Surface mount technology (SMT) is the industry standard technology to equip Printed Circuit Boards (PCBs) with resistors, transistors, LEDs, Integrated Circuit Chips (ICs) and other components that are necessary to complete the desired electronic circuit. SMT lines are used to create almost every electronic device today.

An SMT line starts with a solder mask which applies a predefined amount of solder on the PCBs contact pads. In the next step a robotic arm places SMT components on the PCB at the programmed location and orientation at a very high speed. The PCB is then "baked" to meld the solder using a stream of super heated air, or run over or through a pool of liquid solder, a so called solder "wave", permanently fusing the PCB with the SMT components.

The PCB later undergoes automated visual and at advanced lines x-ray scans, which points out possible defects and irregularities to the machine operator for eventual manual rework.


Advantages of SMT 

Design Benefits:
  • Significant savings in weight and real estate
  • Electrical noise reduction
  • Improved shock and vibration resistance
Manufacturing Benefits:
  • Reduced board cost by mass production
  • Reduced material handling cost
  • A controlled manufacturing process


SMT Process Summary
PCB loading (push hander) Long Stars
Automatic printing machine (HP-620S)
SMT (YAMAHA-YG12)
(Medium-High speed)
SMT (YAMAHA-YG12F)
(Multi Mount)
Reflow Oven (KINCE KWA-1225 SUPER EP10 N2)
Wave solder (KINCE KWA-350 SUPER)
Solder thickness test machine
I CHECK 3000
Stencil clearing check equipment

Stencil clearing Machine
ICT
BGA repair station

Moisture equipment
(to check the exterior of PCBA by engineer)
Bake equipment
(to bake the deliquescence device)
 

Standard Printed Circuit Board + Assembly (PCBA)