Pressure sensing module, manufacturing method thereof, and electronic device

Abstract

The present application is applicable to the technical field of printed circuit boards, and proposes a method for manufacturing a pressure sensing module, comprising: providing a first sub-board provided with a first solder pad, a second sub-board provided with a second solder pad, and an insulating dielectric layer, the first sub-board and the second sub-board respectively having a preset area for forming a capacitor gap; aligning and pressing the first sub-board, the insulating dielectric layer, and the second sub-board, the insulating dielectric layer being provided between the first solder pad and the corresponding second solder pad and avoiding the preset area, the first solder pad and the second solder pad being fixedly bonded by the insulating dielectric layer; drilling holes on the first sub-board and the second sub-board, the holes passing through the first solder pad and the corresponding second solder pad; processing the holes into metallized holes, the metallized holes connecting the first solder pad and the corresponding second solder pad, and forming a capacitor gap between the first sub-board and the second sub-board. The present application also provides a pressure sensing module and an electronic device. The present application solves the problem that the gap height value in the pressure sensing module is difficult to control.

Description

Technical Field

[0001] The present application relates to the technical field of printed circuit board manufacturing, and in particular to a pressure sensing module, a manufacturing method thereof, and an electronic device. Background Art

[0002] The pressure-sensing module used in True Wireless Stereo (TWS) earphones works by applying external pressure, causing subtle changes in the gap height between the modules. This, in turn, changes the capacitance. This signal is then transmitted to the chip, where it is processed and operated accordingly, enabling pressure sensing and control interaction, ultimately controlling the earphones. The pressure-sensing module consists of a daughterboard and a flexible printed circuit board (Flexible Printed Circuit, the first daughterboard). The gap height between the two is a key control point for this type of module product.

[0003] Currently, daughterboards are typically soldered to flexible circuit boards using SMT (surface mount technology), with the gap between them controlled by the thickness of the solder paste at each end. However, the solder paste must melt during the SMT reflow process, making it difficult to maintain consistent solder joint height. Consequently, it's difficult to control the gap height within the pressure sensing module, impacting product performance. Summary of the Invention

[0004] In view of this, the present application provides a pressure sensing module and a manufacturing method thereof, and an electronic device, which can solve the problem that the gap height value in the pressure sensing module is difficult to control.

[0005] An embodiment of a first aspect of the present application provides a method for manufacturing a pressure sensing module, comprising: providing a first sub-board having a first solder pad, a second sub-board having a second solder pad, and an insulating dielectric layer, wherein the first sub-board and the second sub-board each have a predetermined area for forming a capacitor gap;

[0006] Aligning and pressing the first sub-board, the insulating dielectric layer, and the second sub-board, wherein the insulating dielectric layer is disposed between the first solder pad and the corresponding second solder pad and avoids the preset area, and the first solder pad and the second solder pad are fixedly bonded by the insulating dielectric layer;

[0007] Drilling holes on the first sub-board and the second sub-board, the holes passing through the first soldering pads and the corresponding second soldering pads;

[0008] The hole is processed into a metallized hole, the metallized hole conducts the first pad and the corresponding second pad, and the capacitor gap is formed between the first sub-board and the second sub-board.

[0009] In one embodiment, the insulating dielectric layer is a prepreg or pure adhesive.

[0010] In one embodiment, before the first sub-board, the insulating dielectric layer and the second sub-board are aligned and pressed together, the manufacturing method further includes: attaching an auxiliary film on the surface of the first sub-board or the second sub-board, the auxiliary film covering at least a portion of the preset area and exposing the first pad or the second pad, and the thickness of the auxiliary film is equal to the preset height of the capacitor gap; after the hole is processed into a metallized hole, the manufacturing method further includes: removing the auxiliary film.

[0011] In one embodiment, the auxiliary film has an adhesive portion and a window portion, the auxiliary film is adhered to the first sub-board or the second sub-board through the adhesive portion, and the window portion can expose the first pad or the second pad.

[0012] In one embodiment, the first sub-board and the second sub-board both include a circuit area and a board edge area surrounding the circuit area, and a plurality of circuit board units are provided in the circuit area; the auxiliary film is simultaneously provided on the surfaces of the plurality of circuit board units.

[0013] In one embodiment, after the holes are processed into metallized holes, the manufacturing method further includes: manufacturing outer circuits on the first sub-board and the second sub-board, and manufacturing an outer circuit protection layer, wherein the outer circuit protection layer is at least one of a covering film and a solder mask layer.

[0014] In one embodiment, after manufacturing the outer circuit protection layer, the manufacturing method further includes: performing controlled-depth milling from the side where the second sub-board is located toward the side where the first sub-board is located to remove the area of ​​the second sub-board outside the preset area.

[0015] In one embodiment, the first sub-board is a flexible circuit board, and the second sub-board is a rigid circuit board; after the holes are processed into metallized holes, the manufacturing method further includes: attaching a reinforcement plate on a side of the first sub-board away from the capacitor gap.

[0016] A second aspect of the present application provides a pressure sensing module, comprising:

[0017] a first sub-board, wherein a first solder pad is provided on the first sub-board;

[0018] a second sub-board, wherein a second solder pad is provided on the second sub-board;

[0019] an insulating dielectric layer bonded between the first pad and the second pad;

[0020] The pressure sensing module is provided with metallized holes corresponding to the first pad and the second pad, and the metallized holes penetrate and connect the first pad and the corresponding second pad; a capacitor gap is formed between the first sub-board and the second sub-board.

[0021] A third aspect of the present application provides an electronic device, which includes a pressure sensing module manufactured by the pressure sensing module of the first aspect, or the pressure sensing module provided by the second aspect.

[0022] In the manufacturing method of the above-mentioned pressure sensing module, the first sub-board and the second sub-board are pressed together through an insulating dielectric layer, replacing the traditional SMT solder paste mounting process to realize the assembly of the sub-boards, which facilitates the precise control of the thickness of the insulating dielectric layer and the height of the capacitor gap, and is conducive to obtaining a pressure sensing module with good gap consistency, and the size of the gap height value can be flexibly adjusted according to design requirements. In addition, the present application utilizes an insulating dielectric layer to bond the first solder pad and the second solder pad, and utilizes metallized holes to connect the first solder pad and the second solder pad. Compared with the solder mounting and conductive adhesive bonding methods, the metallized holes can obtain better conduction stability, resistance consistency and product reliability, thereby obtaining a more stable pressure sensing value. Therefore, the above-mentioned manufacturing method solves the problem that the gap height value in the pressure sensing module is difficult to control, improves the gap consistency and capacitance consistency, and improves the performance and yield of the product.

[0023] In the aforementioned pressure sensing module and electronic device, the first and second sub-boards are pressed together and fixed via an insulating dielectric layer, facilitating precise control of the thickness of the insulating dielectric layer and the height of the capacitor gap. This results in good gap consistency and good capacitance consistency in the pressure sensing module. Furthermore, the aforementioned pressure sensing module utilizes an insulating dielectric layer to bond the first and second pads, and utilizes metallized vias to provide electrical connection between the first and second pads. Compared to solder mounting and conductive adhesive bonding, metallized vias offer improved conductivity stability, resistance consistency, and product reliability, resulting in more stable pressure sensing values. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0025] Figure 1 A flowchart of a method for manufacturing a pressure sensing module according to an embodiment of the present application;

[0026] Figure 2A schematic diagram of the first sub-board, the second sub-board, and the insulating dielectric layer after lamination provided in one embodiment of the present application;

[0027] Figure 3 for Figure 2 Schematic diagram of the first sub-board, the second sub-board and the insulating dielectric layer after drilling;

[0028] Figure 4 A schematic diagram of the structure of a pressure sensing module is provided for an embodiment of the present application;

[0029] Figure 5 A flowchart of a method for manufacturing a pressure sensing module according to another embodiment of the present application;

[0030] Figure 6 A schematic diagram of the first sub-board, the second sub-board, the insulating dielectric layer, and the auxiliary film after lamination provided in one embodiment of the present application;

[0031] Figure 7 for Figure 6 Schematic diagram of the first sub-board, the second sub-board, the insulating dielectric layer and the auxiliary film after drilling;

[0032] Figure 8 A schematic diagram of a first sub-board provided in an embodiment of the present application;

[0033] Figure 9 A schematic diagram of a first sub-plate and an auxiliary film provided in one embodiment of the present application;

[0034] Figure 10 A schematic diagram of a second daughter board provided in an embodiment of the present application.

[0035] The meanings of the marks in the figure are:

[0036] 100, pressure sensing module; 10, first sub-board; 11, first solder pad; 12, reinforcement sheet; 101, circuit area; 111, circuit board unit; 102, board edge area; 103, hole; 104, metallized hole; 105, capacitor gap; 20, second sub-board; 21, second solder pad; 30, insulating dielectric layer; 40, auxiliary film; 41, window portion; 42, adhesive portion. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the following further describes this application in detail with reference to the accompanying drawings, i.e., embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0038] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it may be directly or indirectly on the other component. When a component is referred to as being "connected to" another component, it may be directly or indirectly connected to the other component. The terms "first" and "second" are used only for descriptive purposes and should not be understood as indicating or implying relative importance or implicitly specifying the number of technical features. "Multiple" means two or more, unless otherwise expressly specified.

[0039] It should also be noted that, in the embodiments of the present application, the same figure mark represents the same component or the same part. For the same parts in the embodiments of the present application, the figure may only mark one of the parts or components as an example. It should be understood that the figure mark also applies to other identical parts or components.

[0040] In order to illustrate the technical solution of the present application, the following description is given with reference to specific drawings and embodiments.

[0041] The embodiment of the first aspect of the present application proposes a method for manufacturing a pressure sensing module. Figures 1 to 4 , the manufacturing method of the pressure sensing module includes:

[0042] Step S110 : providing a first sub-board 10 having a first solder pad 11 , a second sub-board 20 having a second solder pad 21 , and an insulating dielectric layer 30 .

[0043] The first sub-board 10 and the second sub-board 20 respectively have a preset area (A) for forming a capacitor gap, and the preset areas on the first sub-board 10 and the second sub-board 20 are arranged opposite to each other.

[0044] Both the first sub-board 10 and the second sub-board 20 can be flexible circuit boards (first sub-board 10) or rigid circuit boards (PCBs). In one embodiment, the first sub-board 10 is a flexible circuit board, and the second sub-board 20 is a rigid double-sided board. In other embodiments, the first sub-board 10 and the second sub-board 20 can also be single-sided boards, multi-layer boards, etc. Single-sided, double-sided, and multi-layer boards are all measured based on the effective circuit pattern layer, with double-sided boards representing two effective circuit pattern layers. The first solder pad 11 can be located on at least one circuit layer of the first sub-board 10, and the second solder pad 21 can also be located on at least one circuit layer of the second sub-board 20.

[0045] Before lamination, the insulating dielectric layer 30 needs to be cut and formed. The purpose of cutting is to make the insulating dielectric layer 30 adapt to the size of the first sub-board 10 and the second sub-board 20; during forming, the insulating dielectric layer 30 needs to be opened in advance to avoid the position, and only the dielectric layer in the area where the first sub-board 10 and the second sub-board 20 need to be bonded is retained, and other areas need to be removed.

[0046] Step S120 : Align and press the first sub-board 10 , the insulating dielectric layer 30 , and the second sub-board 20 .

[0047] An insulating dielectric layer 30 is disposed between the first solder pad 11 and the corresponding second solder pad 21, leaving a predetermined area. The first solder pad 11 and the second solder pad 21 are fixedly bonded together by the insulating dielectric layer 30. The insulating dielectric layer 30 can be, but is not limited to, prepreg or pure adhesive. It can also be made of other adhesive and insulating materials. The insulating dielectric layer 30 can melt under high temperature and high pressure conditions to bond the first sub-board 10 to the second sub-board 20.

[0048] It should be noted that the thickness of insulating dielectric layer 30 should be determined based on the desired height of the capacitor gap. For example, if insulating dielectric layer 30 is a prepreg, which is commercially available in a variety of thicknesses, a prepreg of a corresponding thickness can be selected for lamination based on the desired height of the capacitor gap. Alternatively, the thickness of insulating dielectric layer 30 can be equal to or slightly greater than the desired height of the capacitor gap.

[0049] Step S130 : drilling holes 103 on the first sub-board 10 and the second sub-board 20 , wherein the holes 103 pass through the first solder pads 11 and the corresponding second solder pads 21 .

[0050] like Figure 3 As shown, the hole 103 can be drilled from one side of the first sub-board 10 or from one side of the second sub-board 20. The drilling position of the hole 103 corresponds to the first solder pad 11 and the second solder pad 21. The hole 103 can pass through the first sub-board 10 and the second sub-board 20, or only pass through one of the sub-boards, but must at least pass through the first solder pad 11 and the second solder pad 21.

[0051] Step S140 : processing the hole 103 into a metallized hole 104 .

[0052] The metallized hole 104 is conductive and can conduct electricity between the first pad 11 and the corresponding second pad 21 , forming a capacitor gap 105 between the first sub-board 10 and the second sub-board 20 .

[0053] like Figure 4 As shown, hole 103 is processed into a metallized hole 104, and the inner wall of metallized hole 104 is provided with a conductive metal layer, so that metallized hole 104 can conduct electricity between first pad 11 and second pad 21, and further conduct electricity between the circuits on first sub-board 10 and second sub-board 20. Optionally, hole 103 can be processed into metallized hole 104 by copper deposition and electroplating, or by using a black hole / black shadow and electroplating method. It is understood that other feasible metallization processes can also be used.

[0054] Since the insulating dielectric layer 30 has a certain thickness, the predetermined area of ​​the first sub-board 10 and the predetermined area of ​​the second sub-board 20 are spaced apart from each other and form a capacitor gap 105 with a predetermined height, so that the pressure sensing module 100 obtains a certain capacitance value.

[0055] During use, the second sub-board 20 may be deformed toward the first sub-board 10 under force, causing the height of the capacitor gap 105 to change, thereby changing the capacitance value of the pressure sensing module 100. The pressure sensing module 100 determines the pressure detection result based on the change in capacitance value.

[0056] The manufacturing method provided in the present application can obtain a pressure sensing module 100, which includes a first sub-board 10 provided with a first solder pad 11 and a second sub-board 20 provided with a second solder pad 21, and an insulating dielectric layer 30 bonded between the first solder pad 11 and the second solder pad 21. The pressure sensing module 100 is provided with metallized holes 104 corresponding to the first solder pad 11 and the second solder pad 21, and the metallized holes 104 pass through and connect the first solder pad 11 and the corresponding second solder pad 21; a capacitor gap 105 is formed between the first sub-board 10 and the second sub-board 20, and the capacitor gap 105 is provided between a preset area of ​​the first sub-board 10 and a preset area of ​​the second sub-board 20.

[0057] In the manufacturing method of the above-mentioned pressure sensing module 100, the first sub-board 10 and the second sub-board 20 are pressed together through the insulating dielectric layer 30, replacing the traditional SMT solder paste mounting process to realize the assembly of the sub-boards. Compared with controlling the amount of solder paste printed and the thickness of the solder paste after reflow soldering and melting and solidification, the manufacturing method provided by the present application facilitates precise control of the thickness of the insulating dielectric layer 30 and the height of the capacitor gap 105, which is conducive to obtaining a pressure sensing module 100 with good gap consistency, and the size of the gap height value can be flexibly adjusted according to design requirements. In addition, the present application uses the insulating dielectric layer 30 to bond the first solder pad 11 and the second solder pad 21, and uses the metallized hole 104 to conduct the first solder pad 11 and the second solder pad 21. Compared with the solder mounting and conductive adhesive bonding methods, the metallized hole 104 can obtain better conduction stability, resistance consistency and product reliability, thereby obtaining a more stable pressure sensing value. Therefore, the above-mentioned manufacturing method solves the problem of difficult control of the gap height value in the pressure sensing module 100, improves the gap consistency and capacitance consistency, and improves the performance and yield of the product.

[0058] The above-mentioned manufacturing method adopts a conventional press-fit assembly process, and there is no need to use an SMT process to complete the assembly of the first daughter board 10 and the second daughter board 20. Therefore, there is no need to be equipped with the production equipment required for SMT. The production and manufacturing of the pressure-capacitive module product can be completed using ordinary circuit board production and processing equipment, saving production costs.

[0059] Optionally, the insulating dielectric layer 30 may be a low-flow prepreg or a no-flow prepreg, which can better control the amount of glue flow and thereby control the thickness of the insulating dielectric layer 30 after lamination to ensure the consistency of the capacitor gap 105; in addition, it can avoid glue overflowing into other areas, such as glue overflowing into the gap position, causing inconsistent height of the capacitor gap 105.

[0060] Please refer to Figures 5 to 7 Another embodiment of the present application provides a method for manufacturing a pressure sensing module 100, wherein steps S210, S230, S240, and S250 are respectively Figure 1 Steps S110, S120, S130, and S140 are the same and will not be repeated here.

[0061] In this embodiment, before the first sub-board 10, the insulating dielectric layer 30 and the second sub-board 20 are aligned and pressed together, the manufacturing method also includes step S220: an auxiliary film 40 is affixed to the surface of the first sub-board 10 or the second sub-board 20, and the auxiliary film 40 covers at least a portion of the preset area and exposes the first pad 11 or the second pad 21, and the thickness of the auxiliary film is equal to the preset height of the capacitor gap 105.

[0062] Figure 6 FIG. 1 shows a schematic diagram of the structure after the first sub-board 10 and the second sub-board 20 are pressed together. Figure 6 As shown, before lamination, an auxiliary film 40 is attached to the first sub-board 10 or the second sub-board 20. The thickness of the auxiliary film 40 is set according to the height value of the gap required by the design. The auxiliary film 40 can be a high-temperature resistant film, such as a polyimide (PI) film, but is not limited thereto.

[0063] During lamination, the auxiliary film 40 is provided at least in a preset area corresponding to the gap between the first sub-board 10 and the second sub-board 20. The auxiliary film 40 can fill the gap between the two first pads 11 (or the two second pads 21) of the first sub-board 10 and the second sub-board 20, thereby supporting the second sub-board 20 and dispersing the pressure, thereby preventing the first sub-board 10 or the second sub-board 20 from tilting, warping, or deformation. Furthermore, the auxiliary film 40 can make the height values ​​of the capacitor gap 105 equal and constant at all locations. Therefore, the provision of the auxiliary film 40 further enhances the stability and uniformity of the capacitor gap 105, thereby facilitating the acquisition of a pressure sensing module 100 with good capacitance consistency and avoiding differences in the height of the capacitor gap 105 between module products of the same model.

[0064] In addition, the insulating dielectric layer 30 and the auxiliary film 40 need to be spaced apart to prevent the insulating dielectric layer 30 from bonding the first sub-board 10, the second sub-board 20 and the auxiliary film 40 together during lamination, which would make it impossible to remove the auxiliary film 40 smoothly in subsequent processes; in particular, it is prevented that the insulating dielectric layer 30 directly bonds to the preset areas of the first sub-board 10 and the second sub-board 20, which would render the product scrapped.

[0065] like Figure 5 、 Figure 7 As shown, after pressing in step S220, step S230 is executed to drill holes on the first sub-board 10 and the second sub-board 20. For steps S240 and S250, please refer to Figure 1 The embodiment shown.

[0066] After the holes are processed into metallized holes 104 in step S250 , the manufacturing method further includes step S260 : removing the auxiliary film 40 . After the auxiliary film 40 is removed, a capacitor gap 105 is formed between the first sub-board 10 and the second sub-board 20 .

[0067] Please refer to Figures 8 to 10 The auxiliary film 40 has an adhesive portion 42 and a window portion 41. The auxiliary film 40 is attached to the first sub-board 10 or the second sub-board 20 via the adhesive portion 42, and the window portion 41 can expose the first solder pad 11 or the second solder pad 21. The window portion 41 can also be used to expose areas that need to be exposed, such as lamination alignment marking points.

[0068] by Figure 9 For example, the auxiliary film 40 is attached to the first sub-board 10 . It is understood that the auxiliary film 40 can also be attached to the second sub-board 20 .

[0069] In this embodiment, by providing an adhesive portion 42 on the auxiliary film 40, there is no need to adhere the entire auxiliary film 40. Only a partial area needs to be adhered to position the auxiliary film 40, and the remaining area can be covered on the first sub-board 10 or the second sub-board 20; by providing a window portion 41, the auxiliary film 40 can avoid positions such as solder pads and alignment marking points.

[0070] It is understood that before step 220 , the manufacturing method further includes: cutting the auxiliary film 40 to form a window portion 41 in the auxiliary film 40 .

[0071] In one embodiment, the first sub-board 10 and the second sub-board 20 both include a circuit area 101 and a board edge area 102 surrounding the outside of the circuit area 101, and a plurality of circuit board units 111 are provided in the circuit area 101; the auxiliary film 40 is simultaneously provided on the surface of the plurality of circuit board units 111.

[0072] In this embodiment, the first sub-board 10 and the second sub-board 20 are both of a panel structure and include multiple circuit board units 111. The panel is mainly for improving production and processing efficiency. Multiple circuit board units 111 can be produced at the same time, and can also be quickly mounted and pressed to form multiple pressure sensing module 100 products during mounting and pressing. After step S140 or S260, the first sub-board 10 and the second sub-board 20 can be cut to form a single pressure sensing module 100 product; or they can be directly shipped to the client in a panel structure, and the client will reprocess it according to subsequent assembly requirements. The shape and arrangement number of the circuit board units 111 in the figure are also for reference only. In other embodiments, the first sub-board 10 and the second sub-board 20 are not limited to the panel structure, and may include only one circuit board unit 111.

[0073] like Figure 6 、 Figures 8 to 10 As shown, in one embodiment, the two first pads 11 in the circuit board unit 111 are arranged along the first direction ( Figure 9 In the first direction, the dimensions of auxiliary film 40 are smaller than those of circuit board area 101. One first solder pad 11 of circuit board unit 111 is located within window 41, while another first solder pad 11 is located on the side of auxiliary film 40 near the board edge. This allows one window 41 to expose the solder pads of multiple circuit board units 111, simplifying the structure of auxiliary film 40 and facilitating cutting.

[0074] In another embodiment, multiple rows of circuit board units 111 are provided on the first sub-board 10 , and there are multiple auxiliary films 40 that are parallel and spaced apart. Each auxiliary film 40 extends along a row of circuit board units 111 and is located between two first pads 11 .

[0075] This embodiment only provides a schematic diagram of an auxiliary film 40. Corresponding to different paneling methods, the cutting size of the auxiliary film 40 and the bonding area with the first sub-panel 10 can be flexibly adjusted. As long as it can support the gap position during lamination and subsequent processes and can be successfully removed at the end, it is feasible.

[0076] Since the auxiliary film 40 is simultaneously provided on the surfaces of multiple circuit board units 111, the auxiliary film 40 can be entirely attached to the first sub-board 10 or the second sub-board 20 and correspond to the capacitor gaps 105 of multiple pressure sensing modules 100. There is no need to apply the auxiliary film 40 to each circuit board unit 111 individually, thereby improving manufacturing efficiency.

[0077] After converting hole 103 into plated hole 104, the manufacturing method further includes: forming outer circuits on first sub-board 10 and second sub-board 20, and forming an outer circuit protective layer, wherein the outer circuit protective layer is at least one of a coverlay film and a solder mask layer. For example, if first sub-board 10 is a flexible circuit board, the outer circuit protective layer of first sub-board 10 can be a coverlay film; if second sub-board 20 is a rigid board, the outer circuit protective layer of second sub-board 20 can be a solder mask layer, but the present invention is not limited thereto.

[0078] After making the outer circuit protection layer, the manufacturing method also includes: performing controlled depth milling from the side where the second sub-board 20 is located toward the side where the first sub-board 10 is located, removing the area of ​​the second sub-board 20 outside the preset area, that is, removing other areas outside the preset pressure sensing module 100.

[0079] The controlled depth milling method may be mechanical milling, laser milling, or a combination of both. Accordingly, the insulating dielectric layer 30 in the controlled depth milling area needs to be removed in advance to avoid increasing the difficulty of removing such areas.

[0080] like Figure 10 As shown, the area shown by the dotted line on the second sub-plate 20 is the area that needs to be removed by controlled depth milling. Figure 10 The structure of the second sub-board 20 is merely an illustration. The specific shapes of the area of ​​the second sub-board 20 used to form the pressure sensing module 100 and the area that needs to be removed by controlled depth milling can be set according to actual needs.

[0081] Please refer again Figure 4 In one embodiment, the first sub-board 10 is a flexible circuit board, and the second sub-board 20 is a rigid circuit board. After the holes are processed into metalized holes 104, the manufacturing method further includes: attaching a reinforcement sheet 12 to the side of the first sub-board 10 facing away from the capacitor gap 105. The reinforcement sheet can be made of steel or epoxy resin (FR4 type).

[0082] The first sub-board 10 is a flexible circuit board, which is easy to assemble in the housing of the electronic device. By attaching a reinforcing sheet 12 on the side of the flexible circuit board away from the capacitor gap 105, the stability of the capacitor gap 105 can be further improved.

[0083] Please refer to Figures 1 to 10 The following describes a method for manufacturing a pressure sensing module 100 using a specific embodiment. The first sub-board 10 is a flexible circuit board, and the second sub-board 20 is a rigid double-sided board. The manufacturing method includes:

[0084] A first daughterboard 10, a second daughterboard 20, and an insulating dielectric layer 30 are provided. The first daughterboard 10 has completed one or more process steps, including cutting, inner layer pattern transfer, AOI inspection, and cover film lamination / pressing. The second daughterboard 20 has completed one or more process steps, including cutting, inner layer pattern transfer, AOI inspection, and solder mask lamination. Inner layer circuit transfer refers to fabricating circuits on the side of the capacitor gap 105 formed by the first and second daughterboards 10 and 20.

[0085] Providing auxiliary film 40: The auxiliary film 40 is cut according to the panel size of the first sub-panel 10. Based on the panelization method of the first sub-panel 10, the auxiliary film 40 is retained in a predetermined area, and windows are opened to make room for the marking points and first pads 11. In this embodiment, the first pads 11 are located on the inner layer circuit and at both ends of the predetermined gap area. The auxiliary film 40 is retained between the two first pads 11, and windows are opened at the necessary marking points to avoid obstruction.

[0086] Laminating auxiliary film 40: Lay the cut auxiliary film 40 on the side opposite to the first sub-board 10 and the second sub-board 20. In order to facilitate the removal of the auxiliary film 40 in the post-pressing process, only a part of the area is bonded to the first sub-board 10. Figure 9 For example, the two ends of the auxiliary film 40 in the longitudinal direction are bonded and fixed to the board edge area 102 (waste area) of the first sub-board 10, while the other positions remain in a detachable state.

[0087] Lamination: The first sub-panel 10 and the second sub-panel 20, already coated with auxiliary film 40, are aligned and laminated together through the insulating dielectric layer 30. After lamination, the first sub-panel 10 and the second sub-panel 20 are bonded together. In this embodiment, the insulating dielectric layer 30 is a low-flow prepreg. Before lamination, the prepreg is pre-cut to create windows, leaving only the prepreg in the areas where bonding is required. The size of the windows is adjusted based on the prepreg's adhesive flow characteristics to prevent adhesive from flowing into non-bonded areas during lamination.

[0088] Drilling and hole metallization: drilling and hole metallization are performed on the pressed daughter board 1 and daughter board 2 to make the first daughter board 10 and the second daughter board 20 conductive through the metallized holes 104 .

[0089] Fabrication of outer layer circuits: The outer layer circuits are fabricated using conventional processes. The outer layer in this embodiment refers to the circuit layer on the side of the first sub-board 10 and the second sub-board 20 away from the capacitor gap 105 .

[0090] Make the outer circuit protection layer: laminate / press a cover film on the outer layer of the first daughter board 10, and print solder mask on the outer layer of the second daughter board 20 to cover and protect the graphic circuits that do not need to be exposed.

[0091] Milling: Use controlled depth milling to remove unnecessary areas on the second sub-board 20. Figure 10For example, remove Figure 10 The area enclosed by the dotted line.

[0092] Surface treatment: Protect the exposed pads, hole walls and other graphic circuits to prevent copper surface oxidation. In this embodiment, nickel-immersion gold is used to form a dense gold layer on the pads and hole walls.

[0093] Reinforcement: A reinforcement sheet 12 is mounted on the outer layer of the first sub-board 10 corresponding to the capacitor gap 105 to support the first sub-board 10 and obtain a more stable capacitor gap 105.

[0094] Remove the auxiliary film 40: Cut off the adhesive portion 42 of the auxiliary film 40 so that it can be separated from the first sub-panel 10, and pull out the auxiliary film 40 from one side until it is completely removed. After removal, follow the normal process to carry out product quality inspection and post-processing.

[0095] Because this embodiment utilizes a panelized structure during production, after removing the auxiliary film 40, it can be cut to form individual pressure sensing modules 100. Each pressure sensing module 100 corresponds to one circuit board unit 111 of the first sub-board 10 and one circuit board unit 111 of the second sub-board 20. Alternatively, the panelized structure can be directly shipped to the customer, who will then process it according to subsequent assembly requirements.

[0096] Please refer again Figure 4 In a second aspect of the present application, a pressure sensing module 100 is proposed, comprising a first sub-board 10, a second sub-board 20 and an insulating dielectric layer 30, wherein a first solder pad 11 is provided on the first sub-board 10, and a second solder pad 21 is provided on the second sub-board 20; the insulating dielectric layer 30 is bonded between the first solder pad 11 and the second solder pad 21; wherein the pressure sensing module 100 is provided with metallized holes 104 at corresponding positions of the first solder pad 11 and the second solder pad 21, and the metallized holes 104 pass through and conduct the first solder pad 11 and the corresponding second solder pad 21; a capacitor gap 105 is formed between the first sub-board 10 and the second sub-board 20.

[0097] In the aforementioned pressure sensing module 100, the first sub-board 10 and the second sub-board 20 are pressed together via an insulating dielectric layer 30, eliminating the need for an SMT solder paste mounting process for sub-board assembly. This allows for precise control of the thickness of the insulating dielectric layer 30 and the height of the capacitor gap 105, resulting in good gap consistency and capacitance consistency in the pressure sensing module 100. Furthermore, the aforementioned pressure sensing module 100 utilizes the insulating dielectric layer 30 to bond the first solder pad 11 and the second solder pad 21, and utilizes the metallized via 104 to provide electrical connection between the first and second solder pads 11, 21. Compared to solder mounting and conductive adhesive bonding, the metallized via 104 provides improved conduction stability, resistance consistency, and product reliability, resulting in more stable pressure sensing values.

[0098] Optionally, the first sub-board 10 is a flexible circuit board, and the second sub-board 20 is a rigid circuit board. Furthermore, a reinforcing sheet 12 is attached to a side of the first sub-board 10 facing away from the capacitor gap 105 .

[0099] Optionally, the metallized hole 104 passes through the first sub-board 10 and the second sub-board 20; it is understandable that the metallized hole 104 may also pass through the second pad 21 of the first sub-board 10 and the second sub-board 20, or pass through the first pad 11 of the second sub-board 20 and the first sub-board 10.

[0100] A third aspect of the present application provides an electronic device comprising the pressure sensing module 100 of any of the above embodiments. The electronic device is, for example, a TWS headset, but is not limited thereto and may also be other electronic devices capable of sensing pressure.

[0101] The pressure sensing module 100 and its manufacturing method and electronic device provided in the present application can accurately control the height of the capacitor gap 105, solving the problem of large height differences of the capacitor gap 105 in the pressure sensing module 100, and can ensure the height consistency of the capacitor gap 105 and the consistency of the capacitance value.

[0102] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A method for manufacturing a pressure sensing module, characterized in that: include: Providing a first sub-board having a first solder pad, a second sub-board having a second solder pad, and an insulating dielectric layer, wherein the first sub-board and the second sub-board each have a preset area for forming a capacitor gap; Aligning and pressing the first sub-board, the insulating dielectric layer, and the second sub-board, wherein the insulating dielectric layer is disposed between the first solder pad and the corresponding second solder pad and avoids the preset area, and the first solder pad and the second solder pad are fixedly bonded together by the insulating dielectric layer, wherein the thickness of the insulating dielectric layer is set according to the preset height of the capacitor gap; Drilling holes on the first sub-board and the second sub-board, the holes passing through the first solder pad and the corresponding second solder pad, wherein the holes pass through the first sub-board and the second sub-board, or the holes pass through one of the first sub-board and the second sub-board; The hole is processed into a metallized hole, the metallized hole conducts the first pad and the corresponding second pad, and the capacitor gap is formed between the first sub-board and the second sub-board.

2. The method for manufacturing a pressure sensing module according to claim 1, wherein: The insulating medium layer is a prepreg or pure glue.

3. The method for manufacturing a pressure sensing module according to claim 1, wherein: Before aligning and pressing the first sub-board, the insulating dielectric layer and the second sub-board, the manufacturing method further includes: attaching an auxiliary film on the surface of the first sub-board or the second sub-board, the auxiliary film covering at least a portion of the preset area and exposing the first pad or the second pad, and the thickness of the auxiliary film is equal to the preset height of the capacitor gap; after processing the hole into a metallized hole, the manufacturing method further includes: removing the auxiliary film.

4. The method for manufacturing a pressure sensing module according to claim 3, wherein: The auxiliary film has a pasting portion and a window portion, and the auxiliary film is pasted to the first sub-board or the second sub-board through the pasting portion. The window portion can expose the first pad or the second pad.

5. The method for manufacturing a pressure sensing module according to claim 4, wherein: The first sub-board and the second sub-board both include a circuit area and a board edge area surrounding the circuit area, and a plurality of circuit board units are arranged in the circuit area; the auxiliary film is simultaneously arranged on the surfaces of the plurality of circuit board units.

6. The method for manufacturing a pressure sensing module according to claim 1, wherein: After processing the holes into metallized holes, the manufacturing method further includes: manufacturing outer circuits on the first sub-board and the second sub-board, and manufacturing outer circuit protection layers, wherein the outer circuit protection layers are at least one of a cover film and a solder resist layer.

7. The method for manufacturing a pressure sensing module according to claim 6, wherein: After manufacturing the outer circuit protection layer, the manufacturing method further includes: performing controlled-depth milling from the side where the second sub-board is located toward the side where the first sub-board is located to remove the area of ​​the second sub-board outside the preset area.

8. The method for manufacturing a pressure sensing module according to claim 1, wherein: The first sub-board is a flexible circuit board, and the second sub-board is a rigid circuit board; After the holes are processed into metallized holes, the manufacturing method further includes: attaching a reinforcing plate to a side of the first sub-board facing away from the capacitor gap.

9. A pressure sensing module, characterized in that: include: a first sub-board, wherein a first solder pad is provided on the first sub-board; a second sub-board, wherein a second solder pad is provided on the second sub-board; an insulating dielectric layer bonded between the first pad and the second pad; The pressure sensing module is provided with a metallized hole at positions corresponding to the first pad and the second pad, the metallized hole passing through and conducting the first pad and the corresponding second pad; a capacitive gap is formed between the first sub-board and the second sub-board; The hole passes through the first sub-board and the second sub-board, or the hole passes through one of the first sub-board and the second sub-board; The capacitor gap is provided between a preset area of ​​the first sub-board and a preset area of ​​the second sub-board, and the insulating dielectric layer is provided between the first pad and the corresponding second pad and avoids the preset area.

10. An electronic device, characterized in that: The electronic device includes a pressure sensing module manufactured by the method for manufacturing a pressure sensing module according to any one of claims 1 to 8, or includes the pressure sensing module according to claim 9.

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