A coil and tape connection process

Abstract

The application relates to the field of inductance manufacturing processes, in particular to a coil and material belt connecting process, which comprises the following steps: S1, tightly matching an inductance coil to a conductive material belt; the inductance coil is provided with a coil pin; the conductive material belt comprises a coil connecting sheet and a material belt frame body, the coil connecting sheet is connected to the material belt frame body, the coil connecting sheet comprises a connecting sheet main body and a pin connecting part, and the pin connecting part is used for connecting the coil pin; S2, the pin connecting part is wrapped around the coil pin through a laser bending process; a laser beam moves along a radiation path Ls, the radiation path Ls passes through the pin connecting part, and the angle of a radiation included angle alpha between the radiation path Ls and a pin axis La of the coil pin is 0 DEG <= alpha < 90 DEG. The application has the effect of reducing the damage of the pin of the coil in the connecting process.

Description

Technical Field

[0001] This application relates to the field of inductor manufacturing processes, and in particular to a process for connecting a coil to a strip. Background Technology

[0002] Inductors are commonly used electronic components, often used to store electrical energy or maintain a stable current. Integrated inductors, due to their advantages in size and impedance, are frequently used in consumer electronics and automobiles.

[0003] In existing related technologies, the manufacturing of integrated inductors requires soldering the coil leads to the poles of the strip, then cutting the coil and poles, embedding the coil and poles in magnetic powder, and finally completing the manufacturing process through hot pressing and electroplating. For example, see patent document CN 115831596 A, entitled "A Method for Processing Integrated Inductors and an Integrated Inductor".

[0004] Regarding the aforementioned technologies, for coils with smaller diameters, the mechanical strength of their pins is poor, making the pins prone to damage during connection. Summary of the Invention

[0005] To reduce the occurrence of coil pin damage during connection, this application provides a connection process between the coil and the material strip.

[0006] The technical solution for connecting a coil and a strip provided in this application is as follows:

[0007] A process for connecting a coil to a strip includes the following steps:

[0008] S1. Fit the inductor coil tightly onto the conductive strip;

[0009] The inductor coil is provided with coil leads;

[0010] The conductive strip includes a coil connecting piece and a strip frame. The coil connecting piece is connected to the strip frame. The coil connecting piece includes a connecting piece body and a pin connecting part. The pin connecting part is used to connect coil pins.

[0011] S2. The pin connection portion is wrapped around the coil pin by a laser bending process;

[0012] The laser beam moves along the irradiation path Ls, which passes through the pin connection part, and the irradiation angle α between the irradiation path Ls and the pin axis La of the coil pin is 0°≤α<90°.

[0013] By adopting the above technical solution, after the coil leads of the inductor are placed in the lead connection part, the laser beam moves along the irradiation path Ls, causing the lead connection part to bend towards and cover the coil leads, thereby connecting the inductor to the conductive strip. This reduces the need for direct soldering between the coil leads and the conductive strip, making the coil leads less susceptible to damage from the heat of the soldering process or the impact of the soldering gun, thus reducing the likelihood of damage to the coil leads during the connection process.

[0014] Optionally, the irradiation path Ls is arranged in a straight line and intersects the pin axis La.

[0015] By adopting the above technical solution, on the one hand, it is easier to reduce the path complexity and start-stop frequency of the laser beam, thereby reducing the difficulty of controlling the laser beam. On the other hand, when the laser beam passes through the coil pin, the laser beam causes local melting of the coil pin, which facilitates a stable connection of the bent pin connection to the coil pin. Furthermore, it allows the bent pin connection parts located on both sides of the coil pin to be deflected towards the front and rear ends of the coil pin, respectively, thereby enabling the pin connection parts to connect to the coil pin over a wider range, thus ensuring a stable mechanical and electrical connection between the coil pin and the pin connection parts.

[0016] Optionally, the included angle α of the illumination is 45°.

[0017] By adopting the above technical solution, it is easy for the bent part of the pin to bend towards the coil pin along the irradiation path Ls.

[0018] Optionally, the diameter of the coil pin is less than 0.2 mm.

[0019] By adopting the above technical solution, for coil pins with a diameter of less than 0.2mm, which have a small diameter, fixing them by bending and wrapping can effectively reduce the occurrence of coil pin damage.

[0020] Optionally, the power of the laser beam is below 30W.

[0021] By adopting the above technical solution, it is beneficial to reduce the thermal damage caused by the laser beam to the coil pins, thereby reducing the occurrence of coil pin damage.

[0022] Optionally, in step S1, before the inductor coil is tightly fitted onto the conductive strip, a contact layer is provided on the coil pin, and the contact layer is provided with conductive material;

[0023] In step S2, when the laser beam irradiates the conductive material, the physical state of the conductive material changes from solid to liquid, and when the laser beam leaves the conductive material, the physical state of the conductive material changes from liquid to solid.

[0024] By adopting the above technical solution, when the laser beam passes through the coil pin along the irradiation path Ls, the contact layer is irradiated by the laser, causing the conductive material of the contact layer to melt. This melted contact layer fills the gap between the coil pin and the pin connection part, which helps to reduce the gap between the coil pin and the pin connection part, thereby helping to ensure that a stable mechanical and electrical connection can be established between the coil pin and the pin connection part.

[0025] Optionally, the contact layer is made of solder paste containing flux, and the contact layer is formed by an immersion process.

[0026] By adopting the above technical solution, the contact layer can be effectively connected to the pin connection after melting, thereby ensuring the stability of the connection. Furthermore, the immersion process allows for rapid contact layer setup, which helps improve the connection efficiency between the inductor coil and the conductive strip.

[0027] Optionally, the connection process between the coil and the strip further includes the following steps:

[0028] S3. The pin connection part is subjected to a hot-press welding process.

[0029] By adopting the above technical solution, on the one hand, after hot pressing, the bent pin connection will tightly wrap around the coil pin, thereby reducing the gap between the coil pin and the pin connection. On the other hand, during the hot pressing process, a molten portion is generated between the coil pin and the pin connection, allowing them to be tightly connected through the molten portion. Furthermore, by hot pressing the bent pin connection that wraps around the coil pin, pressure and heat are transferred to the coil pin through the pin connection, thereby reducing the possibility of damage to the fragile coil pin during the hot pressing process. Moreover, for coil pins with a contact layer, during hot pressing, the contact layer can absorb heat and soften or melt, further filling the gap between the coil pin and the pin connection. This helps to ensure a stable mechanical and electrical connection between the coil pin and the pin connection without damaging the coil pin.

[0030] Optionally, the hot pressing process is carried out through a hot pressing head, which has a hot pressing groove whose shape is adapted to the shape of the coil pin.

[0031] By adopting the above technical solution, it is easier to reduce the occurrence of damage to the coil pins under the pressure of the hot press head.

[0032] Optionally, the coil pin is provided with a covering groove for accommodating the pin connection portion covering the coil pin.

[0033] By adopting the above technical solution, the covering groove limits the pin connection part, making it less likely for the pin connection part to fall off after being covered by the coil pin, thereby helping to ensure the connection stability between the coil pin and the pin connection part.

[0034] In summary, this application includes at least one of the following beneficial technical effects:

[0035] 1. After the coil leads of the inductor are placed in the lead connection part, the laser beam moves along the irradiation path Ls, causing the lead connection part to bend towards and cover the coil leads, thereby connecting the inductor to the conductive strip. This reduces the need for direct soldering between the coil leads and the conductive strip, making the coil leads less susceptible to damage from the heat of the soldering process or the impact of the soldering gun, thus reducing the likelihood of damage to the coil leads during the connection process.

[0036] 2. On the one hand, it facilitates reducing the path complexity and start-stop frequency of the laser beam, thereby simplifying its control. On the other hand, as the laser beam passes through the coil pin, it causes localized melting of the pin, which helps to securely connect the bent pin connection to the coil pin. Furthermore, it allows the bent pin connection portions on both sides of the coil pin to deflect towards the front and rear ends of the coil pin, respectively, enabling the pin connection portion to connect to the coil pin over a wider range, thus ensuring a stable mechanical and electrical connection between the coil pin and the pin connection portion. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the fit between the inductor coil and the conductive strip in Embodiment 1 of this application.

[0038] Figure 2 This is a schematic diagram of the laser bending process in Embodiment 1 of this application.

[0039] Figure 3 This is a schematic diagram of the fit between the coil pin and the pin connection part in Embodiment 1 of this application.

[0040] Figure 4 This is a schematic diagram of the fit between the coil pins, contact layer, and pin connection portion in Embodiment 2 of this application.

[0041] Figure 5 This is a schematic diagram of the hot pressing process for coil pins with contact layers in Embodiment 3 of this application.

[0042] Figure 6This is a schematic diagram of the inductor coil in Embodiment 4 of this application.

[0043] Explanation of reference numerals in the attached drawings: 1. Inductor coil; 101. Covering groove; 11. Coil pin; 2. Conductive strip; 21. Strip frame; 22. Connecting piece body; 23. Pin connection part; 3. Contact layer; 4. Hot press head; 401. Hot press groove. Detailed Implementation

[0044] The following is in conjunction with the appendix Figure 1-6 This application will be described in further detail.

[0045] Example 1:

[0046] Embodiment 1 of this application discloses a process for connecting a coil and a strip. (Refer to...) Figure 1 The connection process between the coil and the strip includes the following steps:

[0047] S1. Attach the inductor coil 1 tightly to the top or bottom of the conductive strip 2.

[0048] The inductor coil 1 is formed by winding one or more layers of conductive wire, and the inductor coil 1 is cylindrical. The conductive wire is conductive, and in Embodiment 1 of this application, the material of the conductive wire is copper. The bottom of the inductor coil 1 is provided with two coil leads 11, which are arranged side by side. In addition, in Embodiment 1 of this application, the diameter of the coil leads 11 is 0.05 mm or more and 0.20 mm or less.

[0049] The conductive strip 2 has a thickness of 0.15 mm or more and 0.25 mm or less. The conductive strip 2 includes coil connecting pieces and a strip frame 21. Several coil connecting pieces are provided, all located inside the strip frame 21, and all coil connecting pieces are conductive and deformable. The coil connecting pieces are grouped in pairs, with each group distributed along the length of the strip frame 21, and the two coil connecting pieces in each group distributed along the width of the strip frame 21.

[0050] The coil connecting piece includes a connecting piece body 22 and a pin connecting portion 23. The connecting piece body 22 is connected to the strip carrier 21, and the pin connecting portion 23 is connected to the connecting piece body 22. In Embodiment 1 of this application, the connecting piece body 22 is integrally connected to the strip carrier 21, and the pin connecting portion 23 is integrally connected to the connecting piece body 22. The strip carrier 21, the connecting piece body 22, and the pin connecting portion 23 are all made of copper. The pin connecting portion 23 protrudes from the connecting piece body 22 and extends along the length direction of the strip carrier 21. The width of the pin connecting portion 23 is greater than the width of the coil pin 11 to facilitate connection of the coil pin 11 through the pin connecting portion 23.

[0051] Furthermore, in step S1, when the inductor coil 1 is tightly fitted to the top or bottom of the conductive strip 2, the coil leads 11 are tightly fitted to the top or bottom surface of the lead connection portion 23, and the coil leads 11 are away from the sides of the lead connection portion 23 so that the lead connection portion 23 bends up from the sides of the coil leads 11. Moreover, to facilitate subsequent connection between the inductor coil 1 and the conductive strip 2, the inductor coil 1 must first be adhered to the conductive strip 2, and the adhesive layer used for adhesion can be provided on the surface of the inductor coil 1 or on the surface of the conductive strip 2.

[0052] S2. The pin connection part 23 is wrapped around the coil pin 11 by laser bending process.

[0053] In this application, the laser bending process refers to: irradiating the coil connecting piece with a laser beam generated by a laser head, causing the side of the coil connecting piece closer to the laser head to cool and shrink, while the other side away from the laser head to heat and expand, thereby bending the coil connecting piece toward the location of the laser head.

[0054] Reference Figure 2 In step S2, the angle α between the laser beam irradiation path Ls and the pin axis La of the coil pin 11 is 0°≤α<90°, so that the pin connection 23 bends at the location traversed by the irradiation path Ls, thereby causing the pin connection 23 to bend towards and cover the coil pin 11. Multiple irradiation paths Ls can be provided, for example, including two irradiation paths Ls located on both sides of the coil pin 11 and arranged in a "V" shape, or including two irradiation paths Ls located on both sides of the coil pin 11 and arranged in a "I" shape.

[0055] Specifically, in Embodiment 1 of this application, the irradiation path Ls is a straight line in the shape of an "I", and the irradiation path Ls intersects with the pin axis La, making the irradiation angle α 45°. This has several advantages: firstly, it simplifies the irradiation path Ls, making it easier to set the motion behavior of the laser head; secondly, it disperses the internal stress generated when the pin connection 23 bends along the length of the coil pin 11, thereby dispersing the creep of the pin connection 23 and allowing it to remain wrapped around the coil pin 11 for an extended period; and thirdly, it helps the pin connection 23 located on both sides of the coil pin 11 to bend towards the front and rear ends of the coil pin 11, respectively, thus ensuring the contact area between the pin connection 23 and the coil pin 11 and guaranteeing the connection strength between the coil pin 11 and the pin connection 23.

[0056] Reference Figure 3When the laser head moves along the irradiation path Ls, it needs to determine whether it needs to move along the irradiation path Ls repeatedly based on the bending condition of the pin connection portion 23. This ensures that the laser beam repeatedly irradiates the pin connection portion 23 located at the point where the irradiation path Ls passes, thereby ensuring that the bending angle of the pin connection portion 23 meets the requirements. In addition, when performing laser bending, the power of the laser beam needs to be below 30W to reduce the thermal damage to the coil pin 11 caused by the laser beam when it needs to pass through the coil pin 11 along the irradiation path Ls.

[0057] The implementation principle of the connection process between a coil and a strip in Embodiment 1 of this application is as follows: by moving the laser beam along the inclined irradiation path Ls, the pin connection portions 23 located on both sides of the coil pin 11 bend toward the coil pin 11 and cover the coil pin 11, thereby ensuring the connection stability between the coil pin 11 and the pin connection portion 23 without easily damaging the coil pin 11, especially for thinner coil pins 11 with a diameter of less than 0.2 mm.

[0058] Example 2:

[0059] Embodiment 2 of this application discloses a connection process between a coil and a strip, which, in addition to all the technical features of Embodiment 1, also includes the following technical features:

[0060] Reference Figure 4 In step S1, before the inductor coil 1 is tightly fitted onto the conductive strip 2, a contact layer 3 is provided on the inductor coil 1. The contact layer 3 is made of a conductive material with a melting point of 100°C or higher, so that the conductive material can be melted by heating and solidified after the contact layer 3 cools down, thereby filling the gap between the inductor coil 1 and other components. In addition, the contact layer 3 can be in a liquid or solid state at room temperature, that is, in an environment with a temperature of 15°C to 28°C.

[0061] By providing the contact layer 3, the intensity of the laser beam's irradiation on the coil pin 11 is reduced when the laser beam passes through it, thereby protecting the coil pin 11 and reducing the possibility of thermal damage. Furthermore, the contact layer 3 melts after absorbing the heat from the laser beam, allowing it to bond tightly with the bent pin connection portion 23, reducing the gap between the coil pin 11 and the pin connection portion 23, and ensuring a stable mechanical and electrical connection between them.

[0062] Regarding the arrangement of the contact layer 3, for contact layers 3 that are solid at room temperature, such as tin metal, the solid material can be applied to the surface of the coil pin 11 to form the contact layer 3 by mechanical processing such as coating, embedding, or winding of tin metal sheets. Alternatively, tin metal can be electroplated onto the surface of the coil pin 11 to form the contact layer 3. For contact layers 3 that are liquid at room temperature, such as solder paste, the liquid material can be applied to the surface of the coil pin 11 to form the contact layer 3 by processes such as brushing, printing, or immersion. In this application, brushing refers to the process of applying liquid material to the surface of the coil pin 11 using a brush; printing refers to the process of applying liquid material to a designated area on the surface of the coil pin 11 by passing through a mesh plate with corresponding shapes; and immersion refers to the process of immersing the coil pin 11 in liquid metal, causing the liquid metal to adhere to the surface of the coil pin 11.

[0063] Specifically, in Embodiment 2 of this application, the contact layer 3 is formed by immersing the coil pin 11 in solder paste, and the solder paste includes solder powder and flux to ensure the connection stability between the contact layer 3 and the coil pin 11 and the pin connection portion 23.

[0064] The implementation principle of the connection process between the coil and the strip in Embodiment 2 of this application is as follows: a contact layer 3 is provided on the surface of the coil pin 11. The contact layer 3 is provided with a conductive material that is conductive and will melt under laser beam irradiation, so that the contact layer 3 can fill the gap between the coil pin 11 and the pin connection part 23, thereby ensuring the stability of the mechanical connection and electrical connection between the coil pin 11 and the pin connection part 23.

[0065] Example 3:

[0066] Embodiment 3 of this application discloses a connection process between a coil and a strip, which, in addition to all the technical features of Embodiment 2, also includes the following technical features:

[0067] S3. The coil pin 11, contact layer 3 and pin connection part 23 are connected to each other by hot pressing welding process.

[0068] Reference Figure 5 In this application, the hot-press welding process refers to the hot pressing of the pin connection part 23 by the hot press head 4, so that the pin connection part 23 is further attached to the coil pin 11, and the contact layer 3 is melted, thereby further reducing the gap between the coil pin 11 and the pin connection part 23, and further ensuring the stability of the mechanical connection and electrical connection between the coil pin 11 and the pin connection part 23.

[0069] The hot pressing head 4 has a hot pressing groove 401, the shape of which is adapted to the shape of the coil pin 11, which has a contact layer 3 and a pin connection portion 23. When the hot pressing head presses the pin connection portion 23, the inner wall of the hot pressing groove 401 presses against the outer surface of the pin connection portion 23 and / or the contact layer 3 from the top of the conductive material strip 2, causing the pin connection portion 23 to undergo thermal deformation and tightly cover its surface. Furthermore, the contact layer 3 melts again to fill the gap between the coil pin 11 and the pin connection portion 23. Additionally, when the hot pressing head 4 approaches the coil pin 11, both the pin connection portion 23 and the contact layer 3 cover the surface of the coil pin 11, making the coil pin 11 less susceptible to damage from the impact of the hot pressing head 4 or from instantaneous heating, thereby reducing the likelihood of damage to the coil pin 11.

[0070] The implementation principle of the coil-to-strip connection process in Embodiment 3 of this application is as follows: after the pin connection part 23 covers the coil pin 11, the gap between the coil pin 11 and the pin connection part 23 is further reduced by hot pressing process, thereby ensuring the stability of the mechanical and electrical connection between the coil pin 11 and the pin connection part 23.

[0071] Example 4:

[0072] Embodiment 4 of this application discloses an inductor coil 1 for use in the coil-strip connection process described in Embodiments 1, 2, or 3. In addition to all the technical features of the inductor coil 1 described in Embodiments 1, 2, or 3, it also includes the following technical features:

[0073] Reference Figure 6 The coil lead 11 of the inductor coil 1 is provided with a covering groove 101, which is used to accommodate the lead connection portion 23 covering the coil lead 11, and the covering groove 101 extends along the length direction of the coil lead 11. When the lead connection portion 23 is bent into the covering groove 101, the inner wall of one end of the covering groove 101 will limit the lead connection portion 23, thereby making it difficult for the coil lead 11 to slide towards its rear end, and also facilitating fixation by the hot pressing head 4 described in Embodiment 3, thereby ensuring the connection strength between the coil lead 11 and the lead connection portion 23. Furthermore, on the one hand, it is convenient for the conductive material of the contact layer 3 to adhere through the covering groove 101, and on the other hand, it is also convenient for the inner wall of the covering groove 101 to block the molten contact layer 3, so that the contact layer 3 is not easy to overflow during the hot pressing process described in Embodiment 3 and the hot pressing process of the integrated inductor manufacturing process, thereby also helping to ensure the stability of the contact layer 3.

[0074] The coating groove 101 can be formed by cutting or stamping. In embodiment 4 of this application, the coating groove 101 is formed by stamping, that is, pressure is applied to the coil pin 11 by a punch, so that the surface of the coil pin 11 is deformed under pressure to form the coating groove 101.

[0075] The implementation principle of an inductor coil 1 in Embodiment 4 of this application is as follows: the pin connection portion 23 is accommodated by the covering groove 101, so that the pin connection portion 23 and / or the contact layer 3 are not easily deflected.

[0076] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A coil-to-tape connection process, characterized by: The method comprises the following steps: S1, tightly fit the inductor coil (1) to the conductive material strip (2); The inductor coil (1) is provided with a coil pin (11); The conductive material strip (2) comprises a coil connecting sheet and a material strip frame body (21), the coil connecting sheet is connected to the material strip frame body (21), the coil connecting sheet comprises a connecting sheet main body (22) and a pin connecting part (23), and the pin connecting part (23) is used for connecting the coil pin (11); In the S1 step, before the inductor coil (1) is tightly fitted to the conductive material strip (2), a contact layer (3) is arranged on the coil pin (11), and the contact layer (3) is made of conductive material; In the S2 step, when the laser beam irradiates the conductive material, the physical state of the conductive material changes from solid state to liquid state, and when the laser beam leaves the conductive material, the physical state of the conductive material changes from liquid state to solid state; The material of the contact layer (3) is solder paste containing flux, and the contact layer (3) is arranged by immersion process; S2, the pin connecting part (23) is wrapped around the coil pin (11) by laser bending process; The laser beam moves along the irradiation path Ls, the irradiation path Ls passes through the pin connecting part (23), and the irradiation angle α between the irradiation path Ls and the pin axis La of the coil pin (11) is 0°≤α<90°; The irradiation path Ls is arranged in a straight line, and the irradiation path Ls intersects with the pin axis La.

2. The coil and tape connecting process according to claim 1, wherein: The angle of the irradiation angle α is 45°.

3. The coil and tape attachment process of claim 1, wherein: The diameter of the coil pin (11) is less than or equal to 0.2mm.

4. The coil and tape connecting process of claim 3, wherein: The power of the laser beam is less than or equal to 30W.

5. The coil and tape attachment process of claim 1, wherein: Further comprising the following steps: S3, the pin connecting part (23) is welded by hot pressing process.

6. The coil and tape connecting process of claim 5, wherein: The hot pressing process is implemented by a hot pressing head (4), the hot pressing head (4) is provided with a hot pressing groove (401), and the shape of the hot pressing groove (401) is matched with the shape of the coil pin (11).

7. The coil and tape attachment process of claim 1, wherein: The coil pin (11) is provided with a cladding groove (101), and the cladding groove (101) is used for accommodating the pin connecting part (23) wrapped around the coil pin (11).

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