Designing for Manufacturability in Electroncs

Being in the Electronics Manufacturing Industry, we have to work with varieties of people with varieties of background in this industry.  Many time engineers or inventors have a varying degree of understanding of how the electronics manufacturing process works.

Jim Barnes, our salesman who called himself "Grey Haired Old Man" recently retired, but he had created a presentation for the Kettering University engineering students, so at an early point in their careers they can understand what goes into desiging a good product that can be manufactured efficiently and cost effectively. So here are the Steps to DFM (Desgin for Manufacturability):

Screen Printing/Stencils

 

The first step entails that the circuitboard be screen printed with a stencil, similar to how a shirt is screen printed.  Many times a board is put into a pannel/array so that more boards can be manufactured at one time.

SMT(Surface Mount Techology) Placement:

 

 

After the board has been screen printed with solder paste it goes to the SMT placement Machine, While the boards are in a panalized form they can be quickly populated by the SMT placement machines.

Reflow - Convection vs Vapor Phase Reflow:

 

After all the sufrace mount parts are placed, the solder paste must be melted so the components can adhere to the board with a conductive connection.  To understand the advantages of Vapor Phase Reflow over the tradition Convection Reflow please watch our video on youtube here.

Through Hole:

 

Finally in the manufacturing process you assemble the Through Hole parts onto the bord. This is ususually done with a Selective Soldering machine which only solders the holes of the through hole components and avoids damaging or removing any of the Surface Mount parts that are already assembled.

 

Now that we understand the process of Manufacturing Electronics, we can move on to see what is important to consider when desiging electronics keeping manufacturing in mind.

 

Build Information Needs:

BOM (Bill of Materials):

One of the major aspects of design is in the BOM (Bill or Materials).  When passing this on to a contract manufacturer you must make sure that the BOM has the following complete:

  • Manufacturer Part Numbers
  • Reference Designators
  • Part Description
  • Notes (i.e. IC's need program burn in prior to placement)

 

Gerber Files:

Another important aspect for Design for Manufacturablity is Gerber Files.  When creating gerber files the following should be included:

  • Silk Screen
  • Polarity Markings
  • Revision Level
  • Fiducials, Tooling Holes & Rails

Look out for a future blog post on Diciphering a good gerber vs bad gerber for Design for Manufacturability.