GB2393333A

GB2393333A - Mounting device for heat sink and cover

Info

Publication number: GB2393333A
Application number: GB0328776A
Authority: GB
Inventors: Alex Horng
Original assignee: Sunonwealth Electric Machine Industry Co Ltd
Current assignee: Sunonwealth Electric Machine Industry Co Ltd
Priority date: 2000-04-18
Filing date: 2000-04-18
Publication date: 2004-03-24
Anticipated expiration: 2020-04-18
Also published as: GB0009603D0; GB2361585B; GB2361585A; GB2393333B; GB0328776D0

Abstract

A number of posts 52 are formed on the underside of a cover 5 of a heat sink 4. The posts 52 are located and secured to the heat sink 4 by screws 46 extending through holes 41. At least two of the posts extend through engaging members 55 that have an engaging peg 552 extending therefrom. Each engaging peg has a snap fastener 553 for engaging with an associated positioning hole 31 of a circuit board. A spring 54 may be sleeved around each post 52 or each engaging peg 552, to provide the fastener 553 with a reliable snapping effect.

Description

I Mountin Devices for a Heat-C;enerating Element and a Heat-Dissipaffng

Deuce g 2 Baclcground of the Invention 3 1. Field of the Invention

4 The present invention relates to mounting devices for a heat-generating element (e.g., a 5 central processing unit) and a heat-dissipating device, and more particularly to mounting 6 devices that can be easily and securely engaged with the heat-generating element to obtain a 7 minimized thickness after assembly, thereby obtaining an optimal heat-dissipating effect.

8 2. Description of the Related Art

9 Taiwan Utility Model Publication No. 346211 issued on Nov. 21, 1998 and entitled 10 "IMPROVED STRCUTRE FOR HEAT-DISSIPATING DEVICES" discloses a heat-dissipating 1 I plate, a fan, and a holding member for facing the fan and for maintaining a gap between the fan 19 and the heat-dissipating plate. A retainer is provided to be engaged with the heat-dissipating 13 plate by bolts and nuts and to retain the central processing unit in place. Thus, the heat 14 dissipating plate may be securely engaged with the central processing unit. Nevertheless, the 15 retainer has a certain thickness and thus fails to obtain a rnirmnized thickness, as the heat 16 dissipating device after assembly is elevated above the surface of the circuit board by an 17 increased height that is equal to the thickness of the retainer.

I Summary of the Invention

19 It is a primary object of the present invention to provide a mounting device for the heat 20 generating element and the heat-dissipating device. The mounting device is simple in structure 21 and easy to manufacture, and the heat dissipating device is elevated by a lower level artier 29 assembly, thereby providing an optimal beat-dissipadng effect.

23 In accordance with the present invention, a number of posts are formed on an underside 24 of a cover plate of a heat-dissipating device. The posts are extended through positioning holes 25 on a base of the heatdissipating device. The posts may have snap fasteners that are extended 26 through positioning holes in a circuit board on which a heat-,, enerating element is mounted.

27 Alternatively, each post is extended through an engaging member that has an engaging peg

I projected therefrom. Each engaging peg has a snap fastener for engaging with art associated 2 positioning hole of the circuit board. An elastic element is sleeved around each post or each 3 engaging peg, thereby providing the snap fastener with reliable snapping effect. Thus, the base 4 of the heat-dissipating device and the heat-generating element are tightly contact with each 5 other to obtain excellent heat conduction therebetween.

6 Other objects, specific advantages, and novel features of the invention will become more 7 apparent from the following detailed description and preferable embodiments when taken in

8 conjunction with the accompanying drawings.

9 Brief Description of the Drawings

10 Fig. 1 is an exploded perspective view of a heat-dissipating device, a circuit board, and a I 1 first embodiment of a mounting device in accordance with the present invention.

12 Fig. 2 is a top view of the heat-dissipating device, the circuit board, and the mounting 13 device in Fig. 1.

14 Fig. 3 is a sectional view taken along line 3-3 in Fig.2.

1' Fig. 4 is a sectional view similar to Fig. 3, illustrating a second embodiment of the 16 mounting device in accordance with the present invention.

17 Fig. is an exploded perspective view of a heat-dissipating device, a circuit board, and a 18 third embodiment of the mounting device in accordance with the present invention.

Fig. 6 is a sectional view of the heat-dissipating device, the circuit board, and the 20 mounting device if Fig. 5.

21 Fig. 7 is an exploded perspective view of a heat-dissipating device, a circuit board, and a 22 fourth embodiment of the mounting device in accordance with the present invention.

23 Fig. 8 is a top view of the heat-dissipating device, the circuit board, and the mounting 24 device in Fig. 7.

AS Fig. 9 is a sectional view taken along line 9-9 in Fig. 8.

26 Fig. 1 0is an exploded perspective view of a heat-dissipating device, a circuit board, and a 27 fifth embodiment of the mounting device in accordance with the present invention.

1 Fig. 11 is an exploded perspective view of a heat-dissipating device, a circuit board, and a 2 sixth embodiment of the mounting device in accordance with the present invention.

3 Fig. 12 is a sectional view of the heat-dissipating device, the circuit board, and the 4 mounting device in Fig. 11.

5 Fig. 13 is a sectional view sinular to Fig. 12, illustrating a seventh embodiment of the 6 mounting device in accordance with the present invention.

7 Detailed Description of the Preferred Embodiments

Preferred embodiments in accordance with the present invention will now be described 9 with reference lo the accompanying drawings.

10 Referring to Fig. 1, a heat-dissipating device in accordance with the present invention I I generally includes a base 1 and a cover plate2. The base 1 is made of metal of excellent thermal 19 conductivity. The base 1 has a flat underside to be in intimate contact with a heat-generating 13 element 32 that is mounted on a circuit board 3. The base 1 includes a number of positioning 14 holes 11 that are respectively aligned with positioning holes 31 defined in the circuit board 3.

15 The base 1 includes a plurality of upright fins 12, wherein each two adjacent fins 12 have a 16 passage 13 therebetween to allow air to flow therethrough, thereby providing a better heat 17 dissipating effect. The fins 12 may by formed along a periphery of the base 1, thereby defining 18 a central compartment 14 for receiving a fan impeller 21 pivotally mounted under the cover Is plate 2. order to have a lower height (smaller thickness) and better positioning effect, the fins 20 12 formed on two opposite sides of the base 1 are of a height lower than the fins 12 formed on 21 the other two opposite sides of the base 1. Thus, the cover plate 2 may rest on tops of the lower 22 fins 12 and two opposite sides of the cover plate 2 are held between the higher fins 12.

23 The cover plate 2 includes a number of downwardly extending posts 22, each post 22 24 having a snap fastener 23 on a lower distal end hereof. As illustrated in Figs. 1 and 3, the snap 25 fastener 23 of each post 22 has a longitudinal slit 231 to provide the snap fastener with required 26 resiliency for compression and expansion in a radial direction when the snap fastener is passed 27 through a positioning hole 11 or 31. Thus, the snap fastener 23 is compressed when passing

1 through a positioning hole 11 or 31 and then expands to its initial shape and retains on an 2 underside of the circuit board 3 after passing through the positioning hole 31. An elastic 3 element 24 is sleeved around each post 22 in which an end of the elastic element 24 is pushing 4 to the cover plate 2 and the other end of the elastic element 24 is pushing to the base 1 for 5 forcing the cover plate 2 away front the base 1 to thereby securely engaging the heat-dissipating 6 device onto the circuit board 3 by the posts 22 of the cover plate 2. The fan impeller 71 may be 7 mounted under the cover plate 2 to drive air to flow, thereby providing the base 1 with better 8 heat-dissipating effect.

9 Figs. and 3 show assembly between the heat-dissipating device and the circuit board.

10 The cover plate 2 and the base 1 are engaged with each other by the posts 22 of the cover plate 11 2 extending throu;,h the positioning holes 11 and 31 of the base I and the circuit board 3, 12 respectively. The snap fasteners 23 are retained on the omer side of the positioning holes 31, as 13 mentioned above, thereby obtaining reliable engagement.

14 Fig 4 illustrates a second embodiment of the invention, wherein the cover plate 2 has an 15 area larger than that of the base 1, and the posts 22 of the cover plate 2 of the heat-dissipating 16 device are not extended through the base 1. stead, the posts 22 of the cover plate 2 are 17 directly extended through the positioning holes 31 of the circuit board 3, thereby providing a 18 reliable engagement in an easier manner.

19 Figs. 5 and 6 illustrate a third embodiment of the invention, wherein the base 1 includes a 20 number of outwardly extending positioning tab 15. Each positioning tab 1' includes a 21 positioning hole 11 through which an associated post 22 of the cover plate 2 extends. As 22 mentioned above, the each post 22 has a snap fastener 23 that is retained on the other side of an 23 associated positioning hole 31 of the circuit board 3. Thus, the heat-dissipating device is 24 securely and easily engaged with the heat-generatin element 32 in an intimate contact 25 manner. 96 Fig. 7 illustrates a fourth embodiment of the invention. The base 4 is made of metal of 27 excellent thermal conductivity. The base 4 has a flat underside to be in intimate contact with a

1 heat-generating element 32 that is mounted on a circuit board 3. The base 4 includes a number 2 of positioning holes 41 through which a fastener 46 (such as a bolt or screw) is extended for 3 engaging with the cover plate 5, which will be described later. The base 4 includes a plurality of 4 upright fins 42, wherein each two adjacent fins 42 have a passage 43 therebetween to allow air S to flow therethrough, thereby providing a better heat-dissipating effect. The fins 42 may be 6 formed along a periphery of the base 4, thereby defining a central compartment 44 for 7 receiving a fan impeller 51 pivotally mounted under the cover plate 5. In order to have a 8 lower height and better positioning effect, the fins 42 formed on two opposite sides of the base 9 4 are of a height lower than the fins 42 formed on the other two opposite sides of the base 4.

10 Thus, the cover plate 5 may rest on tops of the lower fins 42 and two opposite sides of the cover 11 plate 5 are held between the higher fins 42.

12 The cover plate 5 includes a number of downwardly extending posts 52, each post 5' 13 having a positioning hole 53 in a lower distal end thereof for engaging with a fastener 46 14 (such as a bolt or screw) that extends through an associated positioning hole 41 of the base 4, lS thereby securely engaging the cover plate 5 and the base 4 together. A number of engaging 16 members 55 are provided and each includes a positioning hole 551 through which an 17 associated post 52 is extended. Each engaging member 55 further includes an engaging pet 18 552 with a snap fastener 553 on a lower distal end thereof. As illustrated in Figs. 7 and 9, the 19 snap fastener 553 of each engaging peg 552 has a longitudinal slit S54 to provide the snap 20 fastener 553 with required resiliency for compression and expansion in a radial direction 21 when the snap fastener is passed through a positioning hole 31. Thus, the snap fastener S53 is 22 compressed when passing through a positioning hole 31 and then expands to its initial shape 23 and retains on an underside of the circuit board 3 after passing through the positioning hole 31.

24 An elastic element 54 is mounted around each post 52 or engaging peg 552, thereby providing 25 the snap fastener 553 of the engaging member 55 with better positioning effect. Again, the fan 26 impeller 51 may be mounted under cover plate 5 to drive air to flow, thereby providing the 27 base 4 with better heat-dissipating erect.

I Figs. 8 and 9 show assembly between the heat-dissipating device and the circuit board.

2 The cover plate 5 and the base 4 are engaged with each other by the engaging peg 552 of each 3 engaging member 53 extending through the positioning holes 31 of the circuit board 3. The 4 snap fasteners 553 are retained on the other side of the positioning holes 31, as mentioned 5 above, thereby obtaining reliable engagement.

6 Fig 10 illustrates a fifth embodiment of the invention, wherein the base 4 and the cover 7 plate 5 have more positioning holes 41 and more posts 52. Each positioning hole 41 may have a 8 countersink 411 to receive a lower end of an associated post 52, thereby providing a more 9 reliable engagement. It is noted that only two posts 52 are provided with the engaging members 10 55 without adversely affecting the reliable engagement between the base 4 and the cover plate 11 5. 12 Figs. 11 and 12 illustrate a sixth embodunent of the invention, wherein the base 4 13 includes a number of outwardly extending positioning tab 40 each having a positioning hole 45 14 through which an engaging peg 552 of an associated engaging member 55 is extended. The 15 snap fastener 553 of each engaging peg 552 is retained on the other side of the associated 16 positiorung hole 31 of the circuit board 3. Thus, the heat-dissipating device is easily and 17 securely engaged with the heat-generating element in an intimate contact manner.

18 Fig. 13 illustrates a seventh embodiment of the invention, wherein the engaging member 19 (now designated by 56) includes two horizontally extending upper and lower plates 561 and 20 562. Each plate 561, 562 has a positioning hole 563 through which an associated post 52 71 extends. Provision of the upper and lower plates 561 and 562 provide more reliable engagement 92 between the post 52 and the engaging member 56.

23 According to the above description, it is appreciated that the heatdissipating device and

24 the heat-generating element can be easily secured together by the mounting device in 25 accordance with the present invention. The base of the heat-dissipating device is in intimate 26 contact with the heatgenerating element to obtain optimal heat-dissipating eject. The height of 27 the heat-dissipating device is relatively low after the heatdissipating device and the heat

I generating element are engaged together.

2 Although the invention has been explained in relation to its preferred embodiment as 3 mentioned above, it is to be understood that many other possible modifications and variations 4 can be made without departing from the spins and scope of the invention. It is, therefore, 5 contemplated that the appended claims will cover such modifications and variations that fall 6 within the true scope of the invention.

Claims

CLAIMS:

1. A combination of a circuit board and a heat-dissipating device, comprising: 5 a circuit board including a heat-generating element mounted thereon and a plurality of first positioning holes; and a heatdissipating device including a base made of thermal conductive material and a cover plate mounted on top of the base, the base including an underside in intimate contact with the heat-generating element, the base 10 further including a plurality of fins and a plurality of second positioning holes, the cover plate including a plurality of posts, further comprising two engaging members respectively mounted around two of the posts, each said engaging member including an engaging peg, each said peg having a snap fastener formed on a distal end thereof, each said snap fastener being extended through 15 an associated said first positioning hole of the circuit board and retained on an underside of the circuit board.

2. The combination of a circuit board and a heat-dissipating device as claimed in claim 1, wherein each said post of the cover plate includes a 20 further positioning hole for engaging with the base by a fastener.

3. The combination of a circuit board and a heat-dissipating device as claimed in claim 1, wherein each said snap fastener includes a slit to provide the snap fastener with resiliency such that the snap fastener is capable of 25 being compressed and then expanded.

4. The combination of a circuit board and a heat-dissipating device as claimed in claim 1, wherein each said post includes an elastic element sleeved therearound.

5. The combination of a circuit board and a heat-dissipating device as claimed in claim 1, wherein each said engaging peg includes an elastic element sleeved therearound.

5

6. The combination of a circuit board and a heat-dissipating device as claimed in claim 1, wherein the fins are formed along four sides of the base, and wherein the fins formed on two opposite sides of the four sides of the base are lower than the fins formed on the other two opposite sides of the four sides of the base, the cover plate being resting on tops of the fins that are 10 relatively lower, and two opposite sides of the cover plate being held between the fins that are relatively higher.

7. The combination of a circuit board and a heat-dissipating device as claimed in claim 1, wherein each said second positioning hole of the base 15 includes a countersink for receiving a lower end of an associated said post of the cover plate.

8. The combination of a circuit board and a heat-dissipating device as claimed in claim 1, wherein the engaging member includes at least two 20 parallel plates each having a through-hole through which an associated said post of the cover plate extends.

9. The combination of a circuit board and a heat-dissipating device as claimed in claim 1, wherein the cover plate includes a fan impeller pivotally 25 mounted thereon.

10. A combination of a circuit board and a heat-dissipating device, comprising: a circuit board including a heat-generating element mounted thereon 30 and a plurality of first positioning holes; and

a heat-dissipating device including a base made of thermal conductive material and a cover plate mounted on top of the base, the base including an underside in intimate contact with the heat-generating element, the base further including a plurality of fins defining a compartment therebetween, the 5 base further including a plurality of second positioning holes and a plurality of outwardly extending positioning tabs, each said positioning plate including a third positioning hole, the cover plate including a plurality of posts, further comprising two engaging members respectively mounted around two of the posts, each said engaging member including an engaging peg, each said peg 10 having a snap fastener formed on a distal end thereof, each said snap fastener being extended through said third positioning hole of an associated said positioning tab and an associated said first positioning hole of the circuit board and retained on an underside of the circuit board.

IS

11. The combination of a circuit board and a heat-dissipating device as claimed in claim 10, wherein each said post of the cover plate includes a further positioning hole for engaging with the base by a fastener.

12. The combination of a circuit board and a heat-dissipating device as 20 claimed in claim 10, wherein each said snap fastener includes a slit to provide the snap fastener with resiliency such that the snap fastener is capable of being compressed and then expanded.

13. The combination of a circuit board and a heat-dissipating device as 25 claimed in claim 10, wherein each said post includes an elastic element sleeved therearound.

14. The combination of a circuit board and a heat-dissipating device as claimed in claim 10, wherein each said engaging peg includes an elastic 30 element sleeved therearound.

15. The combination of a circuit board and a heat-dissipating device as claimed in claim 10, wherein the fins are formed along four sides of the base, and wherein the fins formed on two opposite sides of the four sides of the base are lower than the fins formed on the other two opposite sides of the four 5 sides of the base, the cover plate being resting on tops of the fins that are relatively lower, and two opposite sides of the cover plate being held between the fins that are relatively higher.

16. The combination of a circuit board and a heat-dissipating device as 10 claimed in claim 10, wherein each said second positioning hole of the base includes a countersink for receiving a lower end of an associated said post of the cover plate.

17. The combination of a circuit board and a heat-dissipating device as 15 claimed in claim 10, wherein the engaging member includes at least two parallel plates each having a through-hole through which an associated said post of the cover plate extends.

18. The combination of a circuit board and a heat-dissipating device as 20 claimed in claim 10, wherein the cover plate includes a fan impeller pivotally mounted thereon.

19. A heat-dissipating device for a heat-generating element, comprising: a base made of thermal conductive material and including a plurality 25 of fins and a plurality of positioning holes; and a cover plate mounted on top of the base and including a plurality of posts, each said post having an engaging member mounted therearound, each said engaging member including an engaging peg, each said peg having a snap fastener formed on a distal end thereof.

20. The heat-dissipating device as claimed in claim 19, wherein each said post of the cover plate includes a further positioning hole for engaging with the base by a fastener.

5

21. The heat-dissipating device as claimed in claim 19, wherein each said snap fastener includes a slit to provide the snap fastener with resiliency such that the snap fastener is capable of being compressed and then expanded.

22. The heat-dissipating device as claimed in claim 19, wherein each said 10 post includes an elastic element sleeved therearound.

23. The heat-dissipating device as claimed in claim 19, wherein each said engaging peg includes an elastic element sleeved therearound.

15

24. The heat-dissipating device as claimed in claim 19, wherein the fins are formed along four sides of the base, and wherein the fins formed on two opposite sides of the four sides of the base are lower than the Ems formed on the other two opposite sides of the four sides of the base, the cover plate being resting on tops of the fins that are relatively lower, and two opposite sides of 20 the cover plate being held between the fins that are relatively higher.

25. The heat-dissipating device as claimed in claim 19, wherein each said positioning hole of the base includes a countersink for receiving a lower end of an associated said post of the cover plate.

26. The heat-dissipating device as claimed in claim 19, wherein the base includes a plurality of outwardly extending positioning tabs, each said positioning tab including a hole through which an associated said engaging peg extends.

27. The heat-dissipating device as claimed in claim 19, wherein the engaging member includes at least two parallel plates each having a through-

hole through which an associated said post of the cover plate extends.

5

28. The heat-dissipating device as claimed in claim 19, wherein the cover plate includes a fan impeller pivotally mounted thereon.

29. A combination of a circuit board and a heat-dissipating device, . compnsmg: 10 a circuit board including a heat-generating element mounted thereon and a plurality of first positioning holes; and a heatdissipating device including a base made of thermal conductive material and a cover plate, the base including an underside in intimate contact with the heat-generating element, the base further including a plurality of 15 second positioning holes aligned with the first positioning holes, respectively, the base further including a plurality of fins, the cover plate including a plurality of posts, each said post including a snap fastener formed on a distal end thereof, each said post being extended through an associated said second positioning hole of the base and an associated said first positioning hole of the 20 circuit board and retained on an underside of the circuit board.

30. The combination of a circuit board and a heat-dissipating device as claimed in claim 29, wherein each said snap fastener includes a slit to provide the snap fastener with resiliency such that the snap fastener is capable of 25 being compressed and then expanded.

31. The combination of a circuit board and a heat-dissipating device as claimed in claim 29, wherein each said post includes an elastic element sleeved therearound.

32. The combination of a circuit board and a heat-dissipating device as claimed in claim 29, wherein the fins are formed along four sides of the base, and wherein the fins formed on two opposite sides of the four sides of the base are lower than the fins formed on the other two opposite sides of the four 5 sides of the base, the cover plate being resting on tops of the fins that are relatively lower, and two opposite sides of the cover plate being held between the fins that are relatively higher.

33. The combination of a circuit board and a heat-dissipating device as 10 claimed in claim 29, wherein the cover plate includes a fan impeller pivotally mounted thereon.

34. A combination of a circuit board and a heat-dissipating device, . comprlsmg: 15 a circuit board including a heat-generating element mounted thereon and a plurality of positioning holes; and a heat-dissipating device including a base made of thermal conductive material and a cover plate, the base including an underside in intimate contact with the heatgenerating element, the base further including a plurality of fins 20 that define a compartment therebetween, the cover plate including a plurality of posts, each said post including a snap fastener formed on a distal end thereof, each said post being extended through an associated said positioning hole of the circuit board and retained on an underside of the circuit board.

25

35. The combination of a circuit board and a heat-dissipating device as claimed in claim 34, wherein each said snap fastener includes a slit to provide the snap fastener with resiliency such that the snap fastener is capable of being compressed and then expanded.

36. The combination of a circuit board and a heat-dissipating device as claimed in claim 34, wherein each said post includes an elastic element sleeved therearound.

S

37. The combination of a circuit board and a heat-dissipating device as claimed in claim 34, wherein the fins are formed along four sides of the base, and wherein the fins formed on two opposite sides of the four sides of the base are lower than the fins formed on the other two opposite sides of the four sides of the base, the cover plate being resting on tops of the fins that are 10 relatively lower, and two opposite sides of the cover plate being held between the fins that are relatively higher.

38. The combination of a circuit board and a heat-dissipating device as claimed in claim 34, wherein each said cover plate includes a fan impeller 15 pivotally mounted "hereon.

39. A heat-dissipating device for a heat-generating element, comprising: a base made of thermal conductive material and including a plurality of fins; and 20 a cover plate including a plurality of posts, each said post including a snap fastener formed on a distal end thereof, each said snap fastener having resiliency such that the snap fastener is capable of being compressed and then expanded. 25

40. The heat-dissipating device as claimed in claim 39, wherein each said post includes an elastic element mounted therearound.

41. The heat-dissipating device as claimed in claim 39, wherein the fins are formed along four sides of the base, and wherein the fins formed on two 30 opposite sides of the four sides of the base are lower than the fins formed on the other two opposite sides of the four sides of the base, the cover plate being

resting on tops of the fins that are relatively lower, and two opposite sides of the cover plate being held between the fins that are relatively higher.

42. The heat-dissipating device as claimed in claim 39, wherein the base 5 includes a plurality of positioning holes through which the posts of the cover plate extend, respectively.

43. The heat-dissipating device as claimed in claim 39, wherein the cover plate includes a fan impeller pivotally mounted thereon.