阅读说明：本技术 拼接式热敏打印单元及热敏打印头和其装配方法 (Spliced thermal printing unit, thermal printing head and assembly method of thermal printing head ) 是由 于浩 王军磊 崔迎平 于 2020-06-09 设计创作，主要内容包括：本发明涉及热敏打印头制造技术领域,具体的说是一种拼接式热敏打印单元及热敏打印头和其装配方法,通过设置陶瓷基板部分悬空式结构,在陶瓷基板悬空部分与散热板之间设置导热性良好且不固化的导热硅脂填充层,保证陶瓷基板上的发热体电阻的散热效果,同时保证了陶瓷基板与散热板之间存在相对位移量,当产品处于由高温固化降至室温或低温保存等过程中,组件热胀冷缩对陶瓷基板产生挤压时,陶瓷基板相适应位移,避免陶瓷基板及其上的组件被损伤,具有结构合理、装配简便、打印质量高等显著的优点。(The invention relates to the technical field of thermal printing head manufacturing, in particular to a spliced thermal printing unit, a thermal printing head and an assembly method thereof.)

1. A spliced thermal printing unit comprises a ceramic substrate, a PCB (printed circuit board) and a bottom plate, wherein the ceramic substrate and the PCB are respectively fixed on the bottom plate, a heating element resistor installation area is arranged on the upper surface of the ceramic substrate, and a heating element resistor is arranged in the heating element resistor installation area; the ceramic substrate is characterized in that a non-heating resistor installation area of the ceramic substrate is fixedly connected with the bottom plate, and the lower side of the ceramic substrate corresponding to the heating element resistor installation area is suspended.

2. The spliced thermal printing unit according to claim 1, wherein the bottom plate is made of a metal base, the position of the back surface of the ceramic substrate corresponding to the non-heat-generating resistor mounting area is glued and fixed with the metal base, the PCB and the metal base are provided with corresponding screw holes, and the screw holes are in a strip shape, wherein the width of the screw holes is 4mm, and the length of the screw holes is 6 mm.

3. The spliced thermal printing unit as claimed in claim 2, wherein more than two strip screw holes are arranged in a straight line on the PCB and the metal base.

4. A spliced thermal printing head is provided with a heat dissipation plate, wherein two or more spliced thermal printing units according to any one of claims 1 to 3 are arranged on the heat dissipation plate, the heat dissipation plate is provided with screw holes, the two or more spliced thermal printing units are respectively fixed on the heat dissipation plate through screws, and a heat-conducting silicone grease filling layer is arranged between the lower surface of a ceramic substrate of each spliced thermal printing unit, which corresponds to a heating element resistor mounting area, and the heat dissipation plate.

5. The thermal printhead of claim 4, wherein the thermally conductive silicone grease filling layer corresponding to the heater resistor mounting region has a height in the range of 0.1 to 0.3mm and a width in the range of 4.0 to 6.0 mm.

6. The thermal printhead of claim 4, wherein two parallel thermal grease grooves are formed on the top surface of the heat spreader, and a thermal grease filling layer is disposed between the two thermal grease grooves.

7. The spliced thermal printing head as claimed in claim 4, wherein the heat dissipation plate has an alignment step on one side of the upper surface thereof, and an alignment step on the side of the heat dissipation plate adjacent to the region where the thermal silicone grease filling layer is disposed, so as to ensure that two or more spliced thermal printing units are aligned quickly during assembly.

8. The spliced thermal printing head as claimed in claim 4, wherein more than two spliced thermal printing units are fixed on the heat dissipation plate by screws respectively, and the adjacent spliced thermal printing units have a gap y, the width of y is less than 0.2 mm.

9. The splicing type thermal printing head of claim 4 is characterized in that a pressing plate is arranged, a strip-shaped screw hole is formed in the pressing plate, when the splicing type thermal printing head is installed, a screw penetrates through the screw hole in the pressing plate and the screw holes in more than two splicing type printing units in sequence and then is locked with the screw hole in the heat dissipation plate, the screw is an M3 pan head type screw, the screw is in clearance fit with the strip-shaped screw hole, and the clearance allowance between the screw and the strip-shaped screw hole is 1mm-3 mm.

10. A method for assembling a spliced thermal printing head is characterized by comprising the following steps:

step 1: assembling a spliced thermal printing unit, and respectively fixing a ceramic substrate and a PCB (printed Circuit Board) on the upper side of a metal base station in an adhesive manner, wherein the lower surface area of the ceramic substrate corresponding to the heating resistor installation area is externally suspended outside the metal base station;

step 2: arranging a heat-conducting silicone grease filling layer on the upper surface of the heat dissipation plate, and brushing the heat-conducting silicone grease filling layer with the height of 0.1-0.3mm and the width of 4-6mm in the arrangement area of the heat-conducting silicone grease filling layer on the upper surface of the heat dissipation plate;

and step 3: placing more than two spliced thermal printing units on a heat dissipation plate, enabling the suspended part of the ceramic substrate of each spliced thermal printing unit to be tightly attached to the heat dissipation plate through a heat-conducting silica gel filling layer, and reserving a gap y between every two adjacent spliced thermal printing units;

and 4, step 4: more than two splicing type thermal printing units are fixed on the heat dissipation plate by utilizing the pressing plate and the locking screws.

The technical field is as follows:

the invention relates to the technical field of thermal printing head manufacturing, in particular to a spliced thermal printing unit, a thermal printing head and an assembly method thereof, wherein the spliced thermal printing unit can prevent adjacent printing units from being extruded with each other, so that the product quality is improved.

Background art:

the thermal print head generally comprises a heating ceramic substrate, a PCB circuit board and a heat dissipation plate, wherein the ceramic substrate and the PCB circuit board are fixed on the heat dissipation plate. The heat dissipation plate is made of aluminum section, and the coefficient of thermal expansion of the aluminum heat dissipation plate is about 24.9x10^-6/° c, the coefficient of thermal expansion of the ceramic substrate is about 8.8x10^-6The temperature is reduced when the temperature is lower and the deformation of the aluminum heat dissipation plate is larger than that of the ceramicA substrate.

At present, the thermal printing head is more and more in the field of wide-width printing, the printing width exceeds 600mm, and the printing width of a single thermal printing head can be 300mm due to the limitation of production technology and cost. More than two groups of printing units need to be spliced to realize banner printing.

However, due to the different expansion coefficients of the different components, when the ambient temperature changes, the adjacent printing monomers are extruded, which not only affects the printing quality of the product, but also causes the ceramic substrate to be damaged after being stressed, and the service life of the product is reduced.

The invention content is as follows:

aiming at the defects and shortcomings in the prior art, the invention provides the splicing type thermal printing unit, the thermal printing head and the assembling method thereof, wherein the splicing type thermal printing unit and the thermal printing head can avoid the mutual extrusion of adjacent printing units so as to improve the product quality.

The invention is achieved by the following measures:

a spliced thermal printing unit comprises a ceramic substrate, a PCB (printed circuit board) and a bottom plate, wherein the ceramic substrate and the PCB are respectively fixed on the bottom plate, a heating element resistor installation area is arranged on the upper surface of the ceramic substrate, and a heating element resistor is arranged in the heating element resistor installation area; the ceramic substrate is characterized in that a non-heating resistor installation area of the ceramic substrate is fixedly connected with the bottom plate, and the lower side of the ceramic substrate corresponding to the heating element resistor installation area is suspended.

The bottom plate adopts a metal base, the position of the back surface of the ceramic substrate, which corresponds to the non-heating resistor installation area, is glued and fixed with the metal base, the PCB and the metal base are provided with corresponding screw holes, the screw holes are in a strip shape, and the width is preferably 4mm, and the length is preferably 6 mm.

In order to improve the fixing stability of the PCB, the metal base and other components, more than two strip-shaped screw holes can be linearly arranged on the PCB and the metal base.

The utility model provides a concatenation formula thermal printhead, is equipped with the heating panel, is equipped with two or more concatenation formula thermal printing units on the heating panel, its characterized in that sets up the screw hole on the heating panel, and two or more concatenation formula printing units are respectively through the fix with screw on the heating panel, and wherein the ceramic substrate of concatenation formula printing unit corresponds and is equipped with heat conduction silicone grease filling layer between the lower surface of heat-generating body resistance installing zone and the heating panel.

The height range of the heat-conducting silicone grease filling layer corresponding to the position of the resistor mounting area of the heating element is 0.1-0.3mm, and the width range is 4.0-6.0 mm.

In order to ensure that the heat-conducting silicone grease filling layer is stably positioned between the ceramic substrate and the heat dissipation plate, two heat-conducting silicone grease guide grooves which are parallel to each other are formed in the upper surface of the heat dissipation plate, a heat-conducting silicone grease filling layer setting area is arranged between the two heat-conducting silicone grease guide grooves, and further, the height of the heat-conducting silicone grease filling layer setting area is slightly higher than that of other areas of the heat dissipation plate, so that the heat-conducting silicone grease filling layer setting area can be quickly aligned to the corresponding positions of more than two spliced thermal printing units during installation.

In order to ensure that more than two spliced thermal printing units are quickly aligned and fixed, an alignment step is arranged on one side of the upper surface of the heat dissipation plate, and preferably, an alignment step is arranged on the side edge of the heat dissipation plate close to the arrangement area of the heat-conducting silicone grease filling layer, so that the more than two spliced thermal printing units are quickly aligned in the assembling process.

More than two spliced thermal printing units are respectively fixed on the heat dissipation plate through screws, and gaps y are reserved between the adjacent spliced thermal printing units, the width of y is smaller than 0.2mm, and the width of y is preferably 0.15 mm.

In order to improve the fixing effect between the spliced thermal printing units and the heat dissipation plate, the heat dissipation plate is provided with the pressing plate, the pressing plate is provided with the strip-shaped screw hole, when the heat dissipation plate is installed, a screw sequentially penetrates through the screw hole on the pressing plate and the screw holes on more than two spliced printing units and then is locked with the screw hole on the heat dissipation plate, the screw is an M3 pan head type screw, the screw is in clearance fit with the strip-shaped screw hole, the clearance allowance between the screw and the strip-shaped screw hole is 1mm-3mm, and when the external environment temperature changes, certain movement allowance exists when all components are mutually extruded due to thermal expansion and cold contraction.

The invention also provides an assembly method of the spliced thermal printing head, which is characterized by comprising the following steps:

step 1: assembling a spliced thermal printing unit, and respectively fixing a ceramic substrate and a PCB (printed Circuit Board) on the upper side of a metal base station in an adhesive manner, wherein the lower surface area of the ceramic substrate corresponding to the heating resistor installation area is externally suspended outside the metal base station;

step 2: arranging a heat-conducting silicone grease filling layer on the upper surface of the heat dissipation plate, and brushing the heat-conducting silicone grease filling layer with the height of 0.1-0.3mm and the width of 4-6mm in the arrangement area of the heat-conducting silicone grease filling layer on the upper surface of the heat dissipation plate;

and step 3: placing more than two spliced thermal printing units on a heat dissipation plate, enabling the suspended part of the ceramic substrate of each spliced thermal printing unit to be tightly attached to the heat dissipation plate through a heat-conducting silica gel filling layer, and reserving a gap y between every two adjacent spliced thermal printing units;

and 4, step 4: more than two splicing type thermal printing units are fixed on the heat dissipation plate by utilizing the pressing plate and the locking screws.

The invention provides a spliced thermal printing unit and a spliced thermal printing head, wherein a ceramic substrate part suspended structure is arranged, a heat-conducting silicone grease filling layer which has good heat conductivity and is not cured is arranged between a ceramic substrate suspended part and a heat dissipation plate, the heat dissipation effect of a heating element resistor on a ceramic substrate is ensured, meanwhile, the relative displacement between the ceramic substrate and the heat dissipation plate is ensured, when a product is in the process of being cooled to room temperature or being stored at low temperature from high-temperature curing, the ceramic substrate is adapted to displacement when a component expands with heat and contracts with cold to extrude the ceramic substrate, the ceramic substrate and the component on the ceramic substrate are prevented from being damaged, and the spliced thermal printing unit and the spliced thermal printing head have the remarkable advantages of reasonable structure, simplicity and convenience in assembly, high printing quality and the like.

Description of the drawings:

fig. 1 is a schematic structural diagram of a splicing type thermal printing unit in embodiment 1 of the present invention.

Fig. 2 is a schematic view of the opening of the PCB and the metal base in embodiment 1 of the present invention.

Fig. 3 is a schematic structural diagram of a spliced thermal print head according to the present invention.

Fig. 4 is a schematic structural view of a platen in embodiment 2 of the present invention.

Fig. 5 is a schematic structural view of a heat dissipating plate in embodiment 2 of the present invention.

Fig. 6 is a schematic structural diagram of a tiled thermal print head according to embodiment 2 of the present invention.

Fig. 7 is a schematic structural view of a bar screw hole in embodiment 2 of the present invention.

Fig. 8 is a schematic diagram of the arrangement of two adjacent spliced thermal printing units in embodiment 2 of the invention.

Reference numerals: the heating element comprises a heating element resistor 1, a ceramic substrate 2, a metal base 3, a double-sided tape 4, a PCB (printed Circuit Board) 5, packaging glue 6, a connector 7, heat-conducting silicone grease 8, a heat dissipation plate 9, a pressing plate 10 and a compression screw 11.

The specific implementation mode is as follows:

the invention is further described below with reference to the accompanying drawings and examples.

As shown in fig. 3, the invention provides a spliced thermal printing unit and a thermal printing head, wherein the spliced thermal printing unit comprises a ceramic substrate 2, a PCB 5 and a bottom plate, the ceramic substrate 2 and the PCB 5 are respectively fixed on the bottom plate, a heating element resistor mounting area is arranged on the upper surface of the ceramic substrate 2, and a heating element resistor 1 is arranged in the heating element resistor mounting area; the non-heating resistor installation area of the ceramic substrate 2 is fixedly connected with the bottom plate, and the lower side of the ceramic substrate 2 corresponding to the heating element resistor installation area is suspended; the bottom plate adopts a metal base 3, the back surface of the ceramic substrate 3 corresponding to the non-heating resistor installation area is glued and fixed with the metal base 3, the PCB 5 and the metal base 3 are provided with corresponding screw holes, the screw holes are in a strip shape, and the preferred width is 4mm, and the preferred length is 6 mm;

the spliced thermal printing head is provided with a heat dissipation plate 9, more than two spliced thermal printing units are arranged on the heat dissipation plate 9, screw holes are formed in the heat dissipation plate 9, the more than two spliced thermal printing units are respectively fixed on the heat dissipation plate 9 through screws, and a heat conduction silicone grease 8 filling layer is arranged between the lower surface of a ceramic substrate 2 of each spliced thermal printing unit, which corresponds to a heating element resistor installation area, and the heat dissipation plate 9; the height range of the heat-conducting silicone grease 8 filling layer is 0.1-0.3mm, and the width range is 4.0-6.0 mm;

in order to ensure that the heat-conducting silicone grease filling layer is stably positioned between the ceramic substrate and the heat dissipation plate, two heat-conducting silicone grease guide grooves which are parallel to each other are formed in the upper surface of the heat dissipation plate, a heat-conducting silicone grease filling layer setting area is arranged between the two heat-conducting silicone grease guide grooves, and further, the height of the heat-conducting silicone grease filling layer setting area is slightly higher than that of other areas of the heat dissipation plate, so that the heat-conducting silicone grease filling layer setting area can be quickly aligned to the corresponding positions of more than two spliced thermal printing units during installation.

In order to ensure that more than two spliced thermal printing units are quickly aligned and fixed, an alignment step is arranged on one side of the upper surface of the heat dissipation plate, and preferably, an alignment step is arranged on the side edge of the heat dissipation plate close to the arrangement area of the heat-conducting silicone grease filling layer, so that the more than two spliced thermal printing units are quickly aligned in the assembling process.

More than two spliced thermal printing units are respectively fixed on the heat dissipation plate through screws, gaps y are reserved between the adjacent spliced thermal printing units, the width range of y is smaller than 0.2mm, and the width of y is further preferably 0.15 mm.

In order to improve the fixing effect between the spliced thermal printing units and the heat dissipation plate, the heat dissipation plate is provided with the pressing plate, the pressing plate is provided with the strip-shaped screw hole, when the heat dissipation plate is installed, a screw sequentially penetrates through the screw hole on the pressing plate and the screw holes on more than two spliced printing units and then is locked with the screw hole on the heat dissipation plate, the screw is an M3 pan head type screw, the screw is in clearance fit with the strip-shaped screw hole, the clearance allowance between the screw and the strip-shaped screw hole is 1mm-3mm, and when the external environment temperature changes, certain movement allowance exists when all components are mutually extruded due to thermal expansion and cold contraction.

The invention also provides an assembly method of the spliced thermal printing head, which comprises the following steps: assembling a spliced thermal printing unit, and respectively fixing a ceramic substrate and a PCB (printed Circuit Board) on the upper side of a metal base station in an adhesive manner, wherein the lower surface area of the ceramic substrate corresponding to the heating resistor installation area is externally suspended outside the metal base station; arranging a heat-conducting silicone grease filling layer on the upper surface of the heat dissipation plate, and brushing the heat-conducting silicone grease filling layer with the height of 0.1-0.3mm and the width of 4-6mm in the arrangement area of the heat-conducting silicone grease filling layer on the upper surface of the heat dissipation plate; placing more than two spliced thermal printing units on a heat dissipation plate, enabling the suspended part of the ceramic substrate of each spliced thermal printing unit to be tightly attached to the heat dissipation plate through a heat-conducting silica gel filling layer, and reserving a gap y between every two adjacent spliced thermal printing units; more than two splicing type thermal printing units are fixed on the heat dissipation plate by utilizing the pressing plate and the locking screws.

Example 1:

as shown in fig. 1 and fig. 2, the present example provides a splicing type thermal printing unit, which includes a ceramic substrate 2, a PCB 5 and a bottom plate, wherein the ceramic substrate 2 and the PCB 5 are respectively fixed on the bottom plate, a heating element resistor mounting region is arranged on the upper surface of the ceramic substrate 2, and a heating element resistor 1 is arranged in the heating element resistor mounting region; the non-heating resistor installation area of the ceramic substrate 2 is fixedly connected with the bottom plate, and the lower side of the ceramic substrate 2 corresponding to the heating element resistor installation area is suspended;

the bottom plate adopts a metal base 3, the position of the back surface of the ceramic substrate 2 corresponding to the non-heating resistor installation area is fixed with the metal base 3 through double-sided tape 4, the PCB 5 and the metal base 3 are also fixed through double-sided tape 4, the PCB 5 and the metal base 3 are provided with corresponding screw holes, and the screw holes are strip-shaped, have the width of 4mm and have the length of 6 mm; in order to improve the fixing stability of the PCB, the metal base, and other components, two or more strip screw holes may be linearly provided in the PCB or the metal base.

Example 2:

this example provides a pin-connected thermal print head and a method for manufacturing the same, as shown in fig. 4 to 8, including an insulating substrate (i.e. a ceramic substrate 3) made of an insulating material, a PCB 5, a metal base 3 and two or more monolithic thermal print units, wherein the metal base 3 is used as a bottom plate, the ceramic substrate 2 and the PCB 5 are fixed on the metal base 3 by a double-sided tape 4, so as to manufacture the monolithic thermal print unit, the back of a heating resistor 1 in a main printing direction of the thermal print unit has no metal base 3, heat of the heating resistor 1 is rapidly conducted to a heat sink 9 through a heat conductive silicone grease, and two oblong holes (strip screw holes) are respectively formed in the PCB 5 and the metal base 3: the diameter of the hole is phi 4mm, the length of the hole is 6mm, the tightening screw is an M3 pan head screw, the outer diameter of the tightening screw is phi 3mm, and the tightening screw can move when the two thermal printing units are extruded due to the change of environmental temperature and the expansion and contraction caused by heat;

when the product is manufactured and assembled, the heat-conducting silicone grease 8 is coated on the metal heat dissipation plate 9, the coating height is 0.1-0.3mm, the coating width is 4-6mm, and the width and the thickness required by the heat-conducting silicone grease ensure the heat dissipation effect;

sequentially combining two or more single thermal printing units on a heat dissipation plate 9, adjusting the corresponding positions of heating element resistors 1 on the two thermal printing units, placing a pressing plate 10, and screwing a compression screw 11 into the heat dissipation plate 9 through the pressing plate 10 and the thermal printing units; the torsion of the compression screw 11 is 3-4 kgf/cm;

wherein fig. 4 is a drawing of the hole of the pressure plate 10 in this example, the diameter D2 of the strip screw hole is 4mm, and the width L2 of the hole is 6 mm; fig. 5 is a cross-sectional view of the heat dissipating plate 9 coated with the heat conductive silicone grease 8 in this example, the specification of the heat conductive silicone grease coating: the thickness t is 0.1-0.3mm, and the width w is 4-6 mm; FIG. 6 is a sectional view of the assembled structure of the present embodiment, wherein no cavity is required to be formed in the heat conductive silicone grease 8 at the lower part of the heating resistor 1 during the assembly process; FIG. 7 is a schematic diagram showing the fit size of the hold-down screw with the thermal print head via the platen in this example; fig. 8 is a sectional view showing the assembled thermal print head in this example, in which a gap x is 1.5mm between the fixing screw 11 and the thermal print unit 1-1 and the thermal print unit 1-2, and a gap y is 0.15mm between the fixing screw 1-1 and the fixing screw 1-2; when the temperature is reduced, the thermal printing unit 1-1 and the thermal printing unit 1-2 are extruded, y is equal to 0, the thermal printing unit and the bottom heat dissipation plate 9 form displacement, the value x is reduced, and the ceramic substrate is prevented from being damaged;

the heat-conducting silicone grease adopted by the embodiment is composed of silicone oil and filler, the existing known silicone oil is basically methyl silicone oil, methyl phenyl silicone oil, chlorohydrocarbon modified silicone oil, chlorofluorocarbon modified silicone oil, long-chain alkyl silicone oil and the like, the filler is ZnO/Al2O 3/boron nitride/silicon carbide/aluminum powder and the like, and because the silicone oil is insensitive to temperature and is not volatile, the silicone oil does not thicken at low temperature and does not thin at high temperature, the silicone oil ensures certain fluidity, and the filler fills a tiny gap between a heat dissipation plate and a thermal printing head, so that the heat conductivity is ensured; specifically, the heat conductive silicone grease has the following characteristics: the heat conduction performance is good, and the heat conduction coefficient is from 1.0w/m.k to 4.5 w/m.k; secondly, the high electric insulation performance is achieved, and the voltage can be withstand more than 1 ten thousand volts; the high and low temperature resistance is good, and the material can be used in the temperature range of minus 50 ℃ to plus 230 ℃; waterproof, permeable, non-curing and stable chemical performance;

the heat-conducting silica gel is not selected to be used because the heat-conducting silica gel is vulcanized into a high-performance elastomer through crosslinking and curing caused by low molecular weight released by condensation reaction of water in the air; and the heat-conducting silicone grease is not solidified, so that the relative displacement between the ceramic substrate and the heat dissipation plate can be ensured.

According to the invention, the heat-conducting silicone grease is adopted for heat dissipation, the thermosensitive printing head is pressed on the heat dissipation plate through the pressing plate by using screws, and by utilizing the good heat conductivity and non-curing property of the heat-conducting silicone grease, when the temperature is reduced, two adjacent thermosensitive printing units are mutually extruded to form displacement, so that the phenomenon of substrate damage caused is avoided, and the service life of the product is prolonged.