Method for manufacturing a composite compensating balance spring

A method for manufacturing a composite compensating balance spring, comprising:

• providing a first wafer made of a first material;
• providing at least one second wafer made of at least one second material having Young's modulus variations with temperature that are of opposite sign as those of the first material;
• etching identical patterns through each of the first wafer and the at least one second wafer;
• joining the first wafer to the at least one second wafer to form a substrate and, by superposition of the etched identical patterns, forming a composite compensating balance spring including a first thickness of the first material and at least a second thickness of the at least one second material;
• and
• releasing the composite compensating balance spring from the substrate.

A method for manufacturing a composite compensating balance spring, comprising:

• providing a first wafer made of a first material;
• providing at least one second wafer made of at least one second material having Young's modulus variations with temperature that are of opposite sign as those of the first material;
• etching identical patterns in each of the first wafer and the at least one second wafer, and in only one part of the respective thicknesses thereof;
• joining the first wafer to the at least one second wafer to form a substrate by superposition of the etched identical patterns;
• etching additional identical patterns, identical to the etched identical patterns, in the rest of the substrate to form a composite compensating balance spring including a first thickness of the first material and at least a second thickness of the at least one second material;
• and
• releasing the composite compensating balance spring from the substrate.