High-reliability glass heating plate

Abstract

The utility model discloses a high-reliability glass heating plate which comprises a control circuit module, a heating module and a cooling module, the three are connected through brazing; the control circuit module is perpendicular to the heating module, and the cooling module is arranged at the bottom of the heating module; the heating module comprises an aluminum nitride plate and a heat conduction layer arranged on the aluminum nitride plate, and the heat conduction layer is printed on the aluminum nitride plate through a silk screen; and the cooling module is selectively connected with the cooling system to realize rapid cooling of the heating plate. The beneficial effects of the utility model are that compared with soldering tin brazing in the prior art, the glass brazing mode adopted by the utility model enables the brazing filler metal to be subjected to atomic diffusion, dissolution and chemical combination with the surfaces of the three parts so as to be connected into a whole for welding; the whole stability of the heating plate after welding is higher, the heating plate is not prone to desoldering after being used at multiple circulating temperatures, normal use of the control circuit module is guaranteed, and the service life of the heating plate is prolonged.

Description

Technical Field

[0001] The utility model belongs to the technical field of biomedicine, and in particular relates to a high-reliability glass heating plate. Background Art

[0002] A heating plate is a form of electric energy utilization that converts electrical energy into thermal energy to heat an object. Existing uses of heating plates are not only satisfied with increasing or heating an object, but also need to be suitable for a specified temperature. For example, in experimental research or applications in biomedicine, it is necessary for the heating plate to be able to heat up to a certain high temperature and cool down to a certain low temperature.

[0003] Among the many methods of electric energy conversion, the method of heating by resistance is currently the most frequently used one. In this heating structure, the heating plate can be divided into a control circuit module and a heating module, and the two are connected by melting welding. The control circuit module is made of a resin board, and a circuit is arranged inside it, and the circuit is electrically connected to the resistor in the heating module. It can be seen that the existing heating of the heating plate is to power the control circuit module with a 220V power supply voltage, so that the resistor in the heating module is heated, and the heating operation of the heating plate is realized; after the control circuit module is powered off, the resistor in the heating module gradually cools down, and after reaching a safe temperature, it is connected to the cooling system for cooling.

[0004] The heating plate of the above structure will cause the strength of the resin board (substrate) of the control circuit module to decrease after multiple hot and cold cycle temperatures, and then cracks or desoldering will occur at the welding points with the heating module, which will eventually cause the circuit to fail and the heating plate to be unusable. In addition, since the heating module has a built-in resistance wire and generates heat through the resistance wire, a 220V power supply voltage is required for preheating during the heating operation, and the preheating time is about 30 minutes, which greatly reduces the experimental efficiency; during the heating process, the temperature on the side close to the low voltage of the power supply is significantly higher than the temperature of the middle of the heating module and the end away from the power supply voltage, so the heat distribution on the surface of the heating plate is uneven, which may cause the heated or tested object to suffer local high temperature damage, or insufficient local heating, affecting the accuracy of the test data. Furthermore, when the use of this heating plate is connected to the power supply voltage, once it is misoperated, it will affect the life safety of the test personnel.

[0005] In order to solve the above problems, designing a high-reliability glass heating plate is an important technical problem that the technicians in this field need to solve. Utility Model Content

[0006] The purpose of the utility model is to solve the above problems existing in the prior art and to provide a high-reliability glass heating plate.

[0007] The purpose of the utility model is achieved through the following technical solutions:

[0008] A high-reliability glass heating plate comprises a control circuit module, a heating module and a cooling module; the three are connected by brazing; the control circuit module and the heating module are vertically arranged, and the cooling module is arranged at the bottom of the heating module; the heating module comprises an aluminum nitride plate and a heat-conducting layer arranged on the aluminum nitride plate, and the heat-conducting layer is screen-printed on the aluminum nitride plate; the cooling module can be selectively connected to a cooling system to achieve rapid cooling of the heating plate.

[0009] Preferably, the thermal conductive layer is a silver-palladium slurry layer with a thickness of 20±0.5 μm; the thermal conductive layer has conductive lines distributed in a U-shaped pattern with a line width of 1±0.3 mm, a thickness of 10±0.5 μm, and a resistance of 10.1±0.1Ω.

[0010] Preferably, the aluminum nitride plate has a size of (45±0.6) mm*(15±0.5) mm and a thickness of 0.638±0.038 mm.

[0011] Preferably, the control circuit module is made of a high-boron glass plate, and the thickness of the high-boron glass plate is 1±0.05 mm.

[0012] Preferably, the control circuit module has a built-in sampling resistor, and a group of wire through holes are provided on the control circuit module.

[0013] Preferably, a receiving groove is provided on a side of the control circuit module close to the heating module, the sampling resistor is at least partially located in the receiving groove, and the size of the receiving groove is (12±0.5) mm*(18±0.5) mm; its width is equivalent to the width of the heating module.

[0014] Preferably, the cooling module is rectangular or T-shaped; the portion of the cooling module located at the bottom of the heating module completely covers the heating module; the cooling module is made of copper plate with a thickness of 1±0.05 mm, and a heat sink may be connected underneath the cooling module.

[0015] The advantages of the technical solution of the utility model are mainly reflected in:

[0016] Compared with the solder brazing used in the prior art, the glass brazing used in the present application heats the brazing material together with the control circuit module, the heating module and the cooling module until the brazing material is molten, and absorbs it into the connection gap, so that the brazing material and the surfaces of the three undergo atomic diffusion, dissolution and chemical combination to form a whole weld; therefore, after welding, the overall stability of the heating plate is higher, and it is not easy to desolder after the heating plate has been used for multiple cycles of temperature, thereby ensuring the normal use of the control circuit module and extending the service life of the heating plate;

[0017] In the present application, a silver-palladium printed circuit is used to control the temperature rise of the heating plate. When the voltage reaches about 24V, the heating plate can be heated, and the heating rate can reach about 35.5°C / S. However, the prior art uses a resistance wire heating method, which requires a 220V high voltage to be connected before use, and the heating plate is heated by the resistance wire heating, and this method requires a preheating treatment of about 30 minutes. Compared with the present application, the heating efficiency and operation safety factor are lower.

[0018] Compared with the prior art that uses a resin plate for the heating module, the present application uses a high-boron glass plate as the substrate of the heating module, which has a higher thermal conductivity, higher mechanical strength, higher softening point temperature, and is not easily deformed by multiple alternations of hot and cold.

[0019] By printing the silver-palladium paste circuit on the aluminum nitride board, it can generate heat within the safe voltage for the human body and heat up quickly, and has low requirements for low power supply voltage, thus ensuring the life safety of the operator;

[0020] Compared with the prior art in which the control circuit module uses a resin board, the high-boron glass board used in the present application makes the circuit more resistant to heat cycles and has stronger thermal stability. The circuit solder joints are not prone to desoldering and failure during multiple temperature increases and decreases, thereby extending the service life of the control circuit module. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 : Schematic diagram of the preferred embodiment of the utility model Figure 1 ;

[0022] Figure 2 : Schematic diagram of the preferred embodiment of the utility model Figure 2 ;

[0023] Figure 3 : A top view of a preferred embodiment of the utility model;

[0024] Figure 4 : A side view of a preferred embodiment of the utility model;

[0025] Figure 5 : A top view of the heating module of a preferred embodiment of the utility model;

[0026] Figure 6 : A line graph showing the temperature / power of the heating plate changing with time in a preferred embodiment of the utility model;

[0027] Figure 7 : Heat distribution diagram of the heating plate in the high temperature maintenance stage of the preferred embodiment of the utility model;

[0028] Figure 8: Heat distribution diagram of the heating plate in the low temperature maintenance stage of the preferred embodiment of the utility model. DETAILED DESCRIPTION

[0029] The purpose, advantages and features of the present invention will be illustrated and explained through the non-limiting description of the following preferred embodiments. These embodiments are only typical examples of the application of the technical solution of the present invention, and any technical solution formed by equivalent replacement or equivalent transformation falls within the scope of protection claimed by the present invention.

[0030] In the description of the scheme, it should be noted that the terms "center", "up", "down", "left", "right", "front", "back", "vertical", "horizontal", "inside", "outside" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of description and simplified description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance. Moreover, in the description of the scheme, with the operator as a reference, the direction close to the operator is the proximal end, and the direction away from the operator is the distal end.

[0031] like Figure 1 As shown, the utility model discloses a high-reliability glass heating plate, including a control circuit module 1, a heating module 2 and a cooling module 3; the three are connected by brazing. Specifically, the control circuit module 1 is vertically arranged with the heating module 2, and the cooling module 3 is arranged at the bottom of the heating module 2. Compared with the solder brazing used in the prior art, the glass brazing used in the present application is based on the principle of using a metal with a melting point lower than that of the welding metal and a glass powder as a brazing material, heating the brazing material together with the control circuit module, the heating module and the cooling module until the brazing material is molten, and sucking it into the solid gap by means of capillary action, so that the brazing material and the surfaces of the three undergo atomic diffusion, dissolution and chemical combination to form a whole welding; so that after welding, the overall stability of the heating plate is higher, and it is not easy to desolder when the heating plate is used for multiple cycles of temperature, ensuring the normal use of the control circuit module and extending the service life of the heating plate.

[0032] like Figure 4 As shown, the control circuit module 1 described in the present application is preferably made of a high borosilicate glass plate, the thickness of which includes but is not limited to 1±0.05 mm, and the thickness can be adjusted according to the use requirements. Figure 6As shown, compared with the prior art that uses a resin board for the control circuit module, the high borosilicate glass board used in this application makes the circuit more resistant to heat cycles and has stronger thermal stability. The circuit is not easy to fail during multiple temperature increases and decreases, thereby extending the service life of the control circuit module. The control circuit module 1 has a built-in sampling resistor, and a group of wire through holes 10 are provided on the control circuit module 1; the control circuit module 1 is turned on and off through the wire through holes 10, thereby realizing the temperature increase and decrease control of the heating plate.

[0033] Specifically, the control circuit module 1 is provided with a side close to the heating module 2 as follows: Figures 2 to 3 The receiving groove 101 shown, the sampling resistor is at least partially located in the receiving groove 101. Further, the size of the receiving groove 101 in the present application is preferably (12±0.5) mm*(18±0.5) mm; its width is equivalent to the width of the heating module 2. It can be seen that after the heating module 2 and the control circuit module 1 are brazed, the heating module 2 can be controlled to heat up, that is, the two are electrically connected.

[0034] like Figure 2 As shown, the heating module 2 includes an aluminum nitride plate 21 and a heat-conducting layer 22 disposed on the aluminum nitride plate 21, and the heat-conducting layer 22 is screen-printed on the aluminum nitride plate 21. Figure 4 As shown, the size of the aluminum nitride plate 21 is preferably (45±0.6) mm*(15±0.5) mm, and the thickness is preferably 0.638±0.038 mm; the specific size of the aluminum nitride plate 21 can be adjusted according to usage requirements and is not limited here.

[0035] like Figure 4 As shown, the heat-conducting layer 22 is a silver-palladium paste layer, and its thickness includes but is not limited to 20±0.5μm. Compared with the prior art in which the conductive copper wire is arranged on the glass plate by electroplating, the present application uses screen printing to print the silver-palladium paste with conductive properties on the surface of the aluminum nitride plate, so that the temperature uniformity of the entire surface of the heating module is better, and the temperature deviation of the silver-palladium paste to the copper wire is about 1°C, so the temperature stability of the heating plate in the present application is higher.

[0036] Furthermore, the conductive circuit on the heat-conducting layer 22 is preferably designed as follows Figure 5 The U-shaped distribution shown in the figure can, of course, be designed to be other shapes including a straight shape in other embodiments, which is not limited here. The line width of the thermal conductive layer 22 is preferably 1±0.3 mm, the thickness is preferably 10±0.5 μm, and the resistance is preferably 10.1±0.1Ω.

[0037] The cooling module 3 can be selectively connected to a cooling system (not shown in the figure). Since the cooling system is a known prior art, it will not be described here in detail. In addition, a known heat sink can also be connected to the bottom of the cooling module 3. The cooling module 3 is preferably made of copper material, that is, made of copper plate, and its thickness is preferably 1±0.05mm. This is because copper material has good thermal conductivity or cooling effect, and copper material has low cost and is easy to process and use. Cooling pipes are distributed inside the cooling module 3. When the cooling module 3 is connected to the cooling system, due to the pressure difference between the two, the condensed liquid or gas output by the cooling system will be transported to the cooling pipe in the cooling module 3, so as to achieve cooling of the cooling module 3 and the entire heating plate. In this application, the cooling module 3 can be designed as follows Figure 1 to Figure 2 The rectangular or T-shaped portion shown in the figure, located at the bottom of the heating module 2, completely covers the heating module 2; so that the cooling module 3 can achieve rapid cooling of the heating plate after being connected to the cooling system. The cooling module 3 can also be a copper-clad aluminum nitride plate in other embodiments to further enhance the heating and cooling speed of the heating plate and improve the operating efficiency.

[0038] like Figure 6 As shown, the initial temperature is about 20° C. At this time, the voltage on the control circuit module 1 is 7.1V and the current is 0.704A, that is, the power is about 5W.

[0039] When heating up, after starting the control circuit module 1, after 1.5S, the voltage on the control circuit module 1 reaches 23.762V and the current reaches 2.357A, that is, the power can reach 56W, and at the same time, the heating module 2 makes the heating plate heat up to about 105°C; then the heating module 2 starts the high temperature maintenance stage of 10S, during which the voltage on the control circuit module 1 reaches 22.0V and the current reaches 2.182A, that is, the power reaches 48W, and the high temperature maintenance temperature is about 95°C. Since the silver-palladium printed circuit is used in the present application to control the heating plate, the heating plate can be heated when the voltage reaches about 24V, and the heating rate can reach about 35.5°C / S; while the prior art uses a resistance wire heating method, which requires a high voltage of 220V to be connected before use, and the heating plate is heated by the resistance wire heating, and this method requires a preheating treatment of about 30 minutes. Compared with the present application, the heating efficiency and operation safety factor are relatively low. In addition, the heating area of ​​the conventional heating plate using resistance wire heating is distributed linearly, so linear heating and uneven temperature will occur after heating; while the heating area in the present application is distributed in sheets, so it is heated more evenly.

[0040] After the control circuit module 1 is powered off, the cooling module 3 is connected to the cooling system to achieve cooling, and the minimum temperature is about 28°C; then the heating module 2 makes the heating plate warm up to about 57°C, and starts the low temperature maintenance stage of 10S. During this stage, the voltage on the heating plate can reach 15.5V and the current can reach 1.575A, that is, the power is 25W. It can be seen that the cooling rate of the present application can reach about 45.25°C / S. The conventional heating plate made of resistance wire needs to be powered off first when cooling, and the cooling system can be safely connected after the temperature of the heating plate drops to a certain temperature, otherwise it may cause undesirable conditions such as desoldering of the heating plate or circuit failure, which also prolongs the cooling speed to a certain extent; and the aluminum nitride plate used in the application has a higher thermal conductivity and can achieve rapid heating and cooling, so when cooling treatment is required, the heating plate can be directly connected to the cooling system to achieve rapid cooling of the heating plate and improve work efficiency.

[0041] Furthermore, the experimental results show that Figures 7 and 8 The surface temperature distribution diagram of the heating plate shown in the figure shows that in the high temperature maintenance stage or the low temperature maintenance stage, the temperature difference between the highest temperature and the lowest temperature on the heating plate is about 1°C, so the heating plate made of the above structure has the advantages of good thermal uniformity and high stability.

[0042] There are many implementation methods of the utility model, and all technical solutions formed by equivalent transformation or equivalent transformation fall within the protection scope of the utility model.

Claims

1. A high reliability glass heating plate, characterized in that: The invention comprises a control circuit module (1), a heating module (2) and a cooling module (3); the three are connected by brazing; the control circuit module (1) and the heating module (2) are arranged vertically, and the cooling module (3) is arranged at the bottom of the heating module (2); the heating module (2) comprises an aluminum nitride plate (21) and a heat-conducting layer (22) arranged on the aluminum nitride plate (21), and the heat-conducting layer (22) is screen-printed on the aluminum nitride plate (21); the cooling module (3) can be selectively connected to a cooling system to achieve rapid cooling of the heating plate.

2. A high reliability glass heating plate according to claim 1, characterized in that: The heat conducting layer (22) is a silver-palladium slurry layer, and its thickness is 20±0.5 μm; the heat conducting layer (22) has a conductive line distributed in a U-shaped pattern, and its line width is 1±0.3 mm, its thickness is 10±0.5 μm, and its resistance is 10.1±0.1Ω.

3. A high reliability glass heating plate according to claim 2, characterized in that: The aluminum nitride plate (21) has a size of (45±0.6) mm*(15±0.5) mm and a thickness of 0.638±0.038 mm.

4. A high reliability glass heating plate according to claim 3, characterized in that: The control circuit module (1) is made of a high borosilicate glass plate, and the thickness of the high borosilicate glass plate is 1±0.05 mm.

5. A high reliability glass heating plate according to claim 4, characterized in that: The control circuit module (1) has a built-in sampling resistor, and a group of wire through holes (10) are provided on the control circuit module (1).

6. The high reliability glass heating plate according to claim 5, characterized in that: A receiving groove (101) is provided on a side of the control circuit module (1) close to the heating module (2); the sampling resistor is at least partially located in the receiving groove (101); the receiving groove (101) has a size of (12±0.5) mm*(18±0.5) mm; and its width is equivalent to the width of the heating module (2).

7. A high reliability glass heating plate according to claim 6, characterized in that: The cooling module (3) is rectangular or T-shaped; the portion of the cooling module (3) located at the bottom of the heating module (2) completely covers the heating module (2); the cooling module (3) is made of a copper plate with a thickness of 1±0.05 mm, and a heat sink may be connected below the cooling module (3).

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