CSR1001A04-IQQA-R Datasheet, PDF (17/45 Pages) –

1.4 PCB Design and Assembly Considerations
This section lists recommendations to achieve maximum board-level reliability of the 8 x 8 x 0.9mm QFN 56-lead
package:
■ _{NSMD lands (lands smaller than the solder mask aperture) are preferred, because of the greater accuracy}
of the metal definition process compared to the solder mask process. With solder mask defined pads, the
overlap of the solder mask on the land creates a step in the solder at the land interface, which can cause
stress concentration and act as a point for crack initiation.
■ CSR recommends that the PCB land pattern is in accordance with IPC standard IPC-7351.
■ _{Solder paste must be used during the assembly process.}
1.5 Typical Solder Reflow Profile
See Typical Solder Reflow Profile for Lead-free Devices for information.
Production Information
© Cambridge Silicon Radio Limited 2011-2013
Page 16 of 44
CS-216358-DSP5
www.csr.com