Electronic device

Abstract

Provided in the present application is an electronic device. The electronic device comprises: a display screen; a back cover; a middle frame located between the display screen and the back cover, the display screen and the back cover being mounted on the middle frame; a main board mounted on the middle frame and located between the display screen and the back cover; a first chip component soldered to a first surface of the main board by means of solder balls; a first shielding cover arranged on the first surface of the main board and shielding the first chip component; heat transfer layers formed between the first chip component and the first shielding cover and between the first shielding cover and the display screen; and a heat transfer bottom filling adhesive filling between the first chip component and the main board and coating the solder balls, the thermal conductivity of the heat transfer bottom filling adhesive being greater than or equal to 0.5 w / m·K. The present application can increase heat-dissipating paths for chips, so as to help to dissipate the heat of the chips as soon as possible, thereby improving the heat dissipation capability of the chips, promoting the performance release of the chips, and improving user experience.

Description

An electronic device

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on September 25, 2023, with application number 202322610728.3 and application name “An Electronic Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of electronic equipment, and in particular to an electronic equipment. Background Art

[0003] With the continuous development of technology, the performance of electronic devices such as mobile phones is becoming increasingly powerful, while the power consumption of devices is also constantly increasing. Chips such as system-on-chip (SOC), double-bit synchronous dynamic random access memory (DDR), power management unit (PMU), and charger chips are becoming increasingly hot during use, and the heat dissipation requirements of devices are becoming increasingly high. Currently, the main heat dissipation method for electronic devices such as mobile phones is to use thermally conductive gel or thermal pads to guide the heat of the chip to the screen side or back cover side of the phone. For example, thermally conductive gel or thermal pads are placed between the top of the chip and the shielding frame / screen film, and between the shielding frame / shielding film and the middle frame / vapor chamber (VC). This allows the heat of chips such as SOC and DDR to be guided along the screen side, and the heat of chips such as PMU and charger to be guided along the back cover side, thereby achieving chip heat dissipation. However, this heat dissipation method is gradually unable to meet the ever-increasing heat dissipation requirements of devices, causing severe chip heating, inhibiting the full release of chip performance, causing the phone to overheat or freeze, and affecting the user experience.

[0004] Utility Model Content

[0005] In order to solve the above technical problems, the present application provides an electronic device that can increase the heat dissipation path of the chip, thereby helping to dissipate the heat of the chip as quickly as possible, improving the heat dissipation capacity of the chip, promoting the performance release of the chip, and improving the user experience.

[0006] In a first aspect, the present application provides an electronic device, comprising:

[0007] Display screen;

[0008] Back cover;

[0009] a middle frame, the middle frame being located between the display screen and the back cover, and the display screen and the back cover being mounted on the middle frame;

[0010] a mainboard, the mainboard being mounted on the middle frame and located between the display screen and the back cover, the mainboard comprising a first surface facing the display screen and a second surface facing the back cover;

[0011] a first chip assembly, wherein the first chip assembly is soldered to the first surface of the mainboard via solder balls;

[0012] a first shielding cover, the first shielding cover being located on the first surface of the mainboard and shielding the first chip component;

[0013] A heat conducting layer is formed between the first chip assembly and the first shielding cover, and between the first shielding cover and the display screen;

[0014] A thermally conductive bottom filling glue covering the solder balls is filled between the first chip component and the mainboard, and the thermal conductivity of the thermally conductive bottom filling glue is greater than or equal to 0.5w / m·K.

[0015] According to the first aspect, the present application fills a thermally conductive bottom filling glue with a high thermal conductivity coefficient between the first chip component and the mainboard, so that the heat generated by the first chip component can be conducted to the display screen side through the shielding cover for dissipation on the one hand, and can be conducted to the mainboard through the thermally conductive bottom filling glue on the other hand, and dissipated through the mainboard. In this way, the heat of the first chip component can be dissipated through multiple heat dissipation paths, thereby improving the heat dissipation capacity of the chip, promoting the performance release of the chip, and enhancing the user experience.

[0016] According to the first aspect, or any implementation of the first aspect above, the electronic device further includes:

[0017] a second chip assembly, the second chip assembly being soldered to the second surface of the mainboard via solder balls;

[0018] a second shielding cover, the second shielding cover being located on the second surface of the mainboard and shielding the second chip assembly;

[0019] A heat conducting layer is formed between the second chip assembly and the second shielding cover, and between the second shielding cover and the back cover;

[0020] The thermally conductive bottom filling glue covering the solder balls is filled between the second chip component and the mainboard.

[0021] This arrangement fills the second chip assembly with a high thermal conductivity bottom filler between the second chip assembly and the mainboard, so that the heat generated by the second chip assembly can be conducted to the back cover side through the shielding cover for dissipation on the one hand, and can be conducted to the mainboard through the thermal bottom filler on the other hand, and dissipated through the mainboard. In this way, the heat of the second chip assembly can be dissipated through multiple heat dissipation paths, thereby improving the heat dissipation capacity of the chip, promoting the performance release of the chip, and enhancing the user experience.

[0022] According to the first aspect, or any implementation of the first aspect above, the electronic device further includes:

[0023] a heat dissipation hole, the heat dissipation hole being located in the area of ​​the mainboard where the first chip component is located and penetrating the mainboard, the heat dissipation hole being filled with the thermally conductive bottom filling glue;

[0024] a first heat conducting plate, the first heat conducting plate being located on a position on the second surface of the mainboard corresponding to the first chip assembly;

[0025] a third shielding cover, the third shielding cover being located on the second surface of the mainboard at a position corresponding to the first chip assembly and shielding the first heat conducting sheet;

[0026] A heat conducting layer is formed between the first heat conducting sheet and the third shielding cover, and between the third shielding cover and the back cover.

[0027] In this way, the heat generated by the first chip component can also be conducted to the other side of the mainboard through the heat dissipation holes, and conducted to the back cover side through the heat conductive sheet, heat conductive layer and shielding cover for dissipation. In this way, since the heat dissipation path is increased, the heat of the first chip component can be dissipated through multiple heat dissipation paths, thereby improving the heat dissipation capacity of the chip, promoting the performance release of the chip, and improving the user experience.

[0028] According to the first aspect, or any implementation of the first aspect above, the electronic device further includes:

[0029] a heat dissipation hole, the heat dissipation hole being located in the area of ​​the mainboard where the second chip component is located and penetrating the mainboard, the heat dissipation hole being filled with the thermally conductive bottom filling glue;

[0030] a second heat conducting plate, the second heat conducting plate being located on the first surface of the mainboard at a position corresponding to the second chip assembly;

[0031] a fourth shielding cover, the fourth shielding cover being located on the first surface of the mainboard at a position corresponding to the second chip assembly and shielding the second heat conducting sheet;

[0032] A heat conducting layer is formed between the second heat conducting sheet and the fourth shielding cover, and between the fourth shielding cover and the display screen.

[0033] In this way, the heat generated by the second chip component can also be conducted to the other side of the mainboard through the heat dissipation holes, and conducted to the display screen side through the heat conductive sheet, heat conductive layer and shielding cover for dissipation. In this way, due to the increase in the heat dissipation path, the heat of the second chip component can be dissipated through multiple heat dissipation paths, thereby improving the heat dissipation capacity of the chip, promoting the performance release of the chip, and improving the user experience.

[0034] According to the first aspect, or any implementation of the first aspect above, the distance between the heat dissipation hole and the solder ball is greater than or equal to 30 μm. This arrangement can avoid affecting the solder ball.

[0035] According to the first aspect, or any implementation of the first aspect above, the diameter of the heat dissipation hole is 60-90 μm. This arrangement can ensure sufficient heat dissipation capacity so that the heat generated by the chip can be quickly transferred to the other side of the motherboard for dissipation.

[0036] According to the first aspect, or any implementation of the first aspect above, a heat dissipation trench is formed between the first chip assembly and / or the second chip assembly and the middle frame, and the heat dissipation trench is filled with the thermally conductive underfill. This arrangement allows heat generated by the chip to be transferred to the middle frame for dissipation via the heat dissipation trench. Due to the increased heat dissipation paths, heat from the chip can be dissipated through multiple heat dissipation paths, thereby improving the chip's heat dissipation capability, promoting chip performance, and enhancing the user experience.

[0037] According to the first aspect, or any implementation of the first aspect above, a soldering metal member is provided on the middle frame adjacent to the first chip assembly or the second chip assembly, a heat dissipation trench is formed between the soldering metal member and the first chip assembly or the second chip assembly, and the heat dissipation trench is filled with the thermally conductive underfill. This arrangement allows heat generated by the chip to be conducted to the soldering metal member / middle frame via the heat dissipation trench for dissipation. This increased heat dissipation paths allow heat from the chip to be dissipated through multiple heat dissipation paths, thereby improving the chip's heat dissipation capability, facilitating chip performance, and enhancing the user experience.

[0038] According to the first aspect, or any implementation of the first aspect above, the heat-conducting layer includes a heat-conducting gel or a heat-conducting pad, so as to ensure that the heat generated by the chip is quickly conducted away.

[0039] According to the first aspect, or any implementation of the first aspect above, the first chip assembly includes at least one chip, the second chip assembly includes at least one chip, and the thermally conductive underfill covers the solder balls of each chip, thereby ensuring that heat generated by the chips is quickly transferred away. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] FIG1 is a schematic structural diagram of an electronic device;

[0041] FIG2 is a schematic diagram illustrating a heat dissipation structure of an electronic device;

[0042] FIG3 is a schematic cross-sectional view of an electronic device according to an embodiment of the present application;

[0043] FIG4 is a partial enlarged view of the dotted line area in FIG3 ;

[0044] FIG5 is a schematic cross-sectional view of an electronic device according to another embodiment of the present application;

[0045] FIG6 is a partial enlarged view of the dotted line area in FIG5 ;

[0046] FIG7 is a schematic cross-sectional view of an electronic device according to another embodiment of the present application;

[0047] FIG8 is a partial enlarged view of the dotted area in FIG7 . DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0049] The term "and / or" in this article is merely a description of the association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0050] In the description and claims of the embodiments of this application, the terms "first" and "second" are used to distinguish different objects, rather than to describe a specific order of objects. For example, the terms "first target object" and "second target object" are used to distinguish different objects, rather than to describe a specific order of objects.

[0051] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0052] In the description of the embodiments of this application, unless otherwise specified, "multiple" means two or more. For example, "multiple processing units" means two or more processing units; "multiple systems" means two or more systems.

[0053] UNDERFILL: An adhesive used to protect solder balls after soldering certain chips in electronic products, used in the CSP or BGA underfill process. It forms a consistent and defect-free underfill layer, effectively reducing impact caused by mismatched thermal expansion characteristics between the silicon chip and substrate or external forces. It cures rapidly when heated. Its low viscosity allows for better underfilling, while its high fluidity enhances reworkability.

[0054] The present application provides a terminal device, which can be a mobile phone, tablet computer, personal digital assistant (PDA), car computer, or other electronic device with a camera module. The present application does not limit the specific form of the electronic device. As shown in Figure 1, for ease of description, the following description uses a mobile phone as an example.

[0055] To facilitate the clear description of the subsequent structural features and their positional relationships, the positional relationships of the various structures within the mobile phone are defined using the X-axis, Y-axis, and Z-axis directions. As shown in Figure 1, the X-axis direction represents the width of the phone, the Y-axis direction represents the length of the phone, and the Z-axis direction represents the thickness of the phone.

[0056] As shown in FIG1 , a mobile phone 100 includes a housing 101 and a display screen 102 mounted on the housing 101. The housing 101 includes a middle frame (not shown) and a back cover. The mobile phone's motherboard is mounted on the middle frame. Various chips and electronic components are mounted on the motherboard and are covered by the display screen 102 and the back cover. As previously mentioned, the main heat dissipation method for current electronic devices such as mobile phones is to use thermally conductive gel or thermally conductive pads to conduct the heat of the chip to the screen side or back cover side of the mobile phone. For example, thermally conductive gel or thermally conductive pads are provided between the top of the chip and the shielding frame / screen film, or between the shielding frame / shielding film and the middle frame / vapor chamber (VC), so that the heat of chips such as SOC and DDR is conducted along the screen side, and the heat of chips such as PMU and Charger is conducted along the back cover side, thereby achieving heat dissipation of the chips.

[0057] FIG2 is a schematic diagram of a heat dissipation structure of an electronic device. As shown in FIG2 , the electronic device 100 includes a display screen 102, a middle frame 103 and a back cover 104, and the middle frame 103 and the back cover 104 constitute the housing 101 in FIG1 . The display screen 102 and the back cover 104 are mounted on the middle frame 103, and the display screen 102, the middle frame 103 and the back cover 104 together form a housing cavity, in which various devices required for the device are installed, such as a processor (SOC), a battery, a camera module, etc. As shown in FIG2 , the mainboard 105 and the mainboard bracket 106 are mounted on the middle frame 103, and the mainboard 105 is clamped between the middle frame 103 and the mainboard bracket 106, and the mainboard bracket 106 is fixed to the middle frame 103 by fasteners 107 such as screws. In the example shown in FIG2 , a graphite layer 108 is provided in the gap between the display screen 102 and the middle frame 103 , and in the gap between the mainboard bracket 106 and the back cover 104 . The heat generated by the electronic components on the mainboard 105 can be dissipated to the outside through the graphite layer 108 with the aid of the display screen 102 and the back cover 104 .

[0058] As shown in Figure 2, the mainboard 105 includes a first surface and a second surface facing each other. The first surface is the surface facing the display screen 102, and the second surface is the surface facing the back cover 104. Exemplarily, a first chip assembly 109 is fixed on the first surface of the mainboard 105. Exemplarily, the first chip assembly 109 includes a first chip 110, such as a SOC chip, and a second chip 111, such as a DDR chip. The first chip 110 is soldered to the first surface of the mainboard 105 via solder balls 112. The second chip 111 is soldered to the first chip 110 via solder balls 112. A first shielding cover 113 is also installed on the first surface of the mainboard 105 to shield the first chip assembly 109 to prevent external radiation and being radiated, that is, to reduce electromagnetic radiation and prevent signal interference. As shown in FIG2 , a thermal conductive layer 114 is provided in the gap between the second chip 111 and the first shielding cover 113 , and in the gap between the first shielding cover 113 and the middle frame 105 . The thermal conductive layer 114 is, for example, a thermal conductive gel or a thermal conductive pad. The thermal conductive layer 114 can be formed in the aforementioned gap by coating, bonding, or the like.

[0059] Illustratively, a second chip assembly 115 is fixed to the second surface of the mainboard 105. The second chip assembly 115 includes a third chip, such as a PMU chip. The second chip assembly 115 is soldered to the second surface of the mainboard 105 via solder balls 112. A second shielding cover 116 is also mounted on the second surface of the mainboard 105 to shield the second chip assembly 115 from external radiation and radiation, thereby reducing electromagnetic radiation and preventing signal interference. As shown in FIG2 , a thermal conductive layer 114 is provided in the gap between the second chip assembly 115 and the second shielding cover 116, as well as in the gap between the second shielding cover 116 and the mainboard bracket 106. The thermal conductive layer 114 may be, for example, a thermal conductive gel or a thermal conductive pad.

[0060] Exemplarily, electronic components 117 are further provided on the first and / or second surface of the mainboard 105 . The electronic components 117 include, for example, capacitors, inductors, resistors, and other electronic devices that do not generate heat or generate very little heat.

[0061] As shown by the dotted arrows in FIG2 , for the first chip assembly 109, the heat transfer path is: first chip assembly 109 - thermal conductive layer 114 - first shielding cover 113 - thermal conductive layer 114 - middle frame 103 - graphite layer 108 - display screen 102. For the second chip assembly 115, the heat transfer path is: second chip assembly 115 - thermal conductive layer 114 - second shielding cover 116 - thermal conductive layer 114 - motherboard bracket 106 - graphite layer 108 - back cover 104.

[0062] In the method shown in Figure 2, heat is conducted to the chip from only one direction, resulting in low heat dissipation efficiency. This causes the chip to heat up severely, inhibiting the full release of chip performance, and easily causing the phone to heat up or freeze, affecting the user experience.

[0063] Based on the above description, the embodiment of the present application proposes a new heat dissipation structure, which can conduct heat to the chip from two directions, thereby having higher heat dissipation efficiency, thereby alleviating the heat generation of the chip, improving the release of chip performance, and improving user experience.

[0064] FIG3 is a schematic cross-sectional view of an electronic device according to an embodiment of the present application; FIG4 is a partial enlarged view of the dotted area in FIG3 .

[0065] Please refer to Figures 3 and 4. The electronic device 200 provided in the embodiment of the present application includes a display screen 102, a middle frame 103 and a back cover 104. The middle frame 103 and the back cover 104 constitute the housing 101 in Figure 1. The display screen 102 and the back cover 104 are mounted on the middle frame 103. The display screen 102, the middle frame 103 and the back cover 104 together form a receiving cavity, in which various devices required for the device are installed, such as a processor (SOC), a battery, a camera module, etc. As shown in Figure 3, the mainboard 105 and the mainboard bracket 106 are mounted on the middle frame 103. The mainboard 105 is clamped between the middle frame 103 and the mainboard bracket 106. The mainboard bracket 106 is fixed to the middle frame 103 by fasteners 107 such as screws. In the example shown in FIG3 , a graphite layer 108 is coated in the gap between the display screen 102 and the middle frame 103 , and in the gap between the mainboard bracket 106 and the back cover 104 . The graphite layer 108 can dissipate the heat generated by the electronic components on the mainboard 105 to the outside via the display screen 102 and the back cover 104 .

[0066] As shown in FIG3 , the motherboard 105 includes a first surface and a second surface facing each other. The first surface is the surface facing the display screen 102, and the second surface is the surface facing the back cover 104. Illustratively, a first chip assembly 109 is fixed to the first surface of the motherboard 105. Illustratively, the first chip assembly 109 includes a first chip 110, such as a SOC chip, and a second chip 111, such as a DDR chip. The first chip 110 is soldered to the first surface of the motherboard 105 via solder balls 112. The second chip 111 is soldered to the first chip 110 via solder balls 112. A first shielding cover 113 is also mounted on the first surface of the motherboard 105 to shield the first chip assembly 109 from external radiation and external radiation, thereby reducing electromagnetic radiation and preventing signal interference. As shown in FIG3 , a thermal conductive layer 114 is provided in the gap between the second chip 111 and the first shielding cover 113, as well as in the gap between the first shielding cover 113 and the middle frame 105. The thermal conductive layer 114 may be, for example, a thermal conductive gel or a thermal conductive pad. As shown in FIG3 , a thermally conductive underfill 118 is formed between the first chip 110 and the motherboard 105 , and between the first chip 110 and the second chip 111 . That is, a bottom filling process is adopted to fill the bottoms of the first chip 110 and the second chip 111 , and the solder balls 112 of the first chip 110 and the second chip 111 are surrounded by the thermally conductive underfill 118 .

[0067] Illustratively, a second chip assembly 115 is secured to the second surface of the motherboard 105. The second chip assembly 115 includes a third chip, such as a PMU chip. The second chip assembly 115 is soldered to the second surface of the motherboard 105 via solder balls 112. A second shielding cover 116 is also mounted on the second surface of the motherboard 105 to shield the second chip assembly 115 from external radiation and radiation, thereby reducing electromagnetic radiation and preventing signal interference. As shown in FIG3 , a thermally conductive layer 114 is provided in the gap between the second chip assembly 115 and the second shielding cover 116, as well as in the gap between the second shielding cover 116 and the motherboard support 106. The thermally conductive layer 114 may be, for example, a thermally conductive gel or a thermal pad. As shown in FIG3 and FIG4 , a thermally conductive underfill 118 is placed between the second chip assembly 115 and the motherboard 105. Specifically, an underfill process is employed to fill the bottom of the second chip assembly 115, thereby surrounding the solder balls 112 of the second chip assembly 115 with the thermally conductive underfill 118.

[0068] It should be noted that, in the embodiment of the present application, the thermally conductive bottom filler 118 completely wraps the solder balls 112 of the first chip assembly 109 and the second chip assembly 115 , and completely fills the bottoms of the first chip assembly 109 and the second chip assembly 115 .

[0069] For example, in the embodiment of the present application, the thermally conductive bottom filler 118 uses a bottom filler material with a high thermal conductivity coefficient, for example, the thermal conductivity coefficient of the thermally conductive bottom filler 118 is greater than or equal to 0.5w / m·K. In this way, since the thermally conductive bottom filler 118 has a high thermal conductivity coefficient and good thermal conductivity, as shown by the dotted arrows in Figure 3, the heat generated by the first chip 110 and the second chip 111 can be dissipated to the outside world through the path of the first chip assembly 109-thermal conductive layer 114-first shielding cover 113-thermal conductive layer 114-middle frame 103-graphite layer 108-display screen 102 on the one hand; on the other hand, it can be dissipated to the outside world through the path of the first chip assembly 109-thermal conductive bottom filler 118-middle frame 105. In this way, heat can be conducted to the first chip assembly 109 in two directions, thereby improving heat dissipation efficiency, reducing the heat generated by the first chip assembly 109, improving the performance release of the first chip assembly 109, and improving user experience.

[0070] On the one hand, the heat generated by the second chip assembly 115 can be dissipated to the outside through the second chip assembly 115-thermal conductive layer 114-second shielding cover 116-thermal conductive layer 114-mainboard bracket 106-graphite layer 108-back cover 104; on the other hand, it can be dissipated to the outside through the second chip assembly 1115-thermal conductive bottom filling glue 118-middle frame 105. In this way, the second chip assembly 115 can be heat-conducted in two directions, thereby improving the heat dissipation efficiency, reducing the heat generation of the second chip assembly 115, improving the performance release of the second chip assembly 115, and improving the user experience.

[0071] In summary, the heat dissipation structure of the embodiment of the present application can promote the transfer of chip heat not only to the screen side or the back cover side, but also to the mainboard PCB, so that the chip heat is transferred in both the front and rear directions, thereby improving the heat dissipation efficiency, reducing the system heat, and achieving cooling, thereby promoting the performance release of the chip and improving the user experience.

[0072] Exemplarily, electronic components 117 are further provided on the first and / or second surface of the mainboard 105 . The electronic components 117 include, for example, capacitors, inductors, resistors, and other electronic devices that do not generate heat or generate very little heat.

[0073] It should be understood that although the heat dissipation principle of the present application is illustrated by using a first chip component (such as SOC and DDR) and a second chip component (such as PMU) in the embodiments of the present application, it does not mean that the heat dissipation structure of the present application can only be used for these two groups of chip components, but can be applied to all heat-generating chips. In addition, the focus of the present application is to dissipate heat from the chip in two directions. As for the heat dissipation path in each direction, it is not limited to the method shown in Figure 3 and can be modified and improved as needed. For example, there may be no middle frame between the chip and the screen (that is, there is no structural component of the middle frame between the chip and the screen), or there is no mainboard bracket between the chip and the back cover (that is, there is no structural component of the mainboard bracket between the chip and the back cover). In this case, the principle of the present application can also achieve improved heat dissipation efficiency.

[0074] FIG5 is a schematic cross-sectional view of an electronic device according to another embodiment of the present application; FIG6 is a partial enlarged view of the dotted area in FIG5 .

[0075] Please refer to Figures 5 and 6. The electronic device 300 provided in the embodiment of the present application includes a display screen 102, a middle frame 103 and a back cover 104. The middle frame 103 and the back cover 104 constitute the housing 101 in Figure 1. The display screen 102 and the back cover 104 are mounted on the middle frame 103. The display screen 102, the middle frame 103 and the back cover 104 together form a receiving cavity, in which various devices required for the device are installed, such as a processor (SOC), a battery, a camera module, etc. As shown in Figure 5, the mainboard 105 and the mainboard bracket 106 are mounted on the middle frame 103. The mainboard 105 is clamped between the middle frame 103 and the mainboard bracket 106. The mainboard bracket 106 is fixed to the middle frame 103 by fasteners 107 such as screws. In the example shown in FIG5 , a graphite layer 108 is coated in the gap between the display screen 102 and the middle frame 103 , and in the gap between the mainboard bracket 106 and the back cover 104 . The graphite layer 108 can dissipate the heat generated by the electronic components on the mainboard 105 to the outside via the display screen 102 and the back cover 104 .

[0076] As shown in FIG5 , the motherboard 105 includes opposing first and second surfaces. The first surface is the surface facing the display screen 102, and the second surface is the surface facing the back cover 104. Exemplarily, a first chip assembly 109 is secured to the first surface of the motherboard 105. Exemplarily, the first chip assembly 109 includes a first chip 110, such as a SOC chip, and a second chip 111, such as a DDR chip. The first chip 110 is soldered to the first surface of the motherboard 105 via solder balls 112. The second chip 111 is soldered to the first chip 110 via solder balls 112. A first shielding cover 113 is also mounted on the first surface of the motherboard 105 to shield the first chip assembly 109 from external radiation and external radiation, thereby reducing electromagnetic radiation and preventing signal interference. As shown in FIG3 , a thermal conductive layer 114 is provided in the gap between the second chip 111 and the first shielding cover 113, as well as in the gap between the first shielding cover 113 and the middle frame 105. The thermal conductive layer 114 may be, for example, a thermal conductive gel or a thermal conductive pad. As shown in Figures 5 and 6, a thermally conductive underfill 118 is filled between the first chip 110 and the mainboard 105, and between the first chip 110 and the second chip 111. That is, the bottom of the first chip 110 and the second chip 111 is filled using a bottom filling process, and the solder balls 112 of the first chip 110 and the second chip 111 are surrounded by the thermally conductive underfill 118.

[0077] As shown in Figure 5, in this embodiment, a heat dissipation hole 119 is made in the area where the first chip component 109 is located on the mainboard 105, or in other words, a heat dissipation hole 119 is made in the area corresponding to the bottom of the first chip component 109 on the mainboard 105, and a thermally conductive bottom filling glue 118 is filled in the heat dissipation hole 119, so that the heat from the bottom of the first chip component 109 can be transferred to the second surface of the mainboard 105.

[0078] At the same time, a first thermally conductive sheet 120 and a third shielding cover 121 shielding the first thermally conductive sheet 120 are installed on the second surface of the mainboard 105 in the area corresponding to the first chip assembly 109. A thermally conductive layer 114, such as a thermally conductive gel or a thermal pad, is provided in the gap between the first thermally conductive sheet 120 and the third shielding cover 121, as well as in the gap between the third shielding cover 121 and the mainboard bracket 106. The first thermally conductive sheet 120 is made of a metal material, such as copper or other metal material with good thermal conductivity. The first thermally conductive sheet 120 has a planar or sheet-like structure, exhibits no significant deformation, and substantially conforms to the mainboard 105. The gap between the two is completely filled with a thermally conductive underfill 118. In this way, heat generated by the first chip assembly 109 is transferred to the second surface of the mainboard 105 through the heat dissipation holes 119. The heat can then be transferred to the mainboard bracket 106 via the first thermally conductive sheet 120, the thermally conductive layer 114, and the third shielding cover 121. The heat is then transferred to the back cover 104 through the graphite layer 108 for dissipation to the outside world.

[0079] Illustratively, a second chip assembly 115 is secured to the second surface of the motherboard 105. The second chip assembly 115 includes a third chip, such as a PMU chip. The second chip assembly 115 is soldered to the second surface of the motherboard 105 via solder balls 112. A second shielding cover 116 is also mounted on the second surface of the motherboard 105 to shield the second chip assembly 115 from external radiation and radiation, thereby reducing electromagnetic radiation and preventing signal interference. As shown in FIG3 , a thermally conductive layer 114 is provided in the gap between the second chip assembly 115 and the second shielding cover 116, as well as in the gap between the second shielding cover 116 and the motherboard support 106. The thermally conductive layer 114 may be, for example, a thermally conductive gel or a thermal pad. As shown in FIG5 , a thermally conductive underfill 118 is placed between the second chip assembly 115 and the motherboard 105. Specifically, an underfill process is employed to fill the bottom of the second chip assembly 115, thereby surrounding the solder balls 112 of the second chip assembly 115 with the thermally conductive underfill 118.

[0080] As shown in Figure 5, in this embodiment, a heat dissipation hole 119 is made in the area where the second chip component 115 is located on the mainboard 105, or in other words, a heat dissipation hole 119 is made in the area corresponding to the bottom of the second chip component 115 on the mainboard 105, and a thermally conductive bottom filling glue 118 is filled in the heat dissipation hole 119, so that the heat from the bottom of the second chip component 115 can be transferred to the first surface of the mainboard 105.

[0081] At the same time, a second thermally conductive sheet 122 and a fourth shielding cover 123 are installed on the first surface of the mainboard 105 in the area corresponding to the second chip assembly 115. A thermally conductive layer 114, such as a thermally conductive gel or a thermally conductive pad, is provided in the gap between the second thermally conductive sheet 122 and the fourth shielding cover 123, as well as in the gap between the fourth shielding cover 123 and the middle frame 103. The second thermally conductive sheet 122 is made of a metal material, such as copper or other metal material with good thermal conductivity. The second thermally conductive sheet 122 has a planar or sheet-like structure, exhibits no significant deformation, and substantially conforms to the mainboard 105. The gap between the two is completely filled with a thermally conductive bottom filler 118. In this way, the heat generated by the second chip assembly 115 is transferred to the first surface of the mainboard 105 through the heat dissipation holes 119. It can then be transferred to the middle frame 103 through the second thermally conductive sheet 122, the thermally conductive layer 114, and the fourth shielding cover 123. Then, it is transferred to the display screen 102 through the graphite layer 108 for dissipation to the outside world.

[0082] It should be noted that, in the embodiment of the present application, the thermally conductive bottom filler 118 completely wraps the solder balls 112 of the first chip assembly 109 and the second chip assembly 115 , and completely fills the bottoms of the first chip assembly 109 and the second chip assembly 115 .

[0083] It should also be noted that in the embodiment of the present application, the heat dissipation holes 119 are located in the chip area on the motherboard 105 and are spaced a certain distance from the solder balls 112. For example, the distance between the heat dissipation holes 119 and the solder balls 112 is greater than 30 μm.

[0084] For example, in the embodiment of the present application, the diameter of the heat dissipation hole 119 is 60-90 um, for example, it can be 60 um, 70 um, 80 um or 90 um.

[0085] For example, in the embodiment of the present application, the thermally conductive bottom filler 118 uses a bottom filler material with a high thermal conductivity coefficient, for example, the thermal conductivity coefficient of the thermally conductive bottom filler 118 is greater than or equal to 0.5w / m·K. In this way, since the thermally conductive bottom filler 118 has a high thermal conductivity coefficient and good thermal conductivity, as shown by the dotted arrows in Figure 5, the heat generated by the first chip 110 and the second chip 111 can be dissipated to the outside world through the path of the first chip assembly 109-thermal conductive layer 114-first shielding cover 113-thermal conductive layer 114-middle frame 103-graphite layer 108-display screen 102; on the other hand, the heat can be dissipated to the outside world through the path of the first chip assembly 109-heat dissipation hole 119-first thermal conductive sheet 120-thermal conductive layer 114-third shielding cover 121-thermal conductive layer 114-mainboard bracket 106-graphite layer 108-back cover 104, and can also be dissipated to the outside world through the path of the first chip assembly 109-thermal conductive bottom filler 118-middle frame 105. That is, this method allows the heat generated by the first chip component 109 to be dissipated in two directions in the Z direction through the display screen and the back cover, and can also be dissipated in the XY direction through the middle frame. In this way, heat can be conducted to the first chip component 109 in multiple directions, thereby improving the heat dissipation efficiency, reducing the heat generation of the first chip component 109, improving the performance release of the first chip component 109, and improving the user experience.

[0086] The heat generated by the second chip assembly 115 can be dissipated to the outside world through the paths of the second chip assembly 115 - thermal conductive layer 114 - second shielding cover 116 - thermal conductive layer 114 - motherboard bracket 106 - graphite layer 108 - back cover 104; and through the paths of the second chip assembly 115 - heat dissipation holes 119 - second thermal conductive sheet 122 - thermal conductive layer 114 - fourth shielding cover 123 - thermal conductive layer 114 - middle frame 103 - graphite layer 108 - display screen 102. Furthermore, the heat generated by the second chip assembly 1115 can be dissipated to the outside world through the paths of the second chip assembly 1115 - thermally conductive underfill 118 - middle frame 105. This method allows the heat generated by the second chip assembly 115 to be dissipated in two directions in the Z direction through the display screen and back cover, and also in the XY directions through the middle frame. This allows heat to be conducted to the second chip assembly 115 in multiple directions, thereby improving heat dissipation efficiency, reducing the heat generated by the second chip assembly 115, improving the performance of the second chip assembly 115, and enhancing the user experience.

[0087] In summary, the heat dissipation structure of the embodiment of the present application can achieve complete bidirectional (bidirectional in the thickness direction) heat extraction of the chip, improve the heat dissipation efficiency, reduce the system heat, achieve cooling, thereby promoting the performance release of the chip and improving the user experience.

[0088] Exemplarily, electronic components 117 are further provided on the first and / or second surface of the mainboard 105 . The electronic components 117 include, for example, capacitors, inductors, resistors, and other electronic devices that do not generate heat or generate very little heat.

[0089] It should be understood that although the heat dissipation principle of the present application is illustrated by using a first chip component (such as SOC and DDR) and a second chip component (such as PMU) in the embodiments of the present application, it does not mean that the heat dissipation structure of the present application can only be used for these two groups of chip components, but can be applied to all heat-generating chips. In addition, the focus of the present application is to dissipate heat from the chip in two directions. As for the heat dissipation path in each direction, it is not limited to the method shown in Figure 5 and can be modified and improved as needed. For example, there may be no middle frame between the chip and the screen (that is, there is no structural component of the middle frame between the chip and the screen), or there is no mainboard bracket between the chip and the back cover (that is, there is no structural component of the mainboard bracket between the chip and the back cover). In this case, the principle of the present application can also achieve improved heat dissipation efficiency.

[0090] FIG7 is a schematic cross-sectional view of an electronic device according to another embodiment of the present application; FIG8 is a partial enlarged view of the dotted area in FIG7 .

[0091] Please refer to Figures 7 and 8. The electronic device 400 provided in the embodiment of the present application includes a display screen 102, a middle frame 103 and a back cover 104. The middle frame 103 and the back cover 104 constitute the housing 101 in Figure 1. The display screen 102 and the back cover 104 are mounted on the middle frame 103. The display screen 102, the middle frame 103 and the back cover 104 together form a receiving cavity, in which various devices required for the device are installed, such as a processor (SOC), a battery, a camera module, etc. As shown in Figure 7, the mainboard 105 and the mainboard bracket 106 are mounted on the middle frame 103. The mainboard 105 is clamped between the middle frame 103 and the mainboard bracket 106. The mainboard bracket 106 is fixed to the middle frame 103 by fasteners 107 such as screws. In the example shown in FIG3 , a graphite layer 108 is provided in the gap between the display screen 102 and the middle frame 103 , and in the gap between the mainboard bracket 106 and the back cover 104 . The heat generated by the electronic components on the mainboard 105 can be dissipated to the outside through the graphite layer 108 with the aid of the display screen 102 and the back cover 104 .

[0092] As shown in FIG7 , the motherboard 105 includes a first surface and a second surface facing each other. The first surface is the surface facing the display screen 102, and the second surface is the surface facing the back cover 104. Illustratively, a first chip assembly 109 is fixed to the first surface of the motherboard 105. Illustratively, the first chip assembly 109 includes a first chip 110, such as a SOC chip, and a second chip 111, such as a DDR chip. The first chip 110 is soldered to the first surface of the motherboard 105 via solder balls 112. The second chip 111 is soldered to the first chip 110 via solder balls 112. A first shielding cover 113 is also mounted on the first surface of the motherboard 105 to shield the first chip assembly 109 from external radiation and radiation, thereby reducing electromagnetic radiation and preventing signal interference. As shown in FIG7 , a thermal conductive layer 114 is provided in the gap between the second chip 111 and the first shielding cover 113, as well as in the gap between the first shielding cover 113 and the middle frame 105. The thermal conductive layer 114 may be, for example, a thermal conductive gel or a thermal conductive pad. As shown in FIG7 , a thermally conductive underfill 118 is filled between the first chip 110 and the motherboard 105 , and between the first chip 110 and the second chip 111 . That is, a bottom filling process is adopted to fill the bottoms of the first chip 110 and the second chip 111 , and the solder balls 112 of the first chip 110 and the second chip 111 are surrounded by the thermally conductive underfill 118 .

[0093] For example, a second chip assembly 115 is secured to the first surface of the motherboard 105. The second chip assembly 115 includes a third chip, such as a PMU chip. The second chip assembly 115 is soldered to the first surface of the motherboard 105 via solder balls 112. A shielding cover and a heat conducting layer may also be provided on the first surface of the motherboard 105, but are not shown here for simplicity.

[0094] In an embodiment of the present application, in order to improve the heat dissipation efficiency, a trench is formed between the second chip component 115 and the nearby welding metal part 124, and a thermally conductive bottom filling glue 118 is filled in the trench. In this way, the heat can be conducted to the metal parts near the chip, and then the heat is exported to the middle frame 103 through the metal parts, thereby realizing two-way heat export of the chip, improving the heat dissipation efficiency, promoting the release of chip performance, and enhancing the user experience.

[0095] For example, after copper is laid between the second chip assembly 115 and the nearby soldering metal member 124, green oil can be applied on both sides to form a trench, which is then filled with thermally conductive underfill 118. In other words, green oil is used to create a heat dissipation trench between the second chip assembly and the midframe / soldering metal member, and the trench is filled with thermally conductive underfill 118. This way, the green oil on both sides limits the thermally conductive underfill 118, preventing it from flowing freely and ensuring good heat transfer between the second chip assembly 115 and the soldering metal member 124.

[0096] It should be noted that, in the embodiment of the present application, the thermally conductive bottom filler 118 completely wraps the solder balls 112 of the first chip assembly 109 and the second chip assembly 115 , and completely fills the bottoms of the first chip assembly 109 and the second chip assembly 115 .

[0097] For example, in the embodiment of the present application, the thermally conductive bottom filler 118 uses a bottom filler material with a high thermal conductivity coefficient, for example, the thermal conductivity coefficient of the thermally conductive bottom filler 118 is greater than or equal to 0.5w / m·K. In this way, since the thermally conductive bottom filler 118 has a high thermal conductivity coefficient and good thermal conductivity, as shown by the dotted arrows in Figure 7, the heat generated by the first chip 110 and the second chip 111 can be dissipated to the outside world through the path of the first chip assembly 109-thermal conductive layer 114-first shielding cover 113-thermal conductive layer 114-middle frame 103-graphite layer 108-display screen 102 on the one hand; on the other hand, it can be dissipated to the outside world through the path of the first chip assembly 109-thermal conductive bottom filler 118-middle frame 105. In this way, heat can be conducted to the first chip assembly 109 in two directions, thereby improving heat dissipation efficiency, reducing the heat generated by the first chip assembly 109, improving the performance release of the first chip assembly 109, and improving user experience.

[0098] Heat generated by the second chip assembly 115 can be dissipated to the outside world through the display screen 102 in a similar manner to the first chip assembly. Furthermore, the heat can be conducted to the middle frame 105 via the thermally conductive underfill 118 and the soldered metal member 124, and then dissipated to the outside world through the middle frame 105. This allows for bidirectional heat dissipation from the chip, improving heat dissipation efficiency, boosting chip performance, and enhancing the user experience.

[0099] It should be understood that, although in the present embodiment, heat is transferred to the nearby soldering metal member 124 via the thermally conductive underfill 118, and then to the middle frame 103 via the soldering metal member 124, in other embodiments, heat can also be directly transferred to the middle frame 103 via the thermally conductive underfill 118. The specific method used depends on whether the chip is adjacent to the soldering metal member or the middle frame, that is, whether there is a soldering metal member between the chip and the middle frame.

[0100] It should also be understood that in Figures 7 and 8, the thermally conductive bottom filling glue 118 is arranged only near the second chip component 115 to conduct heat to the welding metal parts, but it is only shown as an example to illustrate the principles of this application. In fact, the above structure can also be arranged near the first chip component 109 to conduct heat to the welding metal parts, and then to the middle frame for heat dissipation.

[0101] In summary, the heat dissipation structure of the embodiment of the present application is used to promote the transfer of chip heat not only to the screen side or the back cover side, but also to the mainboard PCB, so that the chip heat is transferred in both the front and rear directions, thereby improving the heat dissipation efficiency, reducing the system heat, and achieving cooling, thereby promoting the performance release of the chip and improving the user experience.

[0102] Exemplarily, electronic components 117 are further provided on the first and / or second surface of the mainboard 105 . The electronic components 117 include, for example, capacitors, inductors, resistors, and other electronic devices that do not generate heat or generate very little heat.

[0103] It should be understood that although the heat dissipation principle of the present application is illustrated by using a first chip component (such as SOC and DDR) and a second chip component (such as PMU) in the embodiments of the present application, it does not mean that the heat dissipation structure of the present application can only be used for these two groups of chip components, but can be applied to all heat-generating chips. In addition, the focus of the present application is to dissipate heat from the chip in two directions. As for the heat dissipation path in each direction, it is not limited to the method shown in Figure 7 and can be modified and improved as needed. For example, there may be no middle frame between the chip and the screen (that is, there is no structural component of the middle frame between the chip and the screen), or there is no mainboard bracket between the chip and the back cover (that is, there is no structural component of the mainboard bracket between the chip and the back cover). In this case, the principle of the present application can also achieve improved heat dissipation efficiency.

[0104] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An electronic device, characterized in that: include: Display screen; Back cover; A middle frame, wherein the middle frame is located between the display screen and the back cover, and the display screen and the back cover are mounted on the middle frame; A mainboard, the mainboard is mounted on the middle frame and is located between the display screen and the back cover, the mainboard comprising a first surface facing the display screen and a second surface facing the back cover; A first chip assembly, wherein the first chip assembly is soldered to the first surface of the mainboard through solder balls; A first shielding cover, the first shielding cover is located on the first surface of the mainboard and shields the first chip component; A heat-conducting layer is formed between the first chip assembly and the first shielding cover, and between the first shielding cover and the display screen; A thermally conductive bottom filling glue covering the solder balls is filled between the first chip component and the mainboard, and the thermal conductivity of the thermally conductive bottom filling glue is greater than or equal to 0.5w / m·K.

2. The electronic device according to claim 1, characterized in that: Also includes: a second chip assembly, the second chip assembly being soldered to the second surface of the mainboard via solder balls; A second shielding cover, the second shielding cover is located on the second surface of the mainboard and shields the second chip component; A heat conducting layer is formed between the second chip assembly and the second shielding cover, and between the second shielding cover and the back cover; The thermally conductive bottom filling glue covering the solder balls is filled between the second chip component and the mainboard.

3. The electronic device according to claim 1, characterized in that: Also includes: A heat dissipation hole, the heat dissipation hole is located in the area where the first chip component is located on the mainboard and passes through the mainboard, and the heat dissipation hole is filled with the thermally conductive bottom filling glue; A first heat conducting sheet, the first heat conducting sheet being located at a position on the second surface of the mainboard corresponding to the first chip assembly; a third shielding cover, the third shielding cover being located on the second surface of the mainboard at a position corresponding to the first chip assembly and shielding the first heat conducting sheet; A heat conducting layer is formed between the first heat conducting sheet and the third shielding cover, and between the third shielding cover and the back cover.

4. The electronic device according to claim 2, characterized in that: Also includes: A heat dissipation hole, the heat dissipation hole is located in the area where the second chip component is located on the mainboard and passes through the mainboard, and the heat dissipation hole is filled with the thermally conductive bottom filling glue; A second heat conducting sheet, the second heat conducting sheet being located at a position on the first surface of the mainboard corresponding to the second chip assembly; a fourth shielding cover, the fourth shielding cover being located on the first surface of the mainboard at a position corresponding to the second chip assembly and shielding the second heat conducting sheet; A heat conducting sheet is formed between the second heat conducting sheet and the fourth shielding cover, and between the fourth shielding cover and the display screen. There is a thermal conductive layer.

5. The electronic device according to claim 3 or 4, characterized in that: The distance between the heat dissipation hole and the solder ball is greater than or equal to 30 um.

6. The electronic device according to claim 3 or 4, characterized in that: The diameter of the heat dissipation hole is 60-90um.

7. The electronic device according to claim 2, characterized in that: A heat dissipation trench is formed between the first chip assembly and / or the second chip assembly and the middle frame, and the heat dissipation trench is filled with the thermally conductive bottom filling glue.

8. The electronic device according to claim 2, characterized in that: A welding metal piece is arranged on the middle frame adjacent to the first chip component or the second chip component, a heat dissipation trench is formed between the welding metal piece and the first chip component or the second chip component, and the heat dissipation trench is filled with the thermal conductive bottom filling glue.

9. The electronic device according to claim 1 or 2, characterized in that: The heat-conducting layer includes a heat-conducting gel or a heat-conducting pad.

10. The electronic device according to claim 2, characterized in that: The first chip assembly includes at least one chip, the second chip assembly includes at least one chip, and the thermally conductive bottom filling glue covers the solder balls of each chip.

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