Spot welding device of winding type chip inductor automatic winding equipment

Abstract

The utility model provides a spot welding device of winding type chip inductor automatic winding equipment. The spot welding device comprises a heat storage type hot-pressing spot welding device and a power source matched with the heat storage type hot-pressing spot welding device and electrically connected with the heat storage type hot-pressing spot welding device. The heat storage type hot-pressing spot welding device comprises a spot welding head, a heat storage body and a heating device. The spot welding head is arranged at the front end of the heat storage body, and the heating device is arranged outside or inside or at the rear end of the heat storage body. The matched power supply heats and stores heat for the heat storage body through the heating device in advance, huge heat instantly needed in spot welding is provided for the spot welding head, and a coil lead is rapidly and directly welded to the end point of a bonding pad. Due to the fact that power supply, heating and heat storage of the matched power supply to the heat storage type hot-pressing spot welding device are continuously accumulated, the power of the matched power supply does not need to be large, and the equipment cost is reduced; and the temperature of the spot welding head is basically constant and does not change from low temperature to high temperature greatly or expand with heat and contract with cold, so that the service life of the spot welding head is prolonged.

Description

Technical Field

[0001] The invention relates to automatic winding equipment for a wire-wound patch inductor, in particular to a spot welding device for a wire-wound patch inductor. Background Art

[0002] Wire-wound chip inductors are components widely used on mounted circuit boards. There are many types, including I-shaped CD chip inductors, E-type chip inductors, and pot-type chip inductors. Their common feature is that the coils are all wound with enameled wire, and the wound coil leads need to be soldered together with the pads on the core or frame.

[0003] Existing wire bonding process:

[0004] 1. Tin immersion process, the coil lead is coated on the pad by molten tin liquid to achieve wire bonding, which uses a large amount of tin, has high cost and complex process. Lead-containing tin is usually used, which pollutes the environment.

[0005] 2. The pulse hot pressing spot welding process consists of a pulse power supply and a pulse hot pressing spot welding device. The pulse power supply provides low voltage and high current to the pulse hot pressing spot welding device. The ohmic heating point and spot welding head on the pulse hot pressing spot welding device instantly generate high temperature. The high temperature of the spot welding head quickly welds the coil lead directly to the pad through a certain pressure. No additional flux and tin are required. It has low cost, less pollution, good welding quality, simple process, and high degree of automation. It is the development trend of the industry.

[0006] Figure 1 This is a schematic diagram of the principle structure of an existing pulse hot pressing spot welding process, in which: a wound chip inductor automatic winding device F, a pulse power supply A, a pulse hot pressing spot welding device A1, a spot welding head A11, a welding head support A101, a wound coil A2, a coil lead A21, and a welding pad A22; the pulse hot pressing spot welding device A1 is electrically connected to the pulse power supply A; the pulse hot pressing spot welding device A1 is an integrated structure, usually made of black steel or black molybdenum alloy, and the spot welding head A11 is both a welding head and an ohmic heating point.

[0007] Figure 2 It is used for the existing pulse hot pressing spot welding process. The composite pulse hot pressing spot welding device diagram shows that A11 only acts as an ohmic heating point, and A111 composited on A11 acts as a spot welding head. A111 is usually made of diamond material and is called a diamond spot welding head.

[0008] The working process of the existing pulse hot pressing spot welding process:

[0009] When the automatic winding equipment F of the wound chip inductor delivers the wound coil A2 to the spot welding position, the pulse hot pressing spot welding device A1 moves to the spot welding position, and at the same time, the spot welding head A11 contacts the coil lead A21 and applies a certain pressure;

[0010] Further, the pulse power supply A outputs low voltage and high current to energize the spot welding head A11;

[0011] Furthermore, ohmic heat is generated on the spot welding head A11, and the temperature instantly reaches about 500 to 600 degrees;

[0012] Further, the high temperature and pressure of the spot welding head A11 are first applied to the insulating layer of the coil lead A21, and the insulating layer is rapidly melted; further, the metal wire of the coil lead A21 is deformed by the high temperature and pressure of the spot welding head A11, and changes from a circular shape to an elliptical shape; further, the insulating layer of the coil lead A21 in contact with the pad A22 is melted and converted into solder flux;

[0013] Further, the tinned layer on the pad A22 is melted and welded to the metal wire of the coil lead A21;

[0014] Further, the pulse power supply A stops outputting, and the pulse hot pressing spot welding device A1 returns to its original position and enters a waiting state.

[0015] Each cycle includes a spot welding time of 0.2 seconds to 0.5 seconds and a waiting time of 2 seconds to 5 seconds.

[0016] According to the above principle structure and working process, the disadvantages of the existing pulse hot pressing spot welding process are:

[0017] 1. The equipment cost is high. The pulse power supply works in an instantaneous low-voltage and high-current state. The instantaneous current is about 2000A to 5000A, and the instantaneous power is 2000W to 5000W. The requirements for the pulse power supply are high, the cost is high, and the price is about 2000 yuan to 5000 yuan.

[0018] 2. The spot welding head has a short life. The spot welding head works in an intermittent high temperature and pressure mode. The temperature alternates from low temperature to high temperature. The spot welding head constantly expands and contracts with heat and cold, and has a short life. Usually, the spot welding head made of black steel or black molybdenum alloy has a life of about 100,000 times.

[0019] 3. Figure 2Theoretically, the diamond spot welding head A111 in the welding process will have a much longer service life. However, in practical applications, due to the large difference in thermal expansion coefficients between the diamond spot welding head A111 and the ohmic heating point A11 materials, the diamond spot welding head A111 and the ohmic heating point A11 are easily torn off when the diamond spot welding head A111 and the ohmic heating point A11 are constantly expanding and contracting. At the same time, when the diamond spot welding head A111 heats up quickly, a large temperature difference will occur between the diamond spot welding head A111 and the ohmic heating point A11. When the diamond spot welding head A111 is heated up quickly, a large temperature difference will occur between the diamond spot welding head A111 and the ohmic heating point A11. When the temperature of the diamond spot welding head A111 reaches 500 to 600 degrees, the temperature of the ohmic heating point A11 has reached 800 to 900 degrees, and the temperature of the diamond part closest to the ohmic heating point A11 will reach 700 to 800 degrees. This temperature has reached or is close to the carbonization or graphitization temperature of diamond. The carbonization or graphitization temperature of diamond is about 700 to 900 degrees. When this part of the diamond is carbonized or graphitized, the diamond on the head will collapse due to insufficient support, and its lifespan will not be long. Summary of the invention

[0020] In view of the above-mentioned shortcomings of the existing pulse hot pressing spot welding process, the purpose of the present invention is to provide a spot welding device for automatic winding equipment of a wound chip inductor, aiming to solve the problems of high equipment cost and short life of the spot welding head in the existing pulse hot pressing spot welding process.

[0021] The technical solution of the present invention is as follows:

[0022] 1. A spot welding device for an automatic winding device for a wound patch inductor, comprising: a heat storage hot pressing spot welding device, and a power supply matched and electrically connected thereto, defined as a matching power supply;

[0023] 2. A heat storage hot pressing spot welding device, comprising: a spot welding head, a heat storage body, and a heating device;

[0024] 3. The spot welding head is arranged at the front end of the heat storage body, and the heating device is arranged outside, inside, or at the rear end of the heat storage body.

[0025] Working principle:

[0026] The matching power supply energizes the heating device, the heat storage body heats up and stores heat, and after the temperature of the heat storage body and the spot welding head reaches 500 to 600 degrees, it enters the waiting state; after the spot welding starts, the high temperature of the spot welding head quickly welds the coil lead directly to the welding pad through a certain pressure; during spot welding, the heat consumed by the spot welding head is quickly replenished by the heat storage body; after the spot welding is completed and enters the waiting state, the matching power supply continues to heat and store heat in the heat storage body through the heating device to provide heat reserve for the next spot welding.

[0027] Accordingly, the beneficial effects of the present invention are:

[0028] 1. The matching power supply preheats the heat storage body through the heating device to store heat, which provides the spot welding head with the huge heat required for spot welding, and quickly welds the coil lead directly to the pad. The effect is the same as the existing pulse hot pressing spot welding process, but the matching power supply supplies power, heats and stores heat for the heat storage hot pressing spot welding device in a continuous and cumulative manner. The power of the matching power supply does not need to be very large, usually 200W to 500W can meet the requirements, and the price is about 200 to 500 yuan, which is only one tenth of the price of the existing pulse hot pressing spot welding process, and the economic benefits are significant.

[0029] 2. The temperature of the spot welding head is basically constant, with only slight fluctuations within the cycle. There is no large alternation from low temperature to high temperature, and no thermal expansion and contraction. The life of the spot welding head is extended, especially the diamond spot welding head. The heat storage body and the diamond spot welding head do not have large thermal expansion and contraction. The diamond spot welding head is not easy to fall off. The temperature of the heat storage body and the diamond spot welding head is below 600 degrees, which is far from the carbonization and graphitization temperature of diamond of 700 to 900 degrees. The life can be extended several times. The measured number of spot welding times is more than 500,000 times. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is the principle structure diagram of the existing pulse spot welding process.

[0031] Figure 2 It is a structural diagram of a composite pulse hot-pressing spot welding device used in existing pulse spot welding technology.

[0032] Figure 3 It is a principle structure diagram or embodiment of the spot welding device of the present invention.

[0033] Figures 4 to 8 It is a structural diagram of the heat storage spot welding device in the present invention.

[0034] Fig. 9 This is a diagram of a connection method between a heat storage body and a spot welding head in the present invention.

[0035] Fig.10 The temperature control device of the present invention is DETAILED DESCRIPTION

[0036] Figure 3 It is a principle structure diagram or embodiment of the spot welding device of the present invention, in which: a wound chip inductor automatic winding device F, a matching power supply B, a heat storage hot pressing spot welding device B1, a spot welding head B11, a heat storage body B12, a heating device B13, a wound coil A2, a coil lead A21, and a welding pad A22; the heat storage hot pressing spot welding device B1 and the matching power supply B are electrically connected.

[0037] Working process:

[0038] First, power the matching power supply B to energize the heating device B13, the heat storage body B12 heats up and stores heat, and the spot welding head B11 is also heated at the same time. After the temperature reaches 500 to 600 degrees, it enters the waiting state;

[0039] When the automatic winding equipment F of the wound chip inductor delivers the wound coil A2 to the spot welding position, the heat storage hot pressing spot welding device B1 moves to the spot welding position, and at the same time, the spot welding head B11 contacts the coil lead B21 and applies a certain pressure;

[0040] Further, the high temperature and pressure of the spot welding head B11 are first applied to the insulating layer of the coil lead A21, and the insulating layer is rapidly melted; further, the metal wire of the coil lead A21 is deformed by the high temperature and pressure of the spot welding head B11, and changes from a round shape to an elliptical shape; further, the insulating layer of the coil lead A21 in contact with the pad A22 is melted and converted into solder flux;

[0041] Further, the tin-plated layer of the pad A22 is melted and welded to the metal wire of the coil lead A21;

[0042] Further, the heat storage hot pressure spot welding device B1 returns to its original position and enters a waiting state.

[0043] Each cycle includes a spot welding time of 0.2 seconds to 0.5 seconds and a waiting time of 2 seconds to 5 seconds. During spot welding, the heat consumed by the spot welding head B11 is quickly replenished by the heat storage body B12. At the same time, the matching power supply B continues to replenish heat to the heat storage body B12 through the heating device B13. After the spot welding is completed and enters the waiting state, the matching power supply B continues to heat and store heat in the heat storage body B12 through the heating device B13 to provide heat reserve for the next spot welding.

[0044] Figures 4 to 8 It is a structural diagram of the heat storage spot welding device in the present invention.

[0045] in:

[0046] Figure 4 It is an internal heating type, and the heating device B13 is inside the heat storage body B12.

[0047] Figure 5 It is an external heating type, and the heating device B14 is outside the heat storage body B12.

[0048] Figure 6 It is a resistive type. The heat storage body B12 uses a material with a relatively large resistivity. Electricity is directly supplied through the electrode sheets B33 at both ends to generate ohmic heat, thereby heating and storing heat in the heat storage body B12. The heat storage body B12 serves as a heat storage body and is also combined with the electrode sheet B33 to form a heating device.

[0049] Figure 7It is an induction type. The heating device B15 is a high-frequency induction coil, which is arranged outside the heat storage body B12. The matching power supply B is a high-frequency power supply. The matching power supply B and the high-frequency induction coil B15 are electrically connected. The high-frequency current flowing into the high-frequency induction coil B15 causes the heat storage body B12 to generate eddy currents, generate heat, and store heat. The induction heating device has the advantages of fast heating and long service life.

[0050] Figure 8 It is also an induction type. The heating device B16 is a high-frequency induction coil, which is arranged at the rear end of the heat storage body B12. The matching power supply B is a high-frequency power supply. The matching power supply B and the high-frequency induction coil B16 are electrically connected. The high-frequency current flowing into the high-frequency induction coil B16 causes the heat storage body B12 to generate eddy currents, generate heat, and store heat.

[0051] Figures 4 to 8 Any of the structures is equivalent to the heat storage hot pressing spot welding device B1 in the present invention, which can be summarized as follows: the heating device B13 can have different heating methods, and the heat storage body B12 can have different shapes or structures. According to different heating methods, the heating device B13 can be arranged outside, inside, or at the rear end of the heat storage body.

[0052] Figures 4 to 8 The spot welding head B11 in any structure can be made of high hardness and high thermal conductivity materials, including: diamond, boron nitride, and silicon carbide.

[0053] Fig. 9 This is a connection diagram of the heat storage body B12 and the spot welding head B11 in the present invention. A part of the spot welding head B11 is embedded in the heat storage body B12, and a part of it is exposed from the heat storage body B12. The contact area between the spot welding head B11 and the heat storage body B12 can be increased, thereby increasing the bonding strength, preventing it from falling off, and increasing the heat transfer speed.

[0054] Fig. 9 The connection method in is suitable for Figures 4 to 8 Any structure in .

[0055] Fig.10 It is a temperature control device used in the present invention. In the figure, there are a matching power supply B, a temperature sensor B3, a temperature sensing head B31, and a temperature sensing signal line B32; the temperature sensing head B31 is in contact with the spot welding head B11 or the heat storage body B12; the temperature sensing signal line B32 is electrically connected to the matching power supply B; the temperature signal of the spot welding head B11 or the heat storage body B12 sensed by the temperature sensing head B31 is transmitted to the matching power supply B through the temperature sensing signal line B32; the matching power supply B automatically adjusts the output current, so that the temperature of the spot welding head B11 or the heat storage body B12 remains constant.

[0056] Fig.10 The temperature control device is suitable for Figures 3 to 9 Any structure in .

Claims

1. A spot welding device for automatic winding equipment of a wound chip inductor, characterized in that: include: The heat storage hot pressure spot welding device (B1), and the power source (B) matched and electrically connected thereto, are defined as a matching power source; The heat storage hot pressure spot welding device (B1) comprises: a spot welding head (B11), a heat storage body (B12), and a heating device (B13); The spot welding head (B11) is arranged at the front end of the heat storage body (B12); The heating device (B13) is arranged outside, inside, or at the rear end of the heat storage body (B12).

2. The spot welding device of the automatic winding equipment of the wound chip inductor according to claim 1 is characterized in that: The spot welding head (B11) is made of high-hardness and high-thermal-conductivity materials, including: diamond, boron nitride, and silicon carbide.

3. The spot welding device of the automatic winding equipment of the wound chip inductor according to claim 2 is characterized in that: The spot welding head (B11) is partially embedded in the heat storage body (B12) and partially exposed from the heat storage body (B12).

4. The spot welding device of a wound chip inductor automatic winding equipment according to claim 1, 2 or 3, characterized in that: The heating device (B13) is a high-frequency induction coil; the matching power supply (B) is a high-frequency power supply.

5. The spot welding device of a wound chip inductor automatic winding equipment according to claim 1, 2 or 3, characterized in that: There is also a temperature control device, which includes: a temperature sensor (B3), a temperature sensing head (B31), and a temperature sensing signal line (B32); The temperature sensing head (B31) is in contact with the spot welding head (B11) or the heat storage body (B12); The temperature sensing signal line (B32) is electrically connected to the matching power supply (B).

6. The spot welding device of the automatic winding equipment of the wound chip inductor according to claim 4 is characterized in that: There is also a temperature control device, which includes: a temperature sensor (B3), a temperature sensing head (B31), and a temperature sensing signal line (B32); The temperature sensing head (B31) is in contact with the spot welding head (B11) or the heat storage body (B12); The temperature sensing signal line (B32) is electrically connected to the matching power supply (B).

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