| 摘要 |
A process is provided for simultaneously attaching surface-mount (SM) integrated circuit (IC) devices (12) and chip-on-board (COB) IC devices (22) to a circuit board (10) using a combined solder reflow and adhesive cure thermal cycle. The process generally entails placing SM and COB devices (12, 22) on the circuit board (10), such that a suitable solder composition (14) and adhesive (24) are present between the circuit board (10) and the SM and COB devices (12, 22), respectively. The circuit board (10) and devices (12, 22) are then heated so as to simultaneously cure the adhesive (24) and reflow the solder composition (14). A preferred heating step entails at least one thermal cycle that attains a peak temperature well above the cure temperature of the adhesive (24), as well as above the melting or liquidus temperature of the solder composition (14). Accordingly, the thermal cycle is employed to cure the adhesive (24) well outside its conventional cure limits. Thereafter, the circuit board (10) and the devices (12, 22) are cooled to solidify the molten solder (14). The COB device (22) can then be wire bonded to the circuit board (10) and encapsulated in accordance with known practices.
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