Interconnect for battery packs
Provided are interconnect circuits for interconnecting arrays of battery cells and methods of forming these interconnect circuits as well as connecting these circuits to the battery cells. An interconnect circuit may include a conductive layer and one or more insulating layers. The conductive layer may be patterned with openings defining contact pads, such that each pad is used for connecting to a different battery cell terminal. In some embodiments, each contact pad is attached to the rest of the conductive layer by a fusible link formed from the same conductive layer as the contact pad. The fusible link controls the current flow to and from this contact pad. The insulating layer is laminated to the conductive layer and provides support to the contacts pads. The insulating layer may also be patterned with openings, which allow forming electrical connections between the contact pads and cell terminals through the insulating layer.
1. A method of forming an interconnect circuit for interconnecting an array of battery cells, the method comprising:
forming a set of conductive layer openings in a conductive layer,
wherein the conductive layer openings in the set are separated from each other by two or more connecting tabs,
wherein the set of the conductive layer openings and the two or more connecting tabs surround and define a region of the conductive layer, and
wherein, after forming the set of the conductive layer openings, the two or more connecting tabs mechanically support and maintain registration of the region of the conductive layer relative to other portions of the conductive layer;
laminating the conductive layer comprising the set of the conductive layer openings to a support layer,
wherein, after laminating the conductive layer to the support layer, the support layer mechanically supports and maintains registration of the region of the conductive layer relative to the other portions of the conductive layer; and
removing at least one of the two or more connecting tabs,
wherein removing the at least one of the two or more connecting tabs converts the set of the conductive layer openings into a continuous conductive layer channel at least partially surrounding and defining the region of the conductive layer.
2. The method of claim 1 , wherein at least another one of the two or more connecting tabs is retained while removing the at least one of the two or more connecting tabs, and wherein the at least one retained of the two or more connecting tabs interconnects the region of the conducive layer with the other portions of the conductive layer.
3. The method of claim 2 , wherein the at least one retained of the two or more connecting tabs is operable as a fusible link and limits an electrical current level between the region of the conducive layer with the other portions of the conductive layer.
4. The method of claim 2 , wherein the continuous conductive channel ends at the at least one retained of the two or more connecting tabs.
5. The method of claim 4 , wherein the continuous conductive channel has an open ring shape.
6. The method of claim 1 , wherein removing the at least one of the two or more connecting tabs comprises removing all of the two or more connecting tabs.
7. The method of claim 1 , wherein removing the at least one of the two or more connecting tabs also removes at least one support layer portion of the support layer laminated to the at least one of the two or more connecting tabs.
8. The method of claim 1 , wherein the support layer is operable as a first insulating layer and remains a part of the interconnect circuit.
9. The method of claim 8 , wherein the support layer remains substantially intact while removing the at least one of the two or more connecting tabs.
10. The method of claim 1 , further comprising:
after removing the at least one of the two or more connecting tabs, laminating a first insulating layer to the conductive layer such that the conductive layer is disposed between the first insulating layer and the support layer; and
after laminating the first insulating layer to the conductive layer, removing the support layer from the conductive layer.
11. The method of claim 10 , wherein the first insulating layer comprises first insulating layer openings prior to laminating the first insulating layer to the conductive layer, and wherein the conductive layer openings provide aligning features for the first insulating layer openings during lamination of the first insulating layer to the conductive layer.
12. The method of claim 10 , wherein the first insulating layer comprises first insulating layer slits prior to laminating the first insulating layer to the conductive layer, and
wherein, after laminating the first insulating layer to the conductive layer, the first insulating layer slits are positioned within a boundary of the continuous conductive layer channel.
13. The method of claim 10 , wherein, prior to laminating the first insulating layer to the conductive layer, the first insulating layer comprises first insulating layer openings, and
wherein, after laminating the first insulating layer to the conductive layer, at least one of the insulating layer openings overlaps with the region of the conductive layer.
14. The method of claim 13 , wherein edges of the region of the conductive layer are supported by the first insulating layer.
15. The method of claim 10 , further comprising:
after removing the support layer from the conductive layer, laminating a second insulating layer to the conductive layer such that the conductive layer is disposed between the first insulating layer and the second insulating layer.
16. The method of claim 15 , wherein the first insulating layer comprises first insulating layer opening, and wherein the second insulating layer comprises a second insulating layer opening partially overlapping with the first layer opening.
17. The method of claim 1 , wherein the interconnect circuit is further bonded to a heat sink.
18. The method of claim 1 , further comprising:
prior to laminating the conductive layer to the support layer, forming the conductive layer comprising a base sublayer and a surface sublayer,
wherein the base sublayer has a different composition than the surface sublayer, and
wherein forming the conductive layer comprises forming the surface sublayer over the base sublayer.
19. The method of claim 18 , wherein forming the conductive layer further comprises forming an intermediate sublayer over the base sublayer and prior to forming the surface sublayer, and wherein a composition of each of the base sublayer and the surface sublayer is different from a composition of the intermediate sublayer.
20. The method of claim 18 , wherein the surface sublayer directly contacts at least one of a first insulating layer or a second insulating layer in the interconnect circuit.