A patch filter and a manufacturing process thereof

Abstract

This invention discloses a plug-in filter and its manufacturing process, comprising: a chip including a stack, with first electrodes at both ends of the stack, the two first electrodes connected to a first lead, a second electrode disposed between the two first electrodes for grounding, and a second lead connected to the second electrode, the first and second leads being independent of each other; the chip being disposed inside a casing, the first and second leads protruding outside the casing. The filter is connected to a circuit board via the first lead connected to the first electrode and the second lead connected to the second electrode. The first and second leads are directly soldered to the circuit board. During board separation, the impact of external force caused by cutting the circuit board on the plug-in filter is reduced. When the board is bent due to external force impact, the connection between the plug-in filter and the circuit board is not affected, improving the yield rate during board separation and extending the service life of the plug-in filter.

Description

Technical Field

[0001] This invention relates to the field of filter technology, and in particular to a plug-in filter and its manufacturing process. Background Technology

[0002] In fields such as new energy vehicles, unmanned robots, and automated equipment, applications are becoming increasingly diverse, circuit integration is increasing, and the number of filters required to eliminate electromagnetic interference is also growing, with ever-higher demands on filtering performance. Currently, surface-mount filters in small-module applications are typically soldered onto a circuit board first, and then the board is divided into multiple smaller boards. However, during board separation, the filters are susceptible to external impacts during cutting, potentially leading to failure. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a plug-in filter and its manufacturing process, which can prevent the filter from being damaged by external impacts and improve the filter's service life.

[0004] According to a first aspect of the present invention, a plug-in filter includes: a chip and a casing; the chip includes a stack, with first electrodes disposed at both ends of the stack, the two first electrodes being connected to a first lead, the stack being disposed with a second electrode located between the two first electrodes, the second electrode being used for grounding, the second electrode being connected to a second lead, the first lead and the second lead being independent of each other; the chip is disposed inside the casing, and the first lead and the second lead protrude outside the casing.

[0005] In some embodiments of the present invention, the stack body has two connection slots, the two connection slots are symmetrically arranged, and the second electrode is provided in both connection slots. One end of the second lead is simultaneously engaged in the two connection slots and is in contact with the two second electrodes.

[0006] In some embodiments of the present invention, one end of the second lead is bent to form a U-shaped buckle, the U-shaped buckle is fastened to the stack body, the U-shaped buckle includes two symmetrical contact portions, the two contact portions are respectively placed in the two connecting grooves, and the two contact portions respectively contact the two second electrodes.

[0007] In some embodiments of the present invention, the stack body includes multiple circuit layers, each circuit layer having printed circuits, and recesses formed on both symmetrical sides of each circuit layer. The multiple circuit layers are stacked and pressed together to form the stack body, and the multiple recesses are sequentially spliced ​​together to form the connecting groove.

[0008] In some embodiments of the present invention, conductive covers are provided at both ends of the stack, the conductive covers cover the first electrode and the conductive covers are in contact with the first electrode, and the first lead is connected to the conductive covers.

[0009] In some embodiments of the present invention, protective blocks are provided on both the upper and lower sides of the stack, and the two ends of the protective blocks are wrapped by the conductive cover.

[0010] According to a manufacturing process described in a second aspect of the present invention, applied to the plug-in filter described in a first aspect of the present invention, the process includes the following steps: S1. Prepare a ceramic film according to the formula, and print circuit patterns on the ceramic film to form a circuit layer; S2. Stack the various circuit layers in a set order to form a stack, thus forming the internal circuit structure of the chip. S3. Perform adhesive removal treatment on the stacked body to reduce the content of organic adhesive in the stacked body; S4. Sinter the stacked body to form a ceramic body with properties; S5. Grind both ends of the stack to expose the first electrode; S6. Etch the middle position of the stack to expose the second electrode; S7. Apply electrode paste to the first and second electrodes and sinter them. S8. Connect the first lead to the first electrode, connect the second lead to the second electrode, and solidify by tin dipping to obtain a chip; S9. The chip is encapsulated to obtain a shell, and the first lead and the second lead are exposed outside the shell.

[0011] Compared with the prior art, the plug-in filter and its manufacturing method according to the present invention have the following advantages: the filter is connected to the circuit board by a first lead connected to a first electrode and a second lead connected to a second electrode. The first and second leads are directly soldered to the circuit board, which reduces the impact of external force caused by cutting the circuit board on the plug-in filter during board separation. When the board is bent due to external force impact, it will not affect the connection between the plug-in filter and the circuit board, thereby improving the yield rate during board separation and extending the service life of the plug-in filter. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of a plug-in filter according to a first aspect embodiment of the present invention; Figure 2 This is a cross-sectional view of the plug filter according to a first aspect embodiment of the present invention; Figure 3This is a schematic diagram of the connection between the plug-in filter and the circuit board according to the first aspect embodiment of the present invention; Figure 4 This is a schematic diagram of the chip in the plug-in filter according to the first aspect of the present invention; Figure 5 This is a schematic diagram of the stacked body in the plug filter according to the first aspect embodiment of the present invention; Figure 6 This is a schematic diagram of the internal structure of the stacked body in the plug filter according to the first aspect of the present invention; Figure 7 This is a schematic diagram of the second lead in the plug filter according to the first aspect embodiment of the present invention; Figure 8 This is a flowchart of the manufacturing process according to a second aspect embodiment of the present invention.

[0013] Explanation of reference numerals in the attached figures: 100 casing; 200 chip; 210 first lead; 220 second lead; 221 U-shaped buckle; 222 contact part; 230 stacked body; 231 conductive cover; 232 connecting groove; 233 protective block; 234 circuit layer; 235 first electrode; 236 second electrode; 237 recess; 300 circuit board. Detailed Implementation

[0014] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0015] like Figures 1 to 3 As shown, a plug-in filter according to a first aspect embodiment of the present invention includes: a chip 200 and a casing 100; the chip 200 includes a stack 230, with first electrodes 235 disposed at both ends of the stack 230, the two first electrodes 235 being connected to a first lead 210, the stack 230 being disposed with a second electrode 236, the second electrode 236 being located between the two first electrodes 235, the second electrode 236 being used for grounding, the second electrode 236 being connected to a second lead 220, the first lead 210 and the second lead 220 being independent of each other; the chip 200 is disposed inside the casing 100, and the first lead 210 and the second lead 220 protrude outside the casing 100.

[0016] The filter is connected to the circuit board 300 via a first lead 210 connected to the first electrode 235 and a second lead 220 connected to the second electrode 236. The first lead 210 and the second lead 220 are directly soldered to the circuit board 300. During board separation, the impact of external force caused by cutting the circuit board 300 on the plug-in filter is reduced. When the board is bent due to external force impact, it will not affect the connection between the plug-in filter and the circuit board 300, thereby improving the yield rate during board separation and extending the service life of the plug-in filter.

[0017] Specifically, the stack 230 includes multiple circuit layers 234, on which printed circuits are disposed. Recesses 237 are symmetrically formed on both sides of each circuit layer 234. Multiple circuit layers 234 are stacked and pressed together to form the stack 230, and multiple recesses 237 are sequentially connected to form a connection groove 232. The stacking and pressing of multiple circuit layers 234 enables circuit integration, increases the circuit density of the stack 230, and meets the filtering requirements of highly integrated devices. The recesses 237 in each circuit layer 234 facilitate the exposure of the second electrode 236 of the circuit layer 234.

[0018] Understandably, referring to Figure 2 , Figure 4 and Figure 5 Conductive caps 231 are provided at both ends of the stack 230. The conductive caps 231 cover the first electrode 235 and are in contact with the first electrode 235. The first lead 210 is connected to the first electrode 235. By covering both ends of the stack 230 with conductive caps 231, the circuit layers 234 that are stacked together are prevented from dispersing and falling off, thus improving the stability of the stack 230 structure. In addition, the conductive caps 231 are conductive. The first lead 210 can be electrically connected to the first electrode 235 by connecting to the conductive caps 231, which is convenient and quick. Furthermore, the conductive caps 231 covering the first electrode 235 can protect the first electrode 235 from corrosion by the external environment.

[0019] It is also understandable that, referring to Figure 6 Protective blocks 233 are provided on both the top and bottom sides of the stack 230, and the two ends of the protective blocks 233 are covered by conductive covers 231. By providing protective blocks 233 on both the top and bottom sides of the stack 230, the exposed circuit structure on the top and bottom sides of the stack 230 is protected, and the internal circuit structure of the stack 230 is prevented from being damaged by the outside.

[0020] Understandably, referring to Figure 4 and Figure 5The stack body 230 has two connecting slots 232, which are symmetrically arranged on both sides of the stack body 230. A second electrode 236 is disposed within each connecting slot 232. One end of the second lead 220 is simultaneously engaged within both connecting slots 232 and in contact with both second electrodes 236. By providing the connecting slots 232, the contact area between the second lead 220 and the stack body 230 is increased, while limiting the displacement of the second lead 220 and reducing the offset of the end of the second lead 220 connected to the stack body 230. This makes the connection between the second lead 220 and the second electrode 236 more balanced and stable, avoiding uneven force or poor contact caused by one-sided connection. At the same time, it facilitates quick docking of the second electrode 236 with the second electrode 236, improving docking accuracy and assembly efficiency.

[0021] Understandably, referring to Figure 4 , Figure 5 and Figure 7 One end of the second lead 220 is bent to form a U-shaped buckle 221, which is then fastened to the stack 230. The U-shaped buckle 221 includes two symmetrical contact portions 222, which are respectively placed in two connecting grooves 232 and respectively contact the two second electrodes 236. By bending one end of the second lead 220 into a U-shaped buckle 221 and aligning the U-shaped buckle 221 with the two connecting grooves 232 of the stack 230, the two symmetrical contact portions 222 of the U-shaped buckle 221 are respectively embedded in the two connecting grooves 232, thus achieving the fastening of the U-shaped buckle 221 with the stack 230. Then, by welding, the connection between the U-shaped buckle 221 and the stack 230 is firmly secured, preventing the second lead 220 from falling off during installation or use and improving the structural stability of the filter. In addition, by aligning the two connecting slots 232 of the stack body 230 with the U-shaped buckle 221, the positioning between the second lead 220 and the stack body 230 is simplified, and the assembly efficiency is improved.

[0022] Reference Figure 8 A manufacturing process according to a second aspect of the present invention, applied to a plug-in filter according to a first aspect of the present invention, includes the following steps: S1. Prepare a ceramic film according to the formula, and print circuit patterns on the ceramic film to form circuit layer 234; S2. Stack each circuit layer 234 in a set order to form a stack body 230. The stack body 230 forms a complete internal circuit structure of the chip 200, providing a circuit basis for the subsequent filtering function. At the same time, by drilling a hole in the middle of the stack body 230, the second electrode 236 can be quickly and accurately exposed in the subsequent step S6. S3. Perform adhesive removal treatment on the stack 230 to reduce the content of organic adhesive in the stack 230 and avoid excessive adhesive residue, which may cause defects such as bubbles and cracks in the stack 230 during subsequent sintering. S4. The ceramic raw materials in the stack 230 undergo a crystallization reaction through high-temperature sintering, and the various circuit layers 234 are tightly bonded together, ultimately forming a ceramic body with good insulation, conductivity and filtering performance. S5. The surface insulating material is removed by grinding to expose the first electrode 235, providing conditions for the connection between the first electrode 235 and the conductive cover 231 and the first lead 210. S6. Before etching, sealant is applied to the part of the stack 230 other than the middle position to prevent other parts of the stack 230 from being etched. The connecting groove 232 formed by drilling is used to guide the etching, improve the etching accuracy, reduce the wear on other parts of the stack 230, avoid damage to the internal circuit structure, and expose the second electrode 236 in the connecting groove 232, providing conditions for the connection between the second electrode 236 and the second lead 220. S7. Electrode paste is coated on the first electrode 235 and the second electrode 236 and sintered to make both the first electrode 235 and the second electrode 236 have good conductivity. The amount of electrode paste is increased at both ends of the stack body 230. After sintering, a conductive cover 231 is formed to wrap the first electrode 235. S8. Connect the first lead 210 to the conductive cover 231, and fasten the U-shaped buckle 221 of the second lead 220 to the connecting groove 232. Immerse the docking part in the molten solder, and then take it out and let the molten solder cool and solidify to obtain the formed chip 200. Through the immersion in tin treatment, the connection between the first lead 210 and the second lead 220 and the stack 230 is strengthened. S9. The chip 200 is encapsulated to obtain a shell 100. The shell 100 protects the chip 200 and exposes the first lead 210 and the second lead 220 outside the shell 100, so that the first lead 210 and the second lead 220 can be connected to the circuit board 300.

[0023] In summary, the embodiments of the present invention provide a plug-in filter and its manufacturing process. The filter is connected to the circuit board 300 through a first lead 210 connected to the first electrode 235 and a second lead 220 connected to the second electrode 236. The first lead 210 and the second lead 220 are directly soldered to the circuit board 300, which reduces the impact of external force caused by cutting the circuit board 300 on the plug-in filter during board separation. When the board body is bent due to external force impact, it will not affect the connection between the plug-in filter and the circuit board 300, thereby improving the yield rate during board separation and extending the service life of the plug-in filter.

[0024] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A patch filter, characterized by, Including: The chip includes a stack, with first electrodes at both ends of the stack, the two first electrodes being connected to a first lead, and a second electrode located between the two first electrodes. The second electrode is used for grounding and is connected to a second lead. The first lead and the second lead are independent of each other. The chip is disposed inside the casing, and the first lead and the second lead protrude outside the casing.

2. A patch filter according to claim 1, wherein, The stack body has two connection slots, which are symmetrically arranged. The second electrode is provided in both connection slots. One end of the second lead is simultaneously engaged in both connection slots and in contact with both second electrodes.

3. A patch filter according to claim 2, wherein, One end of the second lead is bent to form a U-shaped buckle, which is fastened to the stack body. The U-shaped buckle includes two symmetrical contact portions, which are respectively placed in the two connecting grooves and respectively contact the two second electrodes.

4. A patch filter according to claim 2, wherein, The stack includes multiple circuit layers, each with a printed circuit. Recesses are formed on both sides of each circuit layer. The multiple circuit layers are stacked and pressed together to form the stack. The multiple recesses are sequentially spliced ​​together to form the connecting groove.

5. A patch filter according to claim 4, wherein, The stacked body has conductive covers at both ends, the conductive covers cover the first electrode and are in contact with the first electrode, and the first lead is connected to the conductive cover.

6. A patch filter according to claim 5, wherein, The stacked body is provided with protective blocks on both the top and bottom sides, and the two ends of the protective blocks are wrapped by the conductive cover.

7. A manufacturing process characterized by, The method applied to the plug filter according to any one of claims 1 to 6 includes the following steps: S1. Prepare a ceramic film according to the formula, and print circuit patterns on the ceramic film to form a circuit layer; S2. Stack the various circuit layers in a set order to form a stack, thus forming the internal circuit structure of the chip. S3. Perform adhesive removal treatment on the stacked body to reduce the content of organic adhesive in the stacked body; S4. Sinter the stacked body to form a ceramic body with properties; S5. Grind both ends of the stack to expose the first electrode; S6. Etch the middle position of the stack to expose the second electrode; S7. Apply electrode paste to the first and second electrodes and sinter them. S8. Connect the first lead to the first electrode, connect the second lead to the second electrode, and solidify by tin dipping to obtain a chip; S9. The chip is encapsulated to obtain a shell, and the first lead and the second lead are exposed outside the shell.

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