EMS Assembles DR-QFN

Thatcham, UK – Electronic Manufacturing Solutions Limited (EMS), announced today the 100% successful yield of the assembly of a 148 pin Dual Row Quad Flat No lead (DR-QFN) package.

A DR-QFN This package is made up of two rows of pads on all four sides of the package, with pad dimensions of 0.22mm x 0.40mm (220um x 400um) - this package is an example of the constant development and pursuit of miniaturisation of devices as manufacturers and designers face pressure to produce smaller higher density products across a range of applications.

DR-QFN SMT Package

QFN packages are now relatively common place across a range of manufacturers and designs. However DR-QFN's are less common and require careful consideration and technical knowledge to ensure successful assembly.

  • The key to successfully assembling such devices starts with the quotation stage and the detailed assessment of the requirement by EMS' experienced quotation team.  Where we will make an assessment of customer demand, component packages and any specialist assembly requirements.
  • Following identification of the technical requirement, the appropriate tooling needs to be quoted, and where applicable explained to the customer.  In this case a nickel stencil was identified by EMS as a critical component for these devices.  A nickel stencil provides improved paste release and roll compared to stainless steel ensuring that small scale apertures and pads have optimal paste coverage.
  • Communication with the stencil manufacturer is the next key step, ensuring they understand the technical requirement and apply appropriate data adjustments.
  • Internal communication is also vital to success, EMS covers this via two key processes;
    • Contract Review - providing a centralised repository of data for review by Sales, Purchasing, Production and Engineering ensuring standard setup and special instructions are clear to all.
    • PCB & Stencil Approval - a process which compliments the Contract Review by providing specific PCB and Stencil details for each assembly, with approvals at each stage of the process to ensure all of the key requirements are documented and communicated to suppliers.

When all of these elements are brought together at the Production stage, the identification and communication of the initial stages yields 100% successful assembly of complex packages.