Fastening device and LGA chip structure
By employing a combination of locking and pre-tightening structures in the LGA chip structure, a sequential operation of pre-tightening followed by locking and de-locking followed by de-pre-tightening is achieved. This solves the problem of package deformation and damage caused by over-tightening, reduces production costs, and improves the safety and smoothness of the locking process.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-02-15
- Publication Date
- 2026-03-27
AI Technical Summary
Existing fastening devices have high production costs when locking LGA chip packages, and are prone to causing chip package deformation and damage due to over-tightening.
By combining locking and pre-tightening structures, and through the design of pre-tightening sleeves and limiting baffles, the sequential operation of pre-tightening followed by locking and locking followed by pre-tightening is achieved, which avoids over-tightening and reduces production costs.
It effectively ensures the safety of chip packaging, reduces production costs, and ensures a smooth locking process, avoiding packaging deformation and damage caused by over-locking.
Smart Images
Figure CN116314074B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of LGA chip structure, in particular to a fastening device and LGA chip structure. BACKGROUND
[0002] The terminals made of metal are arranged in a certain way in the socket shell of the LGA chip to establish electrical connection with the chip, and each terminal exerts a forward force of about 23g on the packaging structure of the chip. For a large-pin-count chip with more than 4000 terminals, the total forward force reaches about 100kg, and if the LGA chip packaging is not properly supported, the packaging itself will be deformed greatly, and the deformation mainly occurs in the part close to the center of the packaging, which will arch upward, leading to problems such as poor contact of the contacts in the center, breakage of the silicon wafer in the packaging, damage to the connection between the silicon wafer and the substrate inside the chip, and inability of the thermal paste at the edge of the packaging to fill the gap between the top cover and the bottom surface of the heat sink, resulting in a decrease in heat dissipation effect.
[0003] The current mainstream solution is to apply locking force to the packaging through the heat sink to suppress the deformation of the packaging caused by the forward force of the terminals during locking. The existing fastening device has the following scheme: four threaded studs are arranged at the four corners of the mounting seat of the chip, and four T-shaped nuts are arranged at the positions corresponding to the threaded studs on the heat sink shell. In order to prevent the chip packaging from being damaged due to excessive force on one side during the tightening of the nuts, a pre-tightening structure is also provided, which is realized by a torsional spring, i.e. in the initial state, one end of the torsional spring is placed above the T-shaped nut to prevent accidental operation; the other end of the torsional spring must be buckled in the pre-buckling position by actuating the torsional spring, and then a screwdriver can be inserted to tighten the T-shaped nut. The above-mentioned scheme can solve the problem of pressing the chip packaging, but the nuts in the scheme are injection molded parts, and in order to ensure the strength of the nuts when they are engaged with the metal nuts, PEEK or other expensive engineering plastics need to be used. In addition, the mounting seat of the chip needs to be formed with a torsional spring buckling position on the normal forming structure, which undoubtedly greatly increases the sheet metal forming cost of the locking structure. In addition, the T-shaped nut base where the torsional spring is located also needs to use engineering plastics with high strength to adapt to the stress on both ends of the torsional spring, otherwise the base will be deformed when the one end of the torsional spring is pulled for locking, which seriously affects the pre-locking.
[0004] Therefore, how to optimize the structure of the fastening device under the premise of ensuring the safety of the chip packaging and reduce the production cost has become a problem to be solved. SUMMARY
[0005] The main purpose of the present application is to provide a fastening device, which aims to optimize the structure of the fastening device to reduce the production cost under the condition of ensuring the safety of the chip packaging.
[0006] To achieve the above object, the fastening device for fastening the heat sink to the chip package comprises:
[0007] The locking structure comprises a first fastener and a second fastener extending upward from the mounting base of the chip and penetrating the base of the heat sink, one of the first fastener and the second fastener is formed with an internal thread, and the other is formed with an external thread; and
[0008] The pre-tightening structure comprises a fixing member extending upward from the mounting base and located beside the second fastener, the upper end of the fixing member is bent to form a limiting baffle towards the second fastener, the lower end of the pre-tightening sleeve abuts against the upper end face of the base of the heat sink and is sleeved on the upper part of the second fastener, the first fastener is arranged in the pre-tightening sleeve along the up-down axis and partially exposed from the upper end of the pre-tightening sleeve, the lower part of the pre-tightening sleeve is protruded from the outer sidewall thereof and provided with a pre-tightening ring, the upper end face of the pre-tightening ring abuts against the lower end face of the limiting baffle, and the thickness of part of the pre-tightening ring gradually increases from one end to the other end in the up-down direction, so that the first fastener moves downward with the pre-tightening sleeve and is threadedly connected with the second fastener when the pre-tightening sleeve is rotated under the action of an external force.
[0009] Optionally, the first fastener comprises a nut, the second fastener comprises a stud, the stud comprises an engaging rod segment at the lower part thereof and a guide rod segment connected to the upper end of the engaging rod segment and having a smaller diameter than the engaging rod segment, and the engaging rod segment is formed with an external thread for threadedly connecting with the nut.
[0010] Optionally, the base of the heat sink is concavely formed with a first mounting groove from the upper end face of the position penetrated by the stud downward;
[0011] The upper part of the nut is formed with a step face facing downward;
[0012] The fastening device further comprises a first spring arranged in the pre-tightening sleeve, the lower end of the first spring abuts against the groove bottom of the first mounting groove, and the upper end of the first spring abuts against the step face.
[0013] Optionally, a driving gasket is arranged between the first spring and the step face, and the upper end of the spring abuts against the lower end face of the driving gasket.
[0014] Optionally, the upper part of the inner sidewall of the pre-tightening sleeve is protruded inward to form an annular stop ring, and the lower end face of the annular stop ring abuts against the upper end face of the driving gasket.
[0015] Optionally, a rotating handle is further included, which rotates synchronously with the pre-tightening sleeve and is used for externally holding and driving the pre-tightening sleeve to rotate.
[0016] Optionally, a second limiting groove is formed on the upper end surface of the heat sink base, and the second limiting groove is annularly arranged and partially oppositely arranged with the limiting baffle in the up-down direction.
[0017] A mounting side wall is formed on the portion of the pre-tightening sleeve below the pre-tightening ring, the pre-tightening sleeve is mounted in the second limiting groove, and the mounting side wall abuts against the sidewall of the second limiting groove.
[0018] Optionally, a first limiting protrusion is formed on the upper end of the nut along the ring side, and the lower end surface of the first limiting protrusion abuts against the upper end of the rotating handle.
[0019] The fastening device further includes a support column, the lower end of the support column penetrates through the pre-tightening ring and extends into the second limiting groove, the upper end extends into the rotating handle, a second spring is arranged on the support column, and the two ends of the second spring abut against the rotating handle and the pre-tightening sleeve, respectively.
[0020] Optionally, the pre-tightening ring includes:
[0021] a bearing section, the thickness of the bearing section gradually increases from one end to the other end, and the bearing section is used for bearing against the limiting baffle; and
[0022] a mounting section, which is connected to the end of the bearing section with the largest thickness, is partially arranged in penetration, and is used for penetrating the support column.
[0023] Optionally, the two end portions of the mounting section are provided with stop columns, the stop columns are used for limiting the rotation range of the pre-tightening sleeve, and a discharging port is formed between the end portion of the mounting section adjacent to the end of the bearing section with the smallest thickness and the adjacent stop column.
[0024] Optionally, a first limiting groove is formed on the heat sink base by concave arrangement from the lower end surface of the position penetrated by the threaded column, and a clamping spring is clamped in the first limiting groove.
[0025] The lower portion of the nut is provided with a driving limiting groove, the driving limiting groove has two abutting groove walls oppositely arranged in the up-down direction, and the driving limiting groove is used for sleeving the clamping spring.
[0026] The application further provides an LGA chip structure including a fastening device, and the fastening device includes:
[0027] The locking structure comprises a stud extending upward from the mounting base of the chip and penetrating through the base of the heat sink, the stud comprises an engaging rod segment at the lower part thereof and a guide rod segment connected to the upper end of the engaging rod segment and having a smaller diameter than the engaging rod segment, the engaging rod segment is formed with external threads for threaded connection with a nut; and,
[0028] The pre-tightening structure comprises a fixing member extending upward from the mounting base of the chip and arranged beside the stud, the upper end of the fixing member is bent to form a limiting baffle towards the stud, the lower end of the pre-tightening sleeve abuts against the upper end face of the base of the heat sink and is sleeved on the guide rod segment, the nut is arranged in the pre-tightening sleeve along the axis in the up-down direction and is partially exposed from the upper end of the pre-tightening sleeve, the pre-tightening ring is protruded from the outer sidewall of the lower part of the pre-tightening sleeve, the upper end face of the pre-tightening ring abuts against the lower end face of the limiting baffle, and in the up-down direction, the thickness of the pre-tightening ring gradually increases from one end to the other end, so that when the pre-tightening sleeve is rotated under the action of an external force, the nut is movably sleeved on the engaging rod segment or the guide rod segment.
[0029] In the technical scheme of the present application, the pre-tightening ring arranged at the lower part of the pre-tightening sleeve is rotated along with the pre-tightening sleeve, and the upper end face of the pre-tightening ring abuts against the lower end face of the limiting baffle, and during the rotation process, since the thickness of the pre-tightening ring gradually increases and the limiting baffle is arranged on the mounting base of the chip and the pre-tightening sleeve is arranged on the base of the heat sink, the heat sink moves downward relative to the chip, i.e. the pre-locking of the heat sink on the chip is achieved, and during this process, since the second fastening member extends upward from the mounting base of the chip and penetrates through the pre-tightening sleeve, the first fastening member moves downward along with the pre-tightening sleeve and the first fastening member and the second fastening member are threadedly connected, at this time, by driving the exposed part of the first fastening member to rotate, the threads between the two are further engaged, thereby driving the heat sink to be further locked on the chip package, and when the locking of the heat sink on the chip is released, the first fastening member is first rotated to release the thread connection with the second fastening member, and then the pre-tightening sleeve is rotated to release the pre-tightening, the above-mentioned locking and unlocking processes achieve the sequential locking operation of pre-tightening first and then locking, and releasing the locking first and then releasing the pre-tightening, thereby avoiding the problem that the chip package is damaged due to excessive locking when directly locking, so as to ensure the safety of the chip package when the chip is locked with the heat sink, the above-mentioned fastening device has low production difficulty and does not need complex sheet metal forming, thereby reducing the production cost, and the locking process is very smooth, and has high practical value. BRIEF DESCRIPTION OF DRAWINGS
[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0031] Figure 1 An exploded perspective view of an embodiment of the fastening device provided by the present invention;
[0032] Figure 2 for Figure 1 A schematic diagram of the internal structure of an embodiment;
[0033] Figure 3 for Figure 2 A magnified view of a section at point A in the middle;
[0034] Figure 4 for Figure 1 A three-dimensional structural diagram of the pre-tightening sleeve in the embodiment;
[0035] Figure 5 for Figure 1 A cross-sectional schematic diagram of the pre-tightening sleeve in the embodiment;
[0036] Figure 6 for Figure 1 A schematic diagram of the first pre-tightening state in the embodiment;
[0037] Figure 7 for Figure 1 A schematic diagram of the second pre-tightening state in the embodiment;
[0038] Figure 8 for Figure 1 A schematic diagram of the first locking state in an embodiment;
[0039] Figure 9 for Figure 1 A schematic diagram of the second locking state in the embodiment;
[0040] Figure 10 A three-dimensional structural schematic diagram of an embodiment of the LGA chip structure provided by the present invention;
[0041] Figure 11 for Figure 10 A first-angle schematic diagram of the heat sink in an embodiment;
[0042] Figure 12 for Figure 11 A magnified view of a section at point B in the middle;
[0043] Figure 13 for Figure 10A second angle view of the heat sink of the embodiment in FIG.
[0044] Figure 14 To Figure 13 A close-up view at C in FIG.
[0045] BRIEF DESCRIPTION OF DRAWINGS
[0046]
[0047] The implementation, functional features and advantages of the present application will be further described with reference to the accompanying drawings. DETAILED DESCRIPTION
[0048] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.
[0049] It should be noted that all the directionality indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative position relationship, movement condition, etc. between components in a certain specific posture (as shown in the accompanying drawings), and if the specific posture changes, the directionality indications also change accordingly.
[0050] In addition, the descriptions involving “first”, “second” and the like in the present application are only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by “first” and “second” can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of a person of ordinary skill in the art, and when the combination of technical solutions contradicts each other or cannot be realized, it should be considered that the combination of technical solutions does not exist and is not within the protection scope of the present application.
[0051] The terminals made of metal are arranged in a certain way in the socket housing of the LGA chip to establish electrical connection with the chip, and each terminal exerts a forward force of about 23 g on the packaging structure of the chip. For a large-pin-count chip with more than 4000 terminals, the total forward force reaches about 100 kg, which causes great deformation of the packaging structure if the packaging structure is not properly supported. The deformation mainly occurs in the part close to the center of the packaging structure, which arches upward, leading to problems such as poor contact of the gasket at the center, breakage of the silicon wafer in the packaging structure, damage to the connection between the silicon wafer and the substrate inside the chip, and poor heat dissipation due to the inability of the thermal paste at the edge of the packaging structure to fill the gap between the top cover and the bottom surface of the heat sink.
[0052] The current mainstream solution is to apply a locking force to the packaging structure through the heat sink to suppress the deformation of the packaging structure caused by the forward force of the terminals during locking by using the good rigidity of the heat sink itself. The existing fastening device solution is as follows: four studs are arranged at each of the four corners of the mounting seat of the chip, and four T-shaped nuts are arranged at the positions corresponding to the studs on the housing of the heat sink. In order to prevent damage to the packaging structure due to excessive force on one side during the tightening of the nuts, a pre-tightening structure is also provided, which is implemented by a torsion spring, i.e., in the initial state, one end of the torsion spring is placed above the T-shaped nut to prevent accidental operation. The other end of the torsion spring must be held in a pre-made holding position by actuating the torsion spring, and then a screwdriver can be inserted to tighten the T-shaped nut. The above-mentioned solution can solve the problem of pressing the packaging structure of the chip, but the nuts in this solution are injection molded parts. In order to ensure the strength of the nuts when they are engaged with the metal nuts, an expensive engineering plastic such as PEEK needs to be used. The mounting seat of the chip needs to have a torsion spring holding position formed on the normal molding structure, which undoubtedly greatly increases the metal forming cost of the locking structure. In addition, the T-shaped nut base where the torsion spring is located also needs to use an engineering plastic with high strength to adapt to the stress on both ends of the torsion spring, otherwise the base will deform when the one end of the torsion spring is pulled for locking, which seriously affects the pre-locking.
[0053] To solve the above problems, the present application provides an LGA chip structure, which comprises a fastening device for locking a heat sink of the LGA chip structure on a chip, Figures 1 to 14 For an embodiment of the present application, Figures 10 to 14 For an embodiment of the LGA chip structure.
[0054] In an embodiment of the present application (hereinafter referred to as the present embodiment), the fastening device 103 is like Figures 1 to 9As shown, the fastening device 103 is used to fasten the heat sink 102 to the package of the chip 101, the fastening device 103 comprises a locking structure 1 and a pre-tightening structure 2, the locking structure 1 comprises a first fastener 12 and a second fastener 11 which is arranged through the base of the heat sink 102 and extends upward from the mounting base of the chip 101, one of the first fastener 12 and the second fastener 11 is formed with an internal thread, and the other part is formed with an external thread, the pre-tightening structure 2 comprises a fixing piece 21 and a pre-tightening sleeve 22, the fixing piece 21 is arranged to extend upward from the mounting base and is located beside the second fastener 11, the upper end of the fixing piece 21 is bent toward the second fastener 11 to form a limiting baffle 211, the lower end of the pre-tightening sleeve 22 abuts against the upper end surface of the base of the heat sink 102 and is sleeved on the upper part of the second fastener 11, the first fastener 12 is arranged in the pre-tightening sleeve 22 along the up-down axis and is partially exposed from the upper end of the pre-tightening sleeve 22, the lower part of the pre-tightening sleeve 22 is protruded from the outer side wall of the pre-tightening sleeve 22 to form a pre-tightening ring 221, the upper end surface of the pre-tightening ring 221 abuts against the lower end surface of the limiting baffle 211, and in the up-down direction, the thickness of part of the pre-tightening ring 221 gradually increases from one end to the other end, so that when the pre-tightening sleeve 22 is rotated under the action of external force, the first fastener 12 moves downward with the pre-tightening sleeve 22 and is threadedly connected with the second fastener 11.
[0055] In the technical scheme of the present application, the pre-tightening ring 221 arranged at the lower part of the pre-tightening sleeve 22 rotates with the pre-tightening sleeve 22, and the upper end surface of the pre-tightening ring 221 abuts against the lower end surface of the limiting baffle 211. During the rotation, the thickness of the pre-tightening ring 221 gradually increases, the limiting baffle 211 is arranged at the base of the chip 101, and the pre-tightening sleeve 22 is arranged at the base of the heat sink 102, so that the heat sink 102 moves downward relative to the chip 101, that is, the pre-tightening of the heat sink 102 to the chip 101 is achieved. During the process, the second fastener 11 extends upward from the base of the chip 101 and is arranged in the pre-tightening sleeve 22, the first fastener 12 moves downward with the pre-tightening sleeve 22, and the first fastener 12 and the second fastener 11 are threadedly connected. At this time, the exposed part of the first fastener 12 is driven to rotate, the threads between the two are further engaged, so as to drive the heat sink 102 to be further locked on the chip 101 package. When the locking of the heat sink 102 and the chip 101 is released, the first fastener 12 is rotated to release the threaded connection with the second fastener 11, and then the pre-tightening sleeve 22 is rotated to release the pre-tightening. The above locking and unlocking processes achieve the sequential locking operation of pre-tightening first and then locking, and releasing the locking first and then releasing the pre-tightening. The problem that the chip 101 package is damaged due to excessive locking when directly locking and cannot control the locking degree is avoided, so as to ensure the safety of the chip 101 package when the chip 101 is locked with the heat sink 102. The above fastening device 103 has low production difficulty and does not need complex sheet metal forming, so as to reduce the production cost, and the locking process is very smooth, and has high practical value.
[0056] To realize the locking process in the technical scheme of the present application, the first fastener 12 comprises a nut 12a, the second fastener 11 comprises a stud 11a, the stud 11a comprises an engaging rod section 111 at its lower part and a guide rod section 112 connected to the upper end of the engaging rod section 111 and having a smaller diameter than the engaging rod section 111, the engaging rod section 111 is formed with external threads, when the nut 12a moves downward with the pre-tightening sleeve 22, the nut 12a is sleeved downward on the engaging rod section 111 and is threadedly connected with the external threads on the engaging rod section 111, at this time, the nut 12a is further engaged with the engaging rod section 111 by rotating the nut 12a, and the locking process is realized. It should be noted that in the embodiment of the present application, the nut 12a used is a T-shaped nut, and the fastening device 103 is arranged at four corners of the LGA chip structure 1000 to enhance the fastening effect of the heat sink 102 on the chip 101, and the locking sequence is that two fastening devices 103 on the same diagonal are sequentially pre-locked, and after the four fastening devices 103 are pre-tightened, the locking process of the same diagonal is performed, and until the four fastening devices 103 are all locked. It should be noted that when the locking is released, the locking is released first, and then the pre-tightening is released, and the same is that the locking of the four fastening devices 103 is released in diagonal order first, and then the pre-tightening of the four fastening devices 103 is released.
[0057] To realize the locking process in the technical scheme of the present application, the first fastener 12 comprises a nut 12a, the second fastener 11 comprises a stud 11a, the stud 11a comprises an engaging rod section 111 at its lower part and a guide rod section 112 connected to the upper end of the engaging rod section 111 and having a smaller diameter than the engaging rod section 111, the engaging rod section 111 is formed with external threads, when the nut 12a moves downward with the pre-tightening sleeve 22, the nut 12a is sleeved downward on the engaging rod section 111 and is threadedly connected with the external threads on the engaging rod section 111, at this time, the nut 12a is further engaged with the engaging rod section 111 by rotating the nut 12a, and the locking process is realized. It should be noted that in the embodiment of the present application, the nut 12a used is a T-shaped nut, and the fastening device 103 is arranged at four corners of the LGA chip structure 1000 to enhance the fastening effect of the heat sink 102 on the chip 101, and the locking sequence is that two fastening devices 103 on the same diagonal are sequentially pre-locked, and after the four fastening devices 103 are pre-tightened, the locking process of the same diagonal is performed, and until the four fastening devices 103 are all locked. It should be noted that when the locking is released, the locking is released first, and then the pre-tightening is released, and the same is that the locking of the four fastening devices 103 is released in diagonal order first, and then the pre-tightening of the four fastening devices 103 is released. Figure 3 and Figure 12As shown, the base of the heat sink 102 is concave downward from the upper end of the position where the stud 11a penetrates, forming a first mounting groove 1021, the upper portion of the nut 12a is formed with a downward facing step surface 121, the fastening device 103 further comprises a first spring 3, which is arranged in the pre-tightening sleeve 22, and the lower end thereof abuts against the groove bottom of the first mounting groove 1021, and the upper end thereof abuts against the step surface 121, when locking, the first spring 3 is compressed by the external force acting on the nut 12a, so that the nut 12a moves downward and is connected with the threads on the engagement rod segment 111, and then the nut 12a is rotated to cooperate with the engagement rod segment 111, the step surface 121 presses the first spring 3, and the first spring 3 abuts against the base of the heat sink 102, so that the base of the heat sink 102 moves downward relative to the chip 101, that is, the heat sink 102 is locked on the chip 101 by rotating the nut 12a. Since the nut 12a is pressed against the base of the heat sink 102 by the elastic force generated by compressing the first spring 3, even if the nut 12a is excessively tightened, the compressibility of the spring itself can prevent the packaging structure of the chip 101 from being damaged to a certain extent.
[0058] To reduce the friction loss between the nut 12a and the first spring 3 when the nut 12a is rotated, with reference to Figure 1 and Figure 3 a driving washer 4 is further arranged between the first spring 3 and the step surface 121, specifically, the driving washer 4 is sleeved on the nut 12a and located below the step surface 121, the first spring 3 abuts against the driving washer 4 to press it against the step surface 121, preventing the end of the first spring 3 from scratching the nut 12a during locking. If the driving washer 4 is not arranged, the area of the step surface 121 should be designed to be larger so that the first spring 3 can continuously abut against the step surface 121, and the strength of the nut 12a will be affected.
[0059] To prevent the first spring 3 from being pulled out of the pre-tightening sleeve 22 from the upper end and abutting against the nut 12a, with reference to Figure 3 and Figure 5, the upper part of the inner side wall of the pre-tightening sleeve 22 is inwardly protruding and formed with an annular stop ring, the lower end surface of the annular stop ring 222 abuts against the upper end surface of the driving washer 4, so as to limit the driving washer 4 through the abutment of the annular stop ring, preventing the spring from pushing the nut 12a out of the pre-tightening sleeve 22. On the other hand, the annular stop ring 222 is used during pre-tightening, the pre-tightening sleeve 22 pushes the driving washer 4 through the annular stop ring 222 to compress the first spring 3, so as to eliminate the resistance of the first spring 3 that the nut 12a originally receives during the process of moving downward and contacting the engagement rod segment 111, or not to need to compress the first spring 3 through external force again, so that the threads of the two are more easily connected together, facilitating the locking process.
[0060] In order to facilitate the rotation of the pre-tightening sleeve 22, the fastening device 103 further comprises a rotating handle 6, which is sleeved on the upper end of the pre-tightening sleeve 22 and rotates synchronously with the pre-tightening sleeve 22, and the rotating handle 6 is protruding and formed with a pointing protrusion 61, which is used to facilitate the operator to hold and rotate the pre-tightening sleeve 22, and by setting the direction of the pointing protrusion 61, the angle of the pre-tightening sleeve 22 that has been rotated can be judged through the pointing protrusion 61, and whether the rotation has reached a suitable pre-tightening strength can be determined. In order to make the pre-tightening sleeve 22 and the rotating handle 6 rotate synchronously, a driving groove 223 is provided on the pre-tightening sleeve 22, which is matched with the protrusion on the inner side of the rotating handle 6 to drive the pre-tightening sleeve 22 to rotate synchronously with the rotating handle 6.
[0061] In order to prevent the pre-tightening ring 221 from moving out of the abutment range of the limiting stop plate 211 during the rotation of the pre-tightening sleeve 22, in combination with Figure 3 , Figure 5 and Figure 12 , the upper end surface of the heat sink 102 base is formed with a second limiting groove 1023, the second limiting groove 1023 is annularly arranged and partially opposite to the limiting stop plate 211 in the up-down direction, the pre-tightening sleeve 22 is installed in the second limiting groove 1023, and the part of the pre-tightening sleeve 22 below the pre-tightening ring 221 is formed with an installation side wall 224, and the installation side wall 224 abuts against the side wall of the second limiting groove 1023, specifically the side wall of the second limiting groove 1023 adjacent to the stud 11a, to limit the radial movement range of the pre-tightening sleeve 22 during rotation, so that it is in the second limiting groove 1023, to ensure that the pre-tightening ring 221 can always abut against the lower end surface of the limiting stop plate 211 during rotation, and will not be overturned, thereby affecting the operation of the device.
[0062] In order to limit the rotating handle 6 to the upper end of the pre-tightening sleeve 22, as Figures 1 to 3 andFigures 6 to 9 The upper end of the nut 12a is provided with a first limiting protrusion 122 protruding along the ring side, the lower end surface of the first limiting protrusion 122 abuts against the upper end of the rotating handle 6, the fastening device 103 further comprises a support column 7, which is generally a metal rod cut into pieces, the lower end of the support column 7 penetrates through the pre-tightening ring 221 and extends into the second limiting groove 1023, and the upper end is embedded into the pre-fabricated hole of the rotating handle 6, without relative displacement between each other. If the cost is not considered, the support column 7 and the rotating handle 6 are combined into one part. The second spring 8 is sleeved on the support column 7, the two ends of the second spring 8 abut against the pre-tightening ring 22 and the rotating handle 6 respectively, so as to support the rotating handle 6, and the upper end of the rotating handle 6 abuts against the first limiting protrusion 122, which is used to prevent the rotating handle 6 from being separated from the pre-tightening sleeve 22 upwardly, and limits the rotating handle 6 to the upper end of the pre-tightening sleeve 22, so that the device remains an integral whole from this direction.
[0063] As shown in Figure 4 and Figure 5 , the pre-tightening ring 221 comprises an abutting section 2212 and a mounting section 2213, the thickness of the abutting section 2212 gradually increases from one end to the other end, which abuts against the limiting baffle 211, and the mounting section 2213 is provided with a through hole corresponding to the position of the support column 7, which is used to penetrate the support column 7, so as to guide and support the support column 7. The lower end of the second spring 8 abuts against the upper end surface of the mounting section 2213, so as to abut against the pre-tightening ring 221 while supporting the rotating handle 6, and facilitate the limiting downward pressure holding of the pre-tightening sleeve 22 in the second limiting groove 1023. The second limiting groove 1023 is formed with an avoiding hole 1024 corresponding to the position of the support column 7 after pre-tightening, which is used to avoid the downward movement of the support column 7 when the nut 12a is pressed downward after pre-tightening, so that the nut 12a can move downward and be connected with the meshing rod section 111.
[0064] In order to limit the pre-tightening range of the pre-tightening sleeve 22 and the initial alignment installation, referring to Figure 4 , the two ends of the mounting section 2213 are provided with stop columns 2211, which are used to limit the rotating range and direction of the pre-tightening sleeve 22, and prevent the structure from being damaged due to improper operation. The avoiding hole 2214 is formed between the end with the smallest thickness adjacent to the abutting section 2212 and the adjacent stop column 2211, which is used to pass the limiting baffle 211 through the avoiding hole 2214 when installing the radiator 102 and the attached fastening device 103.
[0065] In order to prevent the nut 12a from separating from the pre-tightening sleeve 22 from above, referring toFigure 1 、 Figure 6 、 Figure 13 and Figure 14 , the first limit slot 1022 is formed in the lower end of the position where the heat sink 102 base penetrates the stud 11a, a snap spring 5 is clamped in the first limit slot 1022, the lower part of the nut 12a is provided with a driving limit slot 123, the driving limit slot 123 has two abutting slot walls opposite in the up-down direction, the driving limit slot 123 is used for the snap spring 5 to be sleeved, the two abutting slot walls are used to limit the snap spring 5 to be always sleeved in the driving limit slot 123, the lower abutting slot wall is used to abut against the lower end of the snap spring 5 when the nut 12a moves upward to the range of being about to be separated from the pre-tightening sleeve 22, so as to limit the nut 12a from being separated.
[0066] As Figures 6 to 9 is the pre-tightening process and the locking process in this embodiment, wherein Figure 6 is before the pre-tightening starts, Figure 7 is when the pre-tightening is completed, Figure 8 is when the locking starts, Figure 9To lock, the nut 12a is first placed on the guide rod segment 112, the annular stop ring 222 is abutted against the drive washer 4, and the drive washer 4 is abutted against the first spring 3. Then, the rotating handle 6 is rotated to rotate the pre-tightening ring 221, and the pre-tightening is completed by gradually increasing the thickness of the abutted segment 2212. When the pre-tightening is completed, the support column 7 is aligned with the avoiding hole 1024 formed in the second limiting groove 1023. At this time, the nut 12a is not connected with the engaging rod segment 111. To lock, the nut 12a is gently pressed by a screwdriver, and the rotating handle 6 and the support column 1023 are pushed down and inserted into the avoiding hole 1024. At this time, the nut 12a is moved downward and connected with the engaging rod segment 111. To lock, the nut 12a is rotated by the screwdriver, and the first spring 3 is continuously engaged and compressed to increase the locking strength until the locking process is completed. From the above movements of the components and the interaction during the movements, it can be seen that the locking needs to be performed after the pre-tightening is completed. This is because, if the pre-tightening is not completed, the bottom of the second limiting groove 1023 will prevent the support column 7 / rotating handle 6 from moving downward, the rotating handle 6 is abutted against the first limiting protrusion 122, the nut 12a cannot move downward and connect with the engaging rod segment 111, and the locking cannot be performed. It should be noted that, after the locking is completed, the upper end of the nut 12a will slightly interfere with the rotating handle 6 at the first limiting protrusion 122. However, since the rotating handle 6 is made of plastic, and / or a notch is provided at the position abutting against the first limiting protrusion 122, and double-color injection molding is adopted, the position has a certain deformation ability. The stress generated by the deformation presses the pre-tightening sleeve 22 against the radiator 102 base, so that the pre-tightening sleeve 22 will not shake when subjected to severe vibration. In addition, if the package needs to be removed from the structure, the locking needs to be released first, and then the pre-tightening is released. This is because, in the locked state, the end of the support column 7 is still located in the avoiding hole 1024 at one end of the second limiting groove 1023, and it is like a pin at this moment, which locks the pre-tightening sleeve 22 in the current position through the through hole of the mounting segment 2213. Only after the locking is released, the second spring 8 pushes the support column 7 out of the avoiding hole 1024, so that the rotation locking of the pre-tightening sleeve 22 and the rotating handle 6 is released, and the pre-tightening can be released. After the required diagonal method is used to perform all the unlocking of the four corner fastening devices first, and then perform the pre-tightening release, the radiator assembly with the fastening device can be removed, and finally the package can be removed.
[0067] The above description is only the preferred embodiments of the present application, and does not limit the patent scope of the present application. Any equivalent structural transformation, direct / indirect application in other related technical fields, or the like within the inventive concept of the present application and the contents of the specification and drawings are included in the patent protection scope of the present application.
Claims
1. A fastening device for fastening a heat sink to an LGA chip package, characterized by, The fastening device comprises: a locking structure comprising a first fastener and a second fastener arranged through the base of the heat sink from the mounting seat of the chip, one of the first fastener and the second fastener is formed with internal threads, and the other is formed with external threads; and a pre-tightening structure comprising a fixing member arranged upward from the mounting seat and located beside the second fastener, and a pre-tightening sleeve, the upper end of the fixing member is bent to form a limiting baffle towards the second fastener, the lower end of the pre-tightening sleeve abuts against the upper end surface of the base of the heat sink, and the pre-tightening sleeve is sleeved on the upper part of the second fastener, the first fastener is arranged in the pre-tightening sleeve along the up-down axis and partially exposed from the upper end of the pre-tightening sleeve, the lower part of the pre-tightening sleeve is protruded from the outer side wall of the pre-tightening sleeve to form a pre-tightening ring, the upper end surface of the pre-tightening ring abuts against the lower end surface of the limiting baffle, and the thickness of part of the pre-tightening ring gradually increases from one end to the other end in the up-down direction, so that the first fastener moves downward with the pre-tightening sleeve and is threadedly connected with the second fastener when the pre-tightening sleeve is rotated under external force.
2. The fastening device of claim 1, wherein The first fastener comprises a nut, and the second fastener comprises a stud, the stud comprises an engaging rod segment at the lower part thereof and a guide rod segment connected to the upper end of the engaging rod segment and having a smaller diameter than the engaging rod segment, and the engaging rod segment is formed with external threads for threadedly connecting with the nut.
3. The fastening device of claim 2, wherein The base of the heat sink is concave downward from the upper end surface of the position through which the stud passes to form a first mounting groove; The upper part of the nut is formed with a step surface facing downward; The fastening device further comprises a first spring arranged in the pre-tightening sleeve, and the lower end of the first spring abuts against the groove bottom of the first mounting groove, and the step surface is used for pressing and compressing the first spring when the nut is threadedly connected with the engaging rod segment.
4. The fastening device of claim 3, wherein A driving washer is arranged between the first spring and the step surface, and the upper end of the first spring abuts against the lower end surface of the driving washer.
5. The fastening device of claim 4, wherein The upper part of the inner side wall of the pre-tightening sleeve is protruded inward to form an annular stop ring, and the annular stop ring is used for abutting against the driving washer to move downward when the pre-tightening sleeve is rotated.
6. The fastening device of claim 2, wherein A rotating handle is further arranged, the rotating handle is synchronously rotated with the pre-tightening sleeve, and is used for externally holding and driving the pre-tightening sleeve to rotate.
7. The fastening device of claim 6, wherein The upper end surface of the base of the heat sink is formed with a second limiting groove, the second limiting groove is annularly arranged, and part of the second limiting groove is opposite to the limiting baffle in the up-down direction; The part of the pre-tightening sleeve located below the pre-tightening ring is formed with a mounting side wall, the pre-tightening sleeve is arranged in the second limiting groove, and the mounting side wall abuts against the side wall of the second limiting groove.
8. The fastening device of claim 7, wherein The upper end of the nut is protruded along the ring side to form a first limiting protrusion, and the lower end surface of the first limiting protrusion abuts against the upper end of the rotating handle; The fastening device further comprises a support column, the lower end of the support column passes through the pre-tightening ring and extends into the second limiting groove, and the upper end of the support column extends into the rotating handle, a second spring is arranged on the support column, and the two ends of the second spring respectively abut against the rotating handle and the pre-tightening sleeve.
9. The fastening device of claim 8, wherein The pre-tightening ring comprises: An abutting section gradually increases in thickness from one end to the other end thereof for abutting against the limiting baffle plate; and An installation section connected to the end of the abutting section with the largest thickness and partially penetratingly arranged for the support column to pass through.
10. The fastening device of claim 9, wherein Both ends of the installation section are provided with stop columns for limiting the rotation range of the pre-tightening sleeve, and a discharge port is formed between the end of the abutting section with the smallest thickness and the adjacent stop column.
11. The fastening device of claim 2, wherein A first limiting groove is formed in the lower end of the position penetrated by the stud and facing upward, and a snap spring is clamped in the first limiting groove. The lower part of the nut is provided with a driving limiting groove with two abutting groove walls opposite in the up-down direction, and the driving limiting groove is used for the snap spring to be sleeved.
12. An LGA chip structure, characterized by The fastening device according to any one of claims 1 to 11.
Citation Information
Patent Citations
BE648223A
AU6785481A