Circuit substrate processing laminate and method for processing circuit substrate

A circuit substrate processing laminate comprising, sequentially in the order of

• a support,
• a temporary adhesive material layer having a monolayer structure, and
• a circuit substrate, which is directly provided on the temporary adhesive material layer,
• wherein
• the temporary adhesive material layer is directly provided on the support and directly contacts the circuit substrate,
• the temporary adhesive material layer is releasably laminated on the support,
• the circuit substrate has a front surface on which a circuit is formed and a back surface to be processed, and
• the temporary adhesive material layer is releasably laminated to the front surface of the circuit substrate,
• the temporary adhesive material layer is composed of a thermosetting siloxane polymer layer (A),
• the polymer layer (A) laminated on the support, after cured, has a first peeling force of 10 to 500 mN/25 mm as measured by a 180° peel test conducted at 5 mm/second using a test piece having a width of 25 mm, where the first peeling force is required for peeling the polymer layer (A) from an interface with the support, and
• the polymer layer (A) laminated on the circuit substrate, after cured, has a second peeling force of 50 to 1000 mN/25 mm as measured by the 180° peel test conducted at 5 mm/second using a test piece having a width of 25 mm, where the second peeling force is required for peeling the polymer layer (A) from an interface with the circuit substrate.