A PTC heating core silicone curing structure and preparation method

Abstract

This application discloses a silicone curing structure and preparation method for a PTC heating element, relating to the field of PTC heating element technology. The structure includes multiple PTC heating elements, a pressure head, a first energized electrode needle, and a second energized electrode needle. Multiple PTC heating elements are stacked and pressed together by the pressure head. Each PTC heating element includes an upper electrode sheet, a PTC sheet, and a lower electrode sheet. The upper and lower electrode sheets are respectively bonded to the upper and lower surfaces of the PTC sheet using silicone. The first energized electrode needle penetrates the pressure head and is in fixed contact with the upper electrode sheet of the first PTC heating element. The second energized electrode needle is in fixed contact with the lower electrode sheet of the last PTC heating element. When energized, the silicone is cured by the first and second energized electrode needles, resulting in a strong bond between the PTC heating elements. The silicone curing structure and preparation method for the PTC heating element provided in this application prevent incomplete curing due to poor contact during energization, and also reduces the number of cured electrodes, resulting in lower equipment manufacturing and maintenance costs.

Description

Technical Field

[0001] This application relates to the field of PTC heating element technology, specifically to a PTC heating element silicone curing structure and preparation method. Background Technology

[0002] A PTC heating element, composed of a positive temperature coefficient thermistor (PTC), is the core component of a PTC heater. The PTC heating element comprises a lower electrode, a heating chip, and an upper electrode (which serves as the positive and negative electrodes, respectively). High-temperature curing adhesive is applied via silkscreen between the lower electrode and the heating chip, and between the heating chip and the upper electrode. After assembly, the PTC heating element requires heating and pressurization to cure the internal adhesive, thus bonding the components together. Current technology utilizes the inherent heating characteristic of the PTC heating element itself. A current is applied to raise the temperature of the PTC heating element, and a suitable pressure is applied while the PTC heating element is heating to ensure proper curing.

[0003] Please see Figure 1 The existing method for curing silicone in PTC heating elements is as follows: electrode sheet 1... ， and PTC film 2 ， After applying the adhesive, the pieces are stacked and leveled using a pressing head 3. ， After pressing, use the positive electrode needle 5 ， and negative electrode needle 4 ， The contact electrode plates energize the heating element, PTC plate 2 ， After being powered on, the heat reaches the adhesive curing temperature and the electrode plate 1... ， and PTC film 2 ， Strong adhesion.

[0004] The aforementioned method of stacking multiple PTC heating elements and then energizing and curing them in parallel can lead to misalignment of some positive and negative electrode needles due to cumulative errors in the thickness of the electrode sheets and PTC. This results in some heating elements not being cured. Furthermore, this curing structure cannot collect on / off signals, making it impossible to accurately determine whether the heating element is energized. In addition, this structure requires a large number of positive and negative electrode needles, resulting in high equipment manufacturing and maintenance costs. Summary of the Invention

[0005] Therefore, this application provides a PTC heating core silicone curing structure and preparation method to solve the problems of incomplete curing of the heating core and the large number of positive and negative electrode needles caused by the parallel curing method in the prior art.

[0006] To achieve the above objectives, this application provides the following technical solution:

[0007] In a first aspect, a silicone curing structure for a PTC heating element includes multiple PTC heating elements, a pressure head, a first energized electrode pin, and a second energized electrode pin. The multiple PTC heating elements are stacked and pressed together by the pressure head. Each PTC heating element includes an upper electrode sheet, a PTC sheet, and a lower electrode sheet. The upper electrode sheet and the lower electrode sheet are respectively bonded to the upper and lower surfaces of the PTC sheet via silicone. The first energized electrode pin penetrates the pressure head and is in fixed contact with the upper electrode sheet of the first PTC heating element. The second energized electrode pin is in fixed contact with the lower electrode sheet of the last PTC heating element. When the first and second energized electrode pins are energized, the silicone is cured, thereby firmly bonding the PTC heating elements.

[0008] Preferably, the PTC heating element has 10 cores.

[0009] Preferably, the PTC sheet is a ceramic sheet.

[0010] Preferably, the electrode sheet is made of brass.

[0011] Preferably, the silicone is a high-temperature curing adhesive.

[0012] Secondly, a method for preparing a PTC heating element includes:

[0013] Step 1: Use uncured silicone to stack the upper and lower electrode sheets on the upper and lower surfaces of the PTC sheet to form a single PTC heating core;

[0014] Step 2: Stack and flatten multiple PTC heating elements, and then press them together with a pressure head to obtain the stacked heating elements;

[0015] Step 3: Connect the first energized electrode pin and the second energized electrode pin to the upper electrode plate of the first PTC heating core and the lower electrode plate of the last PTC heating core after stacking.

[0016] Step 4: Power the stacked heating core through the first and second energized electrode needles; during the power-on process, collect the solidified current signal, and determine whether the stacked heating core is in good contact based on the current signal;

[0017] Step 5: If the contact is good, the curing process will proceed normally; if the contact is abnormal, an alarm will be triggered and curing will be stopped for adjustment until good contact is detected before continuing curing.

[0018] Step 6: After curing, release the pressure head to obtain a firmly bonded PTC heating core.

[0019] Preferably, the current signal for solidification in step 4 is acquired using a current acquisition device.

[0020] Preferably, in step 4, the determination of whether the stacked heating cores are in good contact based on the current signal is performed in a PLC.

[0021] Compared with the prior art, this application has at least the following beneficial effects:

[0022] This application provides a silicone curing structure and preparation method for a PTC heating element, including multiple PTC heating elements, a pressure head, a first energized electrode needle, and a second energized electrode needle. The multiple PTC heating elements are stacked and pressed together by the pressure head. Each PTC heating element includes an upper electrode sheet, a PTC sheet, and a lower electrode sheet. The upper and lower electrode sheets are respectively bonded to the upper and lower surfaces of the PTC sheet using silicone. The first energized electrode needle penetrates the pressure head and is in fixed contact with the upper electrode sheet of the first PTC heating element. The second energized electrode needle is in fixed contact with the lower electrode sheet of the last PTC heating element. When energized, the silicone is cured by the first and second energized electrode needles, resulting in a strong bond between the PTC heating elements. This application allows the assembled silicone curing structure of the PTC heating element to be connected in series with a power source. This series connection prevents incomplete curing due to poor contact during energization, and the use of only two electrode needles reduces equipment manufacturing and maintenance costs. Attached Figure Description

[0023] To more intuitively illustrate the prior art and this application, several exemplary figures are provided below. It should be understood that the specific shapes and structures shown in the figures should not generally be regarded as limiting conditions for implementing this application; for example, based on the technical concept disclosed in this application and the exemplary figures, those skilled in the art are able to easily make conventional adjustments or further optimizations to the addition / reduction / classification, specific shapes, positional relationships, connection methods, size ratios, etc. of certain units (components).

[0024] Figure 1 This is a schematic diagram of the silicone curing structure of a PTC heating element in the prior art;

[0025] Figure 2 This is a schematic diagram of the silicone curing structure of the PTC heating element provided in Embodiment 1 of this application;

[0026] Figure 3 This is a schematic diagram of the finished PTC heating element structure provided in Embodiment 2 of this application.

[0027] Explanation of reference numerals in the attached figures:

[0028] 1. PTC plate; 2. Upper electrode plate; 3. Lower electrode plate; 4. Pressure head; 5. First energized electrode needle; 6. Second energized electrode needle. Detailed Implementation

[0029] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] In the description of this application: unless otherwise stated, "a plurality of" means two or more. The terms "first," "second," "third," etc., in this application are intended to distinguish the objects referred to and do not have any special meaning in terms of technical connotation (e.g., they should not be construed as an emphasis on importance or order). Expressions such as "comprising," "including," and "having" also mean "not limited to" (certain units, components, materials, steps, etc.).

[0031] The terms used in this application, such as "upper," "lower," "left," "right," and "middle," are generally used to facilitate intuitive understanding by referring to the accompanying drawings, and are not absolute limitations on the positional relationships in the actual product. Changes in these relative positional relationships, without departing from the technical concept disclosed in this application, should also be considered within the scope of this application.

[0032] Example 1

[0033] Please see Figure 1 This embodiment provides a PTC heating core silicone curing structure, including multiple PTC heating cores, a pressure head 4, a first energized electrode needle 5, and a second energized electrode needle 6. The number of layers of the PTC heating core can be increased or decreased as needed, and the size of the PTC heating core can also be adjusted as needed. The first energized electrode needle 5 and the second energized electrode needle 6 are preferably electrode needles with high current resistance, low resistivity, and good contact, such as copper electrode needles plated with gold.

[0034] Multiple PTC heating elements are stacked and pressed together by a pressure head 4. The PTC heating element includes an upper electrode plate 2, a PTC plate 1 and a lower electrode plate 3. The upper electrode plate 2 and the lower electrode plate 3 are respectively stacked with the upper and lower surfaces of the PTC plate 1 by silicone. The material of the upper electrode plate 2 and the lower electrode plate 3 is preferably brass, and the silicone is preferably a high-temperature curing adhesive.

[0035] The first energized electrode needle 5 penetrates the pressure head 4 and is in fixed contact with the upper electrode plate 2 of the first PTC heating element. The second energized electrode needle 6 is in fixed contact with the lower electrode plate 3 of the last PTC heating element. The contact points between the first energized electrode needle 5 and the upper electrode plate 2 of the first PTC heating element, and between the second energized electrode needle 6 and the lower electrode plate 3 of the last PTC heating element, can be selected with different contact points and methods as needed. After the first energized electrode needle 5 and the second energized electrode needle 6 are energized, the silicone will be cured, so that the PTC heating elements are firmly bonded.

[0036] In the PTC heating core silicone curing structure provided in this embodiment, the PTC heating core can preferably be 10 pieces, and correspondingly, the upper electrode sheet 2 needs to be 10 pieces, and the lower electrode sheet 3 also needs to be 10 pieces.

[0037] The PTC heating core silicone curing structure provided in this embodiment is such that the PTC heating cores are pressed together by pressure during the stacking and curing process, so the electrode plates of each PTC heating core are conductive. Therefore, the stacked heating cores can be connected in series with the power supply through the first energized electrode pin 5 and the second energized electrode pin 6. After being connected in series, power is applied. At the beginning of curing, current signal detection can be performed to ensure good contact, thereby preventing incomplete curing due to poor contact. Experiments have shown that it prevents more than 1% of curing defects.

[0038] The silicone curing structure for the PTC heating element provided in this embodiment uses only two energized electrode pins, one positive and one negative, reducing the number of electrodes (6 positive and 5 negative) previously used for 10 PTC heating elements. This lowers the equipment manufacturing and maintenance costs and solves the problem of high equipment manufacturing and maintenance costs caused by a large number of curing electrodes.

[0039] It should be noted that the PTC heating core silicone curing structure provided in this application can also be applied to similar metal resistor bonding silicone curing.

[0040] Example 2

[0041] This embodiment provides a method for preparing a PTC heating element, including:

[0042] Step 1: Use uncured silicone to stack the upper and lower electrode sheets on the upper and lower surfaces of the PTC sheet to form a single PTC heating core;

[0043] Step 2: Stack and flatten multiple PTC heating elements, and then press them together with a pressure head to obtain the stacked heating elements;

[0044] Step 3: Connect the first energized electrode pin and the second energized electrode pin to the upper electrode plate of the first PTC heating core and the lower electrode plate of the last PTC heating core after stacking.

[0045] Step 4: Power the stacked heating core through the first and second energized electrode needles; during the power-on process, collect the solidified current signal, and determine whether the stacked heating core is in good contact based on the current signal;

[0046] Specifically, because the curing time of the PTC heating element is relatively long, it is possible to detect the current signal at the beginning of curing to ensure good contact.

[0047] Step 5: If the contact is good, the curing process will proceed normally; if the contact is abnormal, an alarm will be triggered and curing will be stopped for adjustment until good contact is detected before continuing curing.

[0048] Specifically, when power is applied, the current acquisition unit collects the current signal to be cured and sends this current data signal to the PLC. The PLC determines whether the contact is good based on the collected current data. If the contact is good, the PLC will not issue an alarm command and the curing process will proceed normally; if the current signal is abnormal, the PLC will issue an alarm.

[0049] Step 6: After curing, release the pressure head to obtain a firmly bonded PTC heating core.

[0050] The final PTC heating element product obtained by the method provided in this embodiment is as follows: Figure 3 As shown.

[0051] The technical features of the above embodiments can be combined in any way (as long as there is no contradiction in the combination of these technical features). For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described; these embodiments not explicitly written should also be considered to be within the scope of this specification.

[0052] The present application has been described in a relatively specific and detailed manner above through general descriptions and specific embodiments. It should be understood that, based on the technical concept of the present application, several conventional adjustments or further innovations can be made to these specific embodiments; however, as long as they do not depart from the technical concept of the present application, the technical solutions obtained by these conventional adjustments or further innovations also fall within the protection scope of the claims of the present application.

Claims

1. A PTC heating core silicone curing structure, characterized in that, The device includes multiple PTC heating elements, a pressure head, a first energized electrode needle, and a second energized electrode needle. The multiple PTC heating elements are stacked and pressed together by the pressure head. Each PTC heating element includes an upper electrode sheet, a PTC sheet, and a lower electrode sheet. The upper and lower electrode sheets are respectively bonded to the upper and lower surfaces of the PTC sheet using silicone. The first energized electrode needle penetrates the pressure head and is in fixed contact with the upper electrode sheet of the first PTC heating element. The second energized electrode needle is in fixed contact with the lower electrode sheet of the last PTC heating element. When energized, the first and second energized electrode needles cure the silicone, ensuring a firm bond between the PTC heating elements. The PTC sheet is a ceramic sheet, and the silicone is a high-temperature curing adhesive.

2. The PTC heating core silicone curing structure according to claim 1, characterized in that, The PTC heating element has 10 units.

3. The PTC heating core silicone curing structure according to claim 1, characterized in that, The electrode sheet is made of brass.

4. A method for preparing a PTC heating element, characterized in that, include: Step 1: Use uncured silicone to stack the upper and lower electrode sheets on the upper and lower surfaces of the PTC sheet to form a single PTC heating core; Step 2: Stack and flatten multiple PTC heating elements, and then press them together with a pressure head to obtain the stacked heating elements; Step 3: Connect the first energized electrode pin and the second energized electrode pin to the upper electrode plate of the first PTC heating core and the lower electrode plate of the last PTC heating core after stacking. Step 4: Power the stacked heating core through the first and second energized electrode needles; during the power-on process, collect the solidified current signal, and determine whether the stacked heating core is in good contact based on the current signal; Step 5: If the contact is good, the curing process will proceed normally; if the contact is abnormal, an alarm will be triggered and curing will be stopped for adjustment until good contact is detected before continuing curing. Step 6: After curing, release the pressure head to obtain a firmly bonded PTC heating core.

5. The method for preparing a PTC heating element according to claim 4, characterized in that, In step 4, the solidified current signal is acquired using a current acquisition device.

6. The method for preparing a PTC heating element according to claim 4, characterized in that, In step 4, the determination of whether the stacked heating cores are in good contact based on the current signal is performed in the PLC.

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