Fixed components and their heat dissipation units

Abstract

This invention relates to a fixing element and its heat dissipation unit. The heat dissipation unit has a heated area that is in contact with a bare-crystal heat source. A fixing element is respectively provided at each of the four corners of the heat dissipation unit. The fixing element has: a screw with a spring, a sleeve with a window, and a retaining ring. The screw is fitted onto the sleeve, and the retaining ring is fitted onto the outside of the sleeve. The retaining ring has an upwardly extending hook arm assembly. The plurality of hook arms extend into the aforementioned window and press the top of the spring, causing the spring to be in a compressed state inside the sleeve. When the springs of each fixing element are released simultaneously after assembly, the two ends of the spring can provide the heat dissipation unit with a synchronous and uniform downward pressure, so that the heat dissipation unit and the bare-crystal heat source are tightly and uniformly bonded.

Description

Technical Field

[0001] This invention relates to a fixing element and its heat dissipation unit, and particularly to a fixing element and its heat dissipation unit that can provide synchronous and uniform downward pressure when a heat dissipation unit is combined with a bare crystal heat source, so as to avoid damage or thermal resistance caused by uneven or asynchronous force on the bare crystal heat source. Background Technology

[0002] To provide high-performance computing capabilities for electronic devices, high-efficiency, high-power chips are currently used. These chips generate considerable heat during computation. Traditionally, computing chips are encapsulated in a casing to protect them from damage. However, as computing performance increases, the temperature generated during operation becomes even higher. Furthermore, the existing casing significantly hinders heat dissipation and outward heat conduction efficiency. Therefore, most chips on the market are now available in a bare die form. However, because the surface of this bare die is not flat but rather convex and rounded, and the lack of a protective casing results in a small heat exchange contact area and low strength, it is prone to damage and cracking when combined with heat dissipation devices.

[0003] In addition, when traditional heat dissipation devices are fixed above the heat source (bare die), they are locked sequentially at a single locking point. This causes the locking points to be asynchronous, which can easily lead to contact tilting. The bare die cannot withstand such uneven pressure, which can easily cause problems such as chip breakage and damage.

[0004] Please see Figure 1 , Figure 2 This is a schematic diagram of an existing heat dissipation device and bare die assembly. The heat source A (bare die type) is mounted on a substrate D. Corresponding to the four corners of the outer side of the heat source A, copper pillars B with internal threads are located on the substrate D. The heat dissipation device C also has four holes C3 corresponding to the copper pillars B, through which screw units C1 are inserted. A spring C2 is fitted around each screw unit C1. When the heat dissipation device C is locked to the heat source A, it is usually done manually or by a robotic arm using an electric screwdriver, performing single-point sequential screw-locking operations. To speed up assembly time on the production line and within limited time... Assembly is completed within the time limit. Usually, each fixing screw is fastened into place quickly and directly in one go. When screw unit C1 is tightened to the fixed point one by one, the spring C2 sleeved on the screw unit C1 also supports it in the direction of heat source A. As a result, the uneven force caused by single-point tightening immediately causes the heat source to be hit. As mentioned above, heat source A (bare crystal) is brittle. However, the single-point tightening of screw unit C1 and the pressure of spring C2 cannot provide heat source A (bare crystal) with complete and comprehensive (four corners of the bare crystal) synchronous and uniform downward pressure. The bare crystal is easily damaged due to uneven force.

[0005] Furthermore, bare crystals are quite fragile. As mentioned above, the four corners of the bare crystal must be simultaneously and synchronously subjected to uniform downward pressure to provide bonding force for assembly. If it is not possible to simultaneously apply downward pressure to the four corners of the bare crystal in an even manner, it is easy for the heat sink or heat dissipation device to warp and not fit completely or cause damage between the heat source (bare crystal). It is also easy to form thermal resistance, which will cause uneven heating or failure of heat conduction.

[0006] Therefore, how to improve the heat dissipation device to provide uniform pressure and close contact with the heat source, and how to maintain proper bonding force between the bare die and the heat dissipation device, as well as the ability to be repeatedly installed or adjusted, are the primary problems that manufacturers need to solve at present. Summary of the Invention

[0007] Therefore, in order to effectively solve the above problems, the main purpose of this invention is to solve the problem of uneven and asynchronous force when the heat dissipation device and the bare die heat source are combined, and to provide a fixing element and its heat dissipation unit. It discloses that a fixing element can provide synchronous and uniform downward pressure when the heat dissipation unit and the bare die heat source are combined, effectively avoiding the problem of edge cracking or breakage of the bare die heat source due to uneven and asynchronous force caused by locking a single locking point first.

[0008] This invention provides a fixing element, characterized in that it comprises:

[0009] A screw with an annular groove at its lower end, a retaining ring being held in the annular groove, and a spring being sleeved around the outside of the screw;

[0010] A sleeve has a hollow interior forming a receiving space. The sleeve has two open upper and lower ends. The receiving space is located between the upper and lower ends and communicates with the upper and lower ends. Near the upper end of the sleeve, there is a pair of windows. The pair of windows have an upper edge. The pair of windows correspond to each other and communicate with the receiving space. The sleeve receiving space is provided with the screw.

[0011] A retaining ring has an inner hole and is fitted onto the outside of the sleeve through the inner hole. One side of the retaining ring has an upper surface, and a hook arm assembly extends upward from the upper surface. The hook arm assembly has a plurality of hook arms that extend into the receiving space from the pair of windows to press and lock the upward end of the spring, so that the spring is in a compressed state inside the sleeve.

[0012] The fixing element, wherein: there is a connecting area between the lower edge of the window of the sleeve and the lower end of the sleeve, the outer diameter of the connecting area is smaller than the outer diameter of the rest of the sleeve, so the connection between the connecting area and the sleeve forms a stepped portion, the stepped portion can provide axial limiting of the retaining ring, preventing the retaining ring from disengaging excessively downward from the connecting area.

[0013] The fixing element, wherein: the upper surface of the retaining ring has an annular edge near the outer periphery; the hook arm assembly is formed by extending upward from the upper surface of the retaining ring near the inner hole or from the intersection of the upper surface of the retaining ring and the inner hole; one end of the plurality of hook arms of the hook arm assembly is attached to the upper surface of the retaining ring, and the other end is a free end, and the end of the free end is bent to form a hook end.

[0014] The fixing element, wherein: the hook end has an upper contact surface and a lower contact surface, and a plurality of hook ends extend into the receiving space of the sleeve from corresponding windows, the upper contact surface abuts against the upper edge of the window, and the lower contact surface presses against one end of the spring.

[0015] The present invention also provides a heat dissipation unit, characterized in that it comprises:

[0016] A heat dissipation unit body has a first side, a second side and a heat-receiving area. The four corners of the outer side of the heat-receiving area have a plurality of through holes. The plurality of through holes pass through the first side and the second side. A plurality of fixing elements are respectively disposed at each of the plurality of through holes of the heat dissipation unit body.

[0017] The fixing element includes:

[0018] A screw has an annular groove at the lower end of the through hole of the body. The annular groove is fitted with a retaining ring to prevent the screw from coming off the body. A spring is sleeved on the outside of the screw, and the lower end of the spring is attached to the first side of the body.

[0019] A sleeve with a hollow interior forming an accommodating space. The upper and lower ends of the sleeve are open and communicate with the accommodating space. The lower end of the sleeve abuts against the first side of the heat dissipation unit body. Near the upper end of the sleeve, there is a pair of windows. The pair of windows are arranged correspondingly to each other and communicate with the accommodating space. The aforementioned screw is provided in the accommodating space.

[0020] A retaining ring has an inner hole and is fitted onto the outside of the sleeve through the inner hole. One side of the retaining ring has an upper surface, and a hook arm assembly extends upward from the upper surface. The hook arm assembly has a plurality of hook arms that extend into the receiving space from the pair of windows to press and lock the upward end of the spring, so that the spring is in a compressed state inside the sleeve.

[0021] The heat dissipation unit, wherein: the lower side of the pair of windows of the sleeve has a connecting area, the outer diameter of the connecting area is smaller than the outer diameter of the rest of the sleeve, so the connection between the connecting area and the sleeve forms a stepped portion, the stepped portion can provide axial limiting of the retaining ring, preventing the retaining ring from excessively disengaging downward from the connecting area.

[0022] The heat dissipation unit, wherein: the body of the heat dissipation unit is a heat spreader or a combination of a heat spreader and a heat pipe.

[0023] The heat dissipation unit, wherein: the upper surface of the retaining ring has an annular edge near the outer periphery; the hook arm assembly is formed by extending upward from the upper surface of the retaining ring near the inner hole or from the intersection of the upper surface of the retaining ring and the inner hole; the hook arm assembly has a plurality of hook arms, one end of which is attached to the upper surface of the retaining ring, and the other end is a free end, and the end of the free end is bent to form a hook end.

[0024] The heat dissipation unit, wherein: the hook end has an upper contact surface and a lower contact surface, and a plurality of hook ends extend into the receiving space of the sleeve from corresponding windows, the upper contact surface abuts against the upper edge of the window, and the lower contact surface presses against one end of the spring.

[0025] In use, the heat-receiving area of ​​the heat dissipation unit body is first aligned with the bare-chip heat source. Then, one end of the external thread of the spring screw of the fixing element is pre-locked to the substrate on which the bare-chip heat source is mounted. At this time, the springs are still compressed in the sleeve. After the fixing elements at all four corners are pre-locked, pressure is applied to the retaining ring by an external object. The multiple hook arms are released after being linked, so that the springs can provide a synchronous and uniform downward pressing force to the four corners of the heat dissipation unit body. This allows the heat dissipation unit body and the bare-chip heat source (bare chip) to make stable and tight contact, avoiding uneven force that may cause corner breakage or cracking, or thermal resistance due to incomplete fit. It also avoids excessive pressure during the screwing process that may cause the bare-chip heat source (bare chip) to crack or be damaged. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the existing heat dissipation device combined with a bare-chip heat source.

[0027] Figure 2 This is a schematic diagram showing the combination of an existing heat dissipation device and a heat source in a bare-chip form.

[0028] Figure 3 This is a schematic diagram of the appearance of the fixing element assembly of the present invention.

[0029] Figure 4This is an exploded view of the fixing element of the present invention.

[0030] Figure 5 This is a schematic diagram of the heat dissipation unit assembly of the present invention.

[0031] Figure 6 This is a schematic cross-sectional view of the heat dissipation unit of the present invention.

[0032] Explanation of reference numerals in the attached drawings: Heat source A; Copper pillar B; Heat dissipation device C; Screw unit C1; Spring C2; Hole C3; Fixing element 1; Screw 11; Screw head 112; External thread 113; Ring groove 114; Clip ring 115; Spring 116; Top end 1161; Bottom end 1162; Sleeve 12; Upper end 121; Lower end 122; Accommodation space 123; Joint area 124; Window 125; Upper edge 125 1; Stepped portion 1252; Snap ring 13; Inner hole 131; Upper surface 13A; Edge 13B; Hook arm assembly 132; Hook arm 132A; Hook end 1321; Upper contact surface 13211; Lower contact surface 13212; Heat dissipation unit body 2; First side 21; Second side 22; Heated area 23; Through hole 24; Bare crystal type heat source 3; Connecting hole 4; Pressing fixture 5; Pressing part 51; Fulcrum A. Detailed Implementation

[0033] The above-mentioned objectives of the present invention and its structural and functional characteristics will be described with reference to the preferred embodiments shown in the accompanying drawings.

[0034] Please see Figure 3 , Figure 4 This is a schematic diagram showing the assembly and exploded appearance of the fixing components of the heat dissipation unit for the heat source of the bare die type of the present invention. Figure 5 This is a schematic diagram showing the combination of fixing elements for the heat dissipation unit used in the bare-chip type heat source of the present invention; Figure 6 This is a schematic cross-sectional view of the fixing element of the heat dissipation unit for the heat source of the bare die type of the present invention; the present invention relates to a fixing element, which includes: a screw 11, a sleeve 12, and a retaining ring 13.

[0035] A spring 116 is inserted through the screw 11. The screw 11 has a screw head 112 and a plurality of external threads 113 at its two ends. An annular groove 114 is provided above the external threads 113 of the screw 11. A retaining ring 115 (C-type or E-type retaining ring) is engaged in the annular groove 114. The spring 116 has a top end 1161 and a bottom end 1162. The spring 116 is sleeved between the screw head 112 and the retaining ring 115. The bottom end 1162 abuts against the retaining ring 115.

[0036] The sleeve 12 has open upper and lower ends 121 and 122, and a hollow accommodating space 123 connecting the upper and lower ends 121 and 122. A window 125 is provided near the upper end 121 of the sleeve 12, and the pair of windows 125 communicate with the accommodating space 123. A connecting area 124 is provided between the lower edge of the pair of windows 125 and the lower end 122 of the sleeve 12. The outer diameter of the connecting area 124 of the sleeve 12 can be greater than, less than, or equal to the outer diameter of other parts of the sleeve 12. In this invention, the outer diameter of the connecting area 124 is smaller than the outer diameter of the sleeve 12, thus forming a stepped portion 1252 at the connection between the connecting area 124 and the sleeve 12.

[0037] The sleeve 12 is fitted with the aforementioned screw 11 through which the spring 116 passes (that is, the screw 11 and the spring 116 are disposed in the receiving space 123 of the sleeve 12); the sleeve 12 can be used to ensure that the spring 116 can be compressed or released smoothly, and to avoid the situation where the spring 116 cannot be compressed or released normally due to the entry of foreign objects.

[0038] The retaining ring 13 is a disc-shaped ring with an inner hole 131 on its inner side. The inner hole 131 is formed at the center of the retaining ring 13. The retaining ring 13 is sleeved or fixed to the engagement area 124 of the sleeve 12 through the inner hole 131. The stepped portion 1252 of the sleeve 12 can prevent the retaining ring 13 from sliding out of the lower end 122 of the sleeve 12, so that the retaining ring 13 can only move axially in the engagement area 124 to form a limit.

[0039] The retaining ring 13 has an upper surface 13A facing the screw head 112. Near the outer periphery of the upper surface 13A, the retaining ring 13 has an annular edge 13B. A hook arm assembly 132 extends upwards (towards the screw head 112) from the upper surface 13A near the inner hole 131 or where the two intersect. The hook arm assembly 132 has a plurality of hook arms 132A. One end of each hook arm 132A is attached to the upper surface 13A of the retaining ring 13, while the other end is a free end. The end of the free end is bent to form a hook tip 1321. 1321 has an upper contact surface 13211 and a lower contact surface 13212. The hooks 1321 extend into the receiving space 123 of the sleeve 12 from the corresponding windows 125. The lower contact surface 13212 of the hooks 1321 presses against the top end 1161 of the spring 116, causing the spring 116 to be compressed in the sleeve. The upper contact surface 13211 of the hooks 1321 abuts against the upper edge 1251 of the window 125. The upper edge 1251 of the window 125 axially limits the hooks 1321 to prevent them from disengaging.

[0040] Please refer to the following: Figure 4 , Figure 5 This embodiment describes the assembly and operation process of the fixing element 1 applied to a heat dissipation unit body 2 and a bare crystal heat source 3. The heat dissipation unit body 2 is provided with a first side 21, a second side 22, a heated area 23 and a plurality of through holes 24 penetrating the first and second sides 21 and 22. The heated area 23 is provided on the second side 22 of the heat dissipation unit body 2, and the four corners of the outer periphery of the heated area 23 are respectively provided with through holes 24.

[0041] The fixing element 1 is disposed on the plurality of through holes 24 of the heat dissipation unit body 2. When the heat dissipation unit body 2 is to be assembled with the bare crystal heat source 3, the external threads 113 at the end of the fixing element 1 are screwed into the internal threads inside the four corner outer sides of the coupling hole 4 of the base of the bare crystal heat source 3, so that the heated area 23 of the heat dissipation unit body 2 can temporarily lightly (micro) contact and abut against the top of the bare crystal heat source 3, and maintain a light (micro) contact fit. This is only a preliminary locking and fixing state. At this time, the heat dissipation unit body 2 does not apply any pressure to the bare crystal heat source 3. Only the weight of the heat dissipation unit body 2 itself slightly touches the top of the bare crystal heat source. In order to provide uniform downward pressure, the fixing elements 1 located at the four corners of the heated area 23 outside the heat dissipation unit body 2 must release their springs 116 simultaneously and synchronously, so as to provide uniform downward pressure on the heat dissipation unit body 2 and the bare crystal heat source 3.

[0042] In order to simultaneously and synchronously trigger the springs 116 of each fixed element 1 to release their elastic force, an external force is used to drive the springs 116 to release synchronously. This external force can be provided manually or by an automated device. This embodiment uses an automated device to provide the external force as an illustrative example, but it is not intended to be limiting. The automated device is equipped with a preset pressing fixture (device) 5. The pressing fixture 5 has at least one pressing part 51. The pressing part 51 is directly corresponding to the fixed element 1 located at the four corners of the heated area 23 of the heat dissipation unit body 2, and abuts against an edge 13B on the upper side of the retaining ring 13 (its position is near the outer periphery of the upper surface 13A of the retaining ring 13). The pressing part 51 can be a hollow ring structure or a plurality of symmetrically extended columnar structures. This embodiment uses a hollow ring structure as an illustrative example, but it is not intended to be limiting.

[0043] When the automated equipment drives the pressing fixture 5 to move downward, the pressing part 51 simultaneously applies downward pressure to the edge 13B of the retaining ring 13. The inner hole 131 of the retaining ring 13 and the outer surface of the sleeve 12 form a pivot point A at the contact point between them. When the pressing fixture 5 applies downward pressure to the edge 13B of the retaining ring 13, the retaining ring 13 is supported by the pivot point A, causing the edge 13B to flip outward and downward. At the same time, the plurality of hook arms 132A are driven out of the window 125 and towards the radially outward direction of the sleeve 12. The outward extension and expansion of the moving arms allow the hook ends 1321 of the plurality of hook arms 132A to release the pressure on the top end 1161 of the spring 116, allowing the spring 117 to fully release its restricted spring tension. The top end 1161 of the spring 116 then presses against the lower end face 1221 of the screw head 112. The bottom end 1162 of the spring 116, which is located on the fixing element 1 at the four corners of the heat dissipation device, simultaneously provides a uniform downward pressure to the four corners of the heat dissipation device 2, thereby allowing the heat dissipation device 2 to uniformly and synchronously conform downward to the bare crystal heat source 3.

[0044] The screws 11 of the fixing element of the present invention only pre-lock and position the heat dissipation unit body 2 above the heat source 3 of the bare die type. The actual downward pressure of the heat dissipation device 2 on the heat source 3 of the bare die type is provided by the springs 116 located outside the screws 11 at the four corners. Therefore, after the springs are released, a synchronous and uniform downward pressure will be provided, which solves the problems of uneven force caused by locking one locking point one by one in the existing fixing element, or the one-time locking force or excessive spring pressure causing uneven force on the wafer, resulting in warping or direct breakage and damage.

[0045] In the above embodiments, the heat dissipation unit body 2 can be a heat spreader, a heat pipe, or a combination of a heat spreader and a heat pipe. The first side 21 of the heat dissipation unit body 2 can be further provided with a plurality of heat pipes (not shown in the figure) or at least one heat dissipation fin group, or the plurality of heat pipes and the heat dissipation fin group can be used in combination. The above usage or combination usage is only an example and is not intended to limit the implementation of this case. By increasing the heat dissipation area in contact with air, the heat dissipation efficiency is improved.

Claims

1. A fixing element, characterized in that, It includes: A screw with an annular groove at its lower end, a retaining ring being held in the annular groove, and a spring being sleeved around the outside of the screw; A sleeve has a hollow interior forming a receiving space. The sleeve has two open upper and lower ends. The receiving space is located between the upper and lower ends and communicates with the upper and lower ends. Near the upper end of the sleeve, there is a pair of windows. The pair of windows have an upper edge. The pair of windows correspond to each other and communicate with the receiving space. The sleeve receiving space is provided with the screw. A retaining ring has an inner hole and is fitted onto the outside of the sleeve through the inner hole. One side of the retaining ring has an upper surface, and a hook arm assembly extends upward from the upper surface. The hook arm assembly has a plurality of hook arms that extend into the receiving space from the pair of windows to press and lock the upward end of the spring, so that the spring is in a compressed state inside the sleeve.

2. The fixing element as described in claim 1, characterized in that: The sleeve has a mating area between the lower edge of the window and the lower end of the sleeve. The outer diameter of the mating area is smaller than the outer diameter of the rest of the sleeve. Therefore, the connection between the mating area and the sleeve forms a stepped portion. The stepped portion can provide axial restraint for the retaining ring and prevent the retaining ring from disengaging excessively downward from the mating area.

3. The fixing element as described in claim 1, characterized in that: The upper surface of the snap ring has an annular edge near the outer periphery. The hook arm assembly is formed by extending upward from the upper surface of the snap ring near the inner hole or from the intersection of the upper surface of the snap ring and the inner hole. One end of the plurality of hook arms of the hook arm assembly is attached to the upper surface of the snap ring, and the other end is a free end, and the end of the free end is bent to form a hook end.

4. The fixing element as described in claim 3, characterized in that: The hook has an upper contact surface and a lower contact surface. A plurality of hooks extend into the receiving space of the sleeve from the corresponding window. The upper contact surface abuts against the upper edge of the window, and the lower contact surface presses against one end of the spring.

5. A heat dissipation unit, characterized in that, It includes: A heat dissipation unit body has a first side, a second side and a heat-receiving area. The four corners of the outer side of the heat-receiving area have a plurality of through holes. The plurality of through holes pass through the first side and the second side. A plurality of fixing elements are respectively disposed at each of the plurality of through holes of the heat dissipation unit body. The fixing element includes: A screw has an annular groove at the lower end of the through hole of the body. The annular groove is fitted with a retaining ring to prevent the screw from coming off the body. A spring is sleeved on the outside of the screw, and the lower end of the spring is attached to the first side of the body. A sleeve with a hollow interior forming an accommodating space. The upper and lower ends of the sleeve are open and communicate with the accommodating space. The lower end of the sleeve abuts against the first side of the heat dissipation unit body. Near the upper end of the sleeve, there is a pair of windows. The pair of windows are arranged correspondingly to each other and communicate with the accommodating space. The aforementioned screw is provided in the accommodating space. A retaining ring has an inner hole and is fitted onto the outside of the sleeve through the inner hole. One side of the retaining ring has an upper surface, and a hook arm assembly extends upward from the upper surface. The hook arm assembly has a plurality of hook arms that extend into the receiving space from the pair of windows to press and lock the upward end of the spring, so that the spring is in a compressed state inside the sleeve.

6. The heat dissipation unit as described in claim 5, characterized in that: The sleeve has a mating area on the lower side of the pair of windows. The outer diameter of the mating area is smaller than the outer diameter of the rest of the sleeve. Therefore, the connection between the mating area and the sleeve forms a stepped portion. The stepped portion can provide axial limiting of the retaining ring to prevent the retaining ring from disengaging excessively downward from the mating area.

7. The heat dissipation unit as described in claim 5, characterized in that: The heat dissipation unit body is a vapor chamber or a combination of a vapor chamber and a heat pipe.

8. The heat dissipation unit as described in claim 5, characterized in that: The upper surface of the snap ring has an annular edge near the outer periphery. The hook arm assembly is formed by extending upward from the upper surface of the snap ring near the inner hole or from the intersection of the upper surface of the snap ring and the inner hole. The hook arm assembly has a plurality of hook arms, one end of which is attached to the upper surface of the snap ring, and the other end is a free end, and the end of the free end is bent to form a hook end.

9. The heat dissipation unit as described in claim 8, characterized in that: The hook has an upper contact surface and a lower contact surface. A plurality of hooks extend into the receiving space of the sleeve from the corresponding window. The upper contact surface abuts against the upper edge of the window, and the lower contact surface presses against one end of the spring.

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