CN115250579A - Manufacturing method of pressure sensing module and pressure sensing module - Google Patents

Abstract

The application is suitable for the technical field of printed circuit boards, and provides a manufacturing method of a pressure sensing module, which comprises the following steps: providing a flexible circuit board and a daughter board, wherein a circuit board unit is arranged on the surface of the flexible circuit board, and a bonding pad is arranged in the circuit board unit; an auxiliary film is pasted on the surface of the flexible circuit board, covers at least part of the circuit board units and exposes the bonding pad; arranging a conductive bonding material on the bonding pad or at the position of the daughter board corresponding to the bonding pad; the daughter board is attached to the circuit board unit, wherein the auxiliary film is positioned between the daughter board and the circuit board unit, and the conductive bonding material bonds the daughter board and the bonding pad; and removing the auxiliary film to obtain the pressure sensing module, wherein a gap is formed between the daughter board and the circuit board unit. The application also provides a forced induction module. The pressure sensing module and the manufacturing method thereof can solve the problem that the gap height value in the pressure sensing module is not easy to control.

Description

Manufacturing method of pressure sensing module and pressure sensing module

Technical Field

The present disclosure relates to the field of printed circuit board manufacturing technologies, and in particular, to a method for manufacturing a pressure sensing module and a pressure sensing module.

Background

The pressure sensing module is applied to a True Wireless Stereo (TWS) earphone, the pressure sensing principle is that pressure is applied from the outside, so that the height value of a gap between the modules is slightly changed, the capacitance value is further changed, signals are transmitted to a chip to be correspondingly operated after calculation, pressure sensing and control interaction are realized, and the purpose of controlling the earphone is achieved. The forced induction module comprises daughter board and Flexible Printed Circuit (FPC), and the clearance height value between the two becomes the core management and control point of this type of module product.

At present, the daughter board is usually welded on the flexible circuit board by adopting an SMT (surface mount technology) process, and the gap between the daughter board and the flexible circuit board is controlled by the thickness of solder paste of welding points at two ends. However, the solder paste must be melted in the SMT reflow process, and in this case, it is difficult to control the uniformity of the solder joint heights at both ends, and further it is difficult to control the gap height in the pressure sensing module, which affects the product performance.

Disclosure of Invention

In view of this, the present application provides a manufacturing method of a pressure sensing module and a pressure sensing module, which can solve the problem that the gap height in the pressure sensing module is not easy to control.

An embodiment of a first aspect of the present application provides a method for manufacturing a pressure sensing module, including: providing a flexible circuit board and a daughter board, wherein a circuit board unit is arranged on the surface of the flexible circuit board, and a bonding pad is arranged in the circuit board unit;

an auxiliary film is pasted on the surface of the flexible circuit board, covers at least part of the circuit board unit and exposes the bonding pad;

arranging a conductive bonding material on the bonding pad or the daughter board corresponding to the bonding pad;

the daughter board is attached to the circuit board unit, wherein the auxiliary film is located between the daughter board and the circuit board unit, and the conductive bonding material bonds the daughter board and the bonding pad;

and removing the auxiliary film to obtain the pressure sensing module, wherein a gap is formed between the daughter board and the circuit board unit.

In one embodiment, the thickness of the auxiliary film is equal to a preset height value of the gap.

In one embodiment, the flexible circuit board comprises a circuit area and a board area surrounding the outer side of the circuit area, and a plurality of circuit board units are arranged in the circuit area; the auxiliary films are simultaneously arranged on the surfaces of the circuit board units.

In an embodiment, before attaching the auxiliary film on the board surface of the flexible printed circuit board, the manufacturing method further includes: the basis flexible circuit board size cuts the supplementary membrane to form a plurality of windowing portions in the supplementary membrane, windowing portion is used for exposing the pad.

In one embodiment, one opening part of the auxiliary film is arranged in the middle of the auxiliary film and simultaneously exposes the bonding pads of the circuit board units.

In one embodiment, the auxiliary films are arranged at intervals, each auxiliary film corresponds to one row of the circuit board units and extends between two rows of the bonding pads, and the width of each auxiliary film is smaller than or equal to the distance between two bonding pads.

In one embodiment, at least one end of the auxiliary film is a pasting part, and the auxiliary film is pasted on the board area through the pasting part.

In one embodiment, the removing the auxiliary film comprises:

cutting off the adhering part of the auxiliary film on the flexible circuit board, and then drawing out the auxiliary film from one side of the flexible circuit board; or the like, or a combination thereof,

and uncovering the pasting part from the board area, and then drawing out the auxiliary film from one side of the flexible circuit board.

In one embodiment, the conductive adhesive material is a conductive adhesive, and attaching the daughter board to the circuit board unit includes: attaching the daughter board to the circuit board unit by using an automatic reinforcing machine, and then pressing the daughter board and the circuit board unit by using a vacuum press; or the like, or, alternatively,

the electrically conductive bonding material is solder paste, with the daughter board subsides adorn on the flexible line way board, include: and attaching the daughter board to the circuit board unit by using an automatic chip mounter, and then performing reflow soldering.

An embodiment of a second aspect of the present application provides a pressure sensing module manufactured by the manufacturing method of the pressure sensing module according to the first aspect.

According to the manufacturing method of the pressure sensing module, the auxiliary film is arranged on the flexible circuit board before the daughter board is mounted, so that the auxiliary film is positioned at the gap position between the flexible circuit board and the daughter board in the mounting step, and the stability of the gap height value is ensured; the auxiliary film can support the daughter board, can play the effect of support and dispersion pressure when pasting the dress, reduces deformation, the warpage of pasting dress in-process daughter board, makes height value everywhere of same clearance position equal and invariable, consequently, the setting up of auxiliary film has promoted the stability and the homogeneity in clearance, and above-mentioned manufacturing method can obtain the forced induction module that the clearance uniformity is good, avoids the clearance height value difference of same model module product. Therefore, the manufacturing method provided by the application can solve the problem that the gap height value in the pressure sensing module is not easy to control.

In addition, the auxiliary film has good processability, can finish the whole board mounting at one time, does not need to mount each circuit board unit one by one, and has high production efficiency; the auxiliary film can be bent like the flexible circuit board, the auxiliary film is attached and the auxiliary film is removed, the daughter board cannot be damaged, the daughter board can be directly pulled away when the auxiliary film is removed, the operation is simple and convenient, and the manufacturing efficiency is high.

The pressure sensing module has the advantages of good gap consistency, good capacity value consistency and better performance.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

Fig. 1 is a flowchart illustrating a method for manufacturing a pressure sensing module according to an embodiment of the disclosure;

fig. 2 is a schematic structural diagram of a flexible circuit board in a pressure sensing module according to an embodiment of the present disclosure;

FIG. 3 is a schematic structural diagram of an auxiliary membrane provided in an embodiment of the present application;

fig. 4 is a schematic structural diagram of a flexible printed circuit board and an auxiliary film according to an embodiment of the present disclosure;

fig. 5 is a schematic structural diagram of a pressure sensing module provided in an embodiment of the present application during a manufacturing process;

fig. 6 is a schematic structural diagram of a flexible printed circuit board and an auxiliary film according to another embodiment of the present disclosure.

The meaning of the labels in the figures is:

100. a pressure sensing module; 10. a flexible circuit board; 11. a pad; 12. a reinforcing sheet; 101. a line area; 111. a circuit board unit; 102. a board area; 20. a daughter board; 30. a conductive adhesive material; 40. an auxiliary film; 41. a window opening part; 42. and a sticking part.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly or indirectly secured to the other element. When an element is referred to as being "connected to" another element, it can be directly or indirectly connected to the other element. The terms "first", "second" and "first" are used merely for descriptive purposes and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features. The meaning of "plurality" is two or more unless specifically limited otherwise.

It should be noted that, in the embodiments of the present application, the same reference numerals are used to refer to the same components or parts, and for the same parts in the embodiments of the present application, only one of the components or parts may be used as an example to refer to the reference numeral, and it should be understood that, for other similar components or parts, the reference numerals are also used.

In order to explain the technical solution of the present application, the following description is made with reference to the specific drawings and examples.

The embodiment of the first aspect of the present application provides a manufacturing method of a pressure sensing module. Referring to fig. 1, a method for manufacturing a pressure sensing module includes:

step S110: a flexible wiring board and a daughter board are provided.

Referring to fig. 2 to 5, fig. 5 (base:Sub>A) isbase:Sub>A cross-sectional view of the flexible printed circuit 10 shown in fig. 2 along the linebase:Sub>A-base:Sub>A. The surface of the flexible printed circuit 10 is provided with a printed circuit board unit 111, and a pad 11 is disposed in the printed circuit board unit 111, and the pad 11 is used for fixing and electrically connecting the daughter board 20. It is understood that the number of the pads 11 may be two, but is not limited thereto. The flexible wiring board 10 has been subjected to one or more process flow treatments of cutting, drilling, black hole, VCP plating, pattern transfer, AOI detection, attaching/pressing of cover film, solder resist, punching, surface treatment, character, testing, die cutting, reinforcement attachment, and the like. Optionally, a reinforcing sheet 12 is disposed on a side of the flexible circuit board 10 away from the pad 11, and the reinforcing sheet 12 may be a steel sheet or a plate made of epoxy resin (FR 4 type).

The daughter Board may be a steel sheet or a Printed Circuit Board (PCB). If the daughter board 20 is a steel sheet, a steel sheet with a designed size can be directly provided; if the daughter board is a PCB, the PCB is manufactured in advance according to a preset circuit pattern, and a pad (not shown) corresponding to the pad 11 is disposed on the PCB, which can be understood that a circuit for conducting or transmitting signals is also disposed on the PCB, but is not limited thereto.

Step S120: an auxiliary film 40 is attached to the surface of the flexible wiring board 10, and the auxiliary film 40 covers at least a part of the wiring board unit 111 and exposes the pad 11.

Referring to fig. 3 to 5, fig. 5 (B) is a cross-sectional view taken along B-B of fig. 4. The auxiliary film 40 covers at least a part of the circuit board unit 111 and exposes the pads 11, the auxiliary film 40 is used for being clamped between the daughter board 20 and the flexible circuit board 10 in a subsequent mounting step, and the auxiliary film 40 is at least located between the two pads 11, namely corresponding to a gap position where a gap is to be formed.

The auxiliary film 40 may be a high temperature resistant film, such as Polyimide (PI) film, but is not limited thereto.

Optionally, the flexible printed circuit board 10 after the auxiliary film 40 is attached is subjected to plasma treatment, so as to clean the flexible printed circuit board 10, especially clean the bonding pads on the flexible printed circuit board 10.

Step S130: the conductive adhesive material 30 is provided on the pad 11 or at a position of the sub-board 20 corresponding to the pad 11.

The conductive adhesive material 30 may be solder paste or conductive paste. For example, the daughter board 20 is a steel sheet, and the conductive adhesive 30 is a solder paste coated on the bonding pad 11 or a conductive adhesive coated on the steel sheet corresponding to the bonding pad 11; as another example, the sub-board 20 is a PCB, the conductive adhesive material 30 may be coated on the pad 11 of the circuit board unit 111 or on a pad of the PCB, and the conductive adhesive material 30 may be solder paste or conductive adhesive.

It is understood that the conductive adhesive material 30 is not limited to solder paste and conductive paste, and may be other conductive and adhesive materials.

It is understood that the order of steps S120 and S130 may be reversed.

Step S140: the daughter board 20 is attached to the wiring board unit 111.

Specifically, the daughter board 20 is attached to the circuit board unit 111, the conductive adhesive material 30 adheres the daughter board 20 and the pad 11, and the conductive adhesive material 30 is used to fix the daughter board 20 and realize a conductive function. When mounting, the auxiliary film 40 is located between the daughter board 20 and the circuit board unit 111, and the auxiliary film 40 can fill the gap between the two pads 11 between the daughter board 20 and the flexible circuit board 10, so as to support the daughter board 20 and disperse pressure, and avoid the inclination and warpage of the daughter board 20.

Step S150: the auxiliary film 40 is removed to obtain the pressure sensing module 100.

Specifically, referring to (b) and (c) of fig. 5, after the daughter board 20 is mounted, the auxiliary film 40 is removed from the flexible printed circuit board 10, and a gap (indicated by G in fig. 5) is formed between the daughter board 20 and the printed circuit board unit 111, so as to obtain the pressure sensing module 100.

The pressure sensing module 100 includes a daughter board 20 and a circuit board unit 111, the daughter board 20 is fixed on the circuit board unit 111 through a conductive adhesive material 30, and since the conductive adhesive material 30 has a certain thickness, after the assembly, a gap with a preset height (H) is formed between the board surfaces of the daughter board 20 and the flexible circuit board 10, so that the pressure sensing module 100 obtains a certain capacitance value. In the using process, the sub-board 20 is stressed and can deform towards the flexible printed circuit board 10, so that the height of the gap between the sub-board 20 and the flexible printed circuit board 10 changes, the capacitance value of the pressure sensing module 100 changes, and the flexible printed circuit board 10 determines the pressure detection result based on the change of the capacitance value.

According to the manufacturing method of the pressure sensing module, before the daughter board 20 is mounted, the auxiliary film 40 is arranged on the flexible circuit board 10, so that the auxiliary film 40 is positioned at the gap position between the flexible circuit board 10 and the daughter board 20 in the mounting step, and the stability of the gap height value is ensured; supplementary membrane 40 can support daughter board 20, can play the effect of support and dispersion pressure when pasting the dress, reduces and pastes deformation, the warpage of dress in-process daughter board 20, makes height value everywhere of same clearance position equal and invariable, consequently, supplementary membrane 40 sets up stability and the homogeneity that promotes the clearance, can obtain the good forced induction module 100 of clearance uniformity, avoids the clearance height value difference of same model module product. Therefore, the manufacturing method provided by the present application can solve the problem that the gap height in the pressure sensing module 100 is not easy to control.

The scheme uses the auxiliary film 40 to fill the gap position, compared with the prior art, the auxiliary film 40 has good machinability, can finish the whole board mounting at one time, does not need to mount each circuit board unit 111 one by one, and has high production efficiency. In addition, the auxiliary film 40 can be folded like the flexible circuit board 10, so that the auxiliary film 40 is attached and the auxiliary film 40 is removed without damaging the daughter board 20, and the auxiliary film can be directly pulled away when being removed, so that the operation is simple and convenient.

The thickness of the auxiliary film 40 is adapted to the gap after the pressure sensing module 100 is assembled. Alternatively, the thickness of the auxiliary film 40 is equal to the preset height value (H) of the gap, that is, the thickness of the auxiliary film 40 is set according to the height value of the gap required by design. The auxiliary film 40 with a preset thickness is arranged between the flexible circuit board 10 and the daughter board 20 before lamination, so that the gap position is not easy to deform. It is understood that the thickness of the auxiliary film 40 may be slightly smaller than the predetermined height of the gap, as long as the sub-board 20 can be supported.

As shown in fig. 2 and 4, the flexible wiring board 10 includes a wiring area 101 and a board area 102 surrounding the outside of the wiring area 101, and the wiring area 101 includes a plurality of wiring board units 111; the auxiliary film 40 is simultaneously provided on the surfaces of the plurality of wiring board units 111.

By adopting the technical scheme, one auxiliary film 40 can be arranged on the surfaces of the circuit board units 111, the auxiliary film 40 does not need to be attached to each circuit board unit 111 independently, and the manufacturing efficiency is improved.

In this embodiment, the flexible printed circuit 10 is a composite structure, and one flexible printed circuit 10 includes a plurality of printed circuit units 111. The plate splicing is mainly used for improving the production and processing efficiency, a plurality of circuit board units 111 can be produced simultaneously by splicing more than one plate, and quick mounting and pressing can be realized during mounting and pressing to form a plurality of pressure sensing module 100 products. It can be understood that each board unit 111 and the corresponding daughter board 20 are assembled to form a pressure sensing module 100. After step S150, the flexible printed circuit board 10 may be cut to form a single pressure sensing module product; or directly delivering the assembly structure to a client, and reprocessing by the client according to the subsequent assembly requirement. The shape and the number of the circuit board units 111 are also only illustrated schematically. In other embodiments, the flexible wiring board 10 is not limited to the imposition structure, and may include only one wiring board unit 111.

In an embodiment, before the auxiliary film 40 is attached to the board surface of the flexible circuit board 10, the manufacturing method further includes: the auxiliary film 40 is cut according to the size of the flexible wiring board 10 to form a plurality of window portions in the auxiliary film 40, the window portions being used to expose the pads 11. Thus, the manufacturing method cuts the auxiliary film 40 in advance to make the auxiliary film 40 fit to the size of the flexible circuit board 10, and manufactures the windowing portion 41 on the auxiliary film 40 to facilitate the subsequent attachment of the auxiliary film 40.

Alternatively, the auxiliary film 40 may be sized to cover all of the board units 111 on the flexible wiring board 10, i.e., the auxiliary film 40 may be integrally attached to the flexible wiring board 10. It will be appreciated that the auxiliary film 40 may also be sized to cover portions of the wiring board units 111, such as one auxiliary film 40 covering a row of wiring board units 111. The window portion 41 is used to expose the pad 11 so as to escape the pad 11. In addition, in the wiring region 101, the connection region between the wiring board unit 111 and the wiring board unit 111 is an auxiliary region. The auxiliary area or the flexible printed circuit board 10 unit is provided therein with a marking point, i.e., an optical recognition point, for performing alignment when the daughter board 20 is mounted, and the windowing portion is also used for exposing the marking point.

In one embodiment, as shown in fig. 3 and 4, one opening part 41 of the auxiliary film 40 is disposed in the middle of the auxiliary film 40 and exposes the pads 11 of the plurality of circuit board units 111. For example, the window 41 has a rectangular shape, and the window 41 corresponds to two rows of the wiring board units 111 and exposes one of the pads 11 in the corresponding wiring board unit 111.

Through adopting above-mentioned technical scheme, conveniently cut supplementary membrane 40, need not to set up the portion of windowing of too much quantity, promoted preparation efficiency.

In one embodiment, the two pads 11 in the wiring board unit 111 are arranged at intervals along a first direction (Y direction); in the first direction, the size of the auxiliary film 40 is smaller than the size of the circuit area 101, one pad 11 in the circuit board unit 111 is provided in the window portion 41, and the other pad 11 is provided on the side of the auxiliary film 40 close to the board area 102.

In the first direction, the auxiliary film 40 can escape from the pad 11 of the wiring board unit 111 while the window 41 of the auxiliary film 40 exposes the other pad 11 in the wiring board unit 111. In this manner, the number of the window portions 41 can be reduced by cutting the auxiliary film 40. In a second direction (X direction) perpendicular to the first direction, the size of the auxiliary film 40 is larger than that of the circuit area 101, so that the end of the auxiliary film 40 can be stuck to the board area 102.

In one embodiment, at least one end of the auxiliary film 40 is a pasting portion 42, and the auxiliary film 40 is pasted to the board region 102 through the pasting portion 42. As shown in fig. 4, alternatively, both ends of the auxiliary film 40 in the length direction thereof are attached portions, and the size of both ends in the width direction thereof is smaller than that of the circuit area 101, so that the auxiliary film 40 can be attached to the board area 102 through the attached portions 42, and the other area of the auxiliary film 40 directly covers the flexible wiring board 10 without being attached. Therefore, the auxiliary film 40 does not need to be pasted on the flexible circuit board 10 in a whole piece, the pasting area is small, and the auxiliary film 40 is convenient to remove in a follow-up mode.

The present embodiment provides only one indication of cutting and bonding of the auxiliary film 40, and the cutting size and bonding area of the auxiliary film 40 can be flexibly adjusted according to different imposition modes, so long as the gap position can be supported in the pressing/soldering and post-process, and the auxiliary film can be smoothly removed at last, which is a feasible category.

In one embodiment, the step S150 of removing the auxiliary film 40 includes: the attaching portion 42 of the auxiliary film 40 is cut on the flexible wiring board 10 so that the attaching portion 42 can be separated from the corresponding board area 102, and then the auxiliary film 40 is pulled out from one side of the flexible wiring board 10.

In another embodiment, step S150 removes the auxiliary film 40, including: the adhesion portion 42 is peeled off from the plate edge region 102, and then the auxiliary film 40 is pulled out from one side of the flexible wiring board 10.

Since the auxiliary film 40 is adhered to the board region only through the adhering portion, when the auxiliary film 40 is removed, only the adhering portion 42 needs to be cut off or the adhering portion 42 needs to be separated from the board region 102, and then the whole auxiliary film 40 can be pulled away, which is convenient and efficient to operate.

The conductive adhesive 30 may be a conductive adhesive, and the step S140 attaches the daughter board 20 to the circuit board unit 111, and includes: the daughter board 20 is attached to the circuit board unit 111 by using an automatic reinforcement machine, the daughter board 20 and the flexible circuit board 10 are pre-fixed, and then the daughter board 20 and the circuit board unit 111 are pressed by using a vacuum press machine, so as to ensure the bonding reliability of the flexible circuit board 10 and the daughter board 20. This embodiment uses the vacuum fast press to suppress, and during the suppression, daughter board 20 is pressed towards the top, and need still set up release film and pressfitting buffer material in the flexible line way board 10 and the daughter board 20 outside. Specifically, a release film is respectively disposed on one side of the sub-board 20 away from the flexible printed circuit board 10 and one side of the flexible printed circuit board 10 away from the sub-board 20, and a press-fit buffer material, such as glass fiber cloth, is disposed below the release film disposed on the flexible printed circuit board 10. The first piece after pressing needs to confirm the peeling strength, deviation condition and clearance height value after pressing, and adjust the technological parameters of subsequent products. Optionally, the conductive adhesive is a thermosetting conductive adhesive, and the conductive adhesive is baked by using an oven after being pressed, so that the conductive adhesive is completely cured.

It should be noted that, the size of the conductive adhesive should be reasonably set according to the fluidity of the conductive adhesive during pressing, so that the conductive adhesive after pressing covers and bonds the bonding pad 11 without overflowing the edge of the flexible circuit board 10/sub-board 20.

The conductive adhesive 30 may also be solder paste, and the step S140 attaches the daughter board 20 to the flexible printed circuit board 10, including: the daughter board 20 is mounted on the circuit board unit 111 using an automatic chip mounter, and then reflow soldering is performed.

Specifically, solder paste is printed on the bonding pad 11 of the flexible printed circuit board 10 by a steel mesh printing method. Attention needs to be paid to control the amount of the tin paste, so that the molten tin paste meets the welding requirement, and the gap height value is not influenced by too much tin paste. During actual production, a first production plate can be arranged according to the height value of the gap, and the solder paste missing printing quantity is adjusted according to the mounting condition of the first plate. And (3) mounting by using an automatic mounting machine, and performing reflow soldering after accurately mounting the daughter board 20 to a preset position. And sending the mounted flexible circuit board 10 and the sub-board 20 into a reflow oven to firmly bond the sub-board 20 and the flexible circuit board 10 together. During reflow soldering, the solder paste melts, and when the solder paste melts to a solidified state, a pulling force is generated between the bonding pad 11 and the daughter board 20, but the auxiliary film 40 fills the gap position and plays a role in supporting the daughter board 20, so that the solder pastes at two ends of the solidified gap position keep relatively constant.

Referring to fig. 1 and 6, in another embodiment, in step S120, a plurality of auxiliary films 40 are disposed at intervals, each auxiliary film 40 corresponds to one row of circuit board units 111 and extends between two rows of pads 11, and a width of each auxiliary film 40 is smaller than or equal to a distance between two pads 11. At this time, it is not necessary to provide a window portion exposing the pad 11 on the auxiliary film 40.

In the present embodiment, it is only necessary to cut out a plurality of auxiliary films 40 to shape and provide a window portion exposing the indication position, and each auxiliary film 40 can still cover a plurality of wiring board units 111 at the same time. It is to be understood that the present application does not limit the shape of the auxiliary film 40.

A second aspect of the present application provides a pressure sensing module 100, which is manufactured by the method for manufacturing the pressure sensing module 100 according to any embodiment of the first aspect.

The pressure sensing module 100 comprises a flexible circuit board 10 and a daughter board 20 for pressure sensing, wherein the flexible circuit board 10 is provided with a bonding pad 11, and the daughter board 20 is fixed on the bonding pad 11 through a conductive bonding material; a gap having a predetermined height is formed between the sub-board 20 and the flexible wiring board 10.

When the daughter board 20 receives pressure applied from the outside, the height of the gap changes, and then the capacitance value of the pressure sensing module 100 changes, and the flexible printed circuit board 10 can determine a pressure detection result based on the change of the capacitance value. The pressure sensing module 100 may be used in a TWS headset or other electronic device requiring pressure detection.

The application provides a pressure sensing module 100 uses supplementary membrane 40 to support daughter board 20 and fill the clearance position in the manufacturing process, has promoted the stability and the homogeneity in clearance. Therefore, the pressure sensing module 100 has a good consistency of the capacitance values, the pressure sensing module 100 is not easy to deform during manufacturing, and the yield is good.

The pressure sensing module 100 and the manufacturing method thereof can ensure the stability and consistency of the gap between the sub-board 20 and the flexible circuit board 10 in the pressure sensing module 100, and improve the product yield and the product quality.

The above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.

Claims (10)

1. A manufacturing method of a pressure sensing module is characterized by comprising the following steps:

providing a flexible circuit board and a daughter board, wherein a circuit board unit is arranged on the surface of the flexible circuit board, and a bonding pad is arranged in the circuit board unit;

an auxiliary film is pasted on the surface of the flexible circuit board, covers at least part of the circuit board unit and exposes the bonding pad;

arranging a conductive bonding material on the bonding pad or the daughter board corresponding to the bonding pad;

the daughter board is attached to the circuit board unit, wherein the auxiliary film is located between the daughter board and the circuit board unit, and the conductive bonding material bonds the daughter board and the bonding pad;

and removing the auxiliary film to obtain the pressure sensing module, wherein a gap is formed between the daughter board and the circuit board unit.

2. The method of claim 1, wherein the auxiliary film has a thickness equal to a predetermined height of the gap.

3. The method of manufacturing a pressure sensing module according to claim 1, wherein the flexible printed circuit board includes a circuit area and a board area surrounding an outer side of the circuit area, and a plurality of the printed circuit board units are disposed in the circuit area; the auxiliary films are simultaneously arranged on the surfaces of the circuit board units.

4. The method for manufacturing a pressure sensing module according to claim 3, wherein before the auxiliary film is attached to the surface of the flexible printed circuit board, the method further comprises: the basis flexible circuit board size cuts the supplementary membrane to form a plurality of windowing portions in the supplementary membrane, windowing portion is used for exposing the pad.

5. The method of manufacturing a pressure sensing module according to claim 4, wherein a window portion of the auxiliary film is disposed in a middle portion of the auxiliary film and exposes the pads of the plurality of circuit board units.

6. The method of claim 3, wherein the plurality of auxiliary films are spaced apart from one another, each auxiliary film extends between two rows of the pads and corresponds to one row of the circuit board units, and a width of each auxiliary film is less than or equal to a distance between two of the pads.

7. The method of claim 3, wherein at least one end of the auxiliary film is a bonding portion, and the auxiliary film is bonded to the board region through the bonding portion.

8. The method of claim 7, wherein removing the auxiliary membrane comprises:

cutting off the adhering part of the auxiliary film on the flexible circuit board, and then drawing out the auxiliary film from one side of the flexible circuit board; or the like, or, alternatively,

and the pasting part is uncovered from the board area, and then the auxiliary film is drawn out from one side of the flexible circuit board.

9. The method of making a pressure sensing module of any of claims 1-8, wherein the conductive adhesive material is conductive glue, and the attaching the daughter board to the circuit board unit comprises: attaching the daughter board to the circuit board unit by using an automatic reinforcing machine, and then pressing the daughter board and the circuit board unit by using a vacuum press; or the like, or, alternatively,

the electrically conductive bonding material is solder paste, the daughterboard is mounted on the flexible circuit board, including: and attaching the daughter board to the circuit board unit by using an automatic chip mounter, and then performing reflow soldering.

10. A pressure sensing die set, characterized in that it is manufactured by the method for manufacturing a pressure sensing die set according to any one of claims 1 to 9.

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