This paper examines the construction of a notebook mainboard with more than 2000 components and no wave soldering required.

The consumer’s interest for smaller, lighter and higher performance electronics products has increased the use of ultra fine pitch packages, such as Flip Chips and Chip Scale Packages, in printed circuit board (PCB) assembly.

In order to better characterize the performance of wafer bumping stencils, a novel solder transfer ratio has been defined that relates the amount of solder paste volume transferred to a wafer to the actual stencil aperture volume.

In the early days of SMT assembly, step stencils were used to reduce the stencil thickness for 25 mil pitch leaded device apertures. However, as SMT requirements became more complex and, consequently, more demanding, so did the requirements for complex step stencils.

Printing of electronics is an escape route opening up for some in the troubled printing industry. 

Many words have been written about the impending lead-free transition. During this period of frantic discovery, much has been communicated about reflow and alloy concerns, but the print process, which, let’s face it, is the first process that adds value, is often overlooked. 

The 01005-chip component package, ranging from 0.10 x 0.304mm (0.004” x 0.012”) to 0.20 x 0.40mm (0.008” x 0.016”) depending on the supplier and if the 01005 component is a resistor or a capacitor, is dramatically smaller than the previous smallest component package used for resistors and capacitors, the 0201 (0.60 x 0.30mm (0.0236” x 0.0118”) component package.