TWI861867B - Screw fixing structure for heat dissipation unit and heat dissipation unit using same - Google Patents

Abstract

A heat dissipation unit includes a heat sink having a heat receiving zone and a screw fixing structure extended through each of four holes on the heat sink outside the heat receiving zone. The screw fixing structure includes a locating screw having a shank and a spring fitted around the shank; a hollow sleeve located outside the shank and the spring; and a spring stopper including two parallel elastic arms connected at one end and elastically disposed in the hollow sleeve to hold the spring in a compressed state. The spring stopper may be pushed downward to laterally push the two elastic arms open to move away from the spring, allowing the spring to release its elastic force upwardly. The four locating screws can synchronously and evenly apply their elastic force to the through holes outside the heat receiving zone, preventing the heat sink from damaging a contacted heat source.

Description

Screw fixing structure of heat dissipation unit and heat dissipation unit

The present invention relates to a screw fixing structure, and in particular to a screw fixing structure of a heat sink device and a heat sink unit that can provide uniform downward pressure to avoid damage or heat generation caused by uneven contact force between a bare chip computing unit and a heat sink.

In order to provide electronic equipment with high-performance computing capabilities, high-performance and high-power chips are currently used. When the chip is computing, it generates a considerable amount of heat. Traditional computing chips have a packaging shell on the outside, and the packaging shell covers the chip inside to protect the chip from damage. As the computing performance of the chip increases, the chip will generate a higher temperature than the traditional one when performing computing work. In addition, the packaging shell encapsulated on the outside of the chip has seriously affected the heat dissipation and heat conduction efficiency of the chip; therefore, most chips on the market have been changed to bare crystal form for installation. However, since the surface of the bare crystal is not flat but in an outward convex arc shape, and the lack of a protective shell results in a small heat exchange contact surface and low strength, it is easy to be damaged and cracked when combined with a heat sink.

In addition, when the traditional heat sink is fixed on the heat source (bare die), it is locked in sequence at a single locking point, which causes the locking time points to be asynchronous and easily causes contact tilt. The bare die cannot withstand such uneven pressure, which can easily cause problems such as chip cracking and damage.

Refer to Figures 12 and 13, which are schematic diagrams of the heat sink and bare die assembly. The four corners of the heat source A are provided with copper pillars B with internal threads. The heat sink C is also provided with four holes C3 at the positions corresponding to the copper pillars B and is penetrated by screw units C1. The screw units C1 are provided with a spring C2 on the outside. When the heat sink C and the heat source A are locked together, the screwing operation is usually performed by a single point directly by a manual or robot-operated electric screwdriver. In order to speed up the assembly time on the production line and complete the assembly within a limited time, each fixing screw is fastened directly at one time. When the screw unit C1 is locked to the fixed point, the spring C2 sleeved on the screw unit C1 also supports the heat source A, and the uneven force caused by the single-point locking is immediately generated. The heat source A (bare crystal) is hard and brittle. Due to the single-point screw unit C1 locking and the top support of the spring C2, the heat source A (bare crystal) cannot be completely and comprehensively (the four corners of the bare crystal) uniform downward bonding force. In addition to being unable to completely and flatly place the heat sink on the heat source A (bare crystal), it is also impossible to prevent the bare crystal from being damaged by uneven force.

Furthermore, the bare die is quite fragile. As mentioned above, the four corners of the bare die must provide a uniform downward pressure to provide a bonding force for assembly. If the four corners of the bare die cannot be uniformly pressed downward, it is easy to cause the heat sink or heat dissipation device to warp and not completely fit or be damaged between the heat source (bare die), and it is easy to form thermal impedance, which will cause uneven heating or thermal conduction failure.

Therefore, how to improve the heat dissipation device to fully and comprehensively provide uniform pressure to tightly fit the heat source and how to provide and maintain the appropriate bonding force between the bare die and the heat dissipation device are the primary issues that the industry needs to solve at present.

Therefore, in order to effectively solve the above-mentioned problems, the main purpose of the present invention is to provide a screw fixing structure for a heat sink that can simultaneously provide an average downward pressure, effectively avoiding the effect of cracking or breaking the corners of the bare die computing unit caused by locking a single locking point first.

The screw fixing structure of the heat dissipation unit comprises: a positioning screw having a rod and a nut and a threaded portion at both ends, the rod being provided with a retaining ring receiving groove adjacent to the threaded portion, the retaining ring receiving groove being provided with a retaining ring, and the rod being provided with a spring; a hollow sleeve having a receiving space therein, the hollow sleeve having a neck near the upper end, the neck being provided with a pair of notches, a first step and a second step, the notches corresponding to each other and radially connected to the receiving space, the first and second steps being located below the pair of notches, the hollow sleeve being provided on the rod of the positioning screw and the outside of the spring (i.e. the rod and the spring are The spring fixing part is arranged in the pair of notches of the hollow sleeve. The spring fixing part has a pair of mutually parallel first elastic support arms and a second elastic support arm. One end of the first elastic support arm and the second elastic support arm are connected by a connecting part. The other end of the first elastic support arm and the second elastic support arm away from the connecting part is provided with a first end and a second end. The first and second ends are arranged adjacent to each other but not connected. The first and second elastic support arms are respectively inserted into the accommodation space from the pair of notches of the hollow sleeve to prevent the spring from being released upward, so that the spring is in a compressed state.

When the spring fixing part is forced by an external object to expand the first and second elastic arms of the spring fixing part outward, the first and second elastic arms and their first and second ends gradually move away from each other due to the external force, increasing the distance between them, thereby causing the first and second elastic arms to remove the stop on the top end of the spring, allowing the spring to release its elastic force.

1: Screw fixing structure

11: Positioning screw

111: Rod

1111: Nut

1112: Screw thread part

1113: Buckle ring storage slot

1114: Buckle

112: Spring

1121: Top

1122: bottom

12: Hollow sleeve

121: Top

122: Lower end

123: Storage space

124: Neck

1241: Gap

1242: First step

1243: The second step

13: Spring fixings

130:Connection part

131: First elastic support arm

1311: First End

1312: convex part

132: Second elastic arm

1321: Second end

1322: convex part

133: First Area

134: Second Area

2: Press-in fixture

21: Fixed part

211: Fixed end

212: Free end

22: Expansion Department

221: Fixed end

222: Free end

3: Radiator

31: Perforation

32: Heat pipe

33: Heat sink fin assembly

34: Heating zone

4: Base

41: Binding hole

42: Bare computing chip

A: Heat source

B: Copper column

C: Heat dissipation device

C1: Screw unit

C2: Spring

C3: Holes

Figure 1 is a schematic diagram of the screw fixing structure of the heat sink of the present invention.

Figure 2 is a schematic diagram of the screw fixing structure of the heat sink of the present invention.

Figure 2A is a schematic diagram showing the screw fixing structure of the heat sink unit of the present invention from another angle.

Figure 3 is a schematic cross-sectional diagram of the screw fixing structure of the heat sink of the present invention.

Figure 4 is a schematic diagram of the expansion of the spring fixing member of the present invention.

Figure 5 is a schematic diagram of the spring fixing member of the present invention being expanded.

Figure 5A is a schematic diagram of the expansion of the spring fixing member of the present invention.

Figure 6 is a schematic diagram of the spring fixing member of the present invention after expansion.

Figure 7A is a schematic diagram of the AA’ section of Figure 4.

Figure 7B is a schematic diagram of the BB’ section of Figure 5.

Figure 7C is a schematic diagram of the CC’ section of Figure 6.

Figure 8 is a schematic diagram of the appearance of the heat dissipation unit of the present invention.

Figure 9 is a schematic diagram of the front cross-section of the spring fixing member of the heat sink unit of the present invention after expansion.

Figure 10 is a schematic cross-sectional view of the spring fixing member of the heat sink unit of the present invention after expansion.

Figure 11 is a schematic diagram of another embodiment of the heat sink of the heat dissipation unit of the present invention.

Figure 12 is a schematic diagram of the heat sink and the bare die before assembly.

Figure 13 is a schematic diagram of the combination of a conventional heat sink and a bare die.

The above-mentioned purpose of the present invention and its structural and functional characteristics will be explained according to the preferred embodiments of the attached drawings.

Please refer to Figures 1-11. As shown in the figure, the screw fixing structure 1 of the heat sink unit of the present invention comprises: a positioning screw 11, having a rod 111, the upper and lower ends of the rod 111 respectively having a nut 1111 and a threaded portion 1112, and the rod 111 is provided with a retaining ring receiving groove 1113 adjacent to the threaded portion 1112, and the retaining ring receiving groove 1113 is clamped with a retaining ring 1114, and the rod 111 is sleeved with a spring 112, so that the spring 112 can be made to move along the direction of the rod 111 of the positioning screw 11 during compression or release. The spring 112 has a top end 1121 and a bottom end 1122, and the bottom end 1122 abuts against the retaining ring 1114. In one embodiment, the positioning screw 11 is used to be screwed and fixed with other devices or structures, for example, but not limited to, a coupling portion corresponding to the thread portion 1112 is provided on other devices or structures, and the coupling portion may have an internal thread for the thread portion 1112 of the positioning screw 11 to be screwed and fixed, so as to prevent the positioning screw 11 from loosening or displacement, resulting in failure to align with the coupling portion to be coupled.

A hollow sleeve 12 has an open upper end 121, a lower end 122, and an accommodation space 123 between the upper and lower ends 121, 122 and formed in the hollow sleeve 12, wherein a neck 124 is narrowed inward near the upper end 121, and the neck 124 is provided with a pair of notches 1241, a first step 1242 and a second step 1243, wherein the outer diameter of the hollow sleeve 12 is larger than the outer diameter of the neck 124, and the outer diameter of the first step 1242 of the neck 124 is larger than the outer diameter of the second step 1243 to form an inverted step shape, and the The notches 1241 correspond to each other and are radially connected to the accommodating space 123. The first and second steps 1242 and 1243 are located below the notches 1241 and may be connected to or not connected to the accommodating space 123. The hollow sleeve 12 is sleeved on the rod 111 of the positioning screw 11 and the outside of the spring 112 (that is, the rod 111 and the spring 112 are arranged in the accommodating space 123 of the hollow sleeve 12); the hollow sleeve 12 can prevent the spring 112 from being affected in the process of compression or release due to the entry of foreign matter.

A spring fixing member 13 is clamped in the pair of notches 1241 of the aforementioned hollow sleeve 12. The spring fixing member 13 has a pair of mutually corresponding and parallel first elastic support arms 131 and second elastic support arms 132. One end of the first elastic support arm 131 and the second elastic support arm 132 are connected to each other by a connecting portion 130, and the other ends of the first elastic support arm 131 and the second elastic support arm 132 away from the connecting portion 130 are provided with a first end 1311 and a second end 1321. The first and second ends 1311 and 1321 are arranged adjacent to each other but not connected (contacting).

In addition, a virtual dividing line is provided on the first and second elastic arms 131, 132 of the spring fixing member 13 to divide the area surrounded by the first and second elastic arms 131, 132, the connecting portion 130, the first end 1311 and the second end 1321 into a first area 133 and a second area 134; in addition, the first and second elastic arms 131, 132 are respectively inserted or clamped into the accommodating space 123 from a pair of notches 1241 of the hollow sleeve 12 to prevent the spring 112 from releasing its upward elastic force, so that the spring 112 maintains a compressed state.

After the spring 112 of this embodiment is placed in the accommodation space 123 of the hollow sleeve 12, the spring 112 is axially compressed by the first and second elastic arms 131 and 132 of the spring fixing member 13 and cannot be supported or stretched upward, so it is in a compressed state. If the first and second elastic arms 131 and 132 of the spring fixing member 13 remove the stopper on the top end 1121 of the spring 112, the upper end of the spring 112 will release its elastic force upward to provide an upward supporting force (upper pressure), and the lower end of the spring 112 also provides a downward supporting force (lower pressure) at the same time.

Please refer to Figures 1, 4, and 5A, wherein the spring fixing member 13 is provided with a press-in fixture 2, and one end of the press-in fixture 2 is provided with at least one fixing portion 21 and at least one expansion portion 22, and a transverse width H2 of the expansion portion 22 is greater than a transverse width H1 of the fixing portion 21, and the fixing portion 21 and the expansion portion 22 are in contact with the press-in fixture. 2 has a fixed end 211, 221 at the connection position, and a free end 212, 222 away from the connection position. The transverse width H1, H2 of the fixed end 211, 221 is the widest, and the transverse width H1, H2 of the fixed end 211, 221 gradually decreases toward the free end 212, 222, so that the free end 212, 222 forms a sharp angle; refer to Figures 1, 4, and 7A again, the press-in fixture 2 moves downward toward the lower end 122 of the hollow sleeve 12; please continue to refer to Figures 1, 5, and 7B, so that the fixing portion 21 is inserted into the first area 133 of the spring fixing member 13 and the expansion portion 22 is simultaneously inserted into the second area 134 of the spring fixing member 13, and the press-in fixture 2 continues to move downward toward the lower end 122 of the hollow sleeve 12; so that the first elastic support arm 131 and its first end 1311 and the second elastic support arm 132 and its second end 1321 are expanded and separated in opposite directions, thereby increasing the first end 1311 and a second end 1 321, so that the spring 112 is released from the compression of the spring fixing member 13, so that the top end 1121 of the spring 112 is released upward to press against the bottom of the nut 1111 of the positioning screw 11, and the expanded and separated spring fixing member 13 moves downward with the pressing fixture 2 to be fixed on the first step 1242 or the second step 1243 As shown in FIGS. 6 and 7C, the expanded and separated spring fixing member 13 and the hollow sleeve 12 can be directly removed to avoid the inconvenience caused by the expanded spring fixing member 13 in subsequent installation or processing; in some embodiments, the first step 1242 is closer to the pair of notches 1241, and the press-in fixture 2 During the pressing process, the spring fixing member 13 can be expanded and pressed down to be fixed on the first step 1242, thereby reducing the movement stroke of the pressing fixture 2 when pressing down; and the pressing fixture 2 can also press down to fix the spring fixing member 13 on the second step 1243, and the height of the second step 1243 is less than that of the first step. The height of the ladder 1242 and the hollow sleeve 12 allows the spring fixing member 13 to be fixed on the second ladder 1243. The combination stability of the spring fixing member 13 can be further improved to prevent the spring fixing member 13 from coming out from the top (the direction of the first ladder 1242) or the bottom (the junction of the neck 124 and the hollow sleeve 12).

In some embodiments, the first elastic arm 131 or the second elastic arm 132 of the spring fixing member 13 may be provided with an outer protrusion 1312, 1322, and the outer protrusion 1312, 1322 is in the shape of an arc protruding outward. When the spring fixing member 13 is arranged on the top end 1121 of the spring 112, the arc shape of the outer protrusion 1312, 1322 of the spring fixing member 13 can be attached to the top end 1121 of the spring 112 to match the shape (arc shape), thereby increasing the contact area between the spring fixing member 13 and the top end 1121 of the spring 112, so that the spring fixing member 13 and the top end 1121 of the spring 112 can be arranged to match the shape (arc shape) of the top end 1121 of the spring 112. The spring fixing part 13 compresses the spring 112 more stably and has a better effect; when the spring fixing part 13 is expanded and pressed down by the press-in fixture 2, the outer protrusions 1312 and 1322 of the first and second elastic arms 131 and 132 can fit into the first step 1242 or the second step 1243 of the hollow sleeve 12 through their outwardly protruding arc shapes, so that the combination of the expanded spring fixing part 13 and the hollow sleeve 12 can be more stable, avoiding the situation that the spring fixing part 13 cannot be fixed and bounces off during the process of pressing down and expanding the press-in fixture 2.

Referring to FIG. 8, it is a schematic diagram of the appearance of the heat sink unit of the present invention; FIG. 9 and FIG. 10 are schematic diagrams of the cross-sections of the heat sink unit of the present invention before and after the spring fixing member is expanded; as shown in the figure, the heat sink unit of the present invention is combined with the screw fixing structure and the expansion of the spring fixing member is the effect of the present invention to achieve the same force application. The heat sink unit comprises: a heat sink 3, having an upper surface, a lower surface, at least four through The through holes 31 and a heating area 34, the through holes 31 penetrate the upper and lower surfaces of the radiator 3, and the four corners of the outer periphery of the heating area 34 are respectively provided with a through hole 31; a plurality of screw fixing structures 1, the screw fixing structure 1 is substantially the same as the above, and the difference is that the lower end 122 of the hollow sleeve 12 and the bottom end 1122 of the spring 112 abut against the upper surface of the radiator 3 and correspond to the through holes 31. Through hole 31; In some embodiments, the hollow sleeve 12 and the heat sink 3 may be separated structures, so the lower end 122 of the hollow sleeve 12 is in contact with the upper surface of the heat sink 3, or the lower end 122 of the hollow sleeve 12 is directly integrated with the upper surface of the heat sink 3 to form an integrated structure; and the positioning screw 11 of the screw fixing structure 1 is inserted through the through holes of the heat sink 3. After the hole 31 is formed, the position of the retaining ring receiving groove 1113 of the positioning screw 11 is moved from the upper surface to the lower surface of the heat sink 3, and a retaining ring 1114 is clamped in the retaining ring receiving groove 1113 of the positioning screw 11. The retaining ring 1114 is used to combine the screw fixing structure 1 with the heat sink 3 so that the positioning screw 11 of the screw fixing structure 1 and the heat sink 3 will not separate.

The following will explain the usage scenarios of the heat dissipation unit of the present invention. Please refer to the previous figures and descriptions.

When the hollow sleeves 12 are placed on the through holes 31 of the heat sink 3, and the spring 112 is placed in the receiving space 123 of the hollow sleeve 12, so that the spring 112 is partially compressed, the spring fixing member 13 is clamped in the pair of notches 1241 of the hollow sleeve 12 to prevent the spring 112 from being compressed. The accommodation space 123 of the hollow sleeve 12 is in a fully compressed state, the positioning screw 11 passes through the spring fixing member 13, the spring 112, the hollow sleeve 12 and the through hole 31 of the heat sink 3, and is clamped on the retaining ring accommodating groove 1113 of the positioning screw 11 through the retaining ring 1114, so that the spring 112 remains compressed.

The heat sink 3 is fixedly connected to a base 4. The base 4 is provided with at least four connection holes 41 and a heat source. The four corners of the heat source are respectively provided with a connection hole 41 and correspond to the through holes 31 of the heat sink 3. The heat source is, for example but not limited to, a bare die computing chip 42. The connection holes 41 are provided for the threaded parts of the positioning screws 11 of the screw fixing structure 1 to be screwed and fixed, so that the heat receiving area 34 of the heat sink 3 is located above the bare die computing chip 42 of the base 4. The two maintain a lightly touching fit state. At this time, the heat sink 3 does not exert any pressure on the heat source.

The action of the press-in fixture 2 pressing down the screw fixing structures 1 of the heat sink unit is substantially the same as described above, except that the press-in fixture 2 has four pairs of the fixing portions 21 and the expansion portions 22 corresponding to four screw fixing structures 1 (each fixture provides simultaneous and synchronous downward pressure), and the spring fixing member 13 expands to cause the spring fixing member 13 in the compressed state to expand. The spring 112 is released and presses against the heat sink 3 and the bottom of the nut 1111 of the positioning screw 11; since the thread portion 1112 of the positioning screw 11 of the screw fixing structure 1 is screwed and fixed with the coupling hole 41 of the base 4, when one end of the spring 112 of the screw fixing structure 1 presses upward against the bottom of the nut 1111, the screw cannot be released. The screw fixing structures 1 are pushed upward and the limited elastic force of the spring 112 cannot be completely released. Therefore, when the spring 112 is released, the other end will push the radiator 3 downward. The spring 112 of the screw fixing structures 1 is released at the same time. The bottom end 1122 of the spring 112 presses the four corners of the heat receiving area 34 of the radiator 3. At the same time, a uniform downward pressure is provided to make the heat sink 3 and the bare die computing chip 42 of the base 4 in close contact at the same time and reach a specific pressure, so as to avoid uneven force causing corner cracks or cracks or thermal resistance due to incomplete fit, and to avoid excessive pressure during the screw tightening process causing damage to the bare die computing chip 42.

In some implementations, the heat sink 3 may be a temperature averaging plate or a heat pipe or a combination of a temperature averaging plate and a heat pipe, wherein the upper surface of the heat sink 3 may be further provided with a plurality of heat pipes 32 or at least one heat sink fin set 33 or the plurality of heat pipes 32 and the heat sink fin set 33 may be used in combination. The following description of the combination of the plurality of heat pipes 32 and the heat sink fin set 33 does not limit the implementation of this case. The plurality of heat pipes 32 may be attached to the upper surface of the heat sink 3 at one end, and the heat pipes 32 absorb the heat energy of the heat sink 3 by attaching one end to the upper surface of the heat sink 3. The other end of the heat pipes 32 will be inserted into the heat sink fin set 33, as shown in Figure 11, and the heat dissipation efficiency is improved by increasing the contact area with the air.

1: Screw fixing structure

11: Positioning screw

111: Rod

1112: Screw thread part

12: Hollow sleeve

13: Spring fixings

130:Connection part

131: First elastic support arm

132: Second elastic arm

Claims (20)

A screw fixing structure of a heat dissipation unit comprises: a positioning screw having a rod body, wherein the upper and lower ends of the rod body respectively have a nut and a threaded portion, and the rod body is provided with a retaining ring receiving groove adjacent to the threaded portion, and the retaining ring receiving groove is provided with a retaining ring, and the rod body is sleeved with a spring, and the spring has a top end and a bottom end, and the bottom end is abutted against the retaining ring; a hollow sleeve having an upper end and a lower end in an open state and a receiving space between the upper and lower ends and formed in the hollow sleeve, wherein the portion near the upper end is narrowed inwardly and has a Neck, the neck is provided with a pair of notches, the notches correspond to each other and are radially connected to the accommodation space, the hollow sleeve is provided with the rod body through which the spring is penetrated; a spring fixing member is clamped in the notch of the hollow sleeve, and has a pair of first elastic support arms and second elastic support arms corresponding to each other, the first elastic support arm and one end of the second elastic support arm are connected by a connecting portion, and the first and second elastic support arms are respectively embedded in the accommodation space from the notches to prevent the top end of the spring from stretching upward, so that the spring is in a compressed state. The screw fixing structure as described in claim 1, wherein the first and second elastic arms respectively have a first end and a second end away from the connecting portion, and the first and second ends are arranged adjacent to each other but not connected. The screw fixing structure as described in claim 2, wherein a virtual dividing line is provided on the spring fixing member to divide the area enclosed by the first and second elastic arms, the connecting portion, the first end and the second end into a first area and a second area. The screw fixing structure as described in claim 3, wherein the spring fixing member is matched with a press-in fixture, and one end of the press-in fixture is provided with a fixing portion and an expansion portion, and the lateral width of the expansion portion is greater than the lateral width of the fixing portion. The screw fixing structure as described in claim 4, wherein the connection position of the fixing portion and the expansion portion with the press-fit fixture has a fixed end and a free end away from the connection position, the transverse width of the fixed end is the widest, and the transverse width of the fixed end decreases toward the free end, so that a sharp angle is formed at the free end. The screw fixing structure as described in claim 4, wherein the neck of the hollow sleeve is provided with a first step and a second step, the first and second steps are located below the notches and may or may not be connected to the accommodation space, and an outer diameter of the first step is larger than an outer diameter of the second step to form an inverted step shape, and the outer diameter of the hollow sleeve is larger than the outer diameter of the neck. The screw fixing structure as described in claim 4, wherein the pressing fixture is pressed downward toward the lower end of the hollow sleeve so that the fixing portion is inserted into the first area of the spring fixing member, and the expansion portion is inserted into the second area of the spring fixing member to expand and separate the first elastic arm and its first end from the second elastic arm and its second end outward. As described in claim 6, the screw fixing structure, wherein the spring is not pressed by the spring fixing part, so that its top end is released upward and stretched to press against the bottom of the nut of the positioning screw, and the expanded and separated spring fixing part moves downward with the press-in fixture and is fixed on the first step or the second step. The screw fixing structure as described in claim 6, wherein the first elastic arm and the second elastic arm of the spring fixing member are respectively provided with an outer protrusion, the outer protrusion is an arc shape protruding outward, and the outer protrusion can be attached to match the shape of the top end of the spring, and the outer protrusion of the expanded and separated spring fixing member is attached to the first step or the second step of the hollow sleeve through its arc shape protruding outward. A heat dissipation unit comprises: a heat sink having an upper surface, a lower surface, at least four through holes and a heating zone, wherein the through holes penetrate the upper and lower surfaces of the heat sink, and the four corners of the outer periphery of the heating zone are respectively provided with a through hole; a plurality of screw fixing structures, wherein the screw fixing structures are respectively provided with a positioning screw, a hollow sleeve and a spring fixing member, wherein the through holes penetrate the upper and lower surfaces of the heat sink, and the four corners of the outer periphery of the heating zone are respectively provided with a through hole; The positioning screw has a rod body, and the upper and lower ends of the rod body are respectively provided with a nut and a threaded portion, and the rod body is provided with a buckle ring receiving groove adjacent to the threaded portion, and the rod body is sleeved with a spring, and the spring has a top end and a bottom end, the top end abuts against the spring fixing member and the bottom end abuts against the heat sink; wherein the hollow sleeve has an upper end, a lower end and a A receiving space is formed between the upper and lower ends and in the hollow sleeve, wherein a neck is narrowed inward near the upper end, and the neck is provided with a pair of notches, the notches correspond to each other and are radially connected to the receiving space, the hollow sleeve is provided with the rod body through which the spring is passed and is arranged above the through holes of the radiator; wherein the spring fixing member is a hoop provided In the notch of the hollow sleeve, there is a pair of a first elastic support arm and a second elastic support arm corresponding to each other, one end of the first elastic support arm is connected to the second elastic support arm by a connecting portion, and the first and second elastic support arms are respectively embedded in the accommodating space from the notches to prevent the top end of the spring from stretching upward, so that the spring is in a compressed state. As described in claim 10, in the heat sink unit, after the positioning screw of the screw fixing structure is passed through the through hole of the heat sink, a retaining ring is clamped in the retaining ring receiving groove of the positioning screw to prevent the positioning screw from separating from the heat sink. The heat sink as described in claim 10, wherein the heat sink can be a temperature averaging plate or a heat pipe or a combination of a temperature averaging plate and a heat pipe, and the heat sink can further be provided with a heat sink fin assembly in contact with the temperature averaging plate or a heat pipe or a combination of the temperature averaging plate and the heat pipe to improve the heat dissipation efficiency. The heat dissipation unit as described in claim 10, wherein the first and second elastic arms respectively have a first end and a second end away from the connecting portion, and the first and second ends are arranged adjacent to each other but not connected. As described in claim 13, the heat dissipation unit is provided with a virtual dividing line on the spring fixing member to divide the area surrounded by the first and second elastic arms, the connecting portion, the first end and the second end into a first area and a second area. As described in claim 14, the spring fixing members of the screw fixing structure are matched with a press-in fixture, and one end of the press-in fixture is provided with at least four pairs of fixing parts and expansion parts, and the lateral width of the expansion parts is greater than the lateral width of the fixing parts. The heat sink as described in claim 15, wherein the connection position of the fixed parts and the expansion parts with the press-fit fixture has a fixed end and a free end away from the connection position, the transverse width of the fixed end is the widest, and the transverse width of the fixed end decreases toward the free end, so that a sharp angle is formed at the free end. The heat sink as described in claim 15, wherein the neck of the hollow sleeve is provided with a first step and a second step, the first and second steps are located below the notches and may be connected to or not connected to the accommodation space, and an outer diameter of the first step is larger than an outer diameter of the second step to form an inverted step shape, and the outer diameter of the hollow sleeve is larger than the outer diameter of the neck. The heat sink unit as described in claim 15, wherein the press-in fixture is pressed downward toward the lower end of the hollow sleeve so that the fixing portion is inserted into the first area of the spring fixing member, and the expansion portion is inserted into the second area of the spring fixing member to expand and separate the first elastic arm and its first end from the second elastic arm and its second end outward from each other. As described in claim 17, the heat sink unit, wherein the spring is not pressed by the spring fixing part, so that its top end is released upward and stretched to press against the bottom of the nut of the positioning screw, and the expanded and separated spring fixing part moves downward with the press-in fixture and is fixed on the first step or the second step. As described in claim 17, the heat dissipation unit, wherein the first elastic arm and the second elastic arm of the spring fixing member are respectively provided with an outer protrusion, the outer protrusion is an arc shape protruding outward, and the outer protrusion can be attached to match the shape of the top end of the spring, and the outer protrusion of the expanded and separated spring fixing member is attached to the first step or the second step of the hollow sleeve through its arc shape protruding outward.

Images