Coil circuit board and manufacturing method thereof

Abstract

A manufacturing method of a coil circuit board comprises the steps that a first coil winding is arranged on a carrier plate, the first coil winding comprises a plurality of first annular winding wires connected in sequence, a gap is formed between every two adjacent first annular winding wires, and part of the carrier plate is exposed out of the gaps. And arranging an insulating spacing film on the first coil winding, wherein part of the insulating spacing film is concave towards the gap to form a plurality of grooves. A second coil winding is arranged on the insulation spacing film, the second coil winding comprises a plurality of second annular winding wires which are connected in sequence, each second annular winding wire is arranged in one groove, and the carrier plate is removed to obtain the coil circuit board. The manufacturing method of the coil circuit board provided by the invention is beneficial to reducing the gap between the first coil winding and the second coil winding. In addition, the invention also provides a coil circuit board.

Description

Technical Field

[0001] The invention belongs to the field of circuit board manufacturing, and in particular relates to a coil circuit board and a manufacturing method thereof. Background Art

[0002] Inductive charging coil is a technology that uses non-contact energy transmission to achieve the charging process by realizing efficient conversion between magnetic energy and electrical energy. At present, the most widely used production method in wireless charging technology is the flexible printed circuit (FPC) process. FPC coils are produced in a variety of ways, including etching, electroplating and laser processing.

[0003] However, there are some problems that need to be solved in the traditional FPC coil manufacturing method. First, the use of thick copper layer circuits will lead to an increase in manufacturing costs, which is caused by the increase in material cost and processing complexity. Secondly, due to the influence of the pool effect, the circuit spacing is too large, which limits the compactness and charging efficiency of the coil. In addition, the circuit design on both sides of the coil may cause the overall thickness of the coil to increase, which in turn affects its flexibility and applicability in various applications. Summary of the invention

[0004] In order to solve the above deficiencies in the prior art, the present application provides a coil circuit board.

[0005] In addition, the present application also provides a method for manufacturing a coil circuit board.

[0006] A method for manufacturing a coil circuit board includes the following steps: arranging a first coil winding on a carrier board, the first coil winding including a plurality of first annular windings connected in sequence, a gap between each two adjacent first annular windings, and a portion of the carrier board exposed in the gap; arranging an insulating spacer film on the first coil winding, a portion of the insulating spacer film being concave toward the gap to form a plurality of grooves; arranging a second coil winding on the insulating spacer film, the second coil winding including a plurality of second annular windings connected in sequence, each second annular winding being arranged in one of the grooves, and removing the carrier board to obtain the coil circuit board.

[0007] In some possible embodiments, the carrier includes a peelable layer and an insulating substrate layer arranged on one side of the peelable layer, the first coil winding is arranged on the side of the insulating substrate layer away from the peelable layer, and the step of "removing the carrier" includes: removing the peelable layer.

[0008] In some possible embodiments, the step of “arranging a first coil winding at a step” includes: forming an aluminum paste pattern on the carrier by printing aluminum paste, and curing the aluminum paste pattern to form the first coil winding.

[0009] In some possible embodiments, before the step of "arranging an insulating spacer film on the first coil winding", the step further includes: arranging a first cladding metal layer on the outside of each of the first annular windings. After the step of "arranging a second coil winding on the insulating spacer film", the step further includes: arranging a second cladding metal layer on the outside of each of the second annular windings.

[0010] In some possible embodiments, the material of the first coil winding includes aluminum, and the material of the first coating metal layer is copper, and the step of "arranging a first coating metal layer on the outside of each of the first annular windings" includes: setting a copper ion solution outside each of the first annular windings, and the copper ions in the copper ion solution react with the aluminum in the first annular winding to form a copper element, thereby forming the first coating metal layer.

[0011] In some possible embodiments, the material of the second coil winding includes aluminum, and the material of the second coating metal layer includes copper, and the step of "arranging a second coating metal layer on the outside of each of the second annular windings" includes: setting a copper ion solution outside each of the second annular windings, and the copper ions in the copper ion solution react with the aluminum in the second annular winding to form a copper element, thereby forming the second coating metal layer.

[0012] In some possible embodiments, the method further includes the step of providing a covering film on the second coil winding, wherein the covering film also covers the insulating spacer film.

[0013] A coil circuit board comprises a first coil winding, an insulating spacer film and a second coil winding. The first coil winding comprises a plurality of first annular windings connected in sequence, and a gap is provided between each two adjacent first annular windings. The insulating spacer film, part of the insulating spacer film is concave toward the gap to form a plurality of grooves. The second coil winding comprises a plurality of second annular windings connected in sequence, and each second annular winding is arranged in one of the grooves.

[0014] In some possible embodiments, the present invention further includes a first metal covering layer and a second metal covering layer, wherein the first metal covering layer is disposed on the outer side of each of the first annular windings, and the second metal covering layer is disposed on the outer side of each of the second annular windings.

[0015] In some possible embodiments, the distance between each two adjacent first metal covering layers and second metal covering layers is 10-20 micrometers.

[0016] Compared with the prior art, the manufacturing method of the coil circuit board provided by the present application can effectively reduce the distance between the first coil winding and the second coil winding and improve the charging efficiency of the coil by arranging the second coil winding in the gap of the first coil winding and arranging an insulating spacer film between the first coil winding and the second coil winding. At the same time, since the second coil winding is arranged in the gap of the first coil winding, it is beneficial to reduce the overall thickness of the coil circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic cross-sectional view of a carrier provided in accordance with an embodiment of the present application.

[0018] Figure 2 for Figure 1 The cross-sectional schematic diagram shown is a carrier board after the first coil winding is arranged.

[0019] Figure 3 for Figure 2 The cross-sectional schematic diagram of the first coil winding after the first metal covering layer is provided is shown.

[0020] Figure 4 for Figure 3 The cross-sectional schematic diagram shown is a first metal covering layer after an insulating spacer film is provided.

[0021] Figure 5 for Figure 4 The cross-sectional schematic diagram shown is after the insulating spacer film is provided with the second coil winding.

[0022] Figure 6 for Figure 5 The cross-sectional schematic diagram of the second coil winding after the second metal covering layer is provided is shown.

[0023] Figure 7 for Figure 6 The cross-sectional schematic diagram shown is after the second metal covering layer is provided with a covering film.

[0024] Figure 8 A schematic cross-sectional view of a coil circuit board provided in accordance with an embodiment of the present application.

[0025] Main component symbols

[0026] Carrier board 10

[0027] Peelable layer 11

[0028] Insulating base material layer 12

[0029] The first coil winding 20

[0030] First toroidal winding 21

[0031] Gap 22

[0032] First metal cover layer 23

[0033] The first wrapping coil winding 24

[0034] Insulation spacer film 30

[0035] Groove 31

[0036] Second coil winding 40

[0037] Second toroidal winding 41

[0038] Gap 42

[0039] Second metal capping layer 43

[0040] The second covering coil winding 44

[0041] Covering film 50

[0042] Thickness direction A

[0043] The following specific implementation methods will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0045] See also Figures 1 to 8 An embodiment of the present application provides a method for manufacturing a coil circuit board 100, comprising the steps of:

[0046] S1: See Figure 1 A carrier board 10 is provided, wherein the carrier board 10 includes a peelable layer 11 and an insulating substrate layer 12 disposed on one side of the peelable layer 11. The carrier board 10 has a thickness direction A.

[0047] In this embodiment, the material of the strippable layer 11 includes glass, ceramic, iron, etc. The material of the insulating substrate layer 12 includes at least one of polyimide (PI), liquid crystal polymer (LCP), epoxy resin (EP), polytetrafluoroethylene (PTFE), polyether ether ketone (PEEK), polyphenylene oxide (PPO), polyester resin (PET) and polyethylene naphthalatetwo formic acid glycol ester (PEN).

[0048] S2: See Figure 2 , a first coil winding 20 is arranged on the side of the insulating substrate layer 12 away from the strippable layer 11. Observed along the thickness direction A, the first coil winding 20 is roughly in the shape of a circular spiral, and the spiral has a center (not indicated). The first coil winding 20 includes a plurality of first annular windings 21 connected in sequence, and the central angle of each first annular winding 21 corresponding to the center is 180 degrees. There is a gap 22 between each adjacent two first annular windings 21, and part of the insulating substrate layer 12 is exposed in the gap 22. Wherein, along the perpendicular direction A, the width of each gap 22 is 50 to 130 microns.

[0049] It can be understood that in other embodiments of the present application, the first coil winding 20 can also be in other shapes, for example, an elliptical spiral shape, a square spiral shape, etc.

[0050] In this embodiment, the material of the first annular winding 21 includes aluminum, iron, zinc, etc. Preferably, the material of the first annular winding 21 is aluminum. Step S2 specifically includes:

[0051] S21: An aluminum paste pattern (not shown) is provided on the side of the insulating substrate layer 12 away from the strippable layer 11 by printing. The shape of the aluminum paste pattern is substantially the same as the shape of the first coil winding 20. The aluminum paste pattern includes aluminum particles and a binder. The aluminum paste pattern contains 60% to 80% aluminum particles by mass. The dynamic viscosity of the aluminum paste pattern is 12,000 to 26,000 centipoise.

[0052] S22: heating the aluminum paste pattern to 75-90° C. and continuously heating for 1-2 hours, thereby curing the aluminum paste pattern to obtain the first coil winding 20. Along the thickness direction A, the height of the first coil winding 20 is 30-60 microns. It can be understood that in other embodiments of the present application, the height of the first coil winding 20 can also be other values ​​set according to requirements.

[0053] S3: See Figure 3 A first metal covering layer 23 is disposed outside each of the first annular windings 21. The first metal covering layer 23 wraps each of the first annular windings 21 to form a first wrapped coil winding 24. The thickness of the first metal covering layer 23 is 3 to 20 microns, and the gap 22 is not filled by the first metal covering layer 23.

[0054] In this embodiment, the material of the first metal covering layer 23 includes copper, silver, gold, etc. Preferably, the material of the first annular winding 21 is copper. Step S3 specifically includes:

[0055] S31: Immerse the first coil winding 20 in a solution containing copper ions, so that the outer surface of each of the first annular windings 21 can contact the copper ions, and the aluminum in the first annular windings 21 undergoes a replacement reaction with the copper ions. The reaction equation is as follows:

[0056] 2Al+3Cu 2+ →3Cu+2Al 3+

[0057] Thus, single copper is generated and deposited on the outer side of the first annular winding 21 , thereby forming the first metal covering layer 23 .

[0058] S32: taking out the first coil winding 20 from the copper ion-containing solution, and washing the first metal covering layer 23 with clean water to remove the residual copper ions.

[0059] S4: See Figure 4 An insulating spacer film 30 is disposed on the first metal covering layer 23, and a portion of the insulating spacer film 30 is concave toward the gap 22 to form a plurality of grooves 31. The thickness of the insulating spacer film 30 is 15 to 25 microns. The insulating spacer film 30 is a cured pure glue layer, and the specific material can be selected from at least one of epoxy resin, phenolic resin, polyimide, polyurethane, silicone rubber, fluoroplastic (PTFE) and acrylic resin.

[0060] In this embodiment, step S4 specifically includes:

[0061] S41: a pure adhesive layer (not shown) is provided on the first metal covering layer 23 by vacuum lamination, and the pure adhesive layer is made to be concave toward the gap 22 by vacuuming the gap 22, so as to form a plurality of grooves 31 connected in sequence;

[0062] S42: baking and curing the pure glue layer to form the insulating spacer film 30. The baking conditions are: temperature 150-160°C, time 1-2 hours.

[0063] S5: See Figure 5 , a second coil winding 40 is arranged in a plurality of connected grooves 31, and the second coil winding 40 includes a plurality of second annular windings 41 connected in sequence, and each second annular winding 41 is arranged in one of the grooves 31. Similar to the shape of the first coil winding 20, when viewed along the thickness direction A, the second coil winding 40 is roughly in the shape of a circular spiral, and the spiral has a center (not indicated). The central angle of each second annular winding 41 corresponding to the center is 180 degrees. Among them, along the thickness direction A, the thickness of each second annular winding 41 is 30 to 60 microns. The second annular winding 41 does not fill the groove 31, and when viewed perpendicular to the thickness direction A, there is a gap 42 between the two sides of each second annular winding 41 and the side wall of the groove 31.

[0064] In this embodiment, the material of the second coil winding 40 is substantially the same as that of the first coil winding 20 , and the manufacturing method of the second coil winding 40 is substantially the same as that of the first coil winding 20 , which will not be described in detail herein.

[0065] S6: See Figure 6 A second metal covering layer 43 is disposed outside each second annular winding 41, and the second metal covering layer 43 wraps each second annular winding 41 to form a second wrapped coil winding 44, thereby obtaining a second wrapped coil winding 44. The thickness of the second metal covering layer 43 is 3 to 20 microns, and the gap 42 is filled with the second metal covering layer 43. The insulating spacer film 30 electrically isolates the second wrapped coil winding 44 from the first wrapped coil winding 24.

[0066] In this embodiment, the material of the second metal covering layer 43 is substantially the same as that of the first metal covering layer 23 , and the manufacturing method of the second metal covering layer 43 is substantially the same as that of the first coil winding 20 , which will not be described in detail herein.

[0067] S7: See Figure 7 A covering film 50 is provided on the second coil winding 40, and the covering film 50 extends perpendicular to the thickness direction A and covers the insulating spacer film 30. Specifically, the covering film 50 is formed on the insulating spacer film 30 and the second covered coil winding 44 by vacuum pressing. The covering film 50 can be used to protect the second coil winding 40 and the first coil winding 20 from erosion by external pollutants such as water vapor.

[0068] S8: See Figure 8 , remove the peelable layer 11 of the carrier board 10 to obtain the coil circuit board 100.

[0069] Compared with the prior art, the manufacturing method of the coil circuit board 100 provided in the present application has the following advantages:

[0070] (i) By arranging the second coil winding 40 in the gap 22 of the first coil winding 20 and arranging the insulating spacer film 30 between the first coil winding 20 and the second coil winding 40, the distance between the first coil winding 20 and the second coil winding 40 can be effectively reduced, thereby improving the charging efficiency of the coil. At the same time, since the second coil winding 40 is arranged in the gap of the first coil winding 20, it is beneficial to reduce the overall thickness of the coil circuit board 100.

[0071] (ii) By disposing a first metal covering layer 23 on the outside of each first annular winding 21 and by disposing a second metal covering layer 43 on the outside of each second annular winding 41, most of the charges are located in the first metal covering layer 23 and the second metal covering layer 43. By selecting the first metal covering layer 23 and the second metal covering layer 43 of suitable materials, it is possible to reduce the cost of the coil circuit board 100.

[0072] See also Figure 8 , an embodiment of the present application further provides a coil circuit board 100, comprising a first coil winding 20, a second coil winding 40 and an insulating spacer film 30. The first coil winding 20 comprises a plurality of first annular windings 21 connected in sequence, and a gap 22 is provided between each adjacent two first annular windings 21. Part of the insulating spacer film 30 is concave toward the gap 22 to form a plurality of grooves 31. The second coil winding 40 comprises a plurality of second annular windings 41 connected in sequence, and each second annular winding 41 is disposed in one of the grooves 31.

[0073] See also Figure 8In this embodiment, the coil circuit board 100 also includes a first metal covering layer 23 and a second metal covering layer 43 , wherein the first metal covering layer 23 is arranged on the outer side of each of the first annular windings 21 , and the second metal covering layer 43 is arranged on the outer side of each of the second annular windings 41 .

[0074] See also Figure 8 In this embodiment, the distance between each adjacent two first metal covering layers 23 and second metal covering layers 43 is 10 to 20 microns.

[0075] The above description is only an optimized specific implementation of the present application, but it cannot be limited to this implementation in the actual application process. For ordinary technicians in this field, other variations and changes made according to the technical concept of the present application should all fall within the protection scope of the present application.

Claims

1. A method for manufacturing a coil circuit board, characterized in that: Includes steps: A first coil winding is arranged on a carrier plate, wherein the first coil winding includes a plurality of first annular windings connected in sequence, a gap is provided between each two adjacent first annular windings, and a portion of the carrier plate is exposed in the gap; An insulating spacer film is disposed on the first coil winding, and a portion of the insulating spacer film is recessed toward the gap to form a plurality of grooves; A second coil winding is arranged on the insulating spacer film, wherein the second coil winding includes a plurality of second annular windings connected in sequence, each of the second annular windings is arranged in one of the grooves, and The carrier board is removed to obtain the coil circuit board.

2. The manufacturing method according to claim 1, characterized in that The carrier includes a peelable layer and an insulating substrate layer disposed on one side of the peelable layer, the first coil winding is disposed on a side of the insulating substrate layer away from the peelable layer, and the step of "removing the carrier" includes: The peelable layer is removed.

3. The manufacturing method according to claim 1, characterized in that: The step of "arranging a first coil winding at a step" includes: Forming an aluminum paste pattern on the carrier by printing aluminum paste, and The aluminum paste pattern is cured to form the first coil winding.

4. The manufacturing method according to claim 1, characterized in that: Before the step of "arranging an insulating spacer film on the first coil winding", the method further includes: arranging a first cladding metal layer on the outer side of each of the first annular windings; After the step of "arranging a second coil winding on the insulating spacer film", the step further includes: arranging a second cladding metal layer on the outer side of each of the second annular windings.

5. The manufacturing method according to claim 4, characterized in that: The material of the first coil winding includes aluminum, the material of the first cladding metal layer is copper, and the step of "arranging a first cladding metal layer on the outer side of each of the first annular windings" includes: A copper ion solution is disposed outside each of the first annular windings, and copper ions in the copper ion solution undergo a substitution reaction with aluminum in the first annular windings to form a single copper substance, thereby forming the first cladding metal layer.

6. The manufacturing method according to claim 4, characterized in that: The material of the second coil winding includes aluminum, the material of the second cladding metal layer includes copper, and the step of "arranging a second cladding metal layer on the outer side of each of the second annular windings" includes: A copper ion solution is disposed outside each of the second annular windings, and copper ions in the copper ion solution undergo a substitution reaction with aluminum in the second annular windings to form a single copper substance, thereby forming the second cladding metal layer.

7. The manufacturing method according to claim 1, characterized in that: Also includes the steps: A covering film is provided on the second coil winding, and the covering film also covers the insulating spacer film.

8. A coil circuit board, characterized in that: include: A first coil winding, wherein the first coil winding comprises a plurality of first annular windings connected in sequence, and a gap is provided between each two adjacent first annular windings; An insulating spacer film, a portion of which is concave toward the gap to form a plurality of grooves; The second coil winding comprises a plurality of second annular windings connected in sequence, and each of the second annular windings is arranged in one of the grooves.

9. The coil circuit board according to claim 8, characterized in that: The invention also includes a first metal covering layer and a second metal covering layer. The first metal covering layer is disposed on the outer side of each of the first annular windings, and the second metal covering layer is disposed on the outer side of each of the second annular windings.

10. The coil circuit board according to claim 9, characterized in that: The distance between each two adjacent first metal covering layers and the second metal covering layers is 10-20 microns.

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