Abstract:
A protection structure of a ceramic resistor heating module, and more particularly a protection structure of a heating module, which utilizes a ceramic resistor having a positive temperature coefficient and is consisted of cooling fins, includes insulation layers that are heat-insulated. Using the insulation layers, electricity and external hazardous substances such as acids, alkalis and salt are shielded to accomplish all-round protection.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     (a) Field of the Invention  
         [0002]     The invention relates to a protection structure of a ceramic resistor heating module, and more particularly, to a protection structure of a heating module that utilizes ceramic resistors having a positive temperature coefficient as heating elements thereof. The module comprises ceramic resistor heating elements, and dielectric plates and cooling fins at two sides thereof. Insulation layers are adopted to achieve all-round protection, thereby allowing the invention to be applied in hazardous environments.  
         [0003]     (b) Description of the Prior Art  
         [0004]     Referring to  FIG. 1 , a ceramic resistor heating module  1  comprises ceramic heating elements  2 , and cooling fins  3  joined at outer sides of dielectric plates  4  and joining plates  40  at two sides.  
         [0005]     Each the dielectric plate  4  has one end thereof formed with an electricity conducting terminal  41 , and two ends thereof sealed by sealing covers  11  and  12 . A clamp board  14  at assembled to each side of the module  1 , with an elastic device  13  pressed and joined in between.  
         [0006]     The assembly according to the aforesaid description is frequently used, wherein various members including the ceramic heating elements  2  and the dielectric plates  4 , the joining plates  40  and the cooling fins, are pressed and clamped using the elastic devices  13  and the clamp plates  14  from outer sides, followed by sealing using the sealing covers  11  and  12 , thereby forming a heating device.  
         [0007]     Referring to  FIG. 2  showing the prior heat dissipating module in another type of assembly, the heating elements  2  are similarly used, and the dielectric plates  4  are laterally disposed to join with the cooling fins  3 .  
         [0008]     Referring to  FIG. 3 , adhesive  5  is applied between the cooling fin  3  and the dielectric plate  4  to assemble the structure. Similarly, the heating elements  2  are also assembled using adhesion means to further form a heat dissipating module.  
         [0009]     Referring to  FIG. 4  showing another type of assembly means, fundamental parts are used to assemble the dielectric plate  4  and the cooling fin  3  through welding means, and then the dielectric plate  4  and the heating element  2  are joined using any methods.  
         [0010]     Referring to  FIG. 5  showing the aforesaid welding method, between a lower side of the cooling fin  3  and one side of the dielectric plate  4 , a welding point  6  is set for welding to assemble the cooling fin  3  with the dielectric plate  4 .  
         [0011]     Similarly, the heating element  2  is assembled with the dielectric plate  4  using any methods.  
         [0012]     Apart from heat conducting effects by discharging heat energy of the heating element  2  to an exterior, the cooling fins  3  and the dielectric plates  4  are more targeted at conducting electricity. Referring to  FIG. 1 , the electricity conducting terminal  41  conducts electricity and provides the heating element  2  with electricity by conducting through a side of the heating element  2 .  
         [0013]     Besides the aforesaid assembly means as mechanical and elastic pressing or fastening as shown in  FIG. 1 , assembly is also accomplished by welding as shown in  FIG. 5 .  
         [0014]     However, the heating modules formed according to the aforesaid assembly methods are incapable of withstanding wash tests by salty water. Salty water tests are for testing endurance of the heating modules against salt, acids and alkalis  
         [0015]     The purpose of the above tests commonly used by the industrialists is to offer the heating elements with optimal physical property endurance and environment condition endurance when applied outdoors, especially when applied to automobile heating systems, so as to avoid loosening and deterioration. In the test, a liquid containing 5% of salt is used to continuously wash the heating module.  
         [0016]     The aforesaid assembly methods includes a method used by German DBK Corporation to produce heating modules, which are tested by undergoing wash using water containing 5% of salt for 120 hours. The test results show that the heating modules fail to perform normal functions and become incapable of producing heat although overall structures of the heating modules remain intact. Heating modules assembled by adhesion, after undergoing wash tests with water containing 5% of salt for 120 hours, have loosening parts, with short circuits and sparkles resulted during the process. Therefore, for safety reasons, it is essential that the heating module be provided with an all-round protection structure, which is resistant against acids and alkalis or salt, so as to further insulate organic matters such as carbon monoxides or hydrogen oxides contained in moistures or air.  
       SUMMARY OF THE INVENTION  
       [0017]     The object of the invention is to provide an all-round protection structure formed by equally thick membrane-like insulation layers at surfaces of various elements of a heating module. Using thorough coverage of the membrane-like insulation layers on the various elements, all-round resistant strength is produced against physical properties and environmental condition changes, thereby achieving reliable heat operations as well as offering usage safety. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]      FIG. 1  shows a schematic view of an assembly according to a prior heating module.  
         [0019]      FIG. 2  shows a first schematic view illustrating an assembly relationship of a prior heating module.  
         [0020]      FIG. 3  shows a schematic view illustrating adhesion and joining of a prior heating module.  
         [0021]      FIG. 4  shows a second schematic view illustrating an assembly relationship of a prior heating module.  
         [0022]      FIG. 5  shows a schematic view illustrating an assembly relationship using welding means of a prior heating module.  
         [0023]      FIG. 6  shows a schematic view illustrating the main structure according to the invention.  
         [0024]      FIG. 7  shows a schematic view illustrating distribution of the insulation layers according to the invention.  
         [0025]      FIG. 8  shows another embodiment according to the invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0026]     Referring to  FIG. 6 , the invention similarly comprises heating elements  2 , and cooling fins  3  joined at outer sides of dielectric plates  4  and joining plates  40  at two sides of each the ceramic heating element  2 , thereby forming a heating module  1  having alternating electric conditions. Apart from electricity conducting terminals  41 , breadths of the heating module  1  are disposed with insulation layers  7  by complete soaking means as shown in  FIG. 7 . The insulation layers  7  are formed by soaking means, and therefore relative gaps  20  between various elements like the heating elements  2 , or adjoining corners  30  of the cooling fins  3  and the dielectric plates  4 , are completely distributed with the insulation layers  7 . The insulation layers  7  can be made from solvents using Teflon or silicon as a base material thereof. After being processed by soaking means, the solvents are evenly covered at the various elements according evenness of adhesion forces thereof. For instance, outer surfaces of the heating elements  2 , the dielectric plates  4  and the cooling fins  3 , are all formed with effective insulations layers  7  after solidification of the solvents.  
         [0027]     In an embodiment according to the invention, the insulation layers  7  have even thicknesses, and can form fillings at the gaps  20  and at any clamping corners. Owing to intrinsic coherent forces and adjacent adhesion forces, more materials of the insulation layers are accumulated to further form fillings and mechanical reinforcements. In addition, using adhesive forces of the insulation layers  7 , even more enhanced adhesion effects between the cooling fins and the dielectric plates  4  are obtained.  
         [0028]     Referring to  FIG. 8 , when having front and rear ends thereof sealed and assembled with the sealing covers  11  and  12 , the module  1  according to the invention forms a heating device  10 , wherein the terminals  41  can be conducted to electric terminals. The entire device  10  can then be distributed with the insulation layers  7  in an all-round manner. An entire height H including the sealing covers  11  and  12  are completely soaked in a material of the insulation layers  7 , such that the insulation layers  7  are attached to surfaces of the entire structure. The entire heating device  10  formed according to this embodiment can be applied to operations having conditions of high humidity and even to operations in liquids.  
         [0029]     The entire heating device  10  formed by sealing the sealing covers  11  and  12  can further have the sealing covers  11  and  12  be repeated with distribution of the insulation layers  7 , such that gaps  110  and  120  between the sealing covers  11  and  12  and the module  1  are completely filled, thereby effectively and thoroughly shielding against moistures and preventing short circuits at gaps between the various elements.  
         [0030]     The distribution of the reinforced insulation layers at the sealing covers  11  and  12  leaves main thermal operation surfaces of the heat dissipating module  1  unaffected, and thereof performance and efficiency of the heat dissipating surfaces consequently remain unaffected as well.  
         [0031]     A material  70  forming the insulation layers  7  in the embodiment according to the invention can be added with materials such as magnesium oxides having higher heat conductance coefficient to increase heat conductivity thereof.  
         [0032]     According to the invention, the insulation layers  7  are evenly distributed at surfaces of the various elements using soaking means. Through adhesive forces of the material  70  and atmospheric pressures, the insulation layers  7  formed at the surfaces of the various elements of the invention are allowed with even thicknesses, and hence uniform heat conduction efficiency is acquired.  
         [0033]     Before solidifying during the soaking process, the module can be tumbled to cancel out dripping effects incurred by gravity to further ensure even thicknesses of the layers.  
         [0034]     According to the embodiment of the invention, the insulation layers  7  are in fact membrane-like forms with extremely small thicknesses, which impose insignificant influence upon thermal conduction. Furthermore, the layers add a minute increase to an overall weight as well as to assembly dimensions without directly affecting assembly relationships.  
         [0035]     It is of course to be understood that the embodiment described herein is merely illustrative of the principles of the invention and that a wide variety of modifications thereto may be effected by persons skilled in the art without departing from the spirit and scope of the invention as set forth in the following claims.