Package lid structure and methods of testing the same

A method of manufacturing a packaging structure, the method comprising:

• providing a composite package comprising at least one semiconductor die and a die frame;
• attaching the composite package to a packaging substrate to form a bonded assembly;
• providing a lid structure comprising a bottom plate portion, a top plate portion that is vertically spaced from the bottom plate portion, a sidewall frame portion laterally surrounding a cavity located between the bottom plate portion and the top plate portion, and solid block portions located within the sidewall frame portion and vertically extending from a first horizontal plane including a bottom surface of the bottom plate portion to a second horizontal plane including a top surface of the top plate portion and located in corner regions of the lid structure;
• and
• attaching the lid structure to the bonded assembly such that a thermal interface material (TIM) layer is interposed between the at least one semiconductor die and the bottom plate portion, wherein the solid block portions are located entirely outside of areas of the at least one semiconductor die in a plan view along a vertical direction.