Electrically isolated heat dissipating junction box

• US 10,686,402 B2
• Filed: 07/29/2019
• Issued: 06/16/2020
• 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): Estrada, Angel R
• Application Number:
  US16/524,601
• Publication Number:
  US 20190348946A1
• Time in Patent Office: 323 Days
• Field of Search: 174 50, 174520, 174535, 174 505, 174548, 174559, 174560, 174561, 220 32- 39, 220 402, 361600, 361601, 361676, 36167954, 361688, 361697, 361709
• 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 for electrical power conversion. 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.

Claims

1. A junction box comprising:

a circuit board disposed in a first chamber of the junction box, the circuit board configured to convert electrical power; and

a heat sink configured to dissipate heat generated by the circuit board, the heat sink comprising a dovetail structure adapted to prevent mutual separation of the heat sink from the junction box,

wherein the heat sink is bonded inside the first chamber.

2. The junction box of claim 1, further comprising an outer casing mounted to a photovoltaic panel, wherein the outer casing provides non-electrically conductive isolation between the heat sink and the photovoltaic panel.

3. The junction box of claim 2, further comprising a lid configured to provide the non-electrically conductive isolation between the heat sink and the photovoltaic panel.

4. The junction box of claim 1, further comprising a shield configured to electrically connect to the heat sink, wherein the shield and the heat sink, when electrically connected, form a Faraday cage configured to suppress radio frequency interference emission from the junction box.

5. The junction box of claim 4, further comprising a lid configured to cover the first chamber, wherein the shield is bonded to the lid.

6. The junction box of claim 1, further comprising a thermally conductive pad configured to provide electrical isolation and thermal conductivity between the heat sink and the circuit board.

7. The junction box of claim 1, wherein the first chamber comprises a first rate of thermal expansion and the dovetail structure comprises a second rate of thermal expansion different from the first rate of thermal expansion.

8. The junction box of claim 1, wherein the dovetail structure comprises a hollow structure configured to prevent the mutual separation of the heat sink from the junction box during a curing of a bond between the heat sink and the junction box.

9. The junction box of claim 8, wherein the hollow structure is configured to prevent the mutual separation of the heat sink from the junction box by allowing a portion of the dovetail structure to deform.

10. The junction box of claim 1, 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), or a thermoset.

11. A method comprising:

attaching a circuit board in a first chamber of a junction box, the circuit board configured to convert power; and

bonding a heat sink within the first chamber of the junction box, the heat sink configured to dissipate heat generated by the circuit board, the heat sink comprising a dovetail structure configured to prevent mutual separation of the heat sink from the junction box.

12. The method of claim 11, wherein the first chamber is comprised within an outer casing of the junction box.

13. The method of claim 11, further comprising configuring the dovetail structure to prevent mutual separation of the heat sink from the junction box.

14. The method of claim 11, further comprising:

curing the bond between the heat sink and the junction box inside the first chamber,

wherein the dovetail structure comprises a hollow structure configured to deform during the curing to prevent the mutual separation of the heat sink from the junction box.

15. The method of claim 14, further comprising configuring the hollow structure to prevent the mutual separation of the heat sink from the junction box by allowing a portion of the dovetail structure to deform.

16. The method of claim 11, further comprising bonding the heat sink within the first chamber of the junction box with a thermoplastic injection molding process.

17. The method of claim 11, 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), or a thermoset.

18. The method of claim 11, further comprising mounting an outer casing to a photovoltaic panel, wherein the outer casing provides non-electrically conductive isolation between the heat sink and the photovoltaic panel.

19. The method of claim 11, further comprising electrically connecting a shield to the heat sink, wherein the shield and the heat sink, when electrically connected, form a Faraday cage configured to suppress radio frequency interference emission from the junction box.

20. The method of claim 19 further comprising covering the first chamber with a lid, wherein the shield is bonded to the lid.