Thermal printing head capable of preventing packaging adhesive from tilting
By setting grooves and exhaust ducts on the heat sink plate to fill and cure the packaging adhesive layer, the problem of easy bending of thermal print head packaging adhesive is solved, and higher adhesion and firmness are achieved, and the product trust is enhanced.
Patent Information
- Application Number
- CN202421728702.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-22
- Publication Date
- 2025-05-09
- Estimated Expiration
- 2034-07-22
AI Technical Summary
The packaging glue of existing thermal print heads is prone to rise at the joints of the heating substrate and the PCB board, resulting in product failure.
The heat dissipation plate is provided with grooves and exhaust channels, and the encapsulating adhesive layer covers the joints between the heating substrate and the PCB board and fills the grooves. The cured encapsulating adhesive layer forms a downward hook shape at the end of the heating substrate to avoid raising.
Through the groove and exhaust duct structure, the packaging glue forms a snap structure at both ends of the heating substrate and the PCB board, which increases adhesion and firmness, effectively prevents the packaging glue from rising and enhances product trust.
Smart Images
Figure CN222845047U_ABST
Abstract
Description
Technical field:
[0001] The utility model relates to the technical field of thermal print head manufacturing, in particular to a thermal print head which has a reasonable structure, is easy to assemble and can significantly improve product quality and prevent packaging glue from warping. Background technology:
[0002] As we all know, the thermal print head mainly includes a heating substrate, a PCB board and a control IC. The three are electrically connected through a gold wire bonding process. In order to protect the connection parts of the components from damage and corrosion, packaging glue is used to seal the connection parts. The sealing effect mainly depends on the adhesion between the heating substrate and the packaging glue. However, as the package size increases, the internal stress of the packaging glue increases, and the frequent thermal expansion and contraction changes during printing make the packaging glue in contact with the heating substrate prone to warping, which in turn leads to product failure. Summary of the invention:
[0003] The utility model aims at the shortcomings and deficiencies in the prior art and proposes a thermal printing head which has a reasonable structure, is easy to assemble and can significantly improve product quality and prevent the packaging glue from warping.
[0004] The utility model achieves this through the following measures:
[0005] A thermal print head for preventing packaging glue from warping is provided with a heating substrate, a PCB board, a control IC and a heat sink, wherein the heating substrate, the PCB board and the control IC are arranged on the heat sink, and is characterized in that a groove is provided on the upper surface of the heat sink corresponding to below the joint between the heating substrate and the PCB board, and an exhaust passage connected to the groove is provided on the surface of the heat sink, and the packaging glue layer covers the joint between the heating substrate and the PCB board and fills the groove.
[0006] The groove of the utility model is arranged on the upper surface of the heat dissipation plate and is located at the ends of the heating substrate and the PCB board. Furthermore, the groove is shielded by the heating substrate or the PCB board, so that after the encapsulation adhesive layer covers the joint between the heating substrate and the PCB board, it is filled into the groove along the end of the heating substrate. The cured encapsulation adhesive layer forms a downwardly bent hook shape at the end of the heating substrate, thereby effectively preventing the encapsulation adhesive layer from warping.
[0007] The utility model further provides grooves on the upper surface of the heat sink corresponding to the two ends of the heating substrate and the PCB board, and correspondingly provides exhaust ducts connected to the grooves. Furthermore, the exhaust duct extends from the bottom of the PCB board to the edge of the heat sink, and is used to timely discharge the gas in the groove during the process of filling the groove with packaging glue, thereby improving the filling quality of the packaging glue.
[0008] The groove of the utility model is in a hemispherical or funnel shape, thereby expanding the filling space of the packaging glue and improving the connection stability between the packaging glue layer and the heat dissipation plate.
[0009] The inner wall of the groove of the utility model is provided with threads or convex points, so as to increase the friction between the packaging glue and the inner wall of the groove and ensure the stability of the packaging glue filled into the groove.
[0010] The depth of the groove of the utility model is 10%-50% of the thickness of the metal heat dissipation plate; the maximum width of the groove in the direction perpendicular to the heating line is 50%-100% of the width of the packaging glue in this direction, and the maximum width of the groove in the direction parallel to the heating line is 0.5-2 times the maximum width of the hole in the direction perpendicular to the heating line.
[0011] The exhaust channel of the utility model is connected with the outside through the groove through the bottom of the PCB, the depth of the exhaust channel is 10%-30% of the depth of the groove, and the width of the exhaust channel is 0.1-1mm.
[0012] The two grooves on the upper surface of the metal heat sink of the utility model are located at both ends of the heating substrate and are within the coverage of the packaging glue. They are partially blocked by the heating substrate or PCB, and the area blocked by the heating substrate or PCB is 30%-70% of the total area of the hole.
[0013] Compared with the prior art, the groove and exhaust duct structure of the metal heat sink of the utility model can fill the packaging glue into the groove, and after hardening, a snap-on structure is formed at both ends of the heating substrate and the PCB. At this time, there is not only surface adhesion between the heating substrate and the packaging glue of the product, but also mechanical grip, which greatly increases the firmness between the heating substrate and the packaging glue, effectively prevents the packaging glue from warping, and improves product reliability. Description of the drawings:
[0014] Attached Figure 1 It is a schematic diagram of the structure of a thermal print head in the prior art.
[0015] Attached Figure 2 It is a cross-sectional structural diagram of a thermal print head in the prior art.
[0016] Attached Figure 3 It is a cross-sectional structural diagram of the thermal print head in the utility model.
[0017] Attached Figure 4 It is a structural schematic diagram of the heat dissipation plate in an embodiment of the utility model.
[0018] Attached Figure 5 This is a schematic diagram of the structure of the groove on the heat dissipation plate of the utility model, wherein Figure 5 (a) is a schematic diagram of the thread structure on the inner wall of the groove. Figure 5 (b) is a schematic diagram of the implementation structure of the cylindrical groove, Figure 5 (c) is a schematic diagram of the implementation structure of the conical groove, Figure 5 (d) is a schematic diagram of the implementation structure in which the groove is hemispherical.
[0019] Figure numerals: heat sink 1, heating substrate 2, PCB board 3, control IC 4, packaging glue layer 5, groove 6, exhaust duct 7. Specific implementation method:
[0020] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.
[0021] The utility model aims at the prior art, the heating substrate of the thermal print head and the PCB board (such as the attached Figure 1 In order to solve the problem that the gap packaging glue layer is easy to warp, a thermal print head that prevents the packaging glue from warping is proposed, as shown in the attached Figure 3 As shown, the utility model is still provided with a heating substrate 2, a PCB board 3, a control IC 4 and a metal heat sink 1, wherein the heating substrate 2, the PCB board 3 and the control IC 4 are arranged on the heat sink 1. Figure 3 As shown, a groove 6 is provided on the upper surface of the heat dissipation plate 1 of the utility model corresponding to below the joint between the heating substrate 2 and the PCB board 3, and an exhaust passage 7 connected to the groove 6 is opened on the surface of the heat dissipation plate 1, and a packaging glue layer 5 covers the joint between the heating substrate 2 and the PCB board 3 and fills the groove 6.
[0022] The groove 6 of the utility model is arranged on the upper surface of the heat dissipation plate 1 and is located at the ends of the heating substrate 2 and the PCB board 3. Further, the groove 6 is shielded by the heating substrate 2 or the PCB board 3, so that after the encapsulation glue layer 5 covers the joint between the heating substrate 2 and the PCB board 3, it is filled into the groove 6 along the end of the heating substrate 2. The cured encapsulation glue layer 5 forms a downwardly bent hook shape at the end of the heating substrate 2, thereby effectively preventing the encapsulation glue layer from warping.
[0023] The utility model further provides grooves 6 on the upper surface of the heat sink 1 corresponding to the two ends of the heating substrate 2 and the PCB board 3, and correspondingly provides an exhaust duct 7 connected with the groove 6. Furthermore, the exhaust duct 7 extends from the bottom of the PCB board 3 to the edge of the heat sink 1, and is used to timely discharge the gas in the groove 6 during the process of filling the groove 6 with packaging glue, thereby improving the filling quality of the packaging glue.
[0024] The groove 6 of the present invention is hemispherical or funnel-shaped, thereby expanding the packaging glue filling space and improving the connection stability between the packaging glue layer 5 and the heat dissipation plate 1 .
[0025] The utility model is as follows Figure 5 middle Figure 5 As shown in (a), the inner wall of the groove 6 is provided with threads or convex points, so as to increase the friction between the packaging glue and the inner wall of the groove 6, thereby ensuring the stability of the packaging glue filled into the groove.
[0026] Embodiment 1:
[0027] The thermal print head for preventing the packaging glue from warping in this example comprises a metal heat sink 1, on which a heating substrate 2, a PCB board 3 and a control IC 4 are arranged, the control IC 4 is arranged at the connection between the heating substrate 2 and the PCB board 3, and a packaging glue layer 5 is used for packaging protection at the connection between the control IC 4 and the heating substrate 2 and the PCB board 3;
[0028] The upper surface of the metal heat sink 1 is provided with two grooves 6 with exhaust channels 7, the grooves 6 are located at both ends of the heating substrate, within the coverage of the packaging glue 5, and are partially blocked by the heating substrate 2 or the PCB board 3, the exhaust channels 7 are located on the upper surface of the metal heat sink 1, and are connected to the outside through the grooves 6 and below the PCB board 3;
[0029] In this example, the two grooves 6 have the same depth, which is 10%-50% of the thickness of the metal heat sink 1. The maximum width of the groove 6 in the direction perpendicular to the heating line is 50%-100% of the width of the packaging glue 5 in this direction. The maximum width of the groove 6 in the direction parallel to the heating line is 0.5-2 times the maximum width of the hole in the direction perpendicular to the heating line.
[0030] In this example, the two grooves 6 are located at both ends of the heating substrate 2 and are within the coverage of the packaging glue 5. They are partially blocked by the heating substrate 2 or the PCB board 3, and the blocked area is 30%-70% of the total area of the groove 6; the exhaust duct 7 is connected to the outside world through the groove 6 through the bottom of the PCB board 3, the depth is 10%-30% of the depth of the groove 6, and the width is 0.1-1mm.
[0031] Embodiment 2:
[0032] This example adopts a structure similar to that of Example 1. In this example, the metal heat sink 1 is 6 mm thick, 20 mm wide, and takes a thermal print head with a length of 100 mm as an example. The metal heat sink 1 is made of metal aluminum. Two grooves 6 are located at both ends of the heating substrate 2, with a depth of 0.6 mm. The width of the packaging glue 5 is 4 mm. The maximum width of the groove 6 in the direction perpendicular to the heating line is 2 mm, and the maximum width in the direction parallel to the heating line is 2 mm. The groove 6 is partially blocked by the heating substrate 2 or the PCB 3 within the coverage area of the packaging glue 5, and the blocked area is 50% of the total area of the groove 6. The exhaust duct 7 is connected to the outside through the groove 6 through the bottom of the PCB 3, with a depth of 0.1 mm and a width of 0.5 mm.
[0033] The beneficial effect of the solution of the utility model is that the groove design of the metal heat sink can allow the packaging glue to be filled into the hole, and after hardening, a snap-on structure is formed at both ends of the heating substrate and the PCB. At this time, there is not only surface adhesion between the heating substrate and the packaging glue of the product, but also mechanical grip, which greatly increases the firmness between the heating substrate and the packaging glue, effectively prevents the packaging glue from warping, and improves product reliability.
Claims
1. A thermal print head for preventing packaging glue from warping, comprising a heating substrate, a PCB board, a control IC and a heat sink, wherein the heating substrate, the PCB board and the control IC are arranged on the heat sink, characterized in that: A groove is provided on the upper surface of the heat dissipation plate corresponding to the joint between the heating substrate and the PCB board, and an exhaust passage connected to the groove is opened on the surface of the heat dissipation plate. The packaging glue layer covers the joint between the heating substrate and the PCB board and fills the groove.
2. The thermal print head for preventing packaging glue from warping according to claim 1, characterized in that: The groove is arranged on the upper surface of the heat dissipation plate and is located at the ends of the heat generating substrate and the PCB board.
3. A thermal print head for preventing packaging glue from warping according to claim 2, characterized in that: The groove is shielded by the heating substrate or the PCB board, so that after the packaging glue layer covers the joint between the heating substrate and the PCB board, it is filled into the groove along the end of the heating substrate, and the cured packaging glue layer forms a downwardly bent hook shape at the end of the heating substrate.
4. The thermal print head for preventing packaging glue from warping according to claim 1, characterized in that: Grooves are respectively arranged on the upper surface of the heat dissipation plate at two ends corresponding to the heating substrate and the PCB board, and exhaust passages communicating with the grooves are correspondingly arranged.
5. The thermal print head for preventing packaging glue from warping according to claim 4, characterized in that: The exhaust channel extends along the bottom of the PCB board to the edge of the heat dissipation plate.
6. The thermal print head for preventing packaging glue from warping according to claim 1, characterized in that: The groove is hemispherical or funnel-shaped.
7. The thermal print head for preventing packaging adhesive from warping according to claim 1, characterized in that: The inner wall of the groove is provided with threads or convex points, so as to increase the friction between the packaging glue and the inner wall of the groove.
8. The thermal print head for preventing packaging adhesive from warping according to claim 1, characterized in that: The depth of the groove is 10%-50% of the thickness of the metal heat sink; the maximum width of the groove in the direction perpendicular to the heating line is 50%-100% of the width of the packaging glue in this direction, and the maximum width of the groove in the direction parallel to the heating line is 0.5-2 times the maximum width of the hole in the direction perpendicular to the heating line.
9. The thermal print head for preventing packaging adhesive from warping according to claim 1, characterized in that: The exhaust channel is connected to the outside through the groove through the bottom of the PCB. The depth of the exhaust channel is 10%-30% of the depth of the groove, and the width of the exhaust channel is 0.1-1mm.
10. The thermal print head for preventing packaging adhesive from warping according to claim 1, characterized in that: The two grooves on the upper surface of the heat dissipation plate are located at both ends of the heating substrate and are within the coverage of the packaging glue. They are partially blocked by the heating substrate or PCB, and the area blocked by the heating substrate or PCB is 30%-70% of the total area of the hole.