Fixed element with heavy-duty function

Abstract

The present application is a fixing element with heavy-duty function, which comprises a screw, a sleeve and a snap spring ring. The screw has a screw head and a plurality of external screw threads at both ends. The screw head has two cutouts. The screw is externally sleeved with a spring and is together arranged in the sleeve. A snap ring is clamped at the lower end of the screw, which is used as a limit for the lower end of the spring to prevent the spring from falling off. The sleeve has a pair of windows at the end and a combination area. The snap spring ring has a pair of upwardly extending hook arms which are sleeved on the combination area. The ends of the hook arms are extended from the windows and press the top end of the spring, so that the spring is in a compressed state in the sleeve. When the spring of the fixing element is released after assembly, the two ends of the spring are respectively upwardly stretched and downwardly pressed to provide uniform downward pressure to complete the assembly. In addition, if reinstallation is required, the spring can be pressed downward from the cutout of the screw head to provide installation again.

Description

TECHNICAL FIELD

[0001] The present invention relates to a fixing element with rework function, in particular to a fixing element with rework function which can provide uniform downward pressure to avoid damage or thermal resistance caused by uneven force contact between a bare die operation unit and a heat dissipation device, and can be reassembled by being used with a rework tool. BACKGROUND

[0002] In order to provide electronic devices with high performance operation capability, high performance and high power chips are used. When the chips operate, they generate a considerable amount of heat. Conventional operation chips have a package shell outside, and the chip is covered inside the package shell to protect the chip from damage. However, as the operation performance of the chip improves, the chip generates higher temperature than conventional chips when operating. The package shell outside the chip has seriously affected the heat dissipation and the efficiency of heat conduction to the outside of the chip. Therefore, most chips on the market have been changed to a bare chip form for setting. Since the surface of the bare chip is not provided with a protective package shell, the heat exchange contact surface is small, and the surface is not a flat surface. Also, without the protection of the outer package shell, the strength is relatively low, so it is easy to crack when combined with the heat dissipation device.

[0003] Therefore, when the heat dissipation device is fixed above the heat source (bare chip), since the heat source itself cannot be directly combined with the heat dissipation device, a copper column with internal threads is set as a supporting locking point on the substrate (mainboard or circuit board) on which the heat source is arranged. The locking point is located at the four corners of the outer side of the heat source. If the conventional single locking point is sequentially locked, the first locking position will be tilted, and the bare chip cannot withstand such uneven pressure, which will cause the chip to crack and damage, etc.

[0004] Reference Figure 1 , Figure 2As shown in the schematic diagram of the existing heat dissipation device combined with a bare chip, the heat source A is arranged on a substrate D, and four corners of the substrate D corresponding to the outer side of the heat source A are provided with copper columns B with internal threads. The heat dissipation device C is also provided with four holes C3 corresponding to the positions of the copper columns B, and the screw units C1 are arranged through the holes. The outer part of the screw units C1 is sleeved with a spring C2. When the heat dissipation device C is combined with the heat source A, the screw locking operation is usually performed by artificial or mechanical arm operation of an electric screwdriver directly at a single point. In order to speed up the assembly time on the production line and complete it within the limited assembly time, each screw is usually locked in place directly and quickly at one time. When the screw units C1 are locked at the fixed points one by one, the spring C2 sleeved on the screw units C1 also supports the heat source A in the direction of the heat source A, and the uneven stress caused by single-point locking immediately causes the heat source to collide and heat up. As mentioned above, the heat source A (bare chip) is fragile, and the single-point locking of the screw units C1 and the pressing of the spring C2 cannot provide complete and comprehensive (downward pressure on the four corners of the bare chip) synchronous and uniform downward pressure on the heat source A (bare chip). In addition, the bare chip is easily damaged due to uneven stress.

[0005] Furthermore, the bare chip is quite fragile. As mentioned above, the four corners of the bare chip must be simultaneously provided with uniform downward pressure to provide a combination force. If the downward pressing force cannot be provided to the four corners of the bare chip by the average stress at the same time, the heat dissipation device and the heat source (bare chip) are easily warped and not completely combined, or damaged, and the thermal resistance is easily formed, which causes uneven heating or heat conduction failure.

[0006] In addition, some manufacturers provide a heat dissipation device combined with a bare chip type heat source by using a spring screw, which is used to solve the above-mentioned problem of not being able to provide uniform downward pressure at the same time. The spring screw is not the same as the general spring screw. The screw body of the spring screw and the outer part of the spring are additionally sleeved with a screw sleeve, and a spring limiting element is additionally arranged outside the screw sleeve. The spring limiting element can temporarily compress the spring in the screw sleeve. After the spring limiting element is damaged by a tool or a hand tool, the spring originally compressed in the screw sleeve is simultaneously released, and the spring tension at both ends of the spring provides upward and downward spring tension to assist the heat dissipation device in providing uniform pressure to the heat source. Although the spring screw can provide spring elasticity by the spring to adjust or assist the downward pressing force, the spring limiting element in the spring screw can only be used once. After the spring limiting element is damaged and the originally compressed spring is released, the spring cannot be reset. If the spring screw is to be reinstalled and used, the spring screw must be removed from the heat dissipation device, and a new spring screw must be replaced to reinstall and lock it again.

[0007] Therefore, how to improve the heat dissipation device to be complete and comprehensive, synchronized and provide uniform pressure close to the heat source, and how to provide the effect of maintaining the appropriate binding force between the bare chip and the heat dissipation device and the repeatable installation or adjustment, is the primary problem for the current industry to solve. SUMMARY

[0008] Therefore, in order to effectively solve the above problems, the main purpose of the present application is to provide a fixing element with a reworking function, which can not only provide synchronous and uniform pressure, but also effectively avoid the effect of single locking point leading to the rupture or collapse of the edge of the bare chip operation unit.

[0009] Furthermore, the fixing element of the present application can be used with a reworking tool, and after the spring is compressed and reset, it can be reassembled for use.

[0010] The present application provides a fixing element with a reworking function for repeatable installation of a heat dissipation device and a bare chip heat source, characterized by comprising:

[0011] A screw is externally provided with a spring, the upper and lower ends of the screw are respectively provided with a screw head and a plurality of external threads, the screw head is penetrated by two cutouts along the axial direction of the screw, the screw is provided with a buckle ring accommodating groove adjacent to the plurality of external threads, and the buckle ring accommodating groove is provided with a buckle ring, the spring is provided with a top end and a bottom end, and the bottom end abuts against the buckle ring;

[0012] A sleeve is provided with an open upper end and a lower end, and a accommodating space is provided between the upper and lower ends, the accommodating space is respectively communicated with the upper and lower ends, the sleeve is provided with a pair of windows adjacent to the upper end, the pair of windows correspond to each other and communicate with the accommodating space, and a combination area is provided between the lower edge of the window and the lower end of the sleeve, the sleeve is externally provided with the screw penetrated by the spring;

[0013] A spring ring is sleeved on the combination area of the sleeve and extends upward a hook arm group, the hook arm group is provided with a pair of hook arms, the pair of hook arms respectively extend from the window to press and buckle the top end of the spring to make the spring in a compressed state, when the heat dissipation device and the heat source are installed, the hook arms are operated to exit the window to release the spring, thereby providing the synchronous and uniform pressure;

[0014] When the reworking is desired, a device capable of providing a downward pressure is prepared and coupled with a downward pressing jig, the device is connected with the downward pressing jig, the downward pressing jig has at least one pressing extension corresponding to the plurality of fixing elements arranged around the heated area of the heat dissipation device, the pressing extension is capable of abutting against a abutting portion on the upper side of the circlip, when the device drives the downward pressing jig to move downward, the pressing extension simultaneously applies downward pressure to the abutting portion of the circlip, the portion where the circlip and the sleeve are in contact forms a rotating fulcrum, when the downward pressing jig applies pressure to the abutting portion of the circlip, the circlip is supported at the fulcrum, and the abutting portion is flipped outward and downward, simultaneously driving the pair of hook arms to exit the window in the radial outward direction of the sleeve, and to be stretched and expanded outward, and the pair of hook arms are disengaged from the pressure buckle on the top end of the spring, allowing the spring to completely release its limited spring tension, and the top end of the spring is pressed against the lower end surface of the screw head, and the bottom end of the spring on the plurality of fixing elements simultaneously provides uniform downward pressure to the surrounding of the heat dissipation device, thereby allowing the heat dissipation device to uniformly adhere to the heat source.

[0015] By extending a reworking jig into the two cuts of the screw head to axially press the top end of the spring downward, the spring is compressed in the sleeve, and the pair of hook arms are extended into the sleeve window to re-press the top end of the spring, allowing the spring to return to the compressed state.

[0016] The fixing element with reworking function, wherein the screw head has an upper end surface and a lower end surface, and the two cuts simultaneously penetrate the upper and lower end surfaces of the screw head.

[0017] The fixing element with reworking function, wherein the pair of hook arms have a hook end bent inward at the free end of the tip, the hook end is extended into the accommodation space of the sleeve from the window, the pair of windows has an upper edge, and the upper side surface of the hook end is abutted against the upper edge to provide axial limitation of the hook end by the upper edge of the window.

[0018] The fixing element with reworking function, wherein the outer diameter of the combination area is smaller than the outer diameter of the remaining part of the sleeve, and the lowermost side of the combination area has a stepped portion capable of axially limiting the circlip to prevent the circlip from excessively separating from the combination area downward.

[0019] The fixing element with reworking function, wherein the ring-shaped body of the circlip is combined with the combination area of the sleeve in a loose or tight fitting manner.

[0020] The fixing element with reworking function, wherein the abutting portion of the circlip is located on the upper side surface of the circlip and is close to the outer edge of the upper side surface of the circlip.

[0021] The fixing element with the reworking function, wherein the reworking tool has a head, and at least two independently arranged pressing columns are protruded from one end of the head, and the at least two independently arranged pressing columns correspond to two cutouts of the screw head respectively.

[0022] The fixing element with the reworking function, wherein when the reworking tool is subjected to a downward pressure, the at least two independently arranged pressing columns synchronously compress the top end of the spring downward, and the spring is compressed downward from the position of supporting the lower end surface of the screw head, so that the top end of the spring is pressed into the accommodating space of the sleeve.

[0023] The fixing element can provide the heat dissipation device assembled with the bare chip type heat source, and can provide the reassembly opportunity when the heat dissipation device needs to be reassembled or replaced. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The existing heat dissipation device and bare chip combination schematic diagram.

[0025] Figure 2 The existing heat dissipation device and bare chip combination schematic diagram.

[0026] Figure 3 The fixing element with the reworking function of the present application is a three-dimensional combination diagram.

[0027] Figure 4 The fixing element with the reworking function of the present application is a three-dimensional exploded view.

[0028] Figure 5 The fixing element with the reworking function of the present application is an action schematic diagram.

[0029] Figure 6 The fixing element with the reworking function of the present application is an action schematic diagram.

[0030] Figure 7 The fixing element with the reworking function of the present application is an action schematic diagram.

[0031] Explanation of reference signs: fixing unit 1; screw 11; screw head 112; upper end face 1121; lower end face 1122; external screw thread 113; notch 114; buckle ring accommodating groove 115; buckle ring 116; spring 117; top end 1171; bottom end 1172; sleeve 12; upper end 121; lower end 122; accommodating space 123; bonding area 124; window 125; upper edge 1251; stepped portion 1252; circlip 13; abutting portion 131; hook arm group 132; hook arm 132A; hook end 1321; rework jig P; head P1; abutting column P2; heat dissipation device 2; first side 21; second side 22; heated area 23; perforation 24; heat source 3; fixing structure 4; pressing jig 5; abutting extension 51. DETAILED DESCRIPTION

[0032] The above-mentioned objects of the present application and its structural and functional characteristics will be explained in accordance with the preferred embodiments of the accompanying drawings.

[0033] Please refer to Figure 3 , Figure 4 , respectively, are the fixing element combination and exploded view with rework function of the present application, as shown in the figure, the fixing element with rework function can be reset by matching a rework jig P for reassembly and use, the fixing unit 1, comprising: a screw 11, a sleeve 12, a circlip 13;

[0034] The upper and lower ends of the screw 11 are respectively provided with a screw head 112 and a plurality of external screw threads 113, the screw head 112 has two notches 114, the two notches 114 penetrate the screw head 112 along the axial direction of the screw 111 and are arranged opposite to each other, the screw head 112 has an upper end face 1121 and a lower end face 1122, the two notches 114 penetrate the upper and lower end faces 1121, 1122 of the screw head 112 at the same time. The screw 111 is provided with a buckle ring accommodating groove 115 adjacent to the upper side of the external screw thread 113, and the buckle ring accommodating groove 115 is provided with a buckle ring 116; a spring 117 is sleeved on the outside of the screw 111, the spring 117 is arranged between the screw head 112 and the buckle ring 116, the spring 117 has a top end 1171 and a bottom end 1172, the bottom end 1172 of the spring 117 abuts against the buckle ring 116, and the bottom end 1172 of the spring 117 is axially limited by the buckle ring 116, preventing the spring 117 from being separated from the screw 11.

[0035] The sleeve 12 has an upper end 121 and a lower end 122, and a receiving space 123 formed between the upper and lower ends 121, 122. A pair of windows 125 are formed on the sleeve 12 near the upper end 121. The pair of windows 125 are spaced apart from each other by 180 degrees or an equal angle, and are radially connected to the receiving space 123. The sleeve 12 is sleeved on the outside of the screw 111 with the spring 117.

[0036] The window 125 has an upper edge 1251. A connecting area 124 is formed between the lower edge of the window 125 and the lower end 122 of the sleeve 12. The connecting area 124 can have the same diameter as the sleeve 12 or be tapered inwardly from the sleeve 12. The outer diameter of the connecting area 124 is smaller than the outer diameter of the rest of the sleeve 12. Therefore, the outer diameter of the sleeve 12 is not uniform, and the lowermost side of the connecting area 124 has a stepped portion 1252 connected to the sleeve 12. The stepped portion 1252 can axially limit the position of the circlip 13, preventing the circlip 13 from moving downwardly too much and separating from the connecting area 124.

[0037] The circlip 13 is sleeved on the connecting area 124 of the sleeve 12. The circlip 13 has a hook arm group 132 extending upwardly on the upper side. The hook arm group 132 has a pair of hook arms 132A. The free ends of the hook arms 132A are bent inwardly to form hook ends 1321. The hook ends 1321 extend into the receiving space 123 of the sleeve 12 from the windows 125. The top end 1171 of the spring 117 supports the hook ends 1321 to move upwardly. When the upper side surface of the hook ends 1321 abuts against the upper edge 1251 of the window 125, the hook ends 1321 stop moving upwardly and are limited in position. At the same time, the hook ends 1321 press the top end 1171 of the spring 117, preventing the spring 117 from continuing to be stretched upwardly. The spring 117 is further compressed in the sleeve 12. The connecting area 124 of the sleeve 12 and the circlip 13 can be combined in a loose or tight fit.

[0038] During assembly, the screw 111 with the spring 117 is placed in the receiving space 123 of the sleeve 12. The spring 117 cannot be stretched upwardly because the hook ends 1321 of the pair of hook arms 132A of the circlip 13 press the spring 117. Therefore, the spring 117 is in a compressed state.

[0039] Please refer to Figure 5 、 Figure 6 、 Figure 7As shown in the actuation diagram of the fixing element with heavy-duty function of the present application, the present application provides a fixing element with heavy-duty function, which is applied in a heat dissipation device 2 and a heat source 3 in bare chip state in the embodiment of the present application as an illustration. The heat dissipation device 2 has a first side 21, a second side 22 and a heated area 23. The heated area 23 is arranged near the center of the second side 22 of the heat dissipation device 2.

[0040] The fixing element 1 is arranged at the four corners outside the heated area 23 of the heat dissipation device 2. When the heat dissipation device 2 is used to exchange or conduct heat with the heat source 3, the screw 11 of the fixing element is first screwed into the fixing structure 4 (threaded stud) arranged near the four corners of the heat source 3. At this time, the spring 117 arranged outside the screw 11 has not released its elastic force. Therefore, the heat dissipation device 2 is only placed above the heat source 3 and does not press the heat source 3. The surface of the heated area 23 (the second side 22) of the heat dissipation device 2 only touches the surface of the heat source 3. In order to provide uniform downward pressure, the fixing element 1 arranged at the four corners outside the heated area 23 of the heat dissipation device 2 must release the elastic force of the spring 117 at the same time and synchronously, so as to provide uniform downward pressing force between the heat dissipation device 2 and the heat source 3.

[0041] In order to simultaneously and synchronously trigger the spring 117 of each fixing element 1 to release its elastic force, a device (not shown in the figure) is required to cooperate with the lower pressing jig 5, so as to provide downward pressure to each fixing element 1 synchronously. The device (not shown in the figure) can be a punch or other mechanical device or tool that can provide downward pressure. The device (not shown in the figure) is connected to the lower pressing jig 5, which has at least one pressing extension 51 corresponding to the fixing element 1 arranged at the four corners of the heat receiving area 23 of the heat dissipation device body 2, and abutting against the abutting portion 131 on the upper side of the circlip 13, and close to the position of the outer edge of the upper surface of the circlip 13. When the device (not shown in the figure) drives the lower pressing jig 5 to move downward, the pressing extension 51 simultaneously applies downward pressure to the abutting portion 131 of the circlip 13. The contact between the circlip 13 and the sleeve 12 forms a rotating fulcrum A. When the lower pressing jig 5 applies downward pressure to the abutting portion 131 of the circlip 13, the circlip 13 is supported at the fulcrum A, and the abutting portion 131 is turned outward and downward, while the pair of hook arms 132A are withdrawn from the window 125 in the radial outward direction of the sleeve 12, and are stretched and expanded outward, and the hook ends 1321 of the pair of hook arms 132A are released from the pressure buckle of the top end 1171 of the spring 117, so that the spring 117 completely releases its limited spring tension, and the bottom end 1172 of the spring 117 arranged on the fixing element 1 at the four corners provides synchronous and uniform downward pressure to the four corners of the heat dissipation device 2, thereby allowing the heat dissipation device 2 to uniformly adhere to the heat source 3.

[0042] The screw 11 of the present application only installs the heat dissipation device body 2 above the heat source 3, and the actual downward pressure of the heat dissipation device 2 against the heat source 3 is provided by the spring 117 arranged outside the screw 11 at the four corners, so that a synchronous and uniform downward pressure is provided after the spring is released, thereby solving the problems of uneven stress or one-time locking force or excessive spring pressure caused by the existing single locking point locking one by one, and warping or direct cracking and damage of the wafer.

[0043] In addition to providing uniform downward pressure of the heat dissipation device 2 and the heat source 3, the fixing element 1 of the present application can also provide the function of reworking (reinstalling) when reinstalling or replacing or adjusting the heat dissipation device 2 or reworking after installation. Therefore, when reworking (reinstalling) is required, a pre-set reworking jig P is used in cooperation to compress and reset the spring 117 in the sleeve, thereby reinstalling.

[0044] The heavy-duty tool P has a head P1, and at least two independently arranged pressing columns P2 are protruded from one end of the head P1. The pressing columns P2 can correspond to two cutouts 114 of the screw head 112 respectively. When downward pressure is applied to the heavy-duty tool P, the pressing columns P2 are simultaneously driven to compress and press the top end 1171 of the spring 117 downward, and the spring 117 is compressed downward from the position of the original top support on the lower end surface 1122 of the screw head 112. The top end 1171 of the spring 117 is pressed into the accommodating space 123 of the sleeve 12, and the other side (lower) position of the abutting portion 131A of the snap spring ring 13 is pushed upward (manually or with the aid of a tool and equipment), and the fulcrum A of the snap spring ring 13 is supported again. The hook ends 1321 of the two hook arms 132A of the snap spring ring 13 are re-docked and clamped into the top end 1171 of the spring 117, and the upper side surfaces of the hook ends 1321 of the pair of hook arms 132A are abutted against the upper edge 1251 of the window 125, and the spring is again axially limited by the window 125, so that the spring returns to the compressed state in the sleeve, facilitating subsequent reinstallation operation.

[0045] The fixing element of the present application can be used for assembling the heat dissipation device 2 with the bare crystal type heat source 3, and can provide the opportunity for reassembly when the heat dissipation device 2 needs to be reassembled or replaced.

Claims

1. A fixing element with rework function for repeatable mounting of a heat dissipating device to a bare die heat source, characterized in that: The application relates to a screw, a sleeve and a spring. The screw is externally sleeved with a spring, the upper and lower ends of the screw are respectively provided with a screw head and a plurality of external threads, the screw head is penetrated by two cutouts along the axial direction of the screw, the screw is provided with a buckle ring accommodating groove adjacent to the plurality of external threads, and the buckle ring accommodating groove is clamped with a buckle ring, the spring is provided with a top end and a bottom end, and the bottom end abuts against the buckle ring. The sleeve is provided with an open upper end and a lower end, and is provided with an accommodating space between the upper and lower ends, the accommodating space is communicated with the upper and lower ends respectively, the sleeve is provided with a pair of windows adjacent to the upper end, the pair of windows correspond to each other and are communicated with the accommodating space, the lower edge of the window to the lower end of the sleeve is provided with a combination area, and the sleeve is sleeved with the screw externally provided with the spring. The clamping spring ring is sleeved on the combination area of the sleeve and extends upwardly to a hook arm group, the hook arm group is provided with a pair of hook arms, the pair of hook arms respectively extend into the accommodating space of the sleeve from the windows to press and clamp the top end of the spring to make the spring in a compressed state, when the heat dissipation device is installed with the heat source, the hook arms are operated to exit the windows to release the spring, so that the synchronous and uniform downward pressure is provided. When reworking is required, a device capable of providing downward pressure is prepared and matched with a downward pressing tool, the device is connected with the downward pressing tool, the downward pressing tool is provided with at least one pressing extension part corresponding to a plurality of fixing elements arranged around the heated area of the heat dissipation device, the pressing extension part can abut against a abutting part on the upper side of the clamping spring ring, when the device drives the downward pressing tool to move downwardly, the pressing extension part simultaneously applies downward pressure to the abutting part of the clamping spring ring, the positions where the clamping spring ring and the sleeve contact form a rotating fulcrum, when the downward pressing tool applies downward pressure to the abutting part of the clamping spring ring, the clamping spring ring is supported at the fulcrum, the abutting part is turned outwardly and downwardly, simultaneously drives the pair of hook arms to exit the windows in the radial outward direction of the sleeve, and is outwardly stretched and expanded, the pair of hook arms are released from the pressure clamping of the top end of the spring, the spring is completely released from the limited spring tension, the top end of the spring abuts against the lower end surface of the screw head, the bottom end of the spring on the plurality of fixing elements synchronously provides uniform downward pressure around the heat dissipation device, so that the heat dissipation device is uniformly attached to the heat source. By extending a reworking tool into the two cutouts of the screw head to axially apply downward pressure to the top end of the spring, the spring is compressed in the sleeve, and the pair of hook arms are extended into the sleeve windows to again press and clamp the top end of the spring, so that the spring can be restored to the compressed state.

2. The fixed element with heavy-duty function according to claim 1, characterized in that: The screw head is provided with an upper end surface and a lower end surface, and the two cutouts simultaneously penetrate the upper and lower end surfaces of the screw head.

3. The fixed element with heavy-duty function according to claim 1, wherein: The free end of the pair of hook arms is inwardly bent to have a hook end, the hook end extends into the accommodating space of the sleeve from the windows, the pair of windows is provided with an upper edge, and the upper side surface of the hook end abuts against the upper edge, so that the upper edge of the window provides axial limitation of the hook end.

4. The fixed element with heavy-duty function according to claim 1, wherein: The outer diameter of the joint area is smaller than the outer diameter of the rest of the sleeve, and the lowermost side of the joint area has a step portion which can provide axial positioning of the circlip ring and prevent the circlip ring from being excessively separated from the joint area.

5. The fixed element with heavy-duty function according to claim 1, wherein: The annular body of the circlip ring is combined with the joint area of the sleeve in a loose or tight fitting manner.

6. The fixed element with heavy-duty function according to claim 1, wherein: The abutting portion of the circlip ring is located on the upper surface of the circlip ring and is close to the outer edge of the upper surface of the circlip ring.

7. The fixed element with heavy-duty function according to claim 1, wherein: The heavy-duty tool has a head, and at least two independently arranged pressing columns are protruded from one end of the head, and the at least two independently arranged pressing columns correspond to the two cutouts of the screw head respectively.

8. The fixed element with heavy-duty function according to claim 7, characterized in that: When the heavy-duty tool is subjected to downward pressure, the at least two independently arranged pressing columns simultaneously compress the top end of the spring downward, so that the top end of the spring is compressed downward from the original position of supporting the lower end surface of the screw head, and the top end of the spring is pressed into the accommodation space of the sleeve.

Images