Terminal device

Abstract

The invention provides a terminal device. The terminal device comprises a first structural member, a second structural member, an adhesive layer, a flexible circuit board and a water stop adhesive. The first structural member and the second structural member are bonded by the adhesive layer; the flexible circuit board is located between the adhesive layer and the first structural member; gaps among the first structural member, the glue layer and / or the flexible circuit board are filled with the water stop glue; wherein the volume of the water-stop glue is increased after the water-stop glue absorbs water. The water stop glue has fluidity before being cured and can fully fill gaps; the water stop glue has the performance of swelling after absorbing water and has a good waterproof effect, so that the high waterproof requirement of the terminal device is met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of terminal devices, in particular to a terminal device. BACKGROUND

[0002] The key is an important part of the terminal device, and the use of the terminal device can be realized through key operation. There is a gap between the key and the middle frame of the terminal device, and the area where the key is located needs to be waterproofed to prevent water from the outside from entering the inside of the terminal device. However, the existing waterproofing process cannot meet the waterproofing requirements. SUMMARY

[0003] Therefore, it is necessary to provide a terminal device with good waterproof performance.

[0004] The present application provides a terminal device, which comprises a first structural member, a second structural member, a glue layer, a flexible circuit board and a waterproof glue. The glue layer bonds the first structural member and the second structural member; the flexible circuit board is located between the glue layer and the first structural member; the waterproof glue fills the gap between the first structural member, the glue layer and / or the flexible circuit board; wherein the waterproof glue increases in volume after absorbing water.

[0005] In the above design, the waterproof glue has fluidity before solidification and can fully fill the gap between the first structural member, the glue layer and / or the flexible circuit board; the waterproof glue has adhesion, and the waterproof glue can be closely combined with the first structural member, the glue layer and the flexible circuit board, thereby increasing the waterproof effect of the interface; the waterproof glue has the performance of water absorption and swelling, and when the water from the outside contacts the waterproof glue, the water can be absorbed by the waterproof glue, thereby limiting the movement of the water towards the inside of the terminal device; further, the waterproof glue swells after absorbing water, which can further fully fill the gap between the first structural member, the glue layer and the flexible circuit board, thereby further improving the waterproof effect to meet the high waterproof requirements of the terminal device.

[0006] In some possible embodiments of the present application, the first structural member comprises an inner side portion, a groove is formed on the inner side portion, the groove is recessed from the surface of the inner side portion facing the glue layer, the groove extends through the opposite surfaces of the inner side portion, the flexible circuit board passes through the inner side portion from the groove, and the waterproof glue fills the groove.

[0007] In the above design, the waterproof glue can swell in various directions after absorbing water. Since the groove extends through the opposite surfaces of the inner side portion, when the waterproof glue swells in the direction of the groove extending through the inner side portion, the width of the waterproof glue is increased, which increases the difficulty of water entering the inside of the terminal device from the groove, thereby further improving the waterproof performance. When the waterproof glue swells in the direction of the glue layer, the flexible circuit board and the first structural member being stacked, a certain extrusion force is generated on the glue layer and the inner side portion, but the waterproof glue can swell in the direction of the groove extending through the inner side portion, thereby relieving part of the extrusion force.

[0008] In some possible implementation manners of the present application, the flexible circuit board comprises a first surface and a second surface arranged oppositely, the first surface is attached to the surface of the first structural member, and the second surface is attached to the surface of the adhesive layer.

[0009] In the above design, for the flexible circuit board in the recess in one possible implementation manner of the present application, the structure of the waterproof adhesive can be changed according to the gap between the adhesive layer, the flexible circuit board and the first structural member, thereby improving the flexibility of the structure of the terminal device.

[0010] In some possible implementation manners of the present application, the flexible circuit board comprises a first surface and a second surface arranged oppositely, the first surface is arranged towards the first structural member, and the second surface is arranged towards the adhesive layer; wherein the first surface is arranged spaced apart from the first structural member, and the waterproof adhesive is filled between the flexible circuit board and the first structural member; and / or the second surface is arranged spaced apart from the adhesive layer, and the waterproof adhesive is filled between the flexible circuit board and the adhesive layer.

[0011] In the above design, for the flexible circuit board in the recess in one possible implementation manner of the present application, the structure of the waterproof adhesive can be changed according to the gap between the adhesive layer, the flexible circuit board and the first structural member, thereby improving the flexibility of the structure of the terminal device.

[0012] In some possible implementation manners of the present application, the first structural member further comprises an outer side portion, the outer side portion and the inner side portion surround to form a receiving hole, and the recess and the receiving hole are communicated; the flexible circuit board comprises a first soft board portion, a bending portion and a second soft board portion, the bending portion connects the first soft board portion and the second soft board portion, the first soft board portion and the second soft board portion are located on opposite sides of the inner side portion, the first soft board portion is located in the receiving hole, and the bending portion passes through the inner side portion from the recess.

[0013] In the above design, the flexible circuit board penetrates through the opposite surfaces of the inner side portion, so as to realize the interaction of the internal and external signals of the terminal device.

[0014] In some possible implementation manners of the present application, a through hole is formed in the outer side portion, the through hole and the receiving hole are communicated, the terminal device further comprises a key assembly, the key assembly is located in the through hole and the receiving hole, and the key assembly is in transmission connection with the flexible circuit board.

[0015] In the above design, the structure with the waterproof function of the present application can be applied to the application scene with the key assembly, and the high waterproof requirement of the terminal device can be realized.

[0016] In some possible implementation manners of the present application, the waterproof adhesive is a high polymer material, the waterproof adhesive comprises a soft segment, a hard segment and a polar hydrophilic chain segment, the soft segment and the hard segment are arranged alternately, and the polar hydrophilic chain segment is embedded in the soft segment.

[0017] In the above design, the polar hydrophilic chain segment has good hydrophilicity. When the waterstop comes into contact with water, the polar hydrophilic chain segment will combine with water molecules, thereby limiting the movement of water toward the interior of the terminal device; the soft segment has good flexibility and is prone to deformation during the waterstop absorption process, causing the volume of the waterstop to expand; the hard segment has good crystallization properties, so that the waterstop has a certain rigidity on the basis of flexibility, which makes the waterstop have a certain mechanical strength, and the waterstop can exhibit high elasticity when subjected to external force.

[0018] In some possible implementations of the present application, the maximum volume expansion rate of the waterstop adhesive is P, and the maximum volume expansion rate satisfies: 15%≤P≤50%.

[0019] In the above design, the maximum volume expansion rate satisfies 15% ≤ P ≤ 50%, ensuring high waterproof performance for the terminal device. If the maximum volume expansion rate is too small, and gaps not filled with the waterstop exist, there is a risk of moisture entering the terminal device. If the maximum volume expansion rate is too small, there is a risk of separation between the adhesive layer and the first structural member, affecting the terminal device's connection reliability and waterproof performance.

[0020] In some possible implementations of the present application, the volume expansion rate of the water-stop adhesive after absorbing water is T, and the volume expansion rate satisfies: 5% / min≤T≤20% / min.

[0021] In the above design, the volume expansion rate satisfies 5% / min ≤ T ≤ 20% / min, ensuring high waterproof performance for the terminal device. If the volume expansion rate is too low, and if there are gaps unfilled by the waterstop, the waterstop will not expand quickly enough when moisture enters, posing a risk of moisture entering the terminal device. If the volume expansion rate is too high, the waterstop will likely expand unevenly, compromising the terminal device's waterproof performance.

[0022] In some possible implementations of the present application, the first structural member is a middle frame, and the second structural member is a rear cover.

[0023] The above design is a specific application scenario of the terminal device. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the overall structure of the terminal device provided in an embodiment of the present application.

[0025] Figure 2 for Figure 1 An exploded view of the terminal unit is shown.

[0026] Figure 3 for Figure 1 An exploded view of area A of the terminal device is shown.

[0027] Figure 4 The embodiment of the present application provides a foam pair Figure 1 Schematic diagram of the cross-sectional process for waterproofing area A.

[0028] Figure 5 This is an enlarged picture of the closed-cell foam provided in the embodiments of the present application.

[0029] Figure 6 This is an enlarged picture of the semi-open-cell foam provided in an embodiment of the present application.

[0030] Figure 7 For moisture to pass through Figure 6 Schematic diagram of the cross section of the foam hole shown.

[0031] Figure 8 For other embodiments of this application, water-stop glue is used to Figure 1 Schematic diagram of a cross section perpendicular to the X-axis in which area A is waterproofed.

[0032] Figure 9 for Figure 8 The water stop glue is used as shown Figure 1 Schematic diagram of a cross section perpendicular to the Y-axis in which area A is waterproofed.

[0033] Figures 10 to 12 Some other embodiments of the present application use water-stop glue to Figure 1 Schematic diagram of a cross section perpendicular to the X-axis in which area A is waterproofed.

[0034] Figure 13 This is a schematic diagram of the volume change of the water-stop glue used in the embodiment of the present application before and after absorbing water.

[0035] Description of main component symbols

[0036]

[0037] DETAILED DESCRIPTION

[0038] In order to more clearly understand the above-mentioned objects, features and advantages of the present application, the present application is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, in the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other. In the following description, many specific details are set forth to facilitate a full understanding of the present application. The embodiments described are only a part of the embodiments of the present application, rather than all of the embodiments.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit this application. The term "and / or" as used herein includes all and any combinations of one or more of the associated listed items.

[0040] In the various embodiments of the present application, for ease of description and not limitation, the term "connection" used in the patent specification and claims of the present application is not limited to physical or mechanical connections, whether direct or indirect. "Up," "down," "above," "below," "left," "right," etc. are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship also changes accordingly.

[0041] See also Figure 1 , Figure 1 This is a schematic diagram of the structure of a terminal device 100 provided in an embodiment of the present application. The terminal device 100 may include, but is not limited to, a mobile phone, a tablet computer, a laptop computer, a camera, a wearable device, or other product with waterproof components. The wearable device includes, but is not limited to, a smart bracelet, a smart watch, and smart glasses.

[0042] In this embodiment, the terminal device 100 is described as a mobile phone. The mobile phone is roughly rectangular and plate-shaped. For ease of description, an XYZ coordinate system is established, defining the width direction of the mobile phone as the X-axis direction, the length direction of the mobile phone as the Y-axis direction, and the thickness direction of the mobile phone as the Z-axis direction. It is understood that the coordinate system setting of the terminal device 100 can be flexibly set according to actual needs and is not specifically limited here. In other embodiments, when the terminal device 100 is other products, the shape of the terminal device 100 can also be a square flat plate, a circular flat plate, an oval flat plate, or an irregular shape, etc., which is not specifically limited here.

[0043] See also Figure 2 , Figure 2 for Figure 1 The terminal device 100 is shown in the exploded view. The terminal device 100 may include a middle frame 10, a rear shell 20, a screen (not shown), a glue layer 25, a key assembly 30, a flexible circuit board 40 and a mainboard 50. Figure 2In the figure, only some components of the terminal device 100 are shown by way of example, rather than all components. For example, the terminal device 100 may also include components such as a battery 55 and a lens module 57. In this embodiment, the middle frame 10 serves as the first structural member, and the rear cover 20 serves as the second structural member. In other embodiments, the specific components of the terminal device 100 may vary depending on the name and relative positions of the specific terminal device 100, and the specific names of the first structural member and the second structural member may also vary accordingly.

[0044] The screen and the rear shell 20 are located on opposite sides of the middle frame 10. The screen is used to display images, videos, etc. The screen can be a rigid display screen or a flexible display screen, and can be a flat screen or a curved screen. The screen can be an organic light-emitting diode (OLED) display screen, an active-matrix organic light-emitting diode or an active-matrix organic light-emitting diode (AMOLED) display screen, a mini organic light-emitting diode (MIL-I) display screen, a micro organic light-emitting diode (MIL-I) display screen, a micro organic light-emitting diode (MIL-I) display screen, a quantum dot light-emitting diode (QLED) display screen, a liquid crystal display (LCD), etc.

[0045] The middle frame 10 and the rear housing 20 are used to protect the components within the terminal device 100. The middle frame 10 may include a main body 11 and a frame 13. The frame 13 surrounds the main body 11 and is fixed to the main body 11. In this embodiment, the frame 13 and the main body 11 are integrally formed. The frame 13 is located between the main body 11 and the rear housing 20. The adhesive layer 25 is annular and adheres the rear housing 20 and the frame 13. The middle frame 10, the rear housing 20, and the adhesive layer 25 together form a relatively enclosed storage space (not shown). The storage space can be used to accommodate components such as the flexible circuit board 40, the main board 50, the battery 55, and the lens module 57.

[0046] The key assembly 30 is used for inputting instructions, and the flexible circuit board 40 is used for controlling internal functional elements of the terminal device 100 according to the instructions input by the key assembly 30. The key assembly 30 can be a volume key assembly, and the size of the sound of the terminal device 100 can be adjusted by triggering the key assembly 30. The key assembly 30 can also be a power key assembly, and the terminal device 100 can be turned on, turned off, locked, or awakened, etc. by triggering the key assembly 30. The key assembly 30 can be a fingerprint recognition assembly, and the terminal device 100 can be unlocked, etc. by recognizing the fingerprint of the user. The key assembly 30 can be arranged on the side or top edge of the frame 13 as a side key or a top key. The number of key assemblies 30 can be one or more, and the specific number and installation position can be adjusted according to the actual application scenario.

[0047] Please refer to Figure 3 , Figure 3 for Figure 1 the exploded view of the A area of the terminal device 100. The key assembly 30 can include a key 31, a connecting piece 33, and a switch 35. The key 31 is generally long strip-shaped and extends along the Y-axis direction; the connecting piece 33 and the switch 35 are both two, the two connecting pieces 33 are arranged along the Y-axis direction and connected to the two ends of the key 31; each connecting piece 33 connects one switch 35, and the key 31, the connecting piece 33, and the switch 35 are arranged along the X-axis direction, and the switch 35 is used for electrically connecting with the flexible circuit board 40 to realize the transmission connection between the key 31 and the flexible circuit board 40. The transmission connection here refers to the connection that can realize the signal transmission from the user acting on the key 31 to the switch 35, so that the electrical connection relationship between the switch 35 and the flexible circuit board 40 changes.

[0048] The frame 13 includes an outer side portion 132 and an inner side portion 134, and the outer side portion 132 and the inner side portion 134 are arranged along the X-axis direction. The outer side portion 132 is located on the outer side of the terminal device 100 and extends along the Y-axis direction, and the inner side portion 134 is located on the inner side of the terminal device 100 relative to the outer side portion 132, and the two ends of the inner side portion 134 arranged along the Y-axis direction are connected with the outer side portion 132. The outer side portion 132 is provided with a through hole 1321 penetrating through the outer side portion 132 along the X-axis direction; and a receiving hole 1341 is formed between the outer side portion 132 and the inner side portion 134, and the receiving hole 1341 and the through hole 1321 are in communication with each other.

[0049] The key assembly 30 is located in the through hole 1321 and the receiving hole 1341. In this embodiment, the key 31 is located in the through hole 1321, and part of the key 31 can protrude out of the through hole 1321 so that the user can act on the key 31. Part of the connecting piece 33 is located in the through hole 1321, and the remaining part of the connecting piece 33 and the switch 35 are located in the receiving hole 1341.

[0050] The flexible circuit board 40 includes a first soft board portion 41, a bending portion 43, and a second soft board portion 45, and the bending portion 43 connects the first soft board portion 41 and the second soft board portion 45. The first soft board portion 41 and the second soft board portion 45 are substantially plate-shaped, and the bending portion 43 is substantially bending-shaped. The first soft board portion 41 and the second soft board portion 45 are located on opposite sides of the inner side portion 134.

[0051] Specifically, the first soft board portion 41 is located in the accommodation hole 1341 and is attached to the inner side portion 134, and the switch 35 is connected to the first soft board portion 41; the bending portion 43 can pass through the inner side portion 134 along the surface of the inner side portion 134; and the second soft board portion 45 extends towards the inside of the terminal device 100. In other embodiments, the shape of the flexible circuit board 40 can be changed according to the actual application scenario.

[0052] The terminal device 100 can further include a first reinforcing plate 47 and a second reinforcing plate 49. The first reinforcing plate 47 is substantially matched with the shape of the first soft board portion 41, and is located between the first soft board portion 41 and the inner side portion 134 and can be attached to the surface of the inner side portion 134; the second reinforcing plate 49 is substantially matched with the shape of the second soft board portion 45, and is located between the second soft board portion 45 and the main body portion 11 and can be attached to the surface of the main body portion 11. The first reinforcing plate 47 and the second reinforcing plate 49 are respectively used to increase the strength of the first soft board portion 41 and the second soft board portion 45.

[0053] The main board 50 includes a circuit board 51 and an electronic element 53 disposed on the circuit board 51, and the electronic element 53 includes but is not limited to a processor, an antenna module, a Bluetooth module, a GPS module, a charging module, a screen display and operation module, etc. The second soft board portion 45 of the flexible circuit board 40 is electrically connected to the circuit board 51. When the user acts on the key 31, the action signal can be transmitted to the main board 50 through the flexible circuit board 40, and the signal is processed by the main board 50.

[0054] The bending portion 43 of the flexible circuit board 40 is located between the adhesive layer 25 and the inner side portion 134 and passes through the opposite surfaces of the inner side portion 134. Because the area for passing through the flexible circuit board 40 between the adhesive layer 25 and the frame 13 also has a certain gap, the outside and the inside of the terminal device 100 are connected.

[0055] Please refer to Figure 4 , Figure 4 The cross-sectional schematic view of the terminal device 100' provided by the embodiment of the present application is shown, and the terminal device 100' is provided with the foam 60 for Figure 1A cross-sectional flow diagram illustrating waterproofing of area A in FIG. In this embodiment, a foam pad 60 can be filled in the gap between the adhesive layer 25 and the frame 13 to prevent external moisture from entering the interior of the terminal device 100' through the gap between the adhesive layer 25 and the frame 13. This prevents the external moisture from affecting components within the terminal device 100', or even causing failure of the components within the terminal device 100'. For ease of distinction, the foam pad 60 is defined as comprising a first foam pad 61 and a second foam pad 63. The first foam pad 61 is positioned between the frame 13 and the flexible circuit board 40, and the second foam pad 63 is positioned between the flexible circuit board 40 and the adhesive layer 25. The first foam pad 61 and the second foam pad 63 are interconnected. Assembling the foam pad 60 to the terminal device 100' may include firstly stacking the flexible circuit board 40, the first foam pad 61, and the frame 13 to form a first assembly 101', stacking the back cover 20, the adhesive layer 25, and the second foam pad 63 to form a second assembly 102', and then pressing the first assembly 101' and the second assembly 102' together. Among them, the first foam 61 and the second foam 63 are both elastic. In the pressing step, the first foam 61 and the second foam 63 are both compressed, and the first foam 61 and the second foam 63 are deformed, thereby filling most of the gap between the glue layer 25 and the frame 13. For the step area of ​​adjacent elements (such as the corner area), the first foam 61 and the second foam 63 are difficult to fill, thereby easily forming a gap 65, and moisture can pass through the gap 65.

[0056] Please also refer to Figure 5 、 Figure 6 and Figure 7 , Figure 5 This is an enlarged picture of the closed-cell foam 60 provided in the embodiment of the present application. Figure 6 This is an enlarged picture of the semi-open-cell foam 60 provided in some other embodiments of the present application. Figure 7 For moisture to pass through Figure 6 A schematic cross-sectional view of the holes 64 of the foam 60 is shown.

[0057] The foam 60 is a porous structure, including a closed-cell structure (see Figure 5 ) and semi-open cell structures (see Figure 6). Among them, the pores of the foam 60 with a closed-cell structure are closed rings. After the foam 60 with a closed-cell structure is compressed, its resilience is small and it is difficult to fully fill the gaps. That is, part of the gaps are difficult to fill, thereby forming voids 65. External moisture can enter the interior of the terminal device 100' through the voids 65. At least part of the pores 64 of the foam 60 with a semi-open-cell structure are semi-closed, that is, the pores 64 and pores 64 are interconnected. The resilience of the foam 60 with a semi-open-cell structure is better than that of the foam 60 with a closed-cell structure, and it is relatively easy to fill the gaps. However, it is still difficult to fill most of the gaps, and external moisture can easily enter the interior of the terminal device 100' from the area where the pores 64 and pores 64 are connected. For details, please refer to Figure 7 ,in, Figure 7 The dashed arrows in the figure represent a cross-sectional diagram of moisture passing through pores 64 in foam 60. Furthermore, the miniaturized design of terminal device 100' leaves little space for foam 60. Especially when dimension d of foam 60 along a particular direction is small, moisture can more easily enter the interior of terminal device 100' through the areas where pores 64 connect. Furthermore, the physical connections between foam 60 and frame 13, and between flexible circuit board 40 and adhesive layer 25, are weak, allowing moisture to easily penetrate these interfaces. Therefore, using foam 60 for waterproofing is difficult to meet the high waterproofing requirements of terminal device 100'.

[0058] See also Figure 8 and Figure 9 , Figure 8 and Figure 9 A cross-sectional schematic diagram of a terminal device 100a is provided for another embodiment of the present application, wherein: Figure 8 Specifically, 70 pairs of water-stop glue are used. Figure 1 A schematic diagram of a cross section perpendicular to the X-axis direction in which area A in the figure is waterproofed. Figure 9 for Figure 8 The water stop glue 70 pairs are shown Figure 1 A schematic cross-sectional view showing waterproofing of area A in the embodiment and perpendicular to the Y-axis. The differences between terminal device 100a and terminal device 100 of the previous embodiment include: terminal device 100a includes water-stopping adhesive 70, which replaces the foam 60 of the previous embodiment. Water-stopping adhesive 70 fills the gaps between the middle frame 10, adhesive layer 25, and / or flexible circuit board 40. Water-stopping adhesive 70 has the property of swelling upon absorption of water, i.e., it absorbs moisture, and after absorbing moisture, the volume of water-stopping adhesive 70 increases, thereby effectively preventing external moisture from entering the interior of terminal device 100a and affecting the components within terminal device 100a.

[0059] During the assembly of the terminal device 100a, the flexible circuit board 40 is first passed through the inner portion 134, and the water-stopping adhesive 70 is provided by dispensing, and then the adhesive layer 25 and the rear shell 20 are provided, and the water-stopping adhesive 70 is cured. The water-stopping adhesive 70 is in liquid form before curing and has fluidity. The water-stopping adhesive 70 can fully fill the gap between the inner portion 134, the adhesive layer 25 and the flexible circuit board 40, reducing the possibility of the formation of the gap 65 in the previous embodiment. After the terminal device 100a is assembled, the water-stopping adhesive 70 has adhesive properties. The water-stopping adhesive 70 can be tightly combined with the inner portion 134, the flexible circuit board 40 and the adhesive layer 25, thereby increasing the waterproof effect of the interface. Furthermore, the water-stopping adhesive 70 can fix the bending portion 43 of the flexible circuit board 40 to the inner portion 134 and / or the adhesive layer 25. When the terminal device 100a is used multiple times or encounters collisions, falls, etc., it can effectively prevent the flexible circuit board 40 from loosening or moving, thereby reducing the waterproof effect; furthermore, when external moisture comes into contact with the water-stop glue 70, the moisture can be absorbed by the water-stop glue 70, thereby limiting the movement of moisture toward the interior of the terminal device 100; further, the water-stop glue 70 expands after absorbing moisture, and can further fully fill the gap between the inner part 134, the glue layer 25 and the flexible circuit board 40, thereby further improving the waterproof effect, so as to meet the high waterproof requirements of the terminal device 100a.

[0060] In the embodiment in which the foam 60 is provided, the foam 60 is assembled manually. In this embodiment, the water-stop glue 70 is provided by dispensing, which can be automated dispensing. Automated dispensing is conducive to realizing automated production, improving production efficiency, and increasing assembly yield.

[0061] Furthermore, the waterstop adhesive 70 is a polymer material, and the middle frame 10 can be made of plastic, metal, or a metal alloy. When the middle frame 10 is made of plastic, the waterstop adhesive 70 can bond with certain groups within the plastic during the curing process, thereby increasing the bonding force between the two and further improving the waterproofing performance. When the middle frame 10 is made of metal or a metal alloy, the waterstop adhesive 70 can bond with the metal or metal alloy through hydrogen bonds during the curing process. In some embodiments, the metal or metal alloy can be modified to carry functional groups capable of bonding with the waterstop adhesive 70, further increasing the bonding force between the waterstop adhesive 70 and the metal or metal alloy. Compared to the technical solution using foam 60 for waterproofing, the waterstop adhesive 70 used in this embodiment has a stronger bonding force with the middle frame 10, thereby improving the waterproofing performance. Furthermore, during the processing of the middle frame 10, there may be microscopic uneven structures on the surface. The fluidity of the waterstop adhesive 70 before curing can fully fill these uneven structures, thereby improving the waterproofing performance.

[0062] See also Figure 8 and Figure 9 , and combined with Figure 3 In one embodiment, a groove 1343 is formed on the inner portion 134. The groove 1343 is formed by a depression along the Z-axis on the surface of the inner portion 134 facing the adhesive layer 25. The groove 1343 extends through two opposing surfaces of the inner portion 134 along the X-axis and communicates with the receiving hole 1341. The bent portion 43 of the flexible circuit board 40 passes through the inner portion 134 through the groove 1343, and the adhesive layer 25 covers the groove 1343. The bent portion 43 includes a first surface 431 and a second surface 433 disposed in opposite directions. The first surface 431 is in contact with the surface of the inner portion 134, and the second surface 433 is in contact with the surface of the adhesive layer 25. The water-stopping adhesive 70 fills the gap between the inner portion 134, the adhesive layer 25, and the flexible circuit board 40. Since the water-stop glue 70 has strong bonding properties and the glue layer 25 also has good bonding properties, the two relative surfaces of the bent portion 43 located in the groove 1343 in this embodiment can respectively fit tightly with the surfaces of the inner portion 134 and the glue layer 25 and can meet the waterproof requirements.

[0063] After absorbing water, the waterstop adhesive 70 can expand in various directions, including along the X-axis and the Z-axis. Because the groove 1343 extends through the two opposing surfaces of the inner portion 134 along the X-axis, there is no other component to hinder the expansion of the waterstop adhesive 70 along the X-axis. Therefore, the expansion of the waterstop adhesive 70 along the X-axis increases the width of the waterstop adhesive 70 along the X-axis, making it more difficult for water to enter the terminal device 100 (or 100b, 100c, 100d) through the groove 1343, thereby further improving the waterproof performance. When the waterstop adhesive 70 expands along the Z-axis, it exerts a certain amount of compressive force on the adhesive layer 25 and the inner portion 134. However, the expansion of the waterstop adhesive 70 along the X-axis can alleviate some of this compressive force. Furthermore, the adhesive force of the adhesive layer 25 can also limit the expansion of the waterstop adhesive 70 along the Z-axis to a certain extent.

[0064] See also Figure 10 Other embodiments provide a terminal device 100b, which differs from the terminal device 100a in that: the first surface 431 of the bending portion 43 and the surface of the inner portion 134 in the terminal device 100b are spaced apart, and the waterproof glue 70 fills the gap between the inner portion 134, the adhesive layer 25 and the flexible circuit board 40, and also fills the gap between the first surface 431 and the inner portion 134.

[0065] See also Figure 11Other embodiments provide a terminal device 100c, which differs from the terminal device 100a in that: in the terminal device 100c, the first surface 431 of the bending portion 43 and the surface of the inner portion 134 are spaced apart, and the second surface 433 of the bending portion 43 and the surface of the adhesive layer 25 are spaced apart. The waterproof adhesive 70 fills the gap between the inner portion 134, the adhesive layer 25 and the flexible circuit board 40, and also fills the gap between the second surface 433 and the adhesive layer 25.

[0066] See also Figure 12 Other embodiments provide a terminal device 100d, which differs from the terminal device 100a in that: the second surface 433 of the bending portion 43 in the terminal device 100d is spaced apart from the surface of the adhesive layer 25, and the waterproof adhesive 70 fills the gap between the inner portion 134, the adhesive layer 25 and the flexible circuit board 40. The waterproof adhesive 70 also fills the gap between the first surface 431 and the inner portion 134 and the gap between the second surface 433 and the adhesive layer 25.

[0067] It can be understood that since the water-stop glue 70 has fluidity during the dispensing process, the water-stop glue 70 can fully fill the gap, and the structure of the water-stop glue 70 after curing is not limited to Figures 8 to 12 In the structure, the structure of the water-stop glue 70 can be changed according to the changes in the space reserved for waterproofing (including regular or irregular space).

[0068] See also Figure 13 , Figure 13 This figure shows the volume change of the waterstop adhesive 70 used in the present embodiment before and after absorbing water. The waterstop adhesive 70 can include soft segments 71, hard segments 73, and polar hydrophilic segments 75. The soft segments 71 and hard segments 73 are arranged alternately, and the polar hydrophilic segments 75 are embedded in the soft segments 71. Microstructurally, the waterstop adhesive 70 forms a network-like structure. The polar hydrophilic chain segment 75 has good hydrophilicity. When the waterstop glue 70 comes into contact with water, the polar hydrophilic chain segment 75 will combine with water molecules, for example through hydrogen bonding, thereby limiting the movement of water toward the interior of the terminal device 100a (or 100b, 100c, 100d); the soft segment 71 is a long chain with good flexibility. It is easy to deform during the water absorption process of the waterstop glue 70, causing the volume of the waterstop glue 70 to expand; the hard segment 73 is in a glassy state at room temperature and has good crystallization properties, so that the waterstop glue 70 has a certain rigidity on the basis of flexibility, so that the waterstop glue 70 has a certain mechanical strength, that is, the waterstop glue 70 can exhibit high elasticity when subjected to external force.

[0069] When the external moisture enters the through hole 1321 and the accommodation hole 1341 and contacts the waterstop glue 70, the polar hydrophilic chain segment 75 in the waterstop glue 70 will contact the water molecule structure; as the water molecules continuously penetrate and diffuse to the inside of the waterstop glue 70, the soft segment 71 is easy to deform in the water absorption process due to good flexibility, and as the water molecules continuously enter, the distance between the soft segments 71 increases, causing the overall volume of the waterstop glue 70 to increase; the hard segment 73 is relatively difficult to deform in the water absorption process due to large cohesive energy and rigidity. After the waterstop glue 70 absorbs moisture, it can block the moisture from entering the inside of the terminal device 100a (or 100b, 100c, 100d); after the waterstop glue 70 absorbs water and expands, it further increases the difficulty of moisture entering the inside of the terminal device 100a (or 100b, 100c, 100d), thereby effectively preventing the external moisture from entering the inside of the terminal device 100a (or 100b, 100c, 100d) and affecting the elements inside the terminal device 100a (or 100b, 100c, 100d).

[0070] In some specific embodiments, the waterstop glue 70 is formed by simultaneously adding a polar hydrophilic prepolymer during the synthesis of polyurethane (PU). Specifically, polyurethane is generated by condensation reaction of isocyanate and polyol, and during the reaction process, a polar hydrophilic prepolymer is added, so that the waterstop glue 70 capable of absorbing moisture and expanding in volume after absorbing moisture can be obtained.

[0071] The soft segment 71 can be composed of flexible long chains such as polyester and / or polyether, and these long chains have good flexibility; the main chain of the long chain is mainly composed of C-C bonds or C-O bonds, and the glass transition temperature of the waterstop glue 70 is much lower than the use temperature or the environmental temperature, so that the molecular chain body has a high degree of free rotation at room temperature, making the soft segment 71 have good flexibility.

[0072] The hard segment 73 can be composed of the reaction of polyisocyanate and a chain extender, and the group in the polyisocyanate has strong polarity, which is easy to form intermolecular and intramolecular hydrogen bonds, limiting the internal rotation of the molecular chain, so that the waterstop glue 70 exhibits rigidity.

[0073] The polar hydrophilic segment 75 can include one or more of isocyanate groups (-N=C=0), carboxyl groups (-COOH), sulfonic acid groups (-S03H), hydroxyl groups (-OH), amino groups (-NH2), amine groups (-NH3), and the like. In the process of synthesizing the polyurethane, the polar hydrophilic prepolymer added is a raw material that includes the above hydrophilic functional groups and is capable of reacting with isocyanate and polyol under certain conditions. The polar hydrophilic segment 75 has relatively strong hydrophilicity and is capable of combining with water molecules, for example, by hydrogen bonding, so that the waterstop glue 70 is capable of absorbing water. Different polar hydrophilic segments 75 have different hydrophilic properties, and a suitable polar hydrophilic segment 75 can be selected according to the demand for waterproof performance; in addition, or different contents of the polar hydrophilic segment 75 also have an impact on the hydrophilic performance of the waterstop glue 70, wherein an increase in the content of the polar hydrophilic segment 75 can improve the volume expansion rate and the volume expansion rate of the waterstop glue 70. That is, different polar hydrophilic segments 75 or different contents of the polar hydrophilic segment 75 have a certain impact on the volume expansion rate and the volume expansion rate of the waterstop glue 70, and further affect the waterproof effect; the presence of the polar hydrophilic segment 75 also has a weak impact on the soft segment 71 and / or the hard segment 73, for example, steric hindrance, interatomic interaction, and the like, and also has a weak impact on the volume expansion rate and the volume expansion rate of the waterstop glue 70.

[0074] The volume of the waterstop glue 70 before swelling is defined as VI, the volume of the waterstop glue 70 after swelling is defined as V2, and the maximum volume of the waterstop glue 70 after swelling is defined as V3; the volume expansion rate of the waterstop glue 70 is defined as p, and the maximum volume expansion rate of the waterstop glue 70 is defined as P, then the calculation formula of the volume expansion rate p of the waterstop glue 70 is: [(V2-V1) / V1]x100%, and the calculation formula of the maximum volume expansion rate P of the waterstop glue 70 is: [(V3-V1) / V1]x100%, wherein the maximum volume expansion rate P satisfies: 15%≤P≤50%. In some embodiments, the maximum volume expansion rate P of the waterstop glue 70 can be 18%, 24%, 30%, 36%, 43%, and the like.

[0075] After the water-stop adhesive 70 absorbs water and expands to a certain extent, it can meet high waterproof requirements. By adjusting the content and type of the polar hydrophilic chain segment 75 in the water-stop adhesive 70, the range of the maximum volume expansion rate P of the water-stop adhesive 70 can be adjusted. Among them, if the maximum volume expansion rate P of the water-stop glue 70 is too small (for example, the maximum volume expansion rate P is 5%, 10%, etc.), when moisture enters from the through hole 1321 and the receiving hole 1341, if there is a gap not filled by the water-stop glue 70, there is a risk that moisture will enter the interior of the terminal device 100a (or 100b, 100c, 100d); among them, if the maximum volume expansion rate P of the water-stop glue 70 is too large (for example, the maximum volume expansion rate P is 80%, 100%, etc.), that is, the volume of the water-stop glue 70 after expansion is too large, the expanded water-stop glue 70 squeezes the glue layer 25 and the inner part 134 along the Z-axis direction, and there is a risk that the glue layer 25 and the inner part 134 will separate, affecting the connection reliability and waterproof performance of the terminal device 100a (or 100b, 100c, 100d). When the maximum volume expansion rate P satisfies 15%≤P≤50%, the waterproof adhesive 70 can achieve high waterproof requirements while ensuring the connection reliability of the terminal device 100a (or 100b, 100c, 100d).

[0076] The volume expansion rate of waterstop adhesive 70 is defined as T. The volume expansion rate T of waterstop adhesive 70 is the volume expansion rate p per minute during the expansion process of waterstop adhesive 70. The volume expansion rate T satisfies the following conditions: 5% / min ≤ T ≤ 20% / min. In some embodiments, the volume expansion rate T of waterstop adhesive 70 can be 7% / min, 10% / min, 13% / min, 16% / min, 18% / min, etc. Among them, if the volume expansion rate T of the water-stop glue 70 is too small (for example, the volume expansion rate T is 1% / min, 2% / min, etc.), and there are gaps that are not filled by the water-stop glue 70, when moisture enters from the through hole 1321 and the receiving hole 1341, the water-stop glue 70 is difficult to expand in time, and there is a risk of moisture entering the interior of the terminal device 100a (or 100b, 100c, 100d); if the volume expansion rate T of the water-stop glue 70 is too large (for example, the volume expansion rate T is 50% / min, 60% / min, etc.), the water-stop glue 70 expands too quickly after absorbing moisture, which can easily cause uneven expansion of the water-stop glue 70, which is not conducive to improving the waterproof performance of the terminal device 100a (or 100b, 100c, 100d).

[0077] The structure of the soft segment 71 in the waterstop adhesive 70 also has a certain impact on the volume expansion rate and volume expansion rate of the waterstop adhesive 70. For example, a polyurethane-based waterstop adhesive 70 does not contain covalent bonds, allowing the waterstop adhesive 70 to fully expand after absorbing water. If it contained covalent bonds, the broken covalent bonds would combine with each other, causing a cross-linking reaction, which would affect the volume expansion rate and volume expansion rate of the waterstop adhesive 70, and thus the waterproofing effect.

[0078] The above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit the present application. Although the present application has been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that modifications or equivalent replacements of the technical solutions of the present application should not depart from the spirit and scope of the technical solutions of the present application.

Claims

1. A terminal device, characterized in that: include: a first structural member; a second structural member; an adhesive layer, bonding the first structural member and the second structural member; a flexible circuit board, located between the adhesive layer and the first structural member; Water-stop adhesive, filling the gap between the first structural member, the adhesive layer and / or the flexible circuit board; The volume of the water-stopping adhesive increases after absorbing water.

2. The terminal device according to claim 1, wherein The first structural member includes an inner portion, which is provided with a groove. The groove is formed by the surface of the inner portion being recessed toward the adhesive layer. The groove runs through two opposite surfaces of the inner portion. The flexible circuit board passes through the inner portion from the groove, and the water-stopping adhesive is filled in the groove.

3. The terminal device according to claim 2, wherein: The flexible circuit board includes a first surface and a second surface disposed back to back, the first surface is bonded to the surface of the first structural member, and the second surface is bonded to the surface of the adhesive layer.

4. The terminal device according to claim 2, wherein: The flexible circuit board includes a first surface and a second surface arranged back to back, the first surface is arranged toward the first structural member, and the second surface is arranged toward the adhesive layer; wherein, the first surface and the first structural member are spaced apart, and the water-stopping adhesive is filled between the flexible circuit board and the first structural member; and / or the second surface and the adhesive layer are spaced apart, and the water-stopping adhesive is filled between the flexible circuit board and the adhesive layer.

5. The terminal device according to any one of claims 2 to 4, characterized in that: The first structural member also includes an outer portion, the outer portion and the inner portion are surrounded by a receiving hole, and the groove and the receiving hole are connected; the flexible circuit board includes a first soft board portion, a bending portion and a second soft board portion, the bending portion connects the first soft board portion and the second soft board portion, the first soft board portion and the second soft board portion are located on opposite sides of the inner portion, the first soft board portion is located in the receiving hole, and the bending portion passes through the inner portion from the groove.

6. The terminal device according to claim 5, characterized in that A through hole is provided on the outer portion, and the through hole is communicated with the receiving hole. The terminal device further comprises a key assembly, and the key assembly is located in the through hole and the receiving hole. The key assembly is transmission-connected to the flexible circuit board.

7. The terminal device according to any one of claims 1 to 6, characterized in that: The water-stop adhesive is a polymer material and includes a soft segment, a hard segment and a polar hydrophilic segment. The soft segment and the hard segment are alternately arranged, and the polar hydrophilic segment is embedded in the soft segment.

8. The terminal device according to any one of claims 1 to 7, characterized in that: The maximum volume expansion rate of the water-stop adhesive is P, and the maximum volume expansion rate satisfies: 15%≤P≤50%.

9. The terminal device according to any one of claims 1 to 8, characterized in that: The volume expansion rate of the water-stop adhesive after absorbing water is T, and the volume expansion rate satisfies: 5% / min≤T≤20% / min.

10. The terminal device according to any one of claims 1 to 9, characterized in that: The first structural component is a middle frame, and the second structural component is a rear shell.

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