Process for localized repair of graphene-coated lamination stacks and printed circuit boards
Processes for localized lasering of a lamination stack and graphene-coated printed circuit board (PCB) are disclosed. An example PCB may include a lamination stack, post-lamination, that may further include a core, an adhesive layer, and at least one graphene-metal structure. A top layer of graphene of the graphene-metal structure may have never been grown before the lamination process or may have been removed post-lamination such that a portion of the top layer of graphene is missing. The localized lasering process described herein may grow (for the first time) or re-grow the graphene layer of the exposed portion of the metal layer without adverse effects to the rest of the lamination stack or PCB and while promoting a uniform layer of graphene on the top surface. A process of growing graphene through application of molecular layer and a self-assembled monolayer (SAM), are also described herein.
1. A method of repairing one or more layers of a lamination stack or Printed Circuit Board (PCB) comprising:
providing a layered structure, wherein an outer layer comprises a graphene-metal structure, and wherein the graphene-metal structure comprises a metal layer and an outer graphene layer disposed on the metal layer;
identifying a defect location in the outer graphene layer, wherein the defect location comprises an absence of graphene due to failed graphene growth or removal of the graphene post-growth on the metal layer, wherein the absence of graphene at the defect location exposes a portion of the metal layer;
preparing a surface of the outer graphene layer for repair, wherein the surface of the outer graphene layer comprises at least the defect location; and
applying localized heat to the defect location,
wherein application of the localized heat encourages growth of graphene in the defect location.
2. The method of claim 1 , wherein preparing the surface of the outer graphene layer comprises cleaning a surface of the metal layer in the defect location prior to the application of localized heat.
3. The method of claim 1 , wherein preparing the surface of the outer graphene layer comprises applying a molecular layer to the metal layer in the defect location.
4. The method of claim 3 , further comprising baking the layers.
5. The method of claim 4 , further comprising washing the lamination stack to clean an excess of the molecular layer.
6. The method of claim 1 , wherein preparing the surface of the outer graphene layer comprises applying a self-assembled monolayer to the metal layer in at least the defect location.
7. The method of claim 6 , further comprising washing the layers to clean the self-assembled monolayer.
8. The method of claim 7 , further comprising baking the layers.
9. The method of claim 1 , wherein the layered structure forms at least a portion of a Printed Circuit Board (PCB) and wherein the metal layer comprises a trace of the PCB.
10. The method of claim 1 , wherein the layered structure forms at least a portion of a lamination stack.
11. The method of claim 1 , wherein applying the localized heat comprises applying the localized heat via a laser.
12. The method of claim 11 , further comprising determining a local temperature for configuring the laser, wherein the local temperature is determined by a laser power density and a laser scan rate.
13. The method of claim 1 , wherein applying the localized heat comprises pulsing the localized heat.
14. The method of claim 1 , wherein applying the localized heat comprises continuously applying the localized heat.
15. The method of claim 1 , further comprising cooling the lamination stack at the defect location by pulsing the localized heat.
16. The method of claim 1 , wherein the absence of graphene at the defect location is caused by a scratch or mechanical damage.
17. The method of claim 1 , wherein the localized heat is incident on an outer two-dimensional material precursor of the defect location.