Mainboard structure and electronic equipment with same

Abstract

The invention provides a mainboard structure and electronic equipment with the mainboard structure, the mainboard structure comprises a mainboard, a chip and a radiator, the chip is arranged on the mainboard, the radiator is connected with the mainboard and located above the chip, the mainboard structure further comprises a supporting part, the supporting part is arranged on the side, away from the radiator, of the mainboard and attached to the mainboard, and the supporting part is connected with the mainboard. At least part of the supporting component penetrates through the main board and is connected with the radiator; the fastening part is respectively connected with the supporting part and the main plate; or, the fastening part is connected with the supporting part and attached to the main board, so that the main board is clamped between the supporting part and the fastening part, and the supporting part and the main board are kept in the attached state. The problem that in the prior art, in the transportation process of the mainboard, due to the fact that the mainboard and the radiator are not firmly assembled, a ball grid array on a chip cracks is solved.

Description

Technical Field

[0001] The invention relates to the technical field of electrical mainboard and radiator assembly, and in particular to a mainboard structure and an electronic device having the same. Background Art

[0002] At present, some server motherboards are found not to work properly after being packaged and shipped. After a red ink test on the motherboard, it was found that the BGA (ball grid array) chip on the motherboard was cracked.

[0003] Regarding the cracking problem, after finding the cause, it was discovered that during the motherboard drop test, the heat sink on the motherboard did not press the motherboard tightly. During the impact, the rivet columns of the motherboard and the back plate shook relatively greatly in the up and down directions, causing stress to directly hit the chip area, resulting in the BGA micro-strain exceeding the standard and the solder joints cracking. Summary of the invention

[0004] The main purpose of the present invention is to provide a motherboard structure and an electronic device having the same, so as to solve the problem in the prior art that the ball grid array on the chip cracks due to the motherboard being loosely assembled with the heat sink during transportation.

[0005] To achieve the above-mentioned purpose, according to one aspect of the present invention, there is provided a motherboard structure, comprising a motherboard, a chip and a heat sink, wherein the chip is arranged on the motherboard, the heat sink is connected to the motherboard and is located above the chip, and the motherboard structure further comprises: a supporting component, which is arranged on a side of the motherboard away from the heat sink and is bonded to the motherboard, wherein at least a part of the supporting component passes through the motherboard and is connected to the heat sink; a fastening component, which is respectively connected to the supporting component and the motherboard; or, the fastening component is connected to the supporting component and is bonded to the motherboard, so that the motherboard is clamped between the supporting component and the fastening component, so that the supporting component and the motherboard remain in a bonded state.

[0006] Furthermore, the fastening component is located on the end surface of the mainboard facing away from the supporting component, so as to clamp the mainboard between the supporting component and the fastening component.

[0007] Furthermore, a first connection portion is provided on the supporting component, and the first connection portion passes through the mainboard and is connected to the heat sink; the fastening component is connected to the first connection portion, and the mainboard is clamped between the fastening component and the supporting component.

[0008] Furthermore, the first connection portion includes: a connection column, the connection column passes through the mainboard and is connected to the heat sink, a fastening component is sleeved on the connection column and connected to the connection column, and at least a portion of the fastening component is in contact with the mainboard.

[0009] Furthermore, the connecting column is provided with an external thread, the fastening component is provided with a threaded hole, and the fastening component is threadedly matched with the connecting column.

[0010] Furthermore, a connecting hole is provided on the fastening component, and at least part of the hole section of the connecting hole is provided with an internal thread; an external thread is provided on the connecting column, and the fastening component is threadedly matched with the connecting column through the connecting hole; an operating groove is provided on the fastening component, and the operating groove extends along the radial direction of the fastening component, and there are multiple operating grooves, and the multiple operating grooves are spaced apart along the circumferential direction of the fastening component.

[0011] Furthermore, the fastening component includes a first end face and a second end face that are arranged opposite to each other, the first end face is in contact with the mainboard, the second end face is opposite to the heat sink, and each operating groove is respectively arranged on the second end face.

[0012] Furthermore, a second connecting portion is provided on the radiator, and the second connecting portion is opposite to the mainboard and spaced apart; a first connecting portion is provided on the supporting component, and an external thread is provided on the first connecting portion, and a mounting hole is provided in the first connecting portion, and the mounting hole is a threaded hole; a connecting hole is provided on the fastening component, and an internal thread is provided in at least a part of the hole section of the connecting hole, and the fastening component is sleeved on the first connecting portion through the connecting hole and is threadedly connected to the first connecting portion; the mainboard structure also includes: a connecting workpiece, the connecting workpiece is passed through the second connecting portion and then inserted into the mounting hole, and is threadedly connected to the mounting hole, and a blocking end is provided at the end of the connecting workpiece; an elastic component, which is sleeved on the connecting workpiece, and the two ends of the elastic component are respectively abutted against the blocking end and the second connecting portion, so that the elastic component is in a compressed state.

[0013] Further, there are a plurality of fastening components, and the plurality of fastening components are arranged at intervals along the circumferential direction of the supporting component.

[0014] According to another aspect of the present invention, an electronic device is provided, including a mainboard structure, wherein the mainboard structure is the mainboard structure described above.

[0015] According to the technical solution of the present invention, the mainboard structure includes a mainboard, a chip and a radiator, the chip is arranged on the mainboard, the radiator is connected to the mainboard and is located above the chip, and the mainboard structure also includes: a supporting component and a fastening component, the supporting component is arranged on the side of the mainboard away from the radiator and is attached to the mainboard, at least part of the supporting component passes through the mainboard and is connected to the radiator; the fastening component is connected to the supporting component and the mainboard respectively; or, the fastening component is connected to the supporting component and is attached to the mainboard, so that the mainboard is clamped between the supporting component and the fastening component, so that the supporting component and the mainboard are kept in a state of attachment. By setting the fastening component, the supporting component is always kept in a state of close attachment to the mainboard, so that the supporting component evenly disperses the stress on the mainboard, and the mainboard is prevented from bending or deforming due to uneven force. Even if it is impacted, the mainboard is always close to the supporting component, and the stress will be preferentially concentrated on the fastening component, reducing the stress in the chip area, thereby protecting the chip BGA solder joints, and solving the problem of cracking of the ball grid array on the chip due to the loose assembly of the mainboard with the radiator during transportation in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0017] Figure 1 A schematic structural diagram showing an embodiment of a mainboard structure according to the present invention is shown;

[0018] Figure 2 Shown according to Figure 1 An enlarged view of part A;

[0019] Figure 3 A front view of a mainboard structure according to the present invention is shown;

[0020] Figure 4 A side view of a mainboard structure according to the present invention is shown;

[0021] Figure 5 A top view of a mainboard structure according to the present invention is shown;

[0022] Figure 6 An assembly diagram of a heat sink and a connecting workpiece in a mainboard structure according to the present invention is shown;

[0023] Figure 7 It shows a structural split diagram of the heat sink and the connecting workpiece in the mainboard structure according to the present invention;

[0024] Figure 8 A structural split diagram showing a connection workpiece and an elastic component in a mainboard structure according to the present invention is shown;

[0025] Fig. 9 A schematic structural diagram of a supporting component in a mainboard structure according to the present invention is shown;

[0026] Fig.10 It shows a structural exploded view of the supporting component in the mainboard structure according to the present invention;

[0027] Fig.11 It shows a schematic structural diagram of a fastening component in a mainboard structure according to the present invention;

[0028] Fig.12 A side view of a fastening component in a mainboard structure according to the present invention is shown;

[0029] Fig.13 A top view of a fastening component in a mainboard structure according to the present invention is shown;

[0030] Fig.14 A schematic structural diagram of a first connecting portion in a mainboard structure according to the present invention is shown;

[0031] Fig.15 A side view of a first connecting portion in a mainboard structure according to the present invention is shown;

[0032] Fig.16 A top view of a first connecting portion in a mainboard structure according to the present invention is shown;

[0033] Fig.17 It shows a schematic diagram of assembling the fastening component and the first connecting portion in the mainboard structure according to the present invention;

[0034] Fig.18 It shows an assembly schematic diagram of a connecting workpiece, a fastening component and a first connecting portion in a mainboard structure according to the present invention;

[0035] Fig.19 A schematic diagram showing the cooperation between the fastening component and the connecting workpiece in the mainboard structure according to the present invention is shown;

[0036] Fig. 20 It shows the distribution cloud diagram of the maximum principal strain of the mainboard in the chip area in the mainboard structure according to the present invention;

[0037] Fig.21 The micro-strain curves of the BGA at the four corners of the chip in the motherboard structure according to the present invention are shown;

[0038] Fig. 22 A model simulation grid diagram of a mainboard structure in the prior art is shown;

[0039] Fig.23 The maximum principal strain distribution cloud diagram of the mainboard in the chip area in the mainboard structure in the prior art is shown;

[0040] Fig.24 The micro-strain curves of BGA at the four corners of the chip in the motherboard structure in the prior art are shown.

[0041] The above drawings include the following reference numerals:

[0042] 100, main board; 200, chip; 300, heat sink; 400, supporting component; 500, fastening component; 410, first connecting part; 411, connecting column; 412, mounting hole; 420, supporting body; 430, protective film; 510, connecting hole; 520, operating groove; 530, first end face; 540, second end face; 310, second connecting part; 311, through hole; 600, connecting workpiece; 610, blocking end; 620, retaining ring; 700, elastic component. DETAILED DESCRIPTION

[0043] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0044] As mentioned in the background technology, during the packaging and transportation process of the existing motherboard structure, it was found that the BGA (ball grid array) on the chip was cracked, and the motherboard could not work normally. During the stress test to find the cause of the cracking, it was found that when the motherboard was impacted, the heat sink and the backplane were locked without pressing the motherboard. During the impact, the motherboard had a relatively large shake relative to the backplane, causing the stress to be directly concentrated in the chip area, resulting in excessive BGA micro-strain and cracking of the solder joints. It can be seen that the fixing method of the heat sink has serious design defects. In response to the above technical problems, the motherboard structure provided by the present application is provided with a fastening component 500, and the fastening component 500 is respectively connected to the supporting component 400 and the mainboard 100, thereby preventing the mainboard 100 from relative movement with the supporting component 400 during the impact process. Alternatively, the fastening component 500 is connected to the supporting component 400 and fits with the mainboard 100 at the same time, and the mainboard 100 is clamped between the supporting component 400 and the fastening component 500, so that the supporting component 400 and the mainboard 100 remain in a fit state. This arrangement utilizes the supporting component 400 to evenly distribute pressure, provides a solid support for the radiator, ensures that the pressure of the radiator is evenly distributed, and protects the mainboard 100 at the same time, and prevents the mainboard 100 from bending or deformation due to uneven force. By adding the fastening component 500, the mainboard 100 is always in close contact with the supporting component 400, so that the supporting component 400 can fully play its role in protecting the mainboard, thereby avoiding the problem of BGA cracking and chip failure when the mainboard 100 is impacted.

[0045] Please refer to Figures 1 to 19 The present application provides a motherboard structure, including a motherboard 100, a chip 200 and a radiator 300, wherein the chip 200 is arranged on the motherboard 100, and the radiator 300 is connected to the motherboard 100 and is located above the chip 200. The motherboard structure also includes: a supporting component 400, which is arranged on a side of the motherboard 100 away from the radiator 300 and is bonded to the motherboard 100, and at least a portion of the supporting component 400 passes through the motherboard 100 and is connected to the radiator 300; a fastening component 500, wherein the fastening component 500 is respectively connected to the supporting component 400 and the motherboard 100; or, the fastening component 500 is connected to the supporting component 400 and is bonded to the motherboard 100, so as to clamp the motherboard 100 between the supporting component 400 and the fastening component 500, so that the supporting component 400 and the motherboard 100 remain in a bonded state.

[0046] According to the motherboard structure provided in the present application, it includes a motherboard 100, a chip 200 and a radiator 300, the chip 200 is arranged on the motherboard 100, the radiator 300 is connected to the motherboard 100 and is located above the chip 200, and the motherboard structure also includes: a supporting component 400 and a fastening component 500, the supporting component 400 is arranged on a side of the motherboard 100 away from the radiator 300 and is attached to the motherboard 100, at least part of the supporting component 400 passes through the motherboard 100 and is connected to the radiator 300; the fastening component 500 is respectively connected to the supporting component 400 and the motherboard 100; or, the fastening component 500 is connected to the supporting component 400 and is attached to the motherboard 100, so as to clamp the motherboard 100 between the supporting component 400 and the fastening component 500, so that the supporting component 400 and the motherboard 100 remain in an attached state. By setting the fastening component 500, the supporting component 400 is always kept in close contact with the mainboard 100, so that the supporting component 400 can evenly disperse the stress on the mainboard 100, avoiding the mainboard 100 from bending or deformation due to uneven force. Even if it is impacted, the mainboard 100 is always in close contact with the supporting component 400, and the stress will be preferentially concentrated on the fastening component 500, reducing the stress in the chip area, thereby protecting the chip BGA solder joints, and solving the problem of cracking of the ball grid array on the chip due to loose assembly with the heat sink during transportation in the prior art.

[0047] In the first embodiment provided in the present application, the fastening component 500 is connected to the supporting component 400 and is attached to the mainboard 100 , and the mainboard 100 is sandwiched between the supporting component 400 and the fastening component 500 .

[0048] Specifically, the fastening component 500 is located on the end surface of the mainboard 100 away from the supporting component 400, so as to clamp the mainboard 100 between the supporting component 400 and the fastening component 500. This arrangement utilizes the clamping effect of the fastening component 500 and the supporting component 400 to ensure that the mainboard 100 and the supporting component 400 are kept in a tightly fitted state, so that the supporting component 400 supports and protects the mainboard 100, and avoids the mainboard 100 from bending or deforming, which may cause the solder joints on the chip to crack.

[0049] In this embodiment, if Fig. 9 and Fig.10As shown, the support component 400 is provided with a first connection portion 410, and the first connection portion 410 passes through the mainboard 100 and is connected to the heat sink 300; the fastening component 500 is connected to the first connection portion 410, and the mainboard 100 is sandwiched between the fastening component 500 and the support component 400. This arrangement not only realizes the connection between the support component 400 and the heat sink 300 by using the first connection portion 410, but also simplifies the overall structure by directly connecting the fastening component 500 to the first connection portion 410, and does not need to separately add other connecting structural parts due to the provision of the fastening component 500.

[0050] In the specific implementation process, Fig.17 As shown, the first connection part 410 includes: a connection column 411, the connection column 411 passes through the mainboard 100 and is connected to the heat sink 300, the fastening component 500 is sleeved on the connection column 411 and connected to the connection column 411, and at least a portion of the fastening component 500 is in contact with the mainboard 100. The fastening component 500 is fixedly connected to the connection column 411 or detachably connected, for example, the fastening component 500 is welded, riveted, clamped, or threadedly connected to the connection column 411.

[0051] Preferably, in the implementation provided by the present application, the connecting column 411 is provided with an external thread, the fastening component 500 is provided with a threaded hole, and the fastening component 500 is threadedly matched with the connecting column 411. Such a configuration is not only simple and convenient to operate, but also can ensure the connection stability between the fastening component 500 and the connecting column 411, and can also adjust the connection position of the fastening component 500 relative to the connecting column 411, thereby adjusting the pressure applied by the fastening component 500 to the mainboard 100, and ensuring that the mainboard 100 is stably fixed between the fastening component 500 and the supporting component 400.

[0052] In the specific implementation process, the fastening component 500 is provided with a connection hole 510, and at least part of the hole section of the connection hole 510 is provided with an internal thread; the connecting column 411 is provided with an external thread, and the fastening component 500 is threadedly matched with the connecting column 411 through the connection hole 510; the fastening component 500 is provided with an operation groove 520, and the operation groove 520 extends along the radial direction of the fastening component 500, and there are multiple operation grooves 520, and the multiple operation grooves 520 are arranged at intervals along the circumferential direction of the fastening component 500. Preferably, the connection hole 510 includes a through hole section and a threaded hole section, and the threaded hole section is located below the through hole section, and is threadedly matched with the connecting column 411 through the threaded hole section. The operation groove 520 is arranged opposite to the through hole section, and the operation groove 520 is used to cooperate with the operating tooling to facilitate the screwing of the fastening component 500. Among them, there are four operation grooves 520, which are distributed in a cross shape, so that it is convenient to tighten with tools during installation.

[0053] Furthermore, the fastening component 500 includes a first end face 530 and a second end face 540 that are arranged opposite to each other, the first end face 530 is in contact with the mainboard 100, the second end face 540 is opposite to the heat sink 300, and each operation groove 520 is respectively arranged on the second end face 540. Specifically, the mainboard 100 is sandwiched between the first end face 530 and the supporting component 400, and when the mainboard 100 is subjected to stress impact, the stress will be limitedly concentrated at the position of the fastening component 500, reducing the stress in the chip area, thereby playing a role in protecting the chip BAG solder joints.

[0054] In the specific implementation process, Figure 6 and Figure 7 As shown, the heat sink 300 is provided with a second connection portion 310, which is opposite to the mainboard 100 and spaced apart; the support component 400 is provided with a first connection portion 410, which is provided with an external thread, and a mounting hole 412 is provided in the first connection portion 410, which is a threaded hole; the fastening component 500 is provided with a connection hole 510, and at least a part of the hole section of the connection hole 510 is provided with an internal thread, and the fastening component 500 is sleeved on the first connection portion 410 through the connection hole 510. The connecting part 410 is threadedly connected to the first connecting part 410; the main board structure also includes: a connecting workpiece 600, which passes through the second connecting part 310 and then is inserted into the mounting hole 412, and is threadedly connected to the mounting hole 412, and a blocking end 610 is provided at the end of the connecting workpiece 600; an elastic component 700 is sleeved on the connecting workpiece 600, and the two ends of the elastic component 700 are respectively abutted against the blocking end 610 and the second connecting part 310, so that the elastic component 700 is in a compressed state. When the connecting workpiece 600 is tightened, the elastic component 700 provides downward pressure to ensure that the heat sink 300 is firmly pressed on the chip. A retaining ring 620 is also provided on the connecting workpiece 600. The retaining ring 620 is located below the second connecting portion 310 to prevent the connecting workpiece 600 from falling off the heat sink 300. Preferably, the second connecting portion 310 is a connecting plate body extending from the heat sink 300, and the connecting workpiece 600 is a connecting screw, which passes through the through hole 311 on the connecting plate body and is threadedly connected to the threaded hole in the connecting column 411.

[0055] Specifically, the minimum distance between the mainboard 100 and the snap ring 620 is greater than the height of the fastening member 500 .

[0056] In the specific implementation process, there are multiple fastening components 500, and the multiple fastening components 500 are arranged at intervals along the circumferential direction of the supporting component 400. The multiple fastening components 500 are used to bear the impact stress when the mainboard is impacted.

[0057] In the present application, the support component 400 includes a support body 420 and a protective film 430. The protective film 430 is attached to the support body 420. The protective film 430 is an insulating material to prevent the motherboard from short-circuiting. The support body 420 is made of metal to provide a solid support point for the radiator, ensuring that the pressure of the radiator is evenly distributed, while reducing deformation of the motherboard and protecting the integrity of the motherboard structure.

[0058] Specifically, when looking for the cause of the BGA cracking problem: (1) The motherboard and heat sink assembly strain test was performed. The test results showed that the maximum microstrain of the BGA did not exceed the threshold of 450με (the standard for static testing), and the test result was PASS. (2) The drop reliability test was performed on the separately packaged motherboard. The test results showed that the maximum microstrain of the BGA exceeded the threshold of 800με (the standard for dynamic testing), and the test result was FAIL. The test result was consistent with the red ink test. In response to the test results of (2), the engineers carried out a series of optimization improvements, such as reducing the weight of the heat sink, optimizing the design of the packaging material lining, etc., and finally reduced the maximum microstrain of the BGA to within the threshold of 800με. The above-mentioned Switch chip BGA cracking phenomenon took about 3 months from the discovery of the problem, analysis of the cause to optimization and improvement. Multiple tests were required in the middle. The motherboard sample for strain testing could only be used once, and multiple tests required multiple samples. The labor cost, testing cost, proofing cost, and time cost were very high. The optimized Switch chip and radiator were reused on another server motherboard. After the whole machine package drop test, a red ink test was performed, and the BGA solder joints were found to be stained, indicating that the Switch chip BGA was cracked. The whole machine shutdown impact stress test was performed, and the maximum microstrain of the BGA exceeded the threshold of 800με, and the test result was also FAIL. The drop reliability test of the single package of this motherboard was retested, and a red ink test was performed. It was found that the BGA solder joints were stained, indicating that the motherboard also had the risk of BGA cracking during transportation. In summary, the optimized Switch chip and radiator are not universal and have not fundamentally solved the problem of BGA cracking. If the improvement method of the previous motherboard is followed, continuous testing and optimization will also require a lot of material and time costs.

[0059] Therefore, the mainboard structure of this application runs CAE simulation technology to analyze the main reasons for the excessive stress of the chip BGA and optimize and improve it. By simulating the real environment and working conditions on the computer, potential design defects can be identified, the need for physical sample production can be reduced, and materials and costs can be saved. According to the simulation data and visualization functions provided by the post-processing of the CAE tool, the root cause of the excessive BGA stress can be quickly analyzed, and targeted optimization and improvement can be carried out. Compared with the traditional trial and error method, CAE simulation significantly shortens the time from design to verification and greatly reduces the time cost.

[0060] This application uses CAE simulation technology to establish a simplified simulation model of the motherboard, simulates the real environment and working conditions for calculations, analyzes the main reasons for the excessive stress of the Switch chip BGA based on the simulation data and visualization functions provided by the CAE tool post-processing, identifies the weak points in the switch heat sink design, and optimizes and improves the weak points so that the maximum microstrain of the Switch chip BGA meets the requirement of not exceeding the threshold value of 800με. The improved Switch chip and heat sink are universal and can be reused on other motherboards.

[0061] After establishing the 3D model of the simplified motherboard, perform stress analysis on the simplified motherboard. The specific steps are as follows:

[0062] 1) Import the simplified 3D model of the motherboard into the Hypermesh software for pre-processing. The simplified CAE model includes: radiator module, motherboard, switch chip and radiator backplane module. It can be seen from the model that Fig. 22 As shown, the rivet studs on the radiator back plate pass through the screw holes of the motherboard, and there is a certain gap between them. The radiator fixing screws are directly locked with the rivet studs and do not contact the motherboard. The retaining rings do not play a big role in CAE analysis, and the influence of the retaining rings is ignored during analysis.

[0063] 2) After the simplified mainboard mesh is divided, assemble and connect it, define the material properties and cross-sectional properties of each part, and save the model as an .inp file for export.

[0064] 3) Import the .inp file exported in step 2 into the Abaqus software, establish the analysis step, set the boundary conditions according to the actual test specifications of the whole machine, apply a 35G impact acceleration to the gourd hole or screw hole on the motherboard that is fixed to the chassis base, and the impact time is a square wave of 11ms. Submit the calculation after the settings are completed.

[0065] 4) After the calculation in step 3 is completed, check the simulation results. Output the maximum principal strain cloud map of the motherboard switch chip area as shown in the attached figure. Fig.23 As shown in the figure, the maximum micro-strain threshold of BGA is 800με, and the area exceeding 800με is displayed in gray. The Switch chip part is intercepted from the motherboard layout diagram. The small dots in the figure represent the BAG solder joints. The intercepted image is set to transparent color and superimposed on the maximum principal strain cloud map of the motherboard Switch chip area. The eight holes in the image are aligned with the corresponding eight holes on the motherboard. It can be seen from the superimposed maximum principal strain cloud map that some BAG solder joints of the Switch chip are located in the gray area and are at risk of cracking, which is consistent with the results of the red ink test. The micro-strain curves of the BAGs at the four corners of the two Switch chips are extracted, as shown in the attached figure. Fig.24As shown, 0.0008ε=800με. It can also be seen from the micro-strain curve that during the impact process, the micro-strain of the four corner BGAs of the Switch chip exceeded the threshold value of 800με, and the maximum value was 1375με.

[0066] 5) According to the simulation results of step 4, it can be judged that the risk of cracking of the BGA solder joints of the Switch chip during the impact process is extremely high. Although the heat sink has undergone a round of optimization, it has not fundamentally solved the problem of BGA solder joint cracking. By observing the animation of the motherboard during the impact process, it can be seen that when the heat sink fixing screws and the back plate rivet columns are locked, the motherboard is not pressed tightly. During the impact process, the rivet columns of the motherboard and the back plate have relatively large shaking in the up and down directions, causing stress to be directly concentrated in the Switch chip area, resulting in excessive BAG micro-strain and cracking of the solder joints. The fixing method of the heat sink has serious design defects.

[0067] 6) Analyze the direction of optimization and improvement based on the results obtained in step 5. The functions of the radiator backplane are, first, to evenly distribute the pressure. The backplane provides a solid support for the radiator to ensure that the pressure of the radiator is evenly distributed; second, to protect the motherboard to prevent the motherboard from bending or deformation due to uneven force. From the analysis results of step 5, it can be seen that the rivet columns between the motherboard and the backplane have relatively large shaking in the up and down directions, indicating that the motherboard and the backplane are not locked, and the radiator backplane has not fully played its role in protecting the motherboard. If the radiator backplane is locked to the motherboard, then during an impact, the motherboard will always be close to the backplane and will not be easily bent or deformed. During an impact, the stress will be concentrated on the eight screws that lock the motherboard and the backplane, reducing the stress in the Switch chip area, thereby protecting the BAG solder joints of the Switch chip.

[0068] 7) Optimize the structure according to the optimization improvement direction analyzed in step 6. Add eight nuts to lock the motherboard and the radiator back plate, as shown in the attached Figure 1 As shown, the specific implementation is as follows: Figure 7 As shown in the figure (1) the retaining ring is raised by 3.5mm, and the retaining ring does not interfere with the heat sink after the raising. (2) 4 nuts (fastening components of the above embodiment) are added to lock the main board and the back plate. (3) The 4 rivet studs on the back plate are lengthened by 3.5mm. The structure of the newly added nuts is shown in the figure. Figure 11-13 As shown in the figure, the nut has threads inside and cross-shaped slots on it, which is convenient for tightening with tools during installation. The optimized structure of the rivet stud is shown in the attached figure. Figure 14-16As shown in the figure, after the rivet stud is lengthened by 3.5mm, the part above the upper surface of the motherboard is added with external threads, and the part below the upper surface of the motherboard retains the original internal threads. When installing, first place the radiator backplane module under the motherboard, pass the backplane rivet stud through the corresponding via hole on the motherboard, then lock the newly added nut on the rivet stud, lock the motherboard and the backplane, and finally place the radiator module on the Switch chip, align the four screws on the radiator with the four rivet studs on the backplane, and lock the radiator and the backplane. The effect after installation is as shown in the figure. Fig.17 and 18 This embodiment only takes 3.5 mm as an example, and the position of the clamping ring and the height of the fastening component can be set according to different specifications of heat sinks and motherboards.

[0069] 8) After completing the structural optimization in step 7, repeat the operations of steps 1 to 4. The maximum principal strain contour of the optimized motherboard switch chip area is shown in the attached figure. Fig. 20 As shown in the figure, the maximum micro strain threshold of BGA is 800με, and the area exceeding 800με is shown in gray. From the superimposed maximum principal strain cloud map, it can be seen that the BAG solder joints of the Switch chip are far away from the gray area, and the risk of cracking is relatively low. The micro strain curves of the BAGs at the four corners of the two Switch chips are extracted, as shown in the attached figure. Fig.21 As shown in the figure, 0.00025ε=250με. It can also be seen from the micro-strain curve that the micro-strain of the Switch chip BGA did not exceed the threshold value of 800με during the impact process, and the maximum value was 251με. Compared with the maximum value of 1375με before optimization, the improvement effect is very obvious.

[0070] 9) The simulation results of step 8 show that after locking the motherboard and the radiator backplane, the stress of the Switch chip BAG is greatly reduced, and the optimization scheme has a significant improvement effect. Prototyping was carried out according to the optimization scheme provided by the simulation, and the whole machine shutdown impact stress test was performed. During the actual measurement, the microstrain of the Switch chip BAG exceeded the threshold of 800με, and the test result was PASS. The drop reliability test of the single package of the motherboard after retesting the optimization was carried out, and a red ink test was performed, and it was found that the BGA solder joints were not dyed. The above test results show that the simulation optimization scheme is feasible.

[0071] The above simulation optimization process only takes 1 to 2 working days from establishing the simulation model to completing the simulation optimization, and it takes a week from optimizing the structure to completing the test. Compared with the first optimization which took 3 months, the time is greatly reduced. The simulation method can quickly and accurately analyze the real cause of the cracking of the Switch chip BAG, find the design defects, and provide practical improvement solutions for the weak points to fundamentally solve the problem. The improved Switch chip and heat sink are universal and can be reused on other motherboards.

[0072] In this application, a specific embodiment is provided:

[0073] Lift the retaining ring on the radiator upward by 3.5mm, raise the rivet studs on the back plate of the radiator by 3.5mm, add external threads to the part of the rivet studs located above the upper surface of the motherboard, and retain the original internal threads on the part located below the upper surface of the motherboard. Add 8 nuts to lock the motherboard and the back plate, and the newly added nuts have internal threads. During installation, first place the radiator back plate module under the motherboard, pass the back plate rivet studs through the corresponding holes on the motherboard, and then lock the newly added nuts on the rivet studs to lock the motherboard and the back plate. Finally, place the radiator module on the Switch chip, align the four screws on the radiator with the four rivet studs on the back plate, and lock the radiator and the back plate. This embodiment only takes 3.5mm as an example. The position of the retaining ring and the height of the fastening components can be set according to radiators and motherboards of different specifications.

[0074] Motherboard optimization simulation process: Establish a simplified finite element analysis model of the motherboard, assemble and connect, define the material properties and cross-sectional properties of each part, save the model as an .inp file and import it into the Abaqus software, establish the analysis step, set the boundary conditions according to the specifications of the actual test of the whole machine, and submit the operation. After the operation is completed, output the maximum principal strain distribution cloud map of the motherboard, intercept the layout distribution map of the motherboard and set it to transparent color, superimpose it on the maximum principal strain distribution cloud map of the motherboard, check whether there is a BAG in the excessive area, output the BGA microstrain curves of the four corners of the Switch chip, and check whether the BAG microstrain exceeds the standard during the entire impact process. If the BAG microstrain exceeds the standard, check the dynamic deformation process of the motherboard, analyze the reasons for the excessive deformation of the motherboard, and make targeted improvements. Simulate and analyze the improved solution again, and perform simulation optimization multiple times to ensure that the simulation optimization solution has obvious improvement effect. For the optimization solution with obvious improvement effect, proofing and actual measurement verification are carried out, and simulation comparison is carried out after actual measurement.

[0075] In another embodiment provided in the present application, the fastening component 500 and the supporting component 400 are arranged on the same side of the mainboard 100, and the fastening component 500 is connected to the supporting component 400 and the mainboard 100 respectively. Preferably, the fastening component 500 is an insulating adhesive layer.

[0076] The present application also provides an electronic device, including a mainboard structure, which is the mainboard structure of the above embodiment.

[0077] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0078] According to the motherboard structure provided in the present application, it includes a motherboard 100, a chip 200 and a radiator 300, the chip 200 is arranged on the motherboard 100, the radiator 300 is connected to the motherboard 100 and is located above the chip 200, and the motherboard structure also includes: a supporting component 400 and a fastening component 500, the supporting component 400 is arranged on a side of the motherboard 100 away from the radiator 300 and is attached to the motherboard 100, at least part of the supporting component 400 passes through the motherboard 100 and is connected to the radiator 300; the fastening component 500 is respectively connected to the supporting component 400 and the motherboard 100; or, the fastening component 500 is connected to the supporting component 400 and is attached to the motherboard 100, so as to clamp the motherboard 100 between the supporting component 400 and the fastening component 500, so that the supporting component 400 and the motherboard 100 remain in an attached state. By setting the fastening component 500, the supporting component 400 is always kept in close contact with the mainboard 100, so that the supporting component 400 can evenly disperse the stress on the mainboard 100, avoiding the mainboard 100 from bending or deformation due to uneven force. Even if it is impacted, the mainboard 100 is always in close contact with the supporting component 400, and the stress will be preferentially concentrated on the fastening component 500, reducing the stress in the chip area, thereby protecting the chip BGA solder joints, and solving the problem of cracking of the ball grid array on the chip due to loose assembly with the heat sink during transportation in the prior art.

[0079] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0080] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0081] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0082] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0083] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0084] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A motherboard structure, comprising a motherboard (100), a chip (200) and a heat sink (300), wherein the chip (200) is arranged on the motherboard (100), and the heat sink (300) is connected to the motherboard (100) and is located above the chip (200), characterized in that: The mainboard structure also includes: a supporting component (400) disposed on a side of the mainboard (100) away from the radiator (300) and in contact with the mainboard (100), wherein at least a portion of the supporting component (400) passes through the mainboard (100) and is connected to the radiator (300); A fastening component (500), wherein the fastening component (500) is respectively connected to the supporting component (400) and the main board (100); or, the fastening component (500) is connected to the supporting component (400) and is fitted to the main board (100), so that the main board (100) is clamped between the supporting component (400) and the fastening component (500), so that the supporting component (400) and the main board (100) are kept in a fitted state.

2. The mainboard structure according to claim 1, characterized in that: The fastening component (500) is located on the end surface of the main board (100) facing away from the supporting component (400) so as to clamp the main board (100) between the supporting component (400) and the fastening component (500).

3. The mainboard structure according to claim 1, characterized in that: The supporting component (400) is provided with a first connecting portion (410), and the first connecting portion (410) passes through the mainboard (100) and is connected to the heat sink (300); The fastening component (500) is connected to the first connecting portion (410), and the main board (100) is sandwiched between the fastening component (500) and the supporting component (400).

4. The mainboard structure according to claim 3, characterized in that: The first connecting portion (410) comprises: A connecting column (411), wherein the connecting column (411) passes through the mainboard (100) and is connected to the heat sink (300), the fastening component (500) is sleeved on the connecting column (411) and is connected to the connecting column (411), and at least a portion of the fastening component (500) is in contact with the mainboard (100).

5. The mainboard structure according to claim 4, characterized in that: The connecting column (411) is provided with an external thread, the fastening component (500) is provided with a threaded hole, and the fastening component (500) is threadably matched with the connecting column (411).

6. The mainboard structure according to claim 4, characterized in that: The fastening component (500) is provided with a connecting hole (510), and at least a portion of the hole section of the connecting hole (510) is provided with an internal thread; The connecting column (411) is provided with an external thread, and the fastening component (500) is threadably matched with the connecting column (411) through the connecting hole (510); The fastening component (500) is provided with an operating groove (520), the operating groove (520) extending in the radial direction of the fastening component (500), and there are a plurality of operating grooves (520), which are arranged at intervals in the circumferential direction of the fastening component (500).

7. The mainboard structure according to claim 6, characterized in that: The fastening component (500) comprises a first end surface (530) and a second end surface (540) which are arranged opposite to each other, the first end surface (530) is in contact with the main board (100), the second end surface (540) is opposite to the heat sink (300), and each of the operating grooves (520) is respectively arranged on the second end surface (540).

8. The mainboard structure according to claim 1, characterized in that: The heat sink (300) is provided with a second connection portion (310), and the second connection portion (310) is opposite to and spaced from the main board (100); The support component (400) is provided with a first connection portion (410), the first connection portion (410) is provided with an external thread, and a mounting hole (412) is provided inside the first connection portion (410), and the mounting hole (412) is a threaded hole; The fastening component (500) is provided with a connecting hole (510), at least a portion of the hole section of the connecting hole (510) is provided with an internal thread, and the fastening component (500) is sleeved on the first connecting portion (410) through the connecting hole (510) and is threadedly connected to the first connecting portion (410); The mainboard structure also includes: A connecting workpiece (600), the connecting workpiece (600) passes through the second connecting portion (310) and is then inserted into the mounting hole (412), and is threadedly connected to the mounting hole (412), and a blocking end (610) is provided at the end of the connecting workpiece (600); An elastic component (700) is sleeved on the connecting workpiece (600), and two ends of the elastic component (700) are respectively in contact with the blocking end (610) and the second connecting portion (310), so that the elastic component (700) is in a compressed state.

9. The mainboard structure according to claim 1, characterized in that: There are a plurality of fastening components (500), and the plurality of fastening components (500) are arranged at intervals along the circumferential direction of the supporting component (400).

10. An electronic device, comprising a mainboard structure, characterized in that: The mainboard structure is the mainboard structure according to any one of claims 1 to 9.

Images