Patent Publication Number: US-9897492-B2

Title: Method for manufacturing temperature measure units of thermometers

Description:
FIELD OF THE INVENTION 
     The present invention relates to an electronic thermometer (thermometer in short hereinafter) and particularly to a method for manufacturing temperature measure units of thermometers. 
     BACKGROUND OF THE INVENTION 
     Thermometer has many advantageous characteristics such as brittle resistant, pollution-free, more accurate measurement and shorter measurement time, hence has gradually replaced the high-contaminated mercury thermometer. In recent years constant advance of technology and higher living standard of the general public make the thermometer a trusted goods among users, hence it also becomes an essential healthcare and medical gadget in public medical institutions such as hospitals or ordinary houses. 
     Prior techniques for making the thermometer, such as Taiwan Patent No. 567054 entitled “Assembly method and structure of electronic thermometer” and its  FIGS. 3, 7 through 9, 11 and 13  indicate that it has a thermistor chip to form electric connection with a distal end connector through welding two wires (usually a Dumet Wire formed by wrapping a copper wire with a nickel iron alloy at a size of Φ0.25 mm). Namely, the conventional technique has to rely on welding to fasten the thermistor chip to the wire to achieve electric conduction. Such a technique has disadvantages in practice, such as 1. Due to the size of the thermistor chip is very small, about 0.71 mm×0.71 mm×0.3 mm, welding two different planes at such a small distance to two wires has to use precise and dedicated fixtures, fabrication facilities and production line that are specially designed; 2. The fabrication process is complicated and product defective rate is higher; 3. The thermistor chip has to convert the measured temperature to electric signals which could have deviations compared with standard value, the maximum positive and negative deviation values in the set deviation range could be very big between them, hence the general practice in the industry is classifying the thermistor chips of the deviation range close to each other to be compensated with different adjustment parameters via a central processing unit (CPU) to improve the measurement precision of the finished thermometers. In the conventional technique, after the thermistor chip has been welded to the wires, measurement is performed and an adjustment parameter is obtained and classification is done, then a connector of a suitable adjustment parameter is selected to form electric connection with the CPU, or a circuit board of a suitable adjustment parameter is selected for welding to form electric connection with the CPU. It is a complex production mode and difficult to improve productivity. 
     SUMMARY OF THE INVENTION 
     The primary object of the present invention is to solve the aforesaid disadvantages and problems of the conventional techniques by modularizing a temperature measure unit to make a thermistor chip to form electric connection in a contact fashion without welding process to facilitate production and assembly, and improve production yield. The invention also directly changes the Identification Code (ID code in short hereinafter) at the distal end of the temperature measure unit to make classification faster and form rapid electric connection with a connector to improve productivity to meet requirements of the industry. 
     To achieve the foregoing object the present invention provides a method for manufacturing temperature measure units of thermometers. Each thermometer measures an object temperature through a temperature measure unit and converts the temperature to an electric signal. The electric signal is sent to a CPU in the thermometer to be processed and converted to an information. The thermometer has an output unit inside to allow users to get the information. The method of the invention includes the steps of: providing a substrate which has surfaces attached a first transmission circuit and a second transmission circuit that are spaced from each other; providing a thermistor chip which is positioned against the substrate such that one side of the thermistor chip forms electric connection with the first transmission circuit and an opposite side forms electric connection with the second transmission circuit; and providing a transmission plate with desired electric conductivity and thermal conductivity to achieve thermal transmission and electric connection between the thermistor chip and the second transmission circuit. 
     In addition, the method of the invention also includes: providing an isolation layer with desired insulation characteristics to position the thermistor chip between the substrate and the transmission plate. The isolation layer has a positioning portion to hold the thermistor chip and at least one aperture to allow the transmission plate to form electric connection with the first transmission circuit or the second transmission circuit. The substrate also has an end surface with an electric signal ID code connection end formed thereon by extending the first transmission circuit or the second transmission circuit to classify temperature measurement deviation values of the thermistor chip. 
     To achieve the foregoing object the present invention provides a method for manufacturing temperature measure units of thermometers. Each thermometer measures an object temperature through a temperature measure unit and converts the temperature to an electric signal. The electric signal is sent to a CPU in the thermometer to be processed and converted to an information. The thermometer has an output unit inside to allow users to get the information. The method of the invention includes the steps of: providing two substrates which have surfaces attached a first transmission circuit and a second transmission circuit; providing a thermistor chip between the two substrates for positioning with one side of the thermistor chip formed electric connection with the first transmission circuit and an opposite side formed electric connection with the second transmission circuit; and providing a transmission plate with a desired thermal conductivity in contact with the thermistor chip so that the thermistor chip can measure the object temperature and transmission heat via the transmission plate. 
     In addition, the method of the invention also includes: providing an isolation layer with desired insulation characteristics to position the thermistor chip between the two substrates. The isolation layer has a positioning portion to hold the thermistor chip. The substrates also have an end surface with an electric signal ID code connection end formed thereon by extending the first transmission circuit or the second transmission circuit to classify temperature measurement deviation values of the thermistor chip. 
     To achieve the foregoing object the present invention provides a method for manufacturing temperature measure units of thermometers. Each thermometer measures an object temperature through a temperature measure unit and converts the temperature to an electric signal. The electric signal is sent to a CPU in the thermometer to be processed and converted to an information. The thermometer has an output unit inside to allow users to get the information. The method of the invention includes the steps of: providing a substrate which has surfaces attached a first transmission circuit and a second transmission circuit that are spaced from each other; providing a thermistor chip which is positioned against the substrate such that one side of the thermistor chip forms electric connection with the first transmission circuit and an opposite forms electric connection with the second transmission circuit via a Chip on Board (COB) fabrication process; and providing a transmission plate for the thermistor chip to transfer heat. 
     In addition, the method of the invention also includes: providing an isolation layer with desired insulation characteristics to position the thermistor chip between the substrate and the transmission plate. The substrate also has an end surface with an electric signal ID code connection end formed thereon by extending the first transmission circuit or the second transmission circuit to classify temperature measurement deviation values of the thermistor chip. 
     Through the techniques set forth above, compared with the conventional techniques, the invention can provide many advantages, notably: 1. Through the method of the invention the temperature measure unit can be modularized in structure to confine the thermistor chip between the substrate and the transmission plate, and form electric connection with the first transmission circuit and the second transmission circuit in a contact manner, hence can save the welding process to facilitate assembly and also improve production yield of the products; 2. By directly change the ID code of the electric signal ID code connection end at the distal end of the temperature measure unit (such as remove at least one of the connection ends to form the ID code), classification can be accomplished quickly, and electric connection with the electric connector also can be done rapidly to transmit the electric signal to the CPU of a corresponding ID code, thereby can improve productivity to meet industry requirements. 
     The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following embodiments and detailed description, which proceed with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a circuit block diagram of an embodiment of the thermometer of the invention. 
         FIG. 2  is an exploded view of a first embodiment of the temperature measure unit of the invention. 
         FIG. 3  is a fragmentary schematic view of a first transmission circuit and a second transmission circuit according to  FIG. 2 . 
         FIG. 4  is a perspective view of an assembly according to FIG.  2 . 
         FIG. 5  is a perspective view of  FIG. 4  against an electric connector. 
         FIG. 6  is an exploded view of a second embodiment of the temperature measure unit of the invention. 
         FIG. 7  is a perspective view of an assembly according to  FIG. 6 . 
         FIG. 8  is a perspective view of  FIG. 7  against an electric connector. 
         FIG. 9  is an exploded view of a third embodiment of the temperature measure unit of the invention. 
         FIG. 10  is an exploded view of a fourth embodiment of the temperature measure unit of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Please refer to  FIGS. 1 through 4  for a first embodiment of the temperature measure unit of the invention. The invention aims to provide a method for manufacturing a temperature measure unit  10  of a thermometer  1 . The temperature measure unit  10  aims to measure an object temperature and convert to an electric signal sent to a CPU  11  located in the thermometer  1  for processing and conversion to an information to be obtained by users via an output unit  13  (such as a monitor  131 , a buzzer  132  or the like) located in the thermometer  1 . The thermometer  1  also can provide an input unit  14  (for setting time, function or restart etc.) as shown in  FIG. 1 . Electric power required by all the elements in the thermometer  1  can be supplied by a power unit  12  (such as a battery or external power). The method of the invention includes the steps of: providing a substrate  20  which surfaces attached a first transmission circuit  21  and a second transmission circuit  22  that are spaced from each other; providing a thermistor chip  30  which is positioned against the substrate  20  such that one side of the thermistor chip  30  forms electric connection with the first transmission circuit  21  and an opposite side forms electric connection with the second transmission circuit  22 ; and providing a transmission plate  40  with desired electric conductivity and thermal conductivity to achieve thermal transmission and electric connection between the thermistor chip  30  and the second transmission circuit  22 . The method of the invention also includes: providing an isolation layer  50  with desired insulation characteristics to allow the thermistor chip  30  to be positioned between the substrate  20  and the transmission plate  40 . The isolation layer  50  has a positioning portion  51  to hold the thermistor chip  30  and at least one aperture  52  to allow the transmission plate  40  to form electric connection with the first transmission circuit  21  or the second transmission circuit  22 . The substrate  20  also has an end surface with an electric signal ID code connection end  23  formed thereon by extending the first transmission circuit  21  or the second transmission circuit  22  to classify temperature measurement deviation values of the thermistor chip  30 . It is to be noted that through the manufacturing method previously discussed the temperature measure unit  10  is formed in a modular structure that includes the substrate  20  with the first transmission circuit  21  and the second transmission circuit  22  attached to the surfaces thereof and spaced from each other. The temperature measure unit  10  also has the thermistor chip  30  located therein that has two opposite sides to form electric connection respectively with the first transmission circuit  21  and the second transmission circuit  22 . As shown in  FIGS. 2, 3 and 4 , the thermistor chip  30  is located between the substrate  20  and the transmission plate  40  through the isolation layer  50  which has desired insulation characteristics. The isolation layer  50  has the positioning portion  51  to hold the thermistor chip  30  and at least one aperture  52  to form electric connection between the transmission plate  40  and the second transmission circuit  22 . The thermistor chip  30  is directly located on the first transmission circuit  21  to form electric connection therewith and also forms electric connection with the second transmission circuit  22  via the transmission plate  40  and two transmission bosses  24  that have desired electric conductivity and thermal conductivity. The electric signal is obtained by converting the object temperature measured by the thermistor chip  30 . It is to be noted that in order to enhance contact stability between the thermistor chip  30  and the first transmission circuit  21  or the transmission plate  40  an adhesive (such as the conductive adhesive commercially called “silver paste”) can be daubed as desired during implementation. Also referring to  FIG. 5 , in the first embodiment the distal end surface of the substrate  20  can have the electric signal ID code connection end  23  formed thereon by extending the second transmission circuit  22  (or by extending the first transmission circuit  21 ) to classify the temperature measurement deviation values of the thermistor chip  30 . After being measured and classified by the electric signal ID code connection end  23  (this embodiment forms the ID code for classifying by removing at least one electric signal ID code connection end  23 , or by daubing an insulation layer on the electric signal ID code connection end  23 , other approaches also can be adopted without limited to the methods mentioned above, and also are deemed within the claims of the invention), through an electric connector  60  interposed between the CPU  11  and the temperature measure unit  10  the electric signal can be transmitted to the CPU  11 . In short, the invention, by forming the temperature measure unit  10  in a modular structure can confine the thermistor chip  30  between the substrate  20  and the transmission plate  40  to form electric connection with the first transmission circuit  21  and the second transmission circuit  22  in a contact fashion, as a result, not only the welding process can be saved to facilitate fast assembly, production yield also can be improved. In addition, by directly changing the 6-piece electric signal ID code connection end  23  at the distal end of the temperature measure unit  10  to facilitate classification, electric connection with the electric connector  60  can be established quickly to send the electric signal to the CPU  11  of a corresponding ID code, hence productivity also can be increased to meet industry requirements. 
     Please refer to  FIGS. 6, 7 and 8  for another embodiment of the method for manufacturing the temperature measure unit  10  of the invention. It includes: providing two substrates  20  which have surfaces attached respectively a first transmission circuit  21  and a second transmission circuit  22 ; providing a thermistor chip  30  between the two substrates  20  for positioning with one side of the thermistor chip  30  formed electric connection with the first transmission circuit  21  and an opposite side formed electric connection with the second transmission circuit  22 ; and providing a transmission plate  40  with a desired thermal conductivity in contact with the thermistor chip  30  so that the thermistor chip  30  can measure object temperature and transmit heat via the transmission plate  40 . The method further provides an isolation layer  50  with desired insulation characteristics between the two substrates  20 . The isolation layer  50  has a positioning portion  51  to hold the thermistor chip  30 . The substrates  20  also have an end surface with an electric signal ID code connection end  23  formed thereon by extending the first transmission circuit  21  or the second transmission circuit  22  to classify temperature measurement deviation values of the thermistor chip  30 .  FIGS. 6 and 7  show that the second embodiment differs from the first embodiment by having two substrates  20  in the temperature measure unit  10  that have the surfaces attached respectively the first transmission circuit  21  and the second transmission circuit  22 , and the temperature measure unit  10  further has the thermistor chip  30  interposed between the first transmission circuit  21  and the second transmission circuit  22  with two opposite sides formed electric connection therewith. The thermistor chip  30  can be located between the two substrates  20  via the isolation layer  50  of desired insulation characteristics. The isolation layer  50  also has a positioning portion  51  to hold the thermistor chip  30 . The thermistor chip  30  can measure and transmit the object temperature through the transmission plate  40  and convert it to an electric signal thereof. It is to be noted that the transmission plate  40  is implemented by an extra addition approach, and be extended to form contact with the second transmission circuit  22 . Of course, the transmission plate  40  also can be formed by extending the second transmission circuit  22 . Also referring to  FIG. 8 , similar to the first embodiment previously discussed, the second transmission circuit  22  also can be extended to an end surface of the substrate  20  (or by extending the first transmission circuit  21 ) to form an electric signal ID code connection end  23  to classify the temperature measurement deviation values of the thermistor chip  30 , and transmit the electric signal from the thermistor chip  30  to the CPU  11  via an electric connector  60  located between the CPU  11  and the temperature measure unit  10 . It is to be noted that the electric connector  60  in the second embodiment has an opening changed to accommodate the two substrates  20  in thickness. 
     Please refer to  FIG. 9  for a third embodiment of the temperature measure unit of the invention. It differs from the second embodiment by directly forming the transmission plate  40  by extending the first transmission circuit  21 . Of course, the transmission plate  40  also can be formed by external addition approach. Similarly, the main focus is that the transmission plate  40  must be extended to form connection with the first transmission circuit  21 . 
     Finally, please refer to  FIG. 10  for a fourth embodiment of the temperature measure unit of the invention. It differs from the first embodiment by positioning of the thermistor chip  30  against the substrate  20 , with one side of the thermistor chip  30  formed electric connection with the first transmission circuit  21  and an opposite side to form electric connection with the second transmission circuit  22  via a COB (Chip On Board) fabrication process, and providing a transmission plate  40  so that the thermistor chip  30  can transfer heat via direct or indirect contact with the transmission plate  40 . The COB fabrication process is a technique that can directly bond the thermistor chip  30  to the second transmission circuit  22  of the substrate  20 , hence can be effectively implemented by converting the existing integrated circuit packaging process. However, the transmission plate  40  also can be directly formed by extending the first transmission circuit  21  or the second transmission circuit  22 . Of course, the first transmission circuit  21  also can form electric connection with the thermistor chip  30  via the COB fabrication process; or by forming electric connection between one side of thermistor chip  30  and the second transmission circuit  22  first, then with the opposite side formed electric connection with the first transmission circuit  21  via the COB fabrication process. In addition, the method mentioned above also includes providing an isolation layer  50  with desired insulation characteristics through which the thermistor chip  30  can be interposed between the substrate  20  and the transmission plate  40 . Of course, the isolation layer  50  also can have a positioning portion  51  to hold the thermistor chip  30 .