Laminated common-mode filter

Abstract

The utility model relates to the technical field of filters, in particular to a laminated common-mode filter. A laminated common-mode filter comprises an identification layer, a plurality of layers of ceramic bodies and an internal conductive coil, the internal conductive coil is located in the ceramic bodies and comprises a plurality of conductive coil layers, the ceramic layers are arranged between the conductive coil layers, and connecting holes are formed in the ceramic layers. Every two adjacent conductive coil layers are connected through the corresponding connecting hole, through holes are formed in the ceramic layers, external electrodes are arranged on the ceramic bodies, and the internal conductive coils are connected with the external electrodes through the through holes. The utility model also provides a preparation method of the laminated common-mode filter. The utility model has the advantages of simple production process and small distributed capacitance.

Description

Technical Field

[0001] The utility model relates to the technical field of filters, in particular to a laminated chip common mode filter. Background Art

[0002] The traditional manufacturing process of multilayer chip common mode filter is as follows Fig.14 , 15 As shown, the process is limited by the end electrode process. The external electrodes of the product will cover the three sides of the product, forming a large distributed capacitance at high frequencies. The distributed capacitance will exist at, and the production process is relatively complicated. As shown in the attached figure of the specification, the internal distributed capacitance is large. Therefore, a multilayer chip common mode filter with simple production process and small distributed capacitance and a preparation method thereof are currently needed. Utility Model Content

[0003] In order to solve the above problems, a multilayer chip common mode filter with simple production process and small distributed capacitance and a preparation method thereof are provided. The utility model adopts the following technical solutions.

[0004] A laminated chip common mode filter comprises an identification layer, several layers of ceramic body and an internal conductive coil, wherein the internal conductive coil is located inside the ceramic body, the internal conductive coil comprises several layers of conductive coil layers, ceramic layers are arranged between the conductive coil layers, the ceramic layers are provided with connecting holes, two adjacent conductive coil layers are connected via the connecting holes, the ceramic layers are provided with through holes, the ceramic body is provided with external electrodes, and the internal conductive coil is connected to the external electrodes via the through holes.

[0005] Preferably, the ceramic body has five layers, including a first ceramic body, a second ceramic body, a third ceramic body, a fourth ceramic body, and a fifth ceramic body. The external electrode is located in the first ceramic body, and the side of the external electrode extends to part or all of the second ceramic body.

[0006] The utility model adopts the above structure, the external electrode is distributed on the fourth surface (first ceramic body), and the external electrode extends to the second ceramic body, and its height is not less than 100um. Through this structure, the distributed capacitance of the utility model can be greatly reduced, thereby improving the stability of the use of the utility model.

[0007] Preferably, the internal conductive coil is located inside the third ceramic body.

[0008] The utility model adopts the above structure. On the one hand, the internal conductive coil is located in the middle of the utility model and can be protected by the external ceramic body, thereby ensuring the stability of the use of the utility model. On the other hand, since the distributed capacitance is generated between the internal conductive coil and the external electrode, the structure can reduce the influence of the distributed capacitance.

[0009] A method for preparing a laminated chip common mode filter comprises the following steps:

[0010] Step 1: Print the first ceramic body using photosensitive ceramic slurry, and carve grooves for external electrodes through exposure and development processes;

[0011] Step 2: Printing a photosensitive conductive paste on the ceramic body with the grooves made therein to fill the grooves, and removing excess conductive paste;

[0012] Step 3: Printing photosensitive ferrite slurry on the first ceramic body after the external electrode is made, and carving a groove of the external electrode extension part through exposure and development process, wherein the external electrode extension part extends from the first ceramic body to the second ceramic body;

[0013] Step 4: Printing photosensitive ceramic slurry on the second ceramic body with the external electrode, carving through holes connecting the external electrode and the internal conductive coil through exposure and development processes, printing photosensitive conductive slurry on the through holes to fill the through holes, removing excess conductive slurry through exposure and development processes, so that the positions of the through holes are retained;

[0014] Step 5: Further print photosensitive conductive paste on the embryonic body with through holes made in the third ceramic body to completely cover the through holes, and make a layer of conductive coils through exposure and development processes.

[0015] Step 6: Then print photosensitive ceramic slurry on the conductive coil layer, and through exposure and development processes, carve out grooves for connecting the internal coil to the external electrode and connection points for connecting to the next conductive coil layer;

[0016] Step 7: Repeat steps 5 and 6 until the coil design of all layers is completed;

[0017] Step 8: Printing a photosensitive ferrite slurry on the third ceramic body having the internal conductive coil formed thereon to obtain a third ceramic body, wherein the photosensitive ferrite slurry is the same as that used for the second ceramic body;

[0018] Step 9: Printing photosensitive ceramic slurry on the fourth ceramic body, wherein the color of the photosensitive ceramic slurry is different from that of the first and third ceramics, and the color of the colored photosensitive ceramic slurry is used to carve out a laminated common mode filter logo through exposure and development processes.

[0019] First of all, the utility model adopts printing, exposure, and development processes, which can simply and quickly prepare external electrodes, while ensuring that the external electrodes are only fixed on the first ceramic body and only extend to the second ceramic body. There is no need to fix the external electrodes, which causes the external electrodes to penetrate the entire filter and cause a large amount of distributed capacitance. In addition, the utility model adopts the process of step 4, which can place multiple layers of conductive coil layers in a very small space, further controlling the distributed capacitance while reducing the volume, and helping to reduce the production cost of the utility model.

[0020] Preferably, the thickness of the ceramic body in step 1 is 15-30 um.

[0021] The utility model has the advantages of small volume, simple process and easy preparation.

[0022] Preferably, in step 2, excess conductive paste is removed by exposure and development processes.

[0023] The utility model adopts the above steps to remove the redundant conductive paste, which is helpful to control the position of the external electrode.

[0024] Preferably, the height of the external electrode is greater than or equal to 100 um.

[0025] The beneficial effects of the utility model are: 1. The utility model has the advantages of small size and easy processing; 2. The utility model has the advantage of small distributed capacitance; 3. The utility model adopts printing, exposure and development processes and has the advantage of high processing accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A structural schematic diagram of the utility model;

[0027] Figure 2 It is a schematic diagram of the internal structure of the utility model;

[0028] Figure 3 is a schematic structural diagram of the first conductive coil layer;

[0029] Figure 4 is a schematic diagram of the structure of the first ceramic layer;

[0030] Figure 5 is a schematic structural diagram of the second conductive coil layer;

[0031] Figure 6 is a schematic diagram of the structure of the second ceramic layer;

[0032] Figure 7 Schematic diagram of the structure of the third conductive coil layer

[0033] Figure 8 is a schematic diagram of the structure of the third ceramic layer;

[0034] Fig. 9 Schematic diagram of the structure of the fourth conductive coil layer

[0035] Fig.10 is a schematic diagram of the structure of the fourth ceramic layer;

[0036] Fig.11 is a schematic structural diagram of the fifth conductive coil layer;

[0037] Fig.12 is a schematic diagram of the structure of the fifth ceramic layer;

[0038] Fig.13 is a schematic structural diagram of the sixth conductive coil layer;

[0039] Fig.14 It is a structural schematic diagram of the prior art;

[0040] Fig.15 The process flow chart of the prior art. DETAILED DESCRIPTION

[0041] The utility model is further explained below in conjunction with specific implementation cases.

[0042] Example 1

[0043] A laminated chip common mode filter includes a marking layer 1, several layers of ceramic bodies 3 and an internal conductive coil 2, wherein the internal conductive coil 2 is located inside the ceramic body 3, and the internal conductive coil 2 includes several layers of conductive coil layers 4, wherein ceramic layers 5 are provided between the conductive coil layers 4, and the ceramic layers 5 are provided with connection holes 6, and two adjacent conductive coil layers 4 are connected through the connection holes 6, and the ceramic layers 5 are provided with through holes 7, and the ceramic body 3 is provided with external electrodes 8, and the internal conductive coil 2 is connected to the external electrodes 8 through the through holes 7. The ceramic body 3 has five layers, including a first ceramic body 31, a second ceramic body 32, a third ceramic body 33, a fourth ceramic body 34, and a fifth ceramic body 35, wherein the external electrode 8 is located in the first ceramic body 31, and the side of the external electrode 8 extends to part or all of the second ceramic body 32, wherein the internal conductive coil 2 is located inside the third ceramic body 33, and the marking layer 1 is located on the fifth ceramic body 35.

[0044] The utility model also provides a method for preparing a laminated chip common mode filter, comprising the following steps:

[0045] Step 1: Use photosensitive ceramic slurry to print the first ceramic body 31, and carve out the groove of the external electrode 8 through exposure and development process. The thickness of the ceramic body 3 is 15-30 um.

[0046] Step 2: Printing photosensitive conductive paste on the ceramic body 3 with the grooves made to fill the grooves, and then removing excess conductive paste through exposure and development processes. The height of the external electrode 8 is greater than or equal to 100 um.

[0047] Step 3: Printing photosensitive ferrite slurry on the first ceramic body 3 on which the external electrode 8 is made, and carving a groove of the extended portion of the external electrode 8 through exposure and development processes, wherein the extended portion of the external electrode 8 extends from the first ceramic body 31 to the second ceramic body 32;

[0048] Step 4: Printing photosensitive ceramic paste on the second ceramic body 32 made of the completed external electrode 8, and carving out a through hole 7 connecting the external electrode 8 and the internal conductive coil 2 through exposure and development processes, and printing photosensitive conductive paste on the through hole 7 to fill the through hole 7, and removing excess conductive paste through exposure and development processes, so that the position of the through hole 7 is retained;

[0049] Step 5: further printing a photosensitive conductive paste on the embryonic body of the third ceramic body 33 where the through hole 7 is made, so that the through hole 7 is completely covered, and a layer of conductive coil is made through exposure and development processes;

[0050] Step 6: Then print photosensitive ceramic slurry on the conductive coil layer 4, and through exposure and development processes, carve out grooves for connecting the internal coil to the external electrode 8 and connection points 9 for connecting to the next conductive coil layer 4 to form a ceramic layer;

[0051] Step 7: Repeat steps 5 and 6 to provide 6 conductive coil layers and 5 ceramic layers in total;

[0052] Step 8: Printing a photosensitive ferrite slurry on the third ceramic body 33 made of the internal conductive coil 2 to obtain the third ceramic body 33, wherein the photosensitive ferrite slurry is the same as the photosensitive ferrite slurry used for the second ceramic body 32;

[0053] Step 9: Printing photosensitive ceramic slurry on the fourth ceramic body 34, wherein the color of the photosensitive ceramic slurry is different from that of the first and third ceramics, and the color of the colored photosensitive ceramic slurry is used to carve out a laminated common mode filter logo through exposure and development processes.

[0054] The utility model adopts the above structure, and the external electrode 8 is distributed on the fourth surface (the first ceramic body 31), and the external electrode 8 extends to the second ceramic body 32, and its height is not less than 100um. Through this structure, the distributed capacitance of the utility model can be greatly reduced, thereby improving the stability of the use of the utility model. At the same time, the internal conductive coil 2 of the utility model is located in the middle of the utility model, and can be protected by the external ceramic body 3, ensuring the stability of the use of the utility model. On the other hand, since the distributed capacitance is generated between the internal conductive coil 2 and the external electrode 8, the use of this structure can reduce the influence of the distributed capacitance.

[0055] First of all, the utility model adopts printing, exposure and development processes, which can simply and quickly prepare the external electrode 8, while ensuring that the external electrode 8 is only fixed on the first ceramic body 31 and only extends to the second ceramic body 32. There is no need to fix the external electrode 8 so that the external electrode 8 runs through the entire filter, resulting in a large amount of distributed capacitance. In addition, the utility model adopts the process of step 4, which can place multiple layers of conductive coil layers 4 in a very small space, further controlling the distributed capacitance while reducing the volume, and at the same time helping to reduce the production cost of the utility model.

Claims

1. A laminated chip common mode filter, characterized in that: It includes a marking layer, several layers of ceramic body and an internal conductive coil, wherein the internal conductive coil is located inside the ceramic body, and includes several layers of conductive coil layers, ceramic layers are arranged between the conductive coil layers, and connecting holes are arranged on the ceramic layers, and two adjacent conductive coil layers are connected via the connecting holes, and through holes are arranged on the ceramic layers, and external electrodes are arranged on the ceramic body, and the internal conductive coil is connected to the external electrodes via the through holes.

2. The multilayer common mode filter according to claim 1, characterized in that: The ceramic body has five layers, including a first ceramic body, a second ceramic body, a third ceramic body, a fourth ceramic body, and a fifth ceramic body. The external electrode is located on the first ceramic body, and the side of the external electrode extends to part or all of the second ceramic body.

3. The multilayer common mode filter according to claim 2, characterized in that: The internal conductive coil is located inside the third ceramic body.

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