Electrically isolated heat dissipating junction box

• US 8,476,524 B2
• Filed: 05/24/2010
• Issued: 07/02/2013
• Est. Priority Date: 05/22/2009
• Status: Active Grant

• Current Assignee: Solaredge Technologies Incorporated
• Original Assignee: Solaredge Technologies Incorporated
• Inventors: Sella, Guy, Handelsman, Lior, Shmukler, Vadim, Adest, Meir, Gazit, Meir, Galin, Yoav
• Primary Examiner(s): Patel, Dhirubhai R
• Application Number:
  US12/785,773
• Publication Number:
  US 20100294528A1
• Time in Patent Office: 1,135 Days
• Field of Search: 174/50, 439/535, 439/709, 439/142, 439/718, 248/906, 220/4.02, 136/244
• US Class Current: 174/50
• CPC Class Codes: G08B 13/1409 for removal detection of electrical appliances by detecting their physical disconnection from an electrical system, e.g. using a switch incorporated in the plug connector
• CPC Class Codes: H02G 15/10 protected by boxes, e.g. by distribution, connection or junction boxes
• CPC Class Codes: H02S 40/34 comprising specially adapted electrical connection means to be structurally associated with the PV module, e.g. junction boxes
• CPC Class Codes: H02S 40/345 with cooling means associated with the electrical connection means, e.g. cooling means associated with or applied to the junction box cooling means for PV cells H01L31/052, for PV modules H02S40/42
• CPC Class Codes: H05K 5/02 Details
• CPC Class Codes: H05K 5/062 sealed by a material injected between a non-removable cover and a body, e.g. hardening in situ
• CPC Class Codes: H05K 7/2039 characterised by the heat transfer by conduction from the heat generating element to a dissipating body arrangements for increasing/decreasing heat-transfer, e.g. fins details, F28F13/00
• CPC Class Codes: H05K 9/0007 Casings standardised racks H05K9/0062
• CPC Class Codes: H05K 9/0009 with provisions to reduce EMI leakage through the joining parts
• CPC Class Codes: H05K 9/0015 Gaskets or seals
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy
• CPC Class Codes: Y10S 248/906 Electrical outlet box support
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing

Abstract

A junction box used for making electrical connections to a photovoltaic panel. The junction box has two chambers including a first chamber and a second chamber and a wall common to and separating both chambers. The wall may be adapted to have an electrical connection therethrough. The two lids are adapted to seal respectively the two chambers. The two lids are on opposite sides of the junction box relative to the photovoltaic panel. The two lids may be attachable using different sealing processes to a different level of hermeticity. The first chamber may be adapted to receive a circuit board. The junction box may include supports for mounting a printed circuit board in the first chamber. The second chamber is configured for electrical connection to the photovoltaic panel. A metal heat sink may be bonded inside the first chamber. The first chamber is adapted to receive a circuit board for electrical power conversion, and the metal heat sink is adapted to dissipate heat generated by the circuit board.

Claims

1. A junction box comprising:

an outer casing configured to be mounted to a photovoltaic panel;

a first chamber within the outer casing, wherein the first chamber includes a plurality of supports adapted to mount a circuit board configured to electrically convert power output from the photovoltaic panel, and wherein the outer casing includes an opening to the first chamber;

a second chamber within the outer casing, wherein the outer casing includes an opening to the second chamber, and wherein the second chamber is configured to provide an electrical connection to the photovoltaic panel;

a double wall adapted to separate the first chamber and the second chamber, wherein the double wall is adapted to allow for mutual separation and re-attachment of the first chamber to the second chamber so that the circuit board is replaceable without requiring disconnection of the second chamber from the photovoltaic panel, and wherein, when the circuit board is mounted in the first chamber, the circuit board in the first chamber is electrically connected to the electrical connection in the second chamber via a re-connectable bus bar, wherein portions of the bus bar are contained in the double wall;

a first lid adapted to seal the opening to the first chamber; and

a second lid adapted to seal the opening to the second chamber.

2. The junction box of claim 1,

wherein the opening to the first chamber and the opening to the second chamber are on opposite sides of the junction box.

3. The junction box of claim 1, wherein the first lid is adapted to seal the first chamber using a first sealing process, and wherein the second lid is adapted to seal the second chamber using a second sealing process different from the first sealing process.

4. The junction box according to claim 1, wherein the first lid is adapted to seal said first chamber with a first level of hermeticity, and wherein the second lid is adapted to seal the second chamber with a second level of hermeticity different from the first level of hermeticity.

5. The junction box of claim 1, wherein the first chamber comprises the circuit board for electrically converting the power output of the photovoltaic panel.

6. The junction box of claim 1, wherein said second chamber comprises an electrical connector for the electrical connection to the photovoltaic panel.

7. The junction box of claim 1, wherein said second chamber is configured to include one or more diodes.

8. The junction box according to claim 1, wherein the second chamber further comprises one or more electrical connection terminals for connecting the circuit board to the photovoltaic panel, wherein the one or more electrical connection terminals are mounted inside said second chamber.

9. The junction box of claim 1, further comprising a metal heat sink bonded to said first chamber during manufacture of the junction box.

10. The junction box of claim 9, wherein said metal heat sink is adapted to dissipate heat generated by said circuit board.

11. The junction box of claim 9, wherein said metal heat sink is molded in the junction box during an injection mold process of manufacture of the first chamber.

12. The junction box of claim 9, wherein said metal heat sink includes a dovetail structure adapted to prevent mutual separation of said metal heat sink from said first chamber.

13. The junction box of claim 12,

wherein the dovetail structure of the metal heat sink comprises a first rate of thermal expansion,

wherein the first chamber comprises a second rate of thermal expansion different from the first rate of thermal expansion,

wherein said dovetail structure comprises a hollow structure adapted to prevent mutual separation of the metal heat sink from the first chamber during a curing of a bond between the metal heat sink and the first chamber by allowing for a deformation of a portion of the dovetail structure.

14. The junction box of claim 9, further comprising a thermal pad adapted to provide thermal conduction and electrical insulation between said circuit board and said metal heat sink.

15. The junction box according to claim 1, wherein each of the first chamber and the second chamber is manufactured by injection molding of one of acrylonitrile butadiene styrene (ABS) thermoplastic, polybutylene terephthalate (PBT), poly(p-phenylene oxide) (PPO), and a thermoset.

16. The junction box of claim 1, wherein the first chamber is a first rectangular chamber, and wherein the second chamber is a second rectangular chamber.

17. A junction box comprising:

an outer casing configured to be mounted to a photovoltaic panel;

a first chamber within the outer casing of the junction box, wherein outer casing includes an opening to the first chamber, and wherein the first chamber includes a plurality of supports adapted to mount a circuit board; and

a metal heat sink having a dovetail structure bonded to the first chamber during manufacture,

wherein the dovetail structure comprises a first rate of thermal expansion,

wherein the first chamber comprises a second rate of thermal expansion different from the first rate of thermal expansion,

wherein the dovetail structure comprises a hollow structure adapted to prevent mutual separation of the metal heat sink from the first chamber during a curing of a bond between the metal heat sink and the first chamber by allowing for a deformation of a portion of the dovetail structure, and

wherein the metal heat sink is adapted to dissipate heat generated by said circuit board.

18. The junction box of claim 17, further comprising:

a second chamber within the outer casing of the junction box, wherein the second chamber is configured to receive an electrical connection to the photovoltaic panel; and

a double wall adapted to separate the first chamber and the second chamber, wherein the double wall is further adapted to allow for mutual separation and re-attachment of the first chamber to the second chamber so that the circuit board is replaceable without requiring disconnection of the second chamber from the photovoltaic panel, and wherein, when the circuit board is mounted in the first chamber, the circuit board in the first chamber is electrically connected to the electrical connection in the second chamber via a re-connectable bus bar, wherein a portion of the bus bar is sealed in the double wall.

19. The junction box according to claim 17, wherein the first chamber is manufactured by injection molding of one of acrylonitrile butadiene styrene (ABS) thermoplastic, polybutylene terephthalate (PBT), poly(p-phenylene oxide) (PPO), and a thermoset.

20. The junction box of claim 17, wherein the first chamber is a first rectangular chamber.

21. A method comprising:

bonding a metal heat sink within a first chamber of an electrically isolated thermoplastic junction box through an injection molding process, wherein the first chamber is within an outer casing of the of electrically isolated thermoplastic junction box; and

forming a junction via a dovetail interface between the metal heat sink and the outer casing inside the first chamber.

22. The method of claim 21, wherein the dovetail interface is adapted to prevent mutual separation of the metal heat sink from the electrically isolated junction box.

23. The method of claim 22, further comprising the step of:

curing the junction between the metal heat sink and the outer casing inside the first chamber,

wherein the dovetail interface comprises a hollow structure adapted to deform during the curing to prevent the mutual separation of the metal heat sink from the electrically isolated thermoplastic junction box.