Patent ID: 11869861
Assignee: TENCENT TECHNOLOGY (SHENZHEN) COMPANY LIMITED
Field: Optics (Instruments)
Classification: CPC G  H | IPC G  H

Claim 14:
15. A method for preparing a solder joint, the method comprising:
applying a first photoresist layer over a substrate;
applying a second photoresist layer over the first photoresist layer;
masking a part of a surface of the second photoresist layer with a mask;
underexposing the part of the second photoresist layer that is not masked by the mask to obtain a processed second photoresist layer;
developing and fixing the processed second photoresist layer to form an undercut structure on the processed second photoresist layer and to expose a portion of the first photoresist layer;
etching the first photoresist layer through the undercut structure to form an exposed area of the substrate; and
depositing a material on the exposed area to form a solder joint.