摘要 |
PURPOSE:To push out bubbles from bonding material when bubbles mix in the bonding material, and prevent effectively bubbles permeating into the bonding material, by pressing a semiconductor substrate in the state where the substrate is bent in the form of a partial sphere surface or in one direction, against a retaining base, via the bonding material. CONSTITUTION:Via bonding material 13, a semiconductor substrate 11 is pressed against a retaining base 12. At first, only a central part of the substrate is pressed against the retaining base 12. Then the vacuum state of a sucking member 14 is relaxed, and as the result, concentric circular ring parts of the semiconductor substrate 11 are pressed, in order, against the retaining substrate 12, by the effect of elastic restoring force of the semiconductor substrate 11. Therefore, even if bubbles are contained in the bonding material 13, they are pushed out in the form of concentric circles toward the outer periphery of the semiconductor substrate 11, and after all, bubbles are discharged from the bonding material 13. The pressing force at the central part of the semiconductor substrate 11 which is applied first to the retaining base 12 is kept, so that bubbles once discharged do not enter again the bonding material 13. |