- Introduction and overview of the SMT assembly process.
PCB Board Fab
- How boards fabbed
- Surface finishes
- Basics of the soldering process including alloys, fluxes, solder paste, rheology and intermetallic bond.
- Analysis of the stencil printing process including using Gerber data to manufacture stencils, different stencil considerations, squeegee selection and considerations, etc. Paste deposition will be discussed along with common defects found during the stenciling process and the best resolution.
- Chem-etch, laser cut, e-form
- Aperture designs
- IPC-7525 stencil design guidelines
- Squeegee speed and pressure plus other important parameters
- Under stencil wiping-wet and dry
- Solder paste inspection
- Defects typically associated with the printing process
- Analysis of component placement process, machine types, where typical defects can occur and the best resolution.
- Machine architecture
- Turret machines
- Modular-all manufacturers now
- Hybrid machines
Overview of the placement process in SMT-tour
- Board Profiling
Analysis of the reflow process and profiling.
- How to build a robust SMT profile, typical defects and the best resolution.
- Straight ramp vs ramp/soak/spike
- Impact of cooling cycle
- Effects of N2
- Defects causes by improper profile
- Analysis of the wave solder and selective solder process including profile generation, flux application and defect recognition/root cause analysis. Hands on at the wave solder machine.
- Flux application-spray, foam, drop jet
- Effects of N2
- Defects at the wave
Cleaning and cleanliness testing
- Why Clean
- Cleaning Chemistries
- Manual Cleaning
- Cleaning Equipment – Automated Cleaning
- Vapor Degreaser
- Aqueous/Semi Aqueous-Batch and In-Line
- Cleanliness testing
- Overview of the test process including AOI, AXI, ICT, flying probe and functional.
- Component ID
- PCB board fab process and tour
- Stencil fab process
- Stencil fab tour
- Printing demonstration
- Solder paste printing and placement demo
- X-ray equipment demo
- Tour of testing facility ICT and flying probe
Testing and certification