Apparatus for and method of cooling molded electronic circuits

• US 7,885,076 B2
• Filed: 09/06/2005
• Issued: 02/08/2011
• Est. Priority Date: 09/07/2004
• Status: Active Grant

• Current Assignee: Flextronics America LLC (Flextronics International Limited)
• Original Assignee: Flextronics America LLC (Flextronics International Limited)
• Inventors: Jansen, Arian, Sharifipour, Bahman
• Primary Examiner(s): Chervinsky; Boris L
• Assistant Examiner(s): SMITH, COURTNEY L
• Application Number:
  US11/220,811
• Publication Number:
  US 20060076124A1
• Time in Patent Office: 1,981 Days
• Field of Search: 361/704, 361/719, 361/713, 361/717, 361/707, 361/709, 361/710, 361/715, 361/730, 361/752, 165/80.3, 165/104.15, 165/80.2, 174/16.3, 439/501, 439/502, 439/505, 439/485, 439/620, 439/957, 439/76.1, 439/146, 439/276, 439/936, 439/120, 439/126, 636/80
• US Class Current: 361/707
• CPC Class Codes: H01R 13/6658 on printed circuit board H01R13/6666 - H01R13/6691 take precedence
• CPC Class Codes: H01R 24/28 Coupling parts carrying pins, blades or analogous contacts and secured only to wire or cable
• CPC Class Codes: H05K 7/20463 Filling compound, e.g. potted resin
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing

Abstract

An electronic device such as an AC/DC power adapter includes a conductive heat dissipation system. The device contains heat generating components and is powered via power supply leads by an external power supply circuit. The device further contains a thermally conductive mass that is thermally coupled to both the heat generating components and to the power supply leads. When the power supply leads are coupled to receive electricity from the external power supply circuit, heat generated by the device is thermally conducted into the external power supply circuit via the power supply leads.

Claims

1. A compact power conversion device comprising:

a) AC power supply leads comprising a prong end configured to plug into an AC wall socket coupled to an AC power supply network and a thermally conductive end;

b) an AC to DC (AC/DC) power conversion circuit configured to receive electric power from the AC power supply network via the AC power supply leads;

c) a heat conductive body thermally coupled with the AC/DC power conversion circuit and thermally coupled to the thermally conductive end of the AC power supply leads, wherein the thermally conductive end is configured to conduct heat generated by the AC/DC power conversion circuit to the AC power supply leads, into the AC wall socket, and into the AC power supply network and further wherein the heat conductive body is molded around the AC/DC power conversion circuit and is molded around the thermally conductive end forming a contact area wherein the contact area is configured for the heat to flow through the AC power supply leads, into the AC wall socket and into the AC power supply network; and

d) a substantially rigid body encasing the heat conductive body and the AC/DC power conversion circuit wherein the prong end of the AC power supply leads protrude from the rigid and wherein a thermal conductivity of the rigid body is configured such that the heat conductive body substantially efficiently transfers heat from AC/DC the power conversion circuit to the AC power supply leads, wherein the substantially rigid body limits thermal conductivity such that the rigid body external surface does not exceed 70°

C. in temperature.

2. The compact power conversion device of claim 1, further comprising power output leads coupled with the power conversion circuit.

3. The compact power conversion device of claim 1, further comprising a substantially rigid body coupled with the heat conductive body and with the AC/DC power conversion circuit to provide structural support.

4. The compact power conversion device of claim 1, wherein the heat conductive body forms also a structural enclosure for the AC/DC power conversion circuit and the thermally conductive end.

5. The compact power conversion device of claim 4, wherein the heat conductive body provides a structural element in an electrical housing.

6. The compact power conversion device power converter of claim 1, wherein the electrically inert, thermally conductive mass heat conductive body forms also a structural enclosure for the circuit and the AC power supply leads.

7. The compact power conversion device power converter of claim 1, wherein the electrically inert, thermally conductive mass heat conductive body is configured to provide structural support in an electrical housing.

15. The compact power conversion device of claim 1, wherein:

the AC power supply leads each extend out of the substantially rigid body all the way to the end of their prong end in a straight path, wherein the straight paths are parallel to one another; and

each AC power supply lead comprises a fixed position relative to the substantially rigid body.

8. A method of cooling an AC/DC electronic device supplied by an external power source, the method comprising:

a) thermally coupling for substantially efficient heat transfer at least a portion of the AC/DC electronic device to a thermally conductive body;

b) thermally coupling, at least a portion of each of a plurality of AC power supply leads and AC/DC electronic device to the thermally conductive body by molding the thermally conductive body around the AC/DC electronic device and each of a plurality of AC power supply leads, wherein the AC power supply leads are configured to plug into an AC wall socket; and

c) encasing the thermally conductive body and the AC/DC electronic device in a substantially rigid body wherein the AC power supply leads protrude from the body and wherein a thermal conductivity of the rigid body is configured so that there is a substantially efficient heat transfer through thermally conductive body to the AC power supply leads, wherein the substantially rigid body limits heat dissipation such that the surface temperature of the substantially rigid body does not exceed 70°

C. in temperature.

9. The method of cooling an AC/DC electronic device of claim 8, enclosing the AC/DC electronic device, at least a portion of each of the plurality of AC power supply leads and the thermally conductive body in any appropriate, rigid shell body, whereby the AC/DC electronic device is simultaneously embedded in the rigid shell material and in the thermally conductive body.

16. The method of cooling the AC/DC electronic device of claim 8, wherein:

the AC power supply leads each extend out of the substantially rigid body in a straight path, wherein the straight paths are parallel to one another; and

each AC power supply lead comprises a fixed position relative to the substantially rigid body.

10. An AC/DC converter assembly comprising:

a) an AC/DC converter circuit having a primary portion and a secondary portion, the primary portion and the secondary portion having a space between them with a thickness;

b) a plurality of AC plugs coupled with the AC/DC converter circuit, wherein the AC plugs are configured to plug into an AC wall socket coupled to an AC power supply network;

c) a housing comprising a thermally conductive and electrically resistive body molded around the primary portion of the AC/DC converter circuit and also around each of the plurality of AC plugs so that the thermally conductive and electrically resistive body is thermally coupled with the AC plugs and the AC/DC converter circuit; and

d) a substantially rigid encasing the housing and the AC/DC converter circuit wherein the AC plugs protrude from the substantially rigid body and wherein a thermal conductivity of the substantially rigid body is configured to substantially efficiently conduct heat transfer from the AC/DC converter circuit through the housing to the AC plugs and one to the AC wall socket and to the AC power supply network, wherein the substantially rigid body limits heat dissipation such that the surface temperature of the substantially rigid body does not exceed 70°

C. in temperature.

11. The AC/DC converter assembly of claim 10, wherein the space between the primary portion and the secondary portion is filled by the substantially rigid body.

12. The AC/DC converter assembly of claim 10, wherein the thickness is less than 1 millimeter.

13. The AC/DC converter assembly of claim 10, wherein the housing is for providing a structural enclosure for the primary portion of the AC/DC converter circuit.

17. The AC/DC converter assembly of claim 10, wherein:

the AC plugs each extend out of the substantially rigid body in a straight path, wherein the straight paths are parallel to one another; and

each AC plug comprises a fixed position relative to the substantially rigid body.

14. A method of manufacturing a power adaptor, comprising the steps of:

a) providing an AC/DC power conversion circuit, including a plurality of AC power supply leads configured to plug into an AC wall socket, power conversion components, and power output leads;

b) molding a heat conductive material around the power conversion components to form an AC plug structure and integrated strain relief structure thermally connected to one or more of the plurality of AC power supply leads and the AC/DC power conversion circuit; and

c) encasing the heat conductive material and the power conversion components with a housing wherein the AC power supply leads protrude from the housing and wherein a thermal conductivity of the housing is configured such that is a substantially efficient heat transfer of the heat generated by the power conversion components through the heat conductive material to the AC power supply leads and into the AC wall socket, of sufficient thermal conductivity to not exceed 70 degrees centigrade.

18. The method of claim 14, wherein:

the AC power supply leads each extend out of the housing in a straight path, wherein the straight paths are parallel to one another; and

each AC power supply lead comprises a fixed position relative to the housing.

19. A compact conversion device comprising:

a) AC power supply leads comprising a prong end configured to plug into an AC wall socket coupled to an AC power supply network and a thermally conductive end;

b) an AC to DC (AC/DC) power conversion circuit configured to receive electric power from the AC power supply network via the AC power supply leads;

c) a heat conductive body thermally coupled with the AC/DC power conversion circuit and thermally coupled to the thermally conductive end of the AC power generated by the AC/DC power conversion circuit to the AC power supply leads, into the AC wall socket, and into the AC power supply network; and

d) a substantially rigid body encasing the heat conductive body and the AC/DC power conversion circuit wherein the prong end of the AC power supply leads protrude from the rigid body and wherein a thermal conductivity of the rigid body is configured such that the heat conductive body substantially efficiently transfers heat from AC/DC the power conversion circuit to the AC power supply leads, wherein the substantially rigid body limits thermal conductivity such that the rigid body external surface does not exceed 70°

C. in temperature, wherein the heat conductive body is positioned between the AC power supply leads and the substantially rigid body.

20. A compact conversion device comprising:

a) AC power supply leads comprising a prong end configured to plug into an AC wall socket coupled to an AC power supply network and a thermally conductive end;

b) an AC to DC (AC/DC) power conversion circuit configured to received electric power from the AC power supply network via the AC power supply leads;

c) a hat conductive body thermally coupled with the AC/DC power conversion circuit and thermally coupled to the thermally conductive end of the AC power supply leads, wherein the thermally conductive end is configured to conduct heat generated by the AC/DC power conversion circuit to the AC Power supply leads, into the AC wall socket, and into the AC power supply network; and

d) a substantially rigid body encasing the heat conductive body and the AC/DC power conversion circuit wherein the prong end of the AC power supply leads protrude from the rigid body and wherein a thermal conductivity of the rigid body is configured such that the heat conductive body substantially efficiently transfers heat from AC/DC the power conversion circuit to the AC power supply leads, wherein the substantially rigid body limits thermal conductivity such that the rigid body external surface does not exceed 70°

C. in temperature, wherein the heat conductive body is positioned between the AC/DC power conversion circuit and the substantially rigid body.

21. A compact power conversion device comprising:

a) AC power supply leads comprising a prong end configured to plug into an AC wall socket coupled to an AC power supply network and a thermally conductive end;

b) an AC to DC (AC/DC) power conversion circuit configured to receive electric power from the AC power supply network via the AC power supply leads;

c) a heat conductive body thermally coupled with the AC/DC power conversion circuit and thermally coupled to the thermally conductive end of the AC power supply leads, wherein the thermally conductive end is configured to conduct heat generated by the AC/DC power conversion circuit to the AC power supply leads, into the AC wall socket, and into the AC power supply network; and

d) a substantially rigid body encasing the heat conductive body and the AC/DC power conversion circuit wherein the prong end of the AC power supply leads protrude from the rigid body and wherein a thermal conductivity of the rigid body is configured such that the heat conductive body substantially efficiently transfers heat from AC/DC the power conversion circuit to the AC power supply leads, wherein the substantially rigid body limits thermal conductivity such that the rigid body external surface does not exceed 70°

C. in temperature, wherein the heat conductive body is positioned between the AC power supply leads, the AC/DC power supply and the substantially rigid body.