Enhanced Double-sided Surface Mounted Assembly
Original Publication Date: 1987-Dec-01
Included in the Prior Art Database: 2005-Feb-02
An improved method is disclosed for double-sided surface mountings that improves the reliability and allows multiple rework capability. Surface mounting of components is facilitated by screening a solder paste on the circuit board through a mask. The components are then transported by a pick-and-place machine to the board and placed onto the screened paste pattern. The component, paste and substrate are heated until the solder melts and reflows. The assembly is then allowed to cool to ambient temperature to obtain adequate bonds between the component leads and the pads. Because the screened paste is wet during component attachment, only one side of the circuit board can be populated with components at a time.