Circuit board assembly, control method of circuit board assembly, and electronic device

Abstract

Embodiments of the present application provide a circuit board assembly, a control method of the circuit board assembly and an electronic device. The circuit board assembly comprises a flexible circuit board and a fitting part. The flexible circuit board is arranged in a fixing part of a rotating assembly in the electronic device, and an end of the flexible circuit board is located outside the rotating assembly and is fixed relative to the rotating assembly. A side of the flexible circuit board facing the rotating assembly has a bending part configured to bend relative to the fixing part along a bending direction during rotation of the rotating assembly from a first mode to a second mode. The fitting part is attached to a surface of the bending part and is configured to elastically deform under an electric field to drive the bending part to bend relative to the fixing part to a preset fixed angle along the bending direction. The circuit board assembly of the present application has a stable bending mode during dynamic bending, thereby effectively avoiding the phenomenon of bending to death and failure of the circuit board assembly during dynamic bending.

Description

Technical Field

[0001] The present application relates to the field of electronic technology, and in particular to a circuit board assembly, a control method for a circuit board assembly, and an electronic device. Background Art

[0002] With the continuous development of science and technology, foldable electronic devices have been widely used in people's lives.

[0003] Taking a foldable phone as an example, a foldable electronic device primarily includes two middle frames, which are rotatably connected to opposite sides of a rotating assembly. This allows the two middle frames to rotate relative to each other, thereby changing the configuration of the foldable electronic device and enabling the foldable electronic device to transition from a flattened state to a folded state. The foldable electronic device also includes a flexible circuit board that passes through the rotating assembly. The two ends of the flexible circuit board are located outside the rotating assembly and are fixed to the two middle frames, respectively. When the foldable electronic device is unfolded from a folded state to a flattened state, the flexible circuit board will dynamically bend along with the relative fixings of the two middle frames.

[0004] However, during the dynamic bending process, the movement shape of the flexible circuit board is unstable, and it may be bent to death during the dynamic bending process, and even cause the flexible circuit board to fail due to the bending phenomenon. Summary of the Invention

[0005] The present application provides a circuit board assembly, a control method for a circuit board assembly, and an electronic device, which can enable the circuit board assembly to have a stable bending shape during a dynamic bending process, thereby effectively avoiding the circuit board assembly from being bent to death and failing during the dynamic bending process.

[0006] According to a first aspect of an embodiment of the present application, a circuit board assembly is provided for use in an electronic device. The circuit board assembly includes a flexible circuit board and a bonding member. The flexible circuit board is inserted into a fixing member of a rotating assembly in the electronic device, and an end portion of the flexible circuit board is located outside the rotating assembly and fixed relative to the rotating assembly.

[0007] The flexible circuit board has a bending portion on the side facing the rotating component, and the bending portion is configured to bend along the bending direction relative to the fixed component during the process of the rotating component rotating from the first form to the second form; the bonding member is attached to the surface of the bending portion and is configured to undergo elastic deformation under the application of an electric field to drive the bending portion to bend in the bending direction relative to the fixed component.

[0008] The embodiment of the present application sets the adhering piece in the circuit board assembly. The adhering piece is attached to the surface of the bending part and is configured to elastically deform under the applied electric field to drive the bending part to bend relative to the fixed part to a preset fixed angle in the bending direction. Thus, by controlling the external voltage of the electric field applied to the adhering piece, the degree of elastic deformation of the adhering piece can be controlled, so that the adhering piece drives the bending part to bend relative to the fixed part along the bending direction during the process of rotating the assembly from the first mode to the second mode (i.e., the bending part performs a dynamic bending action). At the same time, due to the driving of the adhering piece, the bending part can also have a stable bending mode during the dynamic bending process, so that the movement trajectory of the flexible circuit board deviates during the dynamic bending process, and a dead fold phenomenon occurs at the bending part, thereby avoiding failure of the circuit board assembly. In addition, due to the recoverable characteristics of elastic deformation, the circuit board assembly can have a constant and stable movement trajectory during each dynamic bending action, thereby reducing the failure probability of the circuit board assembly during multiple dynamic bending actions.

[0009] In an alternative embodiment, the adhering piece is configured to elastically deform under the applied electric field to drive the bending part to bend relative to the fixed part to a preset fixed angle in the bending direction.

[0010] Thus, the elastic deformation of the adhering piece can control the bending part to bend relative to the fixed part to a preset fixed angle in the bending direction, so that the bending part has a stable bending mode during the dynamic bending process, and the circuit board assembly can have a constant and stable movement trajectory during each dynamic bending action.

[0011] In an alternative embodiment, the adhering piece includes an electroactive polymer film configured to elastically deform in the length direction thereof under the external voltage of the electric field.

[0012] Thus, by providing the electroactive polymer film, the electroactive polymer film can elastically deform in the length direction thereof under the external voltage of the electric field to drive the bending part to have a stable bending mode while reaching the preset fixed angle.

[0013] In an alternative embodiment, the electroactive polymer film is attached to and covers the curved surface of the bending part, so that the electroactive polymer film can enhance the attachment effect of the electroactive polymer film on the surface of the bending part while driving the bending part to bend to the preset fixed angle. Thus, by attaching the adhering piece, the bending part can have a more stable bending mode during the dynamic bending process, so as to avoid the dead fold phenomenon of the flexible circuit board due to the excessive bending angle of the bending part.

[0014] In an optional embodiment, the curved surface includes an outer curved surface that is convex in the bending direction and an inner curved surface that is concave in the bending direction, and the electroactive polymer film is attached to and covers the outer curved surface.

[0015] Since the strain of the outer curved surface of the bending portion is greater than that of the inner curved surface during the dynamic bending process, the electroactive polymer film is attached to and covers the outer curved surface. In this way, the electroactive polymer film can not only be fixed on the bending portion, but also can drive the entire bending portion to bend to a preset fixed angle through the outer curved surface of the bending portion, and maintain a stable bending shape.

[0016] In an optional embodiment, the circuit board assembly further includes a first flexible electrode and a second flexible electrode, the first flexible electrode and the second flexible electrode being adhered to opposite sides of the electroactive polymer film and being configured to be connected to an external voltage to form an electric field; the first flexible electrode is adhered between the electroactive polymer film and the bending portion.

[0017] In this way, by setting the first flexible electrode and the second flexible electrode, when the first flexible electrode and the second flexible electrode are connected to the positive and negative poles of the external voltage, an electric field can be formed on the electroactive polymer film, so that the electroactive polymer film undergoes elastic deformation under the action of the electric field.

[0018] In an optional embodiment, the relationship between the external voltage and the elastic deformation of the electroactive polymer film satisfies:

[0019] U=KX

[0020] Wherein: U is the external voltage, K is the proportional coefficient, and X is the elastic deformation of the electroactive polymer film when the bending portion is bent to the preset fixed angle.

[0021] Since the external voltage U and the elastic deformation X of the electroactive polymer film have a linear proportional relationship (e.g., a directly proportional relationship), the external voltage of the electric field applied to the electroactive polymer film can be determined based on the elastic deformation X required for the bending portion to bend to a preset fixed angle, thereby ensuring that the electroactive polymer film can drive the bending portion to bend to the preset fixed angle under the action of the electric field.

[0022] In an optional embodiment, the elastic deformation satisfies:

[0023]

[0024] Wherein: X is the elastic deformation amount, n is the preset fixed angle, r is the bending radius of the bending portion, and d is the total thickness of the electroactive polymer film, the first flexible electrode, and the second flexible electrode.

[0025] In this way, according to the calculation formula of the elastic deformation X, the elastic deformation X of the electroactive polymer film can be calculated and obtained from the preset fixed angle n of the bending portion, so that the external voltage U applied to the electroactive polymer film can be determined by the elastic deformation X.

[0026] In an optional embodiment, the flexible circuit board has a first bending area, which is located between the end of the flexible circuit board and the fixing member. The first bending area has multiple bending portions, and at least some of the bending portions in the first bending area are correspondingly provided with a bonding member.

[0027] Generally speaking, the preset fixed angle of the flexible circuit board in the first bending area during the dynamic bending process is relatively small, which makes the probability of the flexible circuit board being bent to death in the first bending area higher. Therefore, by attaching the bonding member on at least part of the bending portion in the first bending area, the bonding member can drive at least part of the bending portion in the first bending area to bend to the preset fixed angle, and while having a stable bending shape, it can avoid the occurrence of bending to death in the first bending area.

[0028] In an optional embodiment, there are multiple bending portions in the first bending area, the multiple bending portions include a first bending portion and a second bending portion located on the side of the first bending portion, the preset fixed angle of the first bending portion is smaller than the preset fixed angle of the second bending portion, and the fitting part is attached and covered on the curved surface of the first bending portion facing the side of the fixing part.

[0029] In this way, by attaching the adhesive member to the first bending portion, the flexible circuit board can be prevented from being bent to death at the first bending portion during dynamic bending, thereby preventing the circuit board assembly from failing.

[0030] In an optional embodiment, the bending direction of the first bending portion is configured to bend toward one side of the fixing member, and the fitting is attached to and covers the side of the first bending portion facing the fixing member; the second bending portion is configured to bend toward the side away from the fixing member, and the fitting is attached to and covers the side of the second bending portion facing away from the fixing member.

[0031] In this way, the fitting can be attached to the outer curved surfaces of the first bending portion and the second bending portion, so that the fitting can be fixed on the first bending portion and the second bending portion, and at the same time, the fitting can drive the entire first bending portion and the second bending portion to bend to their respective corresponding preset fixed angles through the outer curved surfaces of the first bending portion and the second bending portion, so that the first bending area maintains a stable bending shape during the dynamic bending process, thereby avoiding the occurrence of dead bending in the first bending area.

[0032] In an alternative embodiment, the flexible circuit board further comprises a second bending region, the second bending region is located at the side of the first bending region and is arranged opposite to the fixing member, and the second bending region has a plurality of bending portions, and at least some of the bending portions in the second bending region are attached with the attaching member.

[0033] In this way, by arranging the attaching member on at least some of the bending portions in the second bending region, the second bending region can maintain a stable bending shape during dynamic bending, thereby avoiding the occurrence of a dead fold in the second bending region and avoiding failure of the flexible circuit board during dynamic bending.

[0034] In an alternative embodiment, the bending portions adjacent to the first bending region in the second bending region are attached with the same attaching member, so as to drive the bending portions adjacent to the first bending region in the second bending region to bend to a preset fixed angle by the same attaching member, while maintaining a stable bending shape, and the number of attaching members in the circuit board assembly can be reduced.

[0035] In an alternative embodiment, the attaching member comprises a first attaching member and a second attaching member, the second attaching member is different from the first attaching member, and at least one of the first attaching member and the second attaching member is attached to the flexible circuit board.

[0036] In this way, while ensuring that the flexible circuit board has a stable bending shape during dynamic bending, the diversity of the attaching members in the circuit board assembly can also be increased.

[0037] In an alternative embodiment, the first shape is a folded state of the rotating assembly, and the second shape is an unfolded state of the rotating assembly, so that the flexible circuit board has a stable motion trajectory during the process of rotating from the folded state to the unfolded state by the attaching member, and failure of the flexible circuit board due to deviation of the motion trajectory during dynamic bending can be avoided.

[0038] The second aspect of the embodiments of the present application provides a control method of a circuit board assembly, the control method is applied to the circuit board assembly of any one of the above, the circuit board assembly comprises a flexible circuit board and an attaching member, the attaching member is attached to a bending portion of the flexible circuit board, and the control method comprises:

[0039] determining a preset fixed angle of the bending portion when the bending portion generates a shape conversion of the rotating assembly;

[0040] applying an electric field to the attaching member, so as to drive the bending portion to bend to the preset fixed angle by elastic deformation of the attaching member under the electric field.

[0041] Since for the same model of electronic equipment, when the bending portion in the circuit board assembly undergoes shape transformation along with the rotating assembly, the preset fixed angle of the bending portion is a determinable known quantity, after determining the preset fixed angle corresponding to the bending portion, an electric field can be applied to the fitting to cause the fitting to produce elastic deformation under the action of the electric field, and the elastic deformation of the fitting drives the bending portion to bend to the preset fixed angle, thereby ensuring that the circuit board assembly has a steady-state motion trajectory during dynamic bending action, and can effectively avoid the circuit board assembly from having an excessively large bending angle of the bending portion during dynamic bending, causing the flexible circuit board to deviate from its motion trajectory during dynamic bending and produce a dead bending phenomenon at the bending portion, thereby avoiding failure of the circuit board assembly.

[0042] In an optional embodiment, an electric field is applied to the bonding member so as to drive the bending portion to bend to a preset fixed angle through elastic deformation of the bonding member under the electric field, specifically including:

[0043] Obtaining the elastic deformation required by the bonding component when the bending portion is bent to a preset fixed angle;

[0044] The external voltage corresponding to the electric field is determined according to the elastic deformation amount, so that the bonding piece produces elastic deformation under the action of the electric field.

[0045] In this way, after obtaining the required elastic deformation of the bonding part, an external voltage corresponding to the electric field determined according to the elastic deformation amount can be applied to the bonding part in the electric field to ensure that the bonding part can drive the bending part to bend to a preset fixed angle under the action of the electric field.

[0046] A third aspect of an embodiment of the present application provides an electronic device, which includes a first structural member, a second structural member, a rotating assembly and a circuit board assembly as described above, wherein the rotating assembly includes a fixing member, the first structural member and the second structural member are rotatably connected to opposite sides of the fixing member, the circuit board assembly is inserted into the fixing member, and the end of the circuit board assembly is connected to the circuit boards in the first structural member and the second structural member.

[0047] In this way, through the arrangement of the first structural member, the second structural member and the rotating assembly, on the basis of making the electronic device foldable, the circuit board assembly can not only realize the connection between the circuit boards in the first structural member and the second structural member, but also realize the connection and conduction of the circuit boards in the first structural member and the second structural member, and the circuit board assembly can have a constant steady-state motion trajectory during each dynamic bending action of the rotating assembly, so as to avoid failure of the circuit board assembly.

[0048] In an optional embodiment, the electronic device further includes a flexible display screen, the peripheral edge of the flexible display screen is located on the same surface of the first structural member and the second structural member, and the flexible display screen is covered on the circuit board assembly.

[0049] In this way, on the basis of realizing the display function of the electronic device through the setting of a flexible display screen, since the flexible circuit board in the circuit board assembly has a constant and steady-state motion trajectory during the dynamic bending process of each opening and closing of the electronic device, it can avoid failure of the flexible circuit board during the dynamic bending process, thereby reducing the scrap rate of the flexible circuit board caused by the maintenance of the flexible circuit board failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 A schematic diagram of the structure of an electronic device in a folded state provided by an embodiment of the present application;

[0051] Figure 2 for Figure 1 Schematic diagram of the opening and closing process of the electronic device;

[0052] Figure 3 for Figure 1 A schematic diagram of the structure of the electronic device in a flattened state;

[0053] Figure 4 An exploded view of an electronic device provided in an embodiment of the present application;

[0054] Figure 5 A schematic diagram of assembling a flexible circuit board on a flexible display screen provided in an embodiment of the present application;

[0055] Figure 6 Schematic diagram of the structure of the flexible circuit board of the electronic device provided in the related art when it is flattened Figure 1 ;

[0056] Figure 7 Schematic diagram of the structure of the flexible circuit board of the electronic device provided in the related art when it is flattened Figure 2 ;

[0057] Figure 8 for Figure 6 Schematic diagram of the structure of a flexible printed circuit board when it is bent;

[0058] Figure 9 Schematic diagram of the structure of the circuit board assembly of the electronic device provided in the embodiment of the present application in the flat state Figure 1 ;

[0059] Figure 10 A schematic diagram of the structure of the bonding member provided in an embodiment of the present application before and after the application of an electric field;

[0060] Figure 11 A schematic structural diagram of a circuit board assembly provided in an embodiment of the present application;

[0061] Figure 12A schematic diagram of the structure of the circuit board assembly at the bending portion provided in an embodiment of the present application;

[0062] Figure 13 for Figure 9 A schematic diagram of a bent state of the middle circuit board assembly in the first bending area;

[0063] Figure 14 for Figure 9 A schematic diagram of the straightened state of the circuit board assembly in the first bending area;

[0064] Figure 15 A schematic diagram of the state transition of the second bending region of the flexible circuit board provided in an embodiment of the present application;

[0065] Figure 16 for Figure 15 the straightened state of the second bending region of the flexible circuit board;

[0066] Figure 17 A schematic structural diagram of the circuit board assembly provided in an embodiment of the present application in the second bending region;

[0067] Figure 18 Schematic diagram of the structure of the circuit board assembly of the electronic device provided in the embodiment of the present application in the flat state Figure 2 ;

[0068] Figure 19 A schematic diagram of a control method for a circuit board assembly provided in an embodiment of the present application.

[0069] Description of reference numerals:

[0070] 100 - electronic device; 1 - first structural member; 2 - second structural member; 3 - rotating assembly; 31 - fixed member; 32 - first rotating member; 33 - second rotating member; 4 - flexible display; 5 - third structural member; 6 - circuit board; 7 - back cover;

[0071] 8-circuit board assembly; 81-flexible circuit board; 811-end; 8111-first end; 8112-second end; 812-bending portion; 8121-first bending portion; 8122-second bending portion; 8123-outer curved surface; 8124-inner curved surface; 813-first bending region; 814-second bending region;

[0072] 82-fitting member; 83-first flexible electrode; 84-second flexible electrode; 85-laminate; 9-display screen;

[0073] 200-Board-to-Board Connector. DETAILED DESCRIPTION

[0074] The terms used in the implementation section of this application are only used to explain the specific embodiments of this application and are not intended to limit this application.

[0075] Strain: refers to the relative deformation of an object's local area under the influence of external forces and non-uniform temperature fields. In other words, an object will deform to a certain extent under the influence of external forces and other factors, and the degree of deformation is called strain.

[0076] An embodiment of the present application provides an electronic device, which may include but is not limited to a foldable fixed terminal or mobile terminal such as a mobile phone, a tablet computer (i.e., a pad), a laptop computer, a personal computer (PC), an ultra-mobile personal computer (UMPC), a handheld computer, a smart wearable device, a personal digital assistant (PDA), a virtual reality (VR) device, etc.

[0077] The structure of the electronic device according to the embodiment of the present application is further described below using a mobile phone, such as a foldable mobile phone, as an example. The foldable mobile phone can be a mobile phone with a foldable function, wherein the display screen folds inward or outward.

[0078] Figures 1 to 3 The schematic diagrams respectively illustrate the structures of electronic devices such as foldable mobile phones in different states.

[0079] refer to Figure 1 and Figure 2 As shown, electronic device 100, such as a foldable mobile phone, includes a first structural member 1, a second structural member 2, and a rotating assembly 3. Rotating assembly 3 can be a hinge assembly or other structural assembly capable of rotation. Rotating assembly 3 includes a fixed member 31. The first structural member 1 and the second structural member 2 are rotatably connected to opposite sides of the fixed member 31, allowing the first structural member 1 and the second structural member 2 to rotate relative to each other. Taking the hinge assembly as an example, fixed member 31 can be understood as the rotating shaft of the hinge assembly.

[0080] refer to Figure 2 As shown, when the first structural member 1 and the second structural member 2 are along Figure 2 When the direction indicated by the arrow in the middle moves toward each other, the electronic device 100 can be made to appear as follows Figure 1 The folded state shown in . Figure 1 As shown in , when the electronic device 100 is in the folded state, the first structural member 1 and the second structural member 2 are stacked on each other, and the rotating assembly 3 is also in the folded state.

[0081] refer to Figure 2As shown, when the first structural member 1 and the second structural member 2 are along Figure 2 When the electronic device 100 moves in opposite directions as shown by the arrows in the middle, the electronic device 100 can be made to appear as shown in FIG. Figure 3 The flattened state shown in . Figure 3 As shown in , when the electronic device 100 is in a flattened state, the first structural member 1 and the second structural member 2 cannot continue to rotate. At this time, the first structural member 1 and the second structural member 2 can be in the same plane, and the rotating component 3 is also in a flattened state.

[0082] It should be noted that the electronic device 100 may include two structural members, that is, the number of the first structural member 1 and the second structural member 2 may both be one, so that the foldable mobile phone can be folded into two layers. Figure 1 As shown, a foldable phone may include a first structural member 1, a second structural member 2, and a rotating assembly 3. The first structural member 1 and the second structural member 2 rotate relative to each other until they overlap, giving the electronic device 100 a two-layered configuration. Taking a foldable phone as an example, the first structural member 1 may be a first middle frame, and the second structural member 2 may be a second middle frame.

[0083] Alternatively, the electronic device 100 may also include multiple structural members, that is, the number of first structural members 1 and second structural members 2 may be multiple, and adjacent first structural members 1 and second structural members 2 are connected by a rotating component 3, so that the electronic device 100 can be folded into a multi-layer form.

[0084] refer to Figure 3 As shown, the electronic device 100 also includes a flexible display screen 4. The peripheral edges of the flexible display screen 4 are located on the first structural member 1 and the second structural member 2. This allows the flexible display screen 4 to be supported on the same surface of the first structural member 1 and the second structural member 2, thereby securing the flexible display screen 4 within the electronic device 100. When the first structural member 1 and the second structural member 2 are folded toward each other, the flexible display screen 4 bends and adheres to the first structural member 1 and the second structural member 2. When the first structural member 1 and the second structural member 2 are unfolded away from each other, the flexible display screen 4 also unfolds.

[0085] In order to better understand the structure of the electronic device 100, Figure 4 An exploded view of an electronic device such as a foldable phone is shown.

[0086] refer to Figure 4As shown, taking the shaft assembly as an example, the rotating assembly 3 may further include a first rotating member 32 and a second rotating member 33, wherein the first rotating member 32 and the second rotating member 33 are rotatably connected to the fixed member 31, such as opposite sides of the rotating shaft. Exemplarily, the first rotating member 32 and the second rotating member 33 may include, but are not limited to, rotating plates extending along the axial direction of the rotating shaft. The first rotating member 32 is connected to the first structural member 1 so that the first structural member 1 and the fixed member 31 are rotatably connected via the first rotating member 32. The second rotating member 33 is connected to the second structural member 2 so that the second structural member 2 and the fixed member 31 are rotatably connected via the second rotating member 33.

[0087] It should be noted that when the rotating assembly 3 is in the folded state, the first rotating member 32 and the second rotating member 33 are stacked on each other. When the rotating assembly 3 is in the flattened state, the first rotating member 32 and the second rotating member 33 can be in the same plane and cannot continue to rotate.

[0088] like Figure 4 As shown in FIG, the electronic device 100 may further include a circuit board 6, which is respectively accommodated on the side of the first structural member 1 and the second structural member 2 facing away from the flexible display screen 4. The electronic device 100 may further include a battery (not shown in the figure), which may be accommodated together with the circuit board 6 on the side of the first structural member 1 or the second structural member 2 facing away from the flexible display screen 4. Figure 4 As shown, the electronic device 100 may further include a back cover 7. In the case of the electronic device 100, such as a foldable mobile phone, the number of back covers 7 may be one or two. The back cover 7 may cover a side of at least one of the first structural member 1 and the second structural member 2 facing away from the flexible display 4. When the back cover 7 is placed over the battery, it may also be referred to as a battery cover.

[0089] Continue to refer Figure 4 As shown, when there is only one back cover 7, the electronic device 100 may further include a display screen 9. The display screen 9 may be provided on the side of the first structural member 1 facing away from the flexible display screen 4. The back cover 7 may be provided on the side of the second structural member 2 facing away from the flexible display screen 4 and also provided on the battery. It should be noted that the number of back covers 7 and display screens 9 in the electronic device 100 is not further limited.

[0090] like Figure 4 As shown in , the electronic device 100 also includes a flexible circuit board 81a, which is inserted into the fixing member 31, and both end portions 811a of the flexible circuit board 81a are located outside the fixing member 31 and are respectively fixed in the first structural member 1 and the second structural member 2, and are connected to the circuit boards 6 in the first structural member 1 and the second structural member 2, thereby realizing connection and conduction of the circuit boards 6 in the first structural member 1 and the second structural member 2 through the flexible circuit board 81a.

[0091] It should be noted that the electronic device 100, such as a foldable mobile phone, may also include other components such as a camera, a microphone, a speaker, etc. Figure 4 The structure of the electronic device 100 is not limited to that of the electronic device 100 .

[0092] Figure 5 A schematic diagram of the assembly of a flexible circuit board on a flexible display screen is shown.

[0093] refer to Figure 5 As shown, the flexible display 4 can be placed over the rotating assembly 3 and the flexible circuit board 81a, so as to shield the rotating assembly 3 and the flexible circuit board 81a without affecting the assembly of the flexible display 4 on the first structural member 1 and the second structural member 2. During the production process of the electronic device 100, the flexible circuit board 81a and the flexible display 4 are assembled together on the first structural member 1 and the second structural member 2.

[0094] It should be noted that when the electronic device 100 is in the folded state, the structure of the flexible circuit board 81a in the electronic device 100 is Figure 1 As the electronic device 100 is opened or closed, such as when a foldable mobile phone is unfolded from a folded state to a flat state, the flexible circuit board 81a will dynamically bend as the electronic device 100 is opened or closed, generating excessive redundancy and transitioning from the straightened state to the bent state.

[0095] Take foldable phones as an example. Figures 6 and 7 Both illustrate the structural schematic diagrams of the flexible circuit board of the electronic device in the related art when it is in a flat state.

[0096] refer to Figure 6 and Figure 7 As shown, for ease of distinction, the reference numerals of components in related art electronic devices and the same components in this application are used, for example, the flexible circuit board is defined as flexible circuit board 81b. When the electronic device 100a is in a flattened state, the flexible circuit board 81b generates more redundancy during the dynamic bending process compared to the stretched state, and the flexible circuit board 81b bends to varying degrees at different locations, resulting in a bent state.

[0097] Figure 8 Indicated Figure 6 Schematic diagram of the structure of a flexible printed circuit board when it is bent.

[0098] refer to Figure 8As shown, the flexible circuit board 81b is inserted into the fixing member 31a of the rotating assembly 3a, and the two ends 811b are fixed in the first structural member 1a and the second structural member 2a, so that the two ends 811a of the flexible circuit board 81a are relatively fixed. Since the flexible circuit board 81b is inserted into the fixing member 31a, and there is no fixed point in the middle part of the flexible circuit board 81b (the area outside the two end parts 811b), when the flexible circuit board 81b is dynamically bent along with the opening and closing of the flexible display screen 4a, the first structural member 1a, the second structural member 2a and the rotating assembly 3a of the electronic device 100a, there is no sufficient fixed structure to constrain the shape of the flexible circuit board 81b during the movement, resulting in an unstable movement shape of the middle part of the flexible circuit board 81b. When the deformation of the flexible circuit board 81b at a certain position, such as position A or position B, causes the bending angle and bending degree of position A or position B to be too large, the flexible circuit board 81b will be bent at position A or position B during the dynamic bending process, resulting in the flexible circuit board 81b not being installed in the predetermined trajectory movement (such as Figure 6 As shown), the flexible circuit board 81b may even fail due to bending.

[0099] Furthermore, the structural components of electronic device 100a surrounding flexible circuit board 81b, such as first structural component 1a and second structural component 2a, are subject to manufacturing tolerances, as is the flexible circuit board 81b itself. When these manufacturing tolerances reach their respective limits, the resulting stacked tolerances around flexible circuit board 81b can also cause the flexible circuit board 81b to buckle at a certain location during dynamic bending, leading to failure.

[0100] Since the flexible circuit board 81b is assembled together with the flexible display screen 4a on the first structural member 1a and the second structural member 2a, if the flexible circuit board 81b fails, the flexible display screen 4a must be removed before the flexible circuit board 81b can be repaired. However, during the removal process, the flexible display screen 4a is easily scrapped.

[0101] To prevent the flexible display screen 4a from being scrapped due to failure of the flexible circuit board 81b, it is necessary to prevent the flexible circuit board 81b from failing due to flexing during the dynamic bending process. Due to the inevitable manufacturing tolerances of the flexible circuit board 81b itself and the structural components of the electronic device 100a surrounding the flexible circuit board 81b, it is necessary to modify the flexible circuit board 81b to reduce the possibility of failure due to flexing during the dynamic bending process.

[0102] To this end, an embodiment of the present application provides a circuit board assembly, which can be applied to electronic devices to replace the original flexible circuit board in the electronic devices, enabling the circuit board assembly to produce a stable bending shape during dynamic bending, and effectively preventing the circuit board assembly from being bent and failing during dynamic bending.

[0103] The structure of the circuit board assembly of the present application is further described below with reference to the accompanying drawings and embodiments.

[0104] Figure 9 A schematic structural diagram of a circuit board assembly 8 of an electronic device in a flattened state is shown.

[0105] refer to Figure 9 As shown, the circuit board assembly 8 includes a flexible circuit board 81 and a fitting 82. The flexible circuit board 81 is inserted into the fixing member 31 of the rotating assembly 3 of the electronic device 100, and the end 811 of the flexible circuit board 81 is located outside the rotating assembly 3 and fixed relative to the rotating assembly 3. Taking the rotating shaft assembly as an example, that is, the flexible circuit board 81 is inserted into the rotating shaft, and the end 811 of the flexible circuit board 81 is fixed relative to the rotating shaft. That is, in this embodiment, the flexible circuit board 81 is inserted into the rotating shaft with the end 811 fixed.

[0106] Continue to refer Figure 9 As shown, the flexible circuit board 81 has a bending portion 812 on the side facing the rotating assembly 3. The bending portion 812 is configured to bend relative to the fixed member 31 along a bending direction during the rotation of the rotating assembly 3 from the first configuration to the second configuration. In other words, the bending portion 812 dynamically bends relative to the fixed member 31, such as the rotating shaft, along the bending direction during the rotation of the rotating assembly 3 from the first configuration to the second configuration.

[0107] like Figure 9 As shown in , the fitting member 82 is attached to the surface of the bending portion 812 and is configured to undergo elastic deformation under the application of an electric field, thereby driving the bending portion 812 to bend in the bending direction relative to the fixed member 31. Due to the provision of the fitting member 82, when the state of the rotating assembly 3 is switched, the degree of elastic deformation of the fitting member 82 (i.e., the amount of elastic deformation of the fitting member 82) can be controlled by controlling the external voltage of the electric field, so that the fitting member 82 drives the bending portion 812 to bend in the bending direction relative to the fixed member 31 as the rotating assembly 3 rotates from the first state to the second state (i.e., the bending portion 812 is driven to undergo dynamic bending).

[0108] At the same time, due to the drive of the fitting 82, the bending angle of the bending portion 812 can also be limited, so that the bending portion 812 has a stable bending shape during the dynamic bending process, so as to ensure that the circuit board assembly 8 as a whole has a steady motion trajectory during the dynamic bending action. At the same time, it can also effectively avoid the circuit board assembly 8 during the dynamic bending process. Due to the bending angle of the bending portion 812 being too large, the motion trajectory of the flexible circuit board 81 during the dynamic bending process deviates, and a dead bending phenomenon occurs at the bending portion 812, thereby avoiding failure of the circuit board assembly 8.

[0109] Due to the property that elastic deformation can be recovered after external conditions such as the removal of the electric field, it can also help ensure that the circuit board assembly 8 has a constant and steady-state motion trajectory during each dynamic bending action, so that the circuit board assembly 8 can bend along the preset motion trajectory during each dynamic bending action and have a constant and stable bending shape, thereby reducing the failure probability of the circuit board assembly 8 during multiple dynamic bending actions.

[0110] Therefore, after the circuit board assembly 8 of the present application replaces the original flexible circuit board 81a in the electronic device 100 and is applied to the electronic device 100, the circuit board assembly 8 can produce a stable bending shape during the dynamic bending process as the electronic device 100 is opened and closed, and can effectively prevent the circuit board assembly 8 from being bent and failing during the dynamic bending process.

[0111] The fitting member 82 is configured to undergo elastic deformation under the application of an electric field to drive the bending portion 812 to bend in the bending direction to a preset fixed angle relative to the fixing member 31, so that the bending portion 812 is controlled to bend along the bending direction to a preset fixed angle relative to the fixing member 31 through the elastic deformation of the fitting member 82, so that the bending portion 812 has a stable bending shape during the dynamic bending process, which can ensure that the circuit board assembly 8 has a constant and steady-state motion trajectory during each dynamic bending action.

[0112] like Figure 9As shown in , the flexible circuit board 81 may include two ends 811, which may be a first end 8111 and a second end 8112. The first end 8111 may extend into the first structural member 1 and be connected to the circuit board 6 in the first structural member 1 via a board-to-board connector (BTB connector) 200 or the like. Correspondingly, the second end 8112 may extend into the second structural member 2 and be connected to the circuit board 6 in the second structural member 2 via a board-to-board connector (BTB connector) 200 or the like. The method for fixing the end 811 of the flexible circuit board 81 may refer to the description in the relevant art and is not further limited in this embodiment.

[0113] The first state can be the folded state of the rotating assembly 3, and the second state can be the flattened state of the rotating assembly 3. That is, the process of the rotating assembly 3 rotating from the first state to the second state can be understood as the process of the rotating assembly 3 and the electronic device 100, such as a foldable mobile phone, rotating from the folded state to the flattened state. Thus, by attaching the fitting 82 to the bending portion 812, the fitting 82 facilitates the process of the flexible circuit board 81 rotating from the folded state to the flattened state, ensuring that the flexible circuit board 81 and the circuit board assembly 8 have a stable motion trajectory. This can prevent the flexible circuit board 81 from being bent during dynamic bending, causing the motion trajectory of the flexible circuit board 81 to deviate, and thus causing failure of the flexible circuit board 81 and the circuit board assembly 8.

[0114] It should be noted that the structure of the rotating assembly 3 and the folded state and flattened state of the rotating assembly 3 can refer to the relevant description above, and will not be further described in this embodiment.

[0115] Taking electroactive polymer films as an example, Figure 10 The schematic diagram of the structure of the bonding part before and after the electric field is applied is shown.

[0116] refer to Figure 10 As shown, in some embodiments, the adhesive member 82 may include an electroactive polymer film (EAP). The EAP film is configured to undergo elastic deformation in its longitudinal direction under the action of an external voltage in an electric field. Alternatively, in other embodiments, the adhesive member 82 may also be a film made of piezoelectric material or other materials that can convert electrical energy into mechanical energy. In other words, the adhesive member 82 of the present application may include, but is not limited to, an EAP film.

[0117] The fitting part 82 of the present application adopts an electroactive polymer film to utilize the principle that the electroactive polymer film can convert electrical pulses into mechanical motion after being electrically stimulated. An electric field can be applied to the electroactive polymer film to utilize the characteristics that the electroactive polymer film thins in its thickness direction and undergoes elastic deformation in its length direction under the action of the external voltage of the electric field, thereby driving the bending portion 812 to reach a preset fixed angle while limiting the bending angle of the bending portion 812 from being too large during the dynamic bending process (that is, the actual bending angle is greater than the preset fixed angle), so that the bending portion 812 produces a stable bending shape during the dynamic bending process.

[0118] It should be noted that the electroactive polymer film also undergoes elastic deformation in its width direction under the action of the external voltage of the electric field. Figure 3 The redundancy generated in the X direction (in the X direction) is relatively high. Therefore, in this embodiment, the elastic deformation of the electroactive polymer film in the longitudinal direction is mainly used to drive the bent portion 812 to reach the preset fixed angle. In this embodiment, the elastic deformation in the width direction of the electroactive polymer film itself is not further explained.

[0119] The length direction of the electroactive polymer film is the same as the length direction of the electronic device 100. The width direction of the electroactive polymer film is the same as the width direction of the electronic device 100. For details, please refer to Figure 3 The thickness direction of the electroactive polymer film is the same as the thickness direction of the electronic device 100. For details, please refer to Figure 3 The Z direction in .

[0120] like Figure 9 As shown in , the electroactive polymer film can be attached to and covered on the curved surface of the bend portion 812. Alternatively, the electroactive polymer film can be attached to and covered on other locations of the bend portion 812, such as the sidewalls in the thickness direction of the bend portion 812. The curved surface of the bend portion 812 can be understood as the surface of the bend portion 812 formed in the length and width directions of the flexible circuit board 81. The length and width directions of the flexible circuit board 81 coincide with the length and width directions of the electroactive polymer film.

[0121] In this embodiment, an electroactive polymer film is used to be attached to the curved surface of the bending portion 812, so that the bending portion 812 is driven by the electroactive polymer film to bend to a preset fixed angle. Compared with the electroactive polymer film being attached to the side wall in the thickness direction of the bending portion 812, the attachment area of ​​the electroactive polymer film on the surface of the bending portion 812 can also be enhanced to achieve a better attachment effect. In this way, through the attachment of the attachment member 82, the bending portion 812 has a more stable bending shape during the dynamic bending process, so as to avoid the flexible circuit board 81 from being bent due to the excessive bending angle of the bending portion 812.

[0122] Continue to refer Figure 9 As shown, the curved surface includes an outer curved surface 8123 that is convex in the bending direction and an inner curved surface 8124 that is concave in the bending direction. Since the strain of the outer curved surface 8123 is greater than that of the inner curved surface 8124 during the dynamic bending process of the bending portion 812, the electroactive polymer film in this embodiment can be attached to and cover the outer curved surface 8123. In this way, the electroactive polymer film can not only be fixed to the bending portion 812 and have a good adhesion effect, but also can drive the outer curved surface 8123 of the bending portion 812 to elongate synchronously through the elastic elongation generated by the electroactive polymer film under the external voltage stimulation of the electric field, so that the outer curved surface 8123 of the bending portion 812 can drive the entire bending portion 812 to bend to a preset fixed angle through the outer curved surface 8123 of the bending portion 812, and maintain a stable bending shape.

[0123] It should be noted that, since the bending portion 812 forms a convex structure when it bends, when the electroactive polymer film is attached to the outer curved surface 8123 of the bending portion 812, it can also be understood that the electroactive polymer film is attached to the convex surface of the convex structure.

[0124] Alternatively, in some embodiments, the bending portion 812 can also adhere to and cover the inner curved surface 8124 of the bending portion 812, so that the elastic contraction generated by the electroactive polymer film under the external voltage stimulation of the electric field can drive the inner curved surface 8124 of the bending portion 812 to stretch and contract synchronously, so that the contraction of the inner curved surface 8124 of the bending portion 812 can drive the entire bending portion 812 to bend to a preset fixed angle and maintain a stable bending shape.

[0125] The structure of the circuit board assembly 8 of the present application is further described below by taking the example of an electroactive polymer film being bonded to and covering the outer curved surface 8123 .

[0126] refer to Figure 10As shown, the circuit board assembly 8 may further include a first flexible electrode 83 and a second flexible electrode 84. The first flexible electrode 83 and the second flexible electrode 84 are attached to opposite sides of the electroactive polymer film and are configured to be connected to an external voltage to form an electric field. The first flexible electrode 83 can be attached between the electroactive polymer film and the bend 812, that is, the first flexible electrode 83 is attached to the inner curved surface 8124 of the bend 812. Since the second flexible electrode 84 is attached to the side of the electroactive polymer film opposite the first flexible electrode 83, the second flexible electrode 84 is attached to the outer curved surface 8123 of the bend 812. In this way, when the first flexible electrode 83 and the second flexible electrode 84 are connected to an external voltage outside the circuit board assembly 8, an electric field can be generated on the electroactive polymer film, so that the electroactive polymer film undergoes elastic deformation under the action of the electric field, causing the bend 812 to bend to a predetermined fixed angle.

[0127] Continue to refer Figure 10 As shown, the first flexible electrode 83 and the second flexible electrode 84 can be connected to the external voltage outside the circuit board assembly 8 at the positive and negative poles, respectively, to form an electric field applied to the electroactive polymer film. Specifically, the first flexible electrode 83 and the second flexible electrode 84 can be electrically connected to the circuit board 6 or other components in the first structural member 1 or the second structural member 2 of the electronic device 100, respectively, so that the first flexible electrode 83 forms a negative electrode and the second flexible electrode 84 forms a positive electrode. A potential difference is formed between the first flexible electrode 83 and the second flexible electrode 84, thereby forming an electric field applied to the electroactive polymer film.

[0128] Figure 11 A schematic structural diagram of another circuit board assembly is shown.

[0129] Alternatively, in some embodiments, when the first flexible electrode 83 and the second flexible electrode 84 are electrically connected to the circuit board 6, a battery, or other components in the first structural member 1 or the second structural member 2 of the electronic device 100, the first flexible electrode 83 can be configured to form a positive and negative electrode, and the second flexible electrode 84 can be configured to form a negative electrode, thereby forming a potential difference between the first flexible electrode 83 and the second flexible electrode 84, thereby forming an electric field applied to the electroactive polymer film. In this application, the polarity of the first flexible electrode 83 and the second flexible electrode 84 and the manner of connection to the components within the electronic device 100 can be specifically referred to as the relationship between the traces on the circuit board 6 and the reference ground in the electronic device 100, and are not further limited here. As long as the first flexible electrode 83 and the second flexible electrode 84 are connected to the external voltage outside the circuit board assembly 8 at the positive and negative poles, an electric field applied to the electroactive polymer film can be formed.

[0130] like Figure 10As shown in , since the electroactive polymer film produces elastic deformation under the stimulation of the electric field, after the electric field applied to the electroactive polymer film is removed, the electroactive polymer film will restore its original state under the action of elastic deformation to facilitate the next dynamic bending of the circuit board assembly 8.

[0131] The relationship between the external voltage and the elastic deformation of the electroactive polymer film satisfies:

[0132] U=KX formula (1)

[0133] Wherein: U is the external voltage, K is the proportional coefficient, and X is the elastic deformation of the electroactive polymer film when the bending portion 812 is bent to a preset fixed angle.

[0134] Since the external voltage U and the elastic deformation X of the electroactive polymer film have a linear proportional relationship (e.g., a directly proportional relationship), the external voltage U of the electric field applied to the electroactive polymer film can be determined based on the elastic deformation X required for the bending portion 812 to bend to a preset fixed angle, thereby ensuring that the electroactive polymer film can undergo elastic deformation X under the action of the external voltage U, so that the elastic deformation X can drive the bending portion 812 to bend to the preset fixed angle.

[0135] When the electroactive polymer film is attached to the outer curved surface 8123 of the bend portion 812, the elastic deformation X can be understood as the elastic extension. Correspondingly, when the electroactive polymer film is attached to the inner curved surface 8124 of the bend portion 812, the elastic deformation X can be understood as the elastic contraction.

[0136] It should be noted that electroactive polymer film is a general term for a class of thin film materials that can convert electrical energy into mechanical energy. There are many types of such electroactive polymer films, which are generally divided into electronic EAP and ionic EAP. Electronic EAP generally includes all-organic composite (AOC) films, dielectric EAP (DEAP), electrostrictive grafted elastomer (ESGE), electrostrictive film (ESP), electroviscoelastic polymer (EVEM) films, ferroelectric polymer (FEP) films and liquid crystal elastomer (LCE) films. Ionic EAP generally includes carbon nanotube (CNT) films, conductive polymer (CP) films, electrorheological fluid (ERF) films, ionic polymer gel (IPG) films and ionic polymer-based metal composite (IPMC) films.

[0137] The electroactive polymer film of the embodiment of the present application can be a film made of polydimethylsiloxane (PDMS) silicone rubber, which can also be called a PDMS elastic member. The film made of the PDMS elastic member can be understood as a type of ionic polymer gel (IPG) film.

[0138] Alternatively, in some embodiments, the electroactive polymer film of the embodiment of the present application may also adopt other types of electroactive polymer films mentioned above. In this embodiment, the type of the electroactive polymer film attached to the bending portion 812 is not further limited.

[0139] Once the type of electroactive polymer film applied to the bending portion 812 is determined, the proportionality coefficient K is also determined based on the characteristics of the electroactive polymer film (i.e., a known quantity). In other words, the proportionality coefficient K depends on the type of electroactive polymer film applied to the bending portion 812. After the proportionality coefficient K and the predetermined bending angle are determined, the external voltage U is determined based on the predetermined elastic deformation X according to the aforementioned formula 1. By controlling the external voltage U, the elastic deformation X of the electroactive polymer film is controlled, thereby causing the bending portion 812 to bend to the predetermined fixed angle.

[0140] Figure 12 The schematic diagram shows the structure of a circuit board assembly at one of its bends.

[0141] refer to Figure 12 As shown, taking the electroactive polymer film attached to one of the bending portions 812 of the flexible circuit board 81 as an example, the elastic deformation X satisfies

[0142]

[0143] Wherein: L1 is the maximum arc length of the stack 85 consisting of the first flexible electrode 83, the second flexible electrode 84 and the electroactive polymer film corresponding to the preset fixed angle, L is the arc length corresponding to the preset fixed angle at half the thickness of the stack 85, n is the preset fixed angle, r is the bending radius of the bending portion 812, and d is the total thickness of the electroactive polymer film and the first flexible electrode 83 and the second flexible electrode 84, that is, d can also be understood as the total thickness of the above-mentioned stack 85.

[0144] According to Formula 2, the elastic deformation X of the electroactive polymer film can be calculated and obtained from the preset fixed angle n of the bending portion 812, so that the external voltage U applied to the electroactive polymer film can be determined by the elastic deformation X.

[0145] It should be noted that when the electroactive polymer film is attached to the outer curved surface 8123 of the bending portion 812, an electric field having a constant external voltage U can be applied to the electroactive polymer film. This constant external voltage U stimulates the electroactive polymer film, causing it to elastically deform by an amount X along its length. This elastic deformation X of the electroactive polymer film then drives the bending portion 812 to bend to a predetermined fixed angle. When all bending portions 812 in the circuit board assembly 8 are bent to their respective predetermined fixed angles, the circuit board assembly 8 completes the dynamic bending process along the predetermined motion trajectory and assumes a stable bent state.

[0146] Accordingly, when the electroactive polymer film is attached to the inner curved surface 8124 of the bending portion 812, an electric field of a rated external voltage can be first applied to the electroactive polymer film so that during the dynamic bending process of the bending portion 812, the rated external voltage can be reduced to a preset external voltage, wherein the difference between the rated external voltage and the preset external voltage is the above-mentioned constant external voltage U, so that the electroactive polymer film contracts as the rated external voltage decreases, causing the inner curved surface 8124 of the bending portion 812 to contract synchronously, so that the bending portion 812 reaches a preset fixed angle.

[0147] Figure 13 and Figure 14 They indicated Figure 9 Schematic diagram of the circuit board assembly in the bent state and straightened state in the first bending area.

[0148] refer to Figure 13 and Figure 14 and combined Figure 9 As shown, the flexible circuit board 81 has a first bending area 813, which is located between the end 811 of the flexible circuit board 81 and the fixing member 31. The first bending area 813 has multiple bending portions 812, and at least some of the bending portions 812 in the first bending area 813 are correspondingly attached with the attachment member 82. Since the flexible circuit board 81 has two ends 811, the flexible circuit board 81 also has two first bending areas 813. Figure 9 As shown in , it was found during the research process that during the dynamic bending process of the flexible circuit board 81, the preset fixed angle of the bending portion 812 at the first bending area 813 is smaller than that of the bending portions 812 in other areas of the flexible circuit board 81, that is, the bending degree of the bending portion 812 in the first bending area 813 is greater, resulting in a greater probability of the flexible circuit board 81 being bent to death in the first bending area 813.

[0149] Therefore, by attaching the fitting 82 to at least part of the bending portion 812 in the first bending area 813, the fitting 82 can drive at least part of the bending portion 812 in the first bending area 813 to bend to a preset fixed angle, and while having a stable bending shape, it can avoid the occurrence of dead bending in the first bending area 813.

[0150] Taking one of the first bending regions 813 as an example, refer to Figure 13 and Figure 14 As shown, the first bending region 813 has a plurality of bending portions 812, including a first bending portion 8121 and a second bending portion 8122 located to the side of the first bending portion 8121. The preset fixed angle of the first bending portion 8121 is smaller than the preset fixed angle of the second bending portion 8122, that is, the bending degree of the first bending portion 8121 is greater than that of the second bending portion 8122. As a result, during the dynamic bending process of the circuit board assembly 8, the probability of the first bending portion 8121 being permanently bent is greater than that of the second bending portion 8122.

[0151] The fitting part 82 can be attached and covered on the curved surface of the first bending portion 8121 facing the side of the fixing part 31, so that the fitting part 82, such as an electroactive polymer film, can drive the first bending portion 8121 to bend during the dynamic bending process and reach a preset fixed angle corresponding to the first bending portion 8121, so as to avoid the flexible circuit board 81 from being bent at the first bending portion 8121 during the dynamic bending process, thereby avoiding the circuit board assembly 8 from failing due to being bent at the first bending portion 8121.

[0152] It should be noted that the number of first bending portions 8121 in the first bending region 813 may include, but is not limited to, two, and electroactive polymer films may be attached to both first bending portions 8121. In some embodiments, the number of first bending portions 8121 in the first bending region 813 may also be one.

[0153] Continue to refer Figure 13 and Figure 14 and combined Figure 9As shown, the first bent portion 8121 is configured to bend toward the side of the fixing member 31, such as the rotating shaft. The fitting member 82 can be attached to and covers the side of the first bent portion 8121 facing the fixing member 31 (i.e., the outer curved surface 8123 of the first bent portion 8121). The second bent portion 8122 is configured to bend toward a side away from the fixing member 31, and the fitting member 82 is attached to and covers the side of the second bent portion 8122 facing away from the fixing member 31 (i.e., the outer curved surface 8123 of the second bent portion 8122). In this way, by setting the fitting 82 on the outer curved surface 8123 of the first bending portion 8121 and the second bending portion 8122, the fitting 82 can be fixed on the first bending portion 8121 and the second bending portion 8122 at the same time, and the fitting 82 can drive the entire first bending portion 8121 and the second bending portion 8122 to bend to their respective corresponding preset fixed angles through the outer curved surface 8123 of the first bending portion 8121 and the second bending portion 8122, thereby realizing the setting of the fitting 82 on all the bending portions 812 in the first bending area 813, so that the first bending area 813 maintains a stable bending shape during the dynamic bending process, thereby avoiding the occurrence of dead bending in the first bending area 813.

[0154] Figure 15 The second bending area 814 of the flexible circuit board 81 is a schematic diagram showing the state transition of the second bending area of ​​the flexible circuit board. Figure 15 It is converted from a bent state to a straightened state. Figure 16 A schematic structural diagram illustrating the straightened state of the second bending region of the flexible circuit board is shown. Figure 17 The schematic diagram of the structure of the circuit board assembly in the second bending area is shown. In this figure, the circuit board assembly 8 is in a straightened state.

[0155] refer to Figure 15 and Figure 16 As shown, the flexible circuit board 81 may further include a second bending region 814, which is located to the side of the first bending region 813 and is arranged opposite to the fixing member 31, such as the rotating shaft. In other words, the second bending region 814 is located between the two first bending regions 813. The second bending region 814 has a plurality of bending portions 812. Figure 17 As shown, at least part of the bending portion 812 in the second bending area 814 is affixed with a fitting 82, so that when the fitting 82 is affixed to the bending portion 812 of the second bending area 814, at least part of the bending portion 812 in the second bending area 814 can reach respective corresponding preset fixed angles during the dynamic bending process and maintain a stable bending shape, thereby avoiding the dead bending phenomenon in the second bending area 814 and avoiding failure of the flexible circuit board 81 during the dynamic bending process.

[0156] Similarly, the second bending region 814 also includes the aforementioned first bending portion 8121 and second bending portion 8122. The number of first bending portions 8121 within the second bending region 814 may include, but is not limited to, two, and the number of second bending portions 8122 within the second bending region 814 may include, but is not limited to, two. The two second bending portions 8122 may be located on opposite sides of the two first bending portions 8121. The placement of the adhesive member 82 on the first bending portions 8121 and the second bending portions 8122 within the second bending region 814 may refer to the description of the first bending region 813, and will not be further elaborated in this embodiment.

[0157] like Figure 9 As shown in , the electronic device 100 may further include a third structural member 5. The number of the third structural members 5 may include, but is not limited to, two. The two third structural members 5 may be respectively connected to the first rotating member 32 and the second rotating member 33 in the rotating assembly 3 and cover the rotating shaft. The third structural member 5 may be located between the fixing member 31 and the flexible display screen 4.

[0158] refer to Figure 9 As shown, when the distance between the flexible circuit board at the junction of the second bending region 814 and the first bending region 813 and the third structural member 5 is large, and the distance between the bends 812 adjacent to the second bending region 814 and the first bending region 813 is small, the bends 812 adjacent to the second bending region 814 and the first bending region 813 can all be attached to the same bonding member 82, so that the bends 812 adjacent to the second bending region 814 and the first bending region 813 are driven by the same bonding member 82 to bend to a preset fixed angle. While having a stable bending shape, the number of bonding members 82 in the circuit board assembly 8 can be reduced, thereby reducing the manufacturing cost of the circuit board assembly 8 and the electronic device 100. When calculating the external voltage U applied to the bonding member 82, the two bends 812 adjacent to the second bending region 814 and the first bending region 813 can be regarded as one bend 812 to obtain a preset fixed angle, and the calculation is performed using the above-mentioned formulas 1 and 2.

[0159] Figure 18 Another structural schematic diagram of the circuit board assembly of the electronic device in a flat state is shown.

[0160] refer to Figure 18As shown, when the distance between the flexible circuit board and the third structural member 5 at the junction of the second bending area 814 and the first bending area 813 is small, and the distance between the second bending area 814 and the bending portion 812 adjacent to the first bending area 813 is large, a bonding member 82 can be respectively bonded to the bending portion 812 adjacent to the first bending area 813 and the second bending area 814, so that the bonding member 82 can drive the bonded bending portion 812 to bend to a preset fixed angle.

[0161] It should be noted that, because the dynamic bending trajectory of the flexible circuit board 81 during the opening and closing process of the same model electronic device 100, such as when it is unfolded from a folded state to a flat state, is constant, the preset fixed angles corresponding to the respective bends 812 on the flexible circuit board 81 are also relatively fixed. The preset fixed angles of the respective bends 812 can be obtained through simulation or other means. In this embodiment, the preset fixed angles of the respective bends 812 are not further limited.

[0162] The adhesive member 82 includes a first adhesive member and a second adhesive member, the second adhesive member being different from the first adhesive member, and at least one of the first adhesive member and the second adhesive member is adhered to the flexible circuit board 81. That is, each bend 812 on the flexible circuit board 81 can be adhered to the same adhesive member, such as a film made of a PDMS elastic member, or, in some embodiments, two or more adhesive members 82 can be adhered to the flexible circuit board 81. Taking the example of the first adhesive member and the second adhesive member adhered to the bend 812 of the first bend region 813 on the flexible circuit board 81, the first bend 8121 of the first bend region 813 can be adhered to the first adhesive member, and the second bend 8122 can be adhered to the second adhesive member. The first adhesive member and the second adhesive member can include, but are not limited to, a film made of the above-mentioned piezoelectric material, or any of the above-mentioned electroactive polymer films. In this way, while ensuring that the first bending area 813 has a stable bending shape during the dynamic bending process, it can also increase the diversity of the bonding parts 82 in the circuit board assembly 8. In this embodiment, the type of bonding parts 82 on the flexible circuit board 81 is not further limited.

[0163] It should be noted that the smaller the preset fixed angle of the bend 812, the greater the probability of failure of the circuit board assembly 8 due to folding at the bend 812. Therefore, in the design of the bonding member 82, the failure probability at the bend 812 can be judged based on the size of the preset fixed angle of each bend 812 to determine whether the bend 812 needs to be attached with the bonding member 82. In this application, the attachment position of the bonding member 82 on the flexible circuit board 81 is not further limited.

[0164] Figure 19A schematic diagram of a control method for a circuit board assembly is shown.

[0165] On the basis of the above, the embodiment of the present application further provides a control method of a circuit board assembly 8, which is applied to the circuit board assembly 8 mentioned above. The circuit board assembly 8 includes a flexible circuit board 81 and a bonding member 82. The bonding member 82 is attached to the bending portion 812 of the flexible circuit board 81. Figure 19 As shown, the control method may include:

[0166] Step S100: determining a preset fixed angle of the bending portion when the bending portion undergoes a shape transformation by a rotating component.

[0167] It should be noted that the morphological transformation of the rotating assembly may include, but is not limited to, rotating the rotating assembly from a first shape to a second shape. The first shape includes, but is not limited to, a folded state, and the second shape includes, but is not limited to, a flattened state. As described above, for the same model of electronic device 100, when the bend 812 in the circuit board assembly 8 undergoes a morphological transformation with the rotating assembly 3, such as rotating from the first shape to the second shape, the preset fixed angle of the bend 812 is a determinable known quantity. The method for determining the preset fixed angle of the bend 812 may include, but is not limited to, determining it by simulating each bend 812 of the flexible circuit board 81 during the opening and closing process of the electronic device 100.

[0168] refer to Figure 19 As shown, after step S100, the control method may further include:

[0169] Step S200: applying an electric field to the bonding member, so as to drive the bending portion to bend to a preset fixed angle through the elastic deformation of the bonding member under the electric field.

[0170] It should be noted that after determining the preset fixed angle corresponding to the bending portion 812, an electric field can be applied to the fitting 82 so as to control the elastic deformation of the fitting 82 by controlling the electric field, and then control the bending portion 812 to bend to the corresponding preset fixed angle, ensuring that the circuit board assembly 8 has a steady-state motion trajectory during the dynamic bending process, and can effectively avoid the circuit board assembly 8 from deviating from the motion trajectory of the flexible circuit board 81 during the dynamic bending process due to the bending angle of the bending portion 812 being too large during the dynamic bending process, and causing a dead bend at the bending portion 812, thereby avoiding failure of the circuit board assembly 8.

[0171] Specifically, an electric field is applied to the bonding member to drive the bending portion to bend to a preset fixed angle through the elastic deformation of the bonding member under the electric field, which specifically includes:

[0172] Obtaining the elastic deformation required by the bonding component when the bending portion is bent to a preset fixed angle;

[0173] The external voltage corresponding to the electric field is determined according to the elastic deformation amount, so that the bonding piece generates elastic deformation under the action of the electric field.

[0174] It should be noted that the determination of the elastic deformation X of the adhesive member 82 can be referred to the relevant description above and will not be further elaborated here. After obtaining the elastic deformation X of the adhesive member 82 required for the bending portion 812 to bend to a predetermined fixed angle, an external voltage U corresponding to the electric field determined based on the elastic deformation X can be applied to the adhesive member 82 to stimulate the adhesive member 82.

[0175] In this way, under the stimulation of the external voltage U, the fitting 82 produces an elastic deformation X, and by controlling the size of the external voltage U, the elastic deformation X is controlled to ensure that the fitting 82 can drive the bending portion 812 to bend to a preset fixed angle, ensuring that the circuit board assembly 8 has a steady-state motion trajectory during the dynamic bending process, and can effectively avoid the circuit board assembly 8 from deviating from the motion trajectory of the flexible circuit board 81 during the dynamic bending process due to the bending angle of the bending portion 812 being too large during the dynamic bending process, and causing a dead bend phenomenon at the bending portion 812, thereby avoiding failure of the circuit board assembly 8.

[0176] It should be noted that after the elastic deformation X is determined, the external voltage U of the electric field can be calculated and determined according to Formula 1. Specifically, when the bonding member 82 is bonded to different locations on the bent portion 812, such as when it is bonded to the outer curved surface 8123 or the inner curved surface 8124 of the bent portion 812, the initial external voltage value of the external voltage U of the electric field applied to the bonding member 82 will also be different. Specifically, when the bonding member 82 is bonded to the outer curved surface 8123 or the inner curved surface 8124 of the bent portion 812, the method for determining the initial external voltage value can refer to the above description regarding the constant external voltage U, and will not be further elaborated here.

[0177] On the basis of the above, an embodiment of the present application provides an electronic device 100. As described above, the electronic device 100 may include a first structural member 1, a second structural member 2, and a rotating assembly 3. The electronic device 100 of this embodiment may also include a circuit board assembly 8 as described above. The circuit board assembly 8 is used to replace the original flexible circuit board 81 in the electronic device 100. It is inserted into the fixing member 31, and the end 811 of the circuit board assembly 8 is connected to the circuit board 6 in the first structural member 1 and the second structural member 2. In this way, through the arrangement of the first structural member 1, the second structural member 2, and the rotating assembly 3, on the basis of making the electronic device 100 foldable, the circuit board assembly 8 can not only realize the connection between the circuit board 6 in the first structural member 1 and the second structural member 2, and realize the connection and conduction of the circuit board 6 in the first structural member 1 and the second structural member 2, but also ensure that the circuit board assembly 8 has a constant and steady-state motion trajectory when the rotating assembly 3 performs each dynamic bending action, so as to avoid failure of the circuit board assembly 8.

[0178] It should be noted that the first structural member 1, the second structural member 2, the rotating assembly 3 and the end 811 of the circuit board assembly 8 in the electronic device 100 are connected to the circuit board 6 in the first structural member 1 and the second structural member 2. Please refer to the relevant description above and no further details will be given here.

[0179] The peripheral edges of the flexible display screen 4 in the electronic device 100 are positioned on the first structural member 1 and the second structural member 2, and the flexible display screen 4 is covered by the circuit board assembly 8. Because the flexible circuit board 81 in the circuit board assembly 8 maintains a constant and steady motion trajectory with each dynamic bending process of the electronic device 100 during opening and closing, failure of the flexible circuit board 81 during dynamic bending can be avoided, thereby reducing the scrap rate of the flexible circuit board 81 caused by repairs due to failure of the flexible circuit board 81, and further reducing the failure rate and repair costs of the electronic device 100.

[0180] It should be noted that the description of other structures in the electronic device 100 can refer to the relevant description above and will not be further elaborated here.

[0181] In the description of the embodiments of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to a fixed connection, an indirect connection via an intermediate medium, internal communication between two components, or an interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of this application based on specific circumstances.

[0182] The terms "first", "second", "third", "fourth", etc. (if any) in the description and claims of the embodiments of this application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

Claims

1. A circuit board assembly, used in electronic equipment, characterized in that: The circuit board assembly includes a flexible circuit board and a fitting, wherein the flexible circuit board is inserted into a fixing member of the rotating assembly of the electronic device, and an end portion of the flexible circuit board is located outside the rotating assembly and fixed relative to the rotating assembly; The flexible printed circuit board has a bending portion on a side facing the rotating assembly, and the bending portion is configured to bend relative to the fixing member along a bending direction during the process of the rotating assembly rotating from the first state to the second state; the bonding member is attached to the surface of the bending portion and is configured to undergo elastic deformation under the application of an electric field to drive the bending portion to bend relative to the fixing member in the bending direction; The flexible circuit board has a first bending area, the first bending area is located between the end of the flexible circuit board and the fixing member, the first bending area has a plurality of bending portions, and at least some of the bending portions in the first bending area are correspondingly attached with the attaching member; The multiple bending portions include a first bending portion and a second bending portion located on the side of the first bending portion. The preset fixed angle of the first bending portion is smaller than the preset fixed angle of the second bending portion. The bonding member is attached to and covers the curved surface of the first bending portion.

2. The circuit board assembly according to claim 1, wherein: The fitting member is configured to undergo elastic deformation when the electric field is applied, so as to drive the bending portion to bend toward the bending direction to a preset fixed angle relative to the fixing member.

3. The circuit board assembly according to claim 2, wherein: The adhesive component includes an electroactive polymer film, and the electroactive polymer film is configured to undergo elastic deformation in its length direction under the action of the external voltage of the electric field.

4. The circuit board assembly according to claim 3, wherein: The electroactive polymer film is attached to and covers the curved surface of the bent portion.

5. The circuit board assembly according to claim 4, wherein: The curved surface includes an outer curved surface that is convex in the bending direction and an inner curved surface that is concave in the bending direction, and the electroactive polymer film is attached to and covers the outer curved surface.

6. The circuit board assembly according to claim 3, wherein: It also includes a first flexible electrode and a second flexible electrode, the first flexible electrode and the second flexible electrode are attached to opposite sides of the electroactive polymer film, and are configured to be connected to an external voltage to form the electric field; the first flexible electrode is attached between the electroactive polymer film and the bending portion.

7. The circuit board assembly according to claim 6, wherein: The relationship between the external voltage and the elastic deformation of the electroactive polymer film satisfies: U=KX Wherein: U is the external voltage, K is the proportional coefficient, and X is the elastic deformation of the electroactive polymer film when the bending portion is bent to the preset fixed angle.

8. The circuit board assembly according to claim 7, wherein: The elastic deformation satisfies: Wherein: X is the elastic deformation, n is the preset fixed angle, r is the bending radius of the bending portion, and d is the total thickness of the electroactive polymer film, the first flexible electrode, and the second flexible electrode.

9. The circuit board assembly according to claim 1, wherein: The bending direction of the first bending portion is configured to bend toward one side of the fixing member, and the bonding member is attached to and covers the side of the first bending portion facing the fixing member; the second bending portion is configured to bend toward a side away from the fixing member, and the bonding member is attached to and covers the side of the second bending portion away from the fixing member.

10. The circuit board assembly according to claim 9, wherein: The flexible circuit board also includes a second bending area, which is located on the side of the first bending area and is arranged opposite to the fixing member. The second bending area has multiple bending portions, and at least some of the bending portions in the second bending area are affixed with the bonding member.

11. The circuit board assembly according to claim 10, wherein: The second bending area and the bending portions adjacent to the first bending area are both bonded to the same bonding member.

12. The circuit board assembly according to claim 1, wherein: The bonding member includes a first bonding member and a second bonding member, the second bonding member is different from the first bonding member, and at least one of the first bonding member and the second bonding member is bonded to the flexible circuit board.

13. The circuit board assembly according to any one of claims 1 to 7, characterized in that: The first state is a folded state of the rotating assembly, and the second state is a flattened state of the rotating assembly.

14. A method for controlling a circuit board assembly, characterized in that: The control method is applied to a circuit board assembly according to any one of claims 1 to 13, wherein the circuit board assembly comprises a flexible circuit board and a bonding member, wherein the bonding member is attached to a bent portion of the flexible circuit board, and the control method comprises: Determining a preset fixed angle of the bending portion when the bending portion undergoes a shape transformation by the rotating assembly; An electric field is applied to the fitting so as to drive the bending portion to bend to the preset fixed angle through elastic deformation of the fitting under the electric field.

15. The control method according to claim 14, characterized in that: The step of applying an electric field to the bonding member to drive the bending portion to bend to the preset fixed angle through elastic deformation of the bonding member under the electric field specifically includes: Obtaining the elastic deformation amount required by the fitting when the bending portion is bent to the preset fixed angle; An external voltage corresponding to the electric field is determined according to the elastic deformation amount, so that the bonding member generates the elastic deformation under the action of the electric field.

16. An electronic device, characterized in that: It includes a first structural member, a second structural member, a rotating assembly and a circuit board assembly according to any one of claims 1 to 13, wherein the rotating assembly includes a fixing member, and the first structural member and the second structural member are rotatably connected to opposite sides of the fixing member; the circuit board assembly is inserted into the fixing member, and the end of the circuit board assembly is connected to the circuit boards in the first structural member and the second structural member.

17. The electronic device according to claim 16, wherein: It also includes a flexible display screen, the peripheral edge of the flexible display screen is located on the same surface of the first structural member and the second structural member, and the flexible display screen is covered on the circuit board assembly.

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