DFX Analysis (DFM, DFA AND DFT)

DFM

What is DFM?

The term "DFM" stands for "Design for Manufacturability". In this process, the topology of the PCB layout is compiled in such a way as to reduce problems that can arise during the manufacture of PCBs and the assembly of an electronic system.

DFM is a set of rules that must be followed to reduce problems that can occur during the PCB fabrication and assembly processes required to manufacture an electronic system.

Inputs required for DFA - ODB++ or Gerber files, IPC netlist, Stack up and other fabrication documents.


Steps followed in DFM

1.Netlist Verification
.

Compares the CAD netlist with the Gerber file and reports shorts/broken if found

2.drill checks
.

Few of the checks in drill checks are listed below:

  • ✔     Drill to Drill spacing
  • ✔    Drill to profile spacing
  • ✔    Missing holes
  • ✔    Extra holes
  • ✔     Power/Ground shorts
3. copper layer checks

(SIGNAL AND POWER GROUND ANALYSIS)

Few of the checks in copper layer checks are listed below:

  • ✔    Spacing Requirement
  • ✔    Sliver problems
  • ✔    Thermal Requirement
  • ✔    Plane spacing
  • ✔    Stubs
  • ✔    Drill to copper issues
  • ✔    Annular ring issues
4. Solder Mask Checks

Few of the checks in solder mask checks are listed below:

  • ✔    Coverage problems
  • ✔    Solder mask bridging requirement
  • ✔    Missing Clearance
  • ✔    Undersize Mask
  • ✔    Extra/irregular mask features
5. SILK SCREEN CHECKS

Few of the checks in silk screen checks are listed below:

  • ✔    Solder mask to PTH clearance
  • ✔    Solder mask to SMD clearance
  • ✔    Line width and height requirement
6. SOLDER PASTE CHECKS

Few of the checks in solder paste checks are listed below:

  • ✔    Presence of paste on all SMT pads
  • ✔    Size of paste matches SMT pad (1:1)