is bonded to the heat sink. After that, a process of heating the whole to an appropriate temperature, that is, a heating device for curing the adhesive is required, so that the manufacturing equipment of the thermal print head becomes complicated and large, and the manufacturing cost is increased. You do it.

In the case where the latter cold-setting adhesive is used as an adhesive for bonding the head substrate to the heat radiating plate, if a curing agent having a high curing speed is used as the curing agent, the head substrate and the heat radiating plate are not radiated. Since the curing progresses until the plate and the plate are bonded, the adhesive strength is reduced, and therefore, a curing agent having a considerably low curing speed must be used as the curing agent. This requires a long time for curing after the process, which also leads to an increase in production cost.

The present invention solves the above-mentioned problems when bonding a head substrate to a heat radiating plate, and also enables the head substrate to be securely bonded to the heat radiating plate without displacement. It is an object of the present invention to provide a manufacturing method that has been made.

[0006]

According to a first aspect of the present invention, there is provided a ceramic head substrate having a heating resistor and / or a metal radiating plate. Of the head substrate and heat sink
An adhesive having an anaerobic curing property that blocks contact with air (oxygen) and cures when contacting metal is applied to a central portion along the longitudinal direction, and the head substrate and the heat radiating plate While the head substrate and the heat radiating plate between the side surface of the head substrate and the surface of the heat radiating plate.
An adhesive having an ultraviolet curing property is applied to a central portion along the longitudinal direction of the heat sink and the heat radiation plate , and this portion is irradiated with ultraviolet rays.

In a second aspect of the present invention, one or both of a surface of a ceramic head substrate provided with a heating resistor and a surface of a metal radiator plate are provided on the head substrate.
And the appropriate length at the center along the longitudinal direction of the heat sink
In part, and anaerobic curing characteristics such as cure when in contact with and the metal blocking contact with air (oxygen), the adhesive is applied with an ultraviolet curing characteristics such as cure an irradiation of ultraviolet light, While bonding the head substrate and the heat sink, the same adhesive as above, the head substrate between the side surface of the head substrate and the surface of the heat sink and
It is also applied to the central portion along the longitudinal direction of the heat sink , and this portion is irradiated with ultraviolet rays.

[0008]

According to the first aspect of the present invention, an adhesive having anaerobic curing properties is applied to one or both of the surface of the head substrate and the surface of the heat sink, and then the head substrate and the heat sink are contacted. When glued, the adhesive is
Since it is in a state of being cut off from the atmospheric air and in a state of being in contact with the metal radiator plate, the curing of the adhesive starts at a normal temperature after the bonding is performed. In addition, since the curing of the adhesive does not start until the head substrate and the heat sink are bonded to each other, the adhesive strength does not decrease.

On the other hand, after applying an adhesive having an ultraviolet curing property between the side surface of the head substrate and the surface of the heat radiating plate, this portion is irradiated with ultraviolet light,
This adhesive cures in a very short time by irradiation of ultraviolet light, and can immediately fix the head substrate to the heat sink, so that the adhesive having the anaerobic curing property is completely cured. In this case, it is possible to reliably prevent the head substrate from moving relative to the heat sink.

[0010] As described above, the curing of the adhesive is performed at room temperature and after the bonding, and the displacement of the head substrate until the adhesive is cured. Preventing the movement can also be achieved by the second invention.

Further , the anaerobic hardening feature of the first invention is provided.
Adhesive having an adhesive property and an adhesive having an ultraviolet curing property,
Has the anaerobic curing property and the ultraviolet curing property in the second invention.
Adhesive along the longitudinal direction of the head substrate and heat sink.
Applied to the center of the head substrate
The top surface is gentle against the platen along its length
It becomes a convex curved surface .

Further, at the time of bonding the head substrate to the heat radiating plate, if a metal surface active agent such as a redox catalyst is applied to the surface of the heat radiating plate in advance, the heat radiated by the metal surface active agent is applied. By activating the surface of the plate, the curing speed of the adhesive having the anaerobic curing property can be accelerated, and the adhesive strength can be improved.

[0013]

Thus, according to the present invention, when the head substrate is bonded to the heat sink with an adhesive, the heating for curing is performed without causing the adhesive strength to be reduced by the adhesive. Since no device is required, the head substrate can be securely and firmly bonded to the heat sink, the manufacturing cost of the thermal print head can be significantly reduced, and the head substrate can be positioned at a predetermined position on the heat sink. Can be fixed accurately in a very short time, and furthermore , the head substrate is bonded to the heat sink.
Presses the upper surface of the head substrate along its longitudinal direction.
Being able to have a gentle convex curved surface with respect to Latin
To ensure uniform contact with the platen
is there.

Further, the curing time of the adhesive can be further reduced by using the metal surfactant, and the productivity can be increased. Therefore, the production cost can be further reduced and the bonding strength can be increased. It also has the effect that it can.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show a first embodiment. In the figures, reference numeral 1 denotes a head substrate formed of ceramic and having a length L, on the upper surface of which a heating resistor 2 has a straight line. It is formed to extend in a shape.

Reference numeral 3 denotes an aluminum radiator plate, and a portion of the upper surface of the radiator plate 3 extending in the center along the longitudinal direction and extending over a length S blocks contact with air (oxygen), and After applying an adhesive A having an anaerobic curing property that cures when it comes into contact with metal, as shown in FIG. 2, the head substrate 1 is bonded to the heat sink 3. In this case, The adhesive A may be applied to the head substrate 1, or may be applied to both the head substrate 1 and the heat sink 3.

Next, the side surface 1 of the head substrate 1
in the long direction of the central smell between the a, and the upper surface of the heat sink 3
From the application length S of the adhesive A having the anaerobic curing property
As shown in FIGS. 2 and 3, an adhesive B having an ultraviolet curing property such that it is cured by irradiation of ultraviolet light
Is applied, and the adhesive B is irradiated with ultraviolet rays.

Then, the adhesive A having the anaerobic curing property is cut off from the atmospheric air when the head substrate 1 is bonded to the heat radiating plate 3 and comes into contact with the metal heat radiating plate 3. Therefore, the curing of the adhesive A starts at a normal temperature after the above-mentioned bonding is performed, and starts before the head substrate 1 and the heat sink 3 are bonded to each other. Because there is no
This does not cause a decrease in the adhesive strength.

On the other hand, after an adhesive B having an ultraviolet curing property is applied between the side surface 1a of the head substrate 1 and the surface of the radiator plate 3, the adhesive B is irradiated by irradiating an ultraviolet ray to this portion. Since the head substrate 1 can be hardened in a very short time by the irradiation of ultraviolet rays and the head substrate 1 can be immediately fixed to the heat sink 3, until the hardening of the adhesive A having the anaerobic hardening property is completed. ,
It is possible to reliably prevent the head substrate 1 from being displaced relative to the heat radiating plate 3, whereby before the curing of the adhesive A having the anaerobic curing characteristics is completed, various processes such as the next assembly are performed. Can be migrated.

FIGS. 4 and 5 show a second embodiment. The second embodiment uses an adhesive C having both the above-described anaerobic curing property and ultraviolet curing property to move the head substrate 1 to the heat radiating plate 3 at an appropriate length at the center in the longitudinal direction. And the adhesive C at the center in the longitudinal direction, between the side surface 1 a of the head substrate 1 and the surface of the heat sink 3.
An adhesive C ′ having both anaerobic curing properties and ultraviolet curing properties is applied to a portion shorter than the application length S in the same manner as described above, and the portion of the adhesive C ′ is irradiated with ultraviolet rays. The curing of the bonded adhesive C used starts from the time of the bonding, while the adhesive C ′ applied between the side surface 1a of the head substrate 1 and the surface of the heat sink 1 is Since the head substrate 1 can be hardened in a very short time by the irradiation of ultraviolet rays and the head substrate 1 can be immediately fixed to the heat radiating plate 3, the head substrate 1 is radiated until the curing of the adhesive C is completed. It can surely be prevented from moving relative to the plate 3.

Further, the head substrate 1 and the heat radiating plate 3 are formed by bonding an adhesive A having an anaerobic curing property and an ultraviolet curing property.
When bonding with the adhesive B or the adhesives C 1 and C ′ having the anaerobic curing property and the ultraviolet curing property, a metal surfactant such as a redox catalyst or the like is previously applied to the surface of the metal heat sink 3. By dissolving and applying in a solvent such as methylene chloride, the surface of the heat radiating plate 3 is activated by the metal surfactant, so that the curing speed of the adhesive A or the adhesive C can be accelerated. At the same time, the adhesive strength can be increased.

In this case, according to the experiment of the present inventor, the curing time of the adhesive A was about 30 minutes when the metal surface active agent was not applied to the surface of the heat sink 3 in advance. The curing time of the adhesive A when a metal surfactant was previously applied to the surface was about 1 to 2 minutes.

In this type of thermal print head, when the heating resistor 2 of the head substrate 1 generates heat, a ceramic head substrate 1 and a metal radiating plate 3 are formed.
Due to the difference in thermal expansion between the thermal printhead and the platen in the printer or facsimile, the longitudinal ends of the thermal printhead are close to the platen, and the longitudinal center of the thermal printhead is away from the platen. On the other hand, it tends to warp into a concave curved shape, and the top surface of the head substrate is
Along the platen to form a gentle concave curved surface.
This ensures uniform contact with the platen at various locations.
Will not be .

Therefore, the thermal print head has a configuration in which both ends in the longitudinal direction of the thermal print head are separated from the platen, and a central portion in the longitudinal direction of the thermal print head approaches the platen.
That is, a warp having a convex curved shape is provided to the platen, and the platen is mounted on a printer, a facsimile, or the like in a state in which the warp having the convex curved shape is provided.

According to the experiment of the present inventor, the head substrate 1
As described above, the heat sink 3 has the anaerobic hardening property.
Adhesive A and adhesive B having ultraviolet curing properties,
Is an adhesive C having an anaerobic curing property and an ultraviolet curing property,
When bonding at C ' , the anaerobic curing characteristics
A having UV curing properties and UV curable properties
B, or adhesive having anaerobic curing property and ultraviolet curing property
Agents C and C 'are placed at the center along the longitudinal direction with a length S
When partially so as to applied over these adhesive
Agents A, B or C, the shrinkage of during curing of the C ', F
As shown by a two-dot chain line in FIGS. 2 and 4,
And warp deformation in a curved shape along its longitudinal direction, the upper surface
Is gently convex to the platen along its length
And than become a curved surface, also warp dimension e when this way to warp, the adhesive A, B or adhesive C, was proportional to the applied length S of C '.

[0027] Therefore, definitive in the thermal print head
On the upper surface of the head substrate 1,
The provision of a convex curved surface can be achieved by bonding the head substrate 1 of the thermal print head to the heat sink 3 with the adhesives A 1 and B or the adhesives C 1 and C ′ . .

[Brief description of the drawings]

FIG. 1 is a perspective view showing an exploded state of a thermal print head according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a thermal print head according to a first embodiment of the present invention.

FIG. 3 is an enlarged sectional view taken along line III-III of FIG. 2;

FIG. 4 is a perspective view of a thermal print head according to a second embodiment of the present invention.

FIG. 5 is an enlarged sectional view taken along line VV of FIG. 4;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Head board 2 Heating resistor 3 Heat sink A Adhesive having anaerobic curing properties B Adhesive having ultraviolet curing properties C, C 'Adhesive having anaerobic curing properties and ultraviolet curing properties

Claims (3)

(57) [Claims] 1. One or both of a surface of a ceramic head substrate provided with a heating resistor and a surface of a metal radiator plate , in which the longitudinal direction of the head substrate and the radiator plate is included.
An adhesive having an anaerobic curing property that blocks contact with air (oxygen) and cures when it comes into contact with metal is applied to a central portion along the line, and the head substrate and the heat sink are attached. On the other hand, the head substrate and the radiator plate between the side surface of the head substrate and the surface of the radiator plate
A method for manufacturing a thermal print head, comprising applying an adhesive having ultraviolet curing properties to a central portion along the longitudinal direction of the above and irradiating the adhesive with ultraviolet rays. 2. One or both of a surface of a ceramic head substrate provided with a heating resistor and a surface of a metal radiator plate, the longitudinal direction of the head substrate and the radiator plate being included therein.
Having an anaerobic curing property that blocks contact with air (oxygen) and cures when it comes into contact with metal, and an ultraviolet curing property that cures when irradiated with ultraviolet light, in the center along the line the was coated, while bonding the said heat dissipation plate and the head substrate, the same adhesive as mentioned above, between the surface of the side surface and the heat sink in the head substrate
A method for manufacturing a thermal print head, wherein the method also applies a central portion along the longitudinal direction of a head substrate and a heat radiating plate, and irradiates this portion with ultraviolet rays. 3. A thermal printhead according to claim 1, wherein a metal surfactant such as a redox catalyst is applied in advance to the surface of said heat radiating plate. Production method.