SMT ASSEMBLY TECHNOLOGY
February 09, 2021
Esemda has been providing electronics manufacturing services to its customers for 19 years. Automated electronics manufacturing processes and consistently increasing productivity are our annual goals. We are moving towards these goals with efficient automated assembly SMT lines for both mass production and prototyping. Due to this we will briefly discuss 5 key issues about surface mount technology (SMT).
- What is Surface Mount Technology (SMT)?
It is a method used to place and solder the electronic components directly onto the PCB‘s surface. This approach has complemented the through-hole technology (THT). SMT helps to reduce manufacturing costs as well as increases the efficiency. Also, it is important that the main currently use components are specifically designed for SMT assembly.
- What are the advantages and disadvantages of SMT printed circuit boards assembly?
Advantages: high speed of components assembly is obtained, which reduces assembly costs; due to the possibility to install ultra-small components up to 01005 (0.4mm x 0.2mm) it is possible to reduce the final product as well; more components are placed in a smaller space without any difficulty; components are mounted very accurate.
Disadvantages: there are limitations on the size of the components (extremely large components cannot be installed, therefore THT is remaining); it is required high investment in equipment and high enough training costs for working with it.
- What are the main steps of SMT process?
The SMT process starts at the design phase. Then PCB assembly data is prepared:
-SMT electronic components assembly machines are being prepared (programs for automatic assembly are prepared according to the provided files);
-Solder paste printer is configurable for solder paste coating on PCBs;
-Components are added. Each component is taken from a special package, inspected and placed at a high speed in the programmed location;
-After assembling all the components, the PCBs enter the soldering machine, where after selecting the necessary temperature parameters, the components are soldered to the board;
-AOI (automated optical inspection) device is used for checking the installed electronic components. X-Ray machine additionally inspects BGA-type components.
- What verification is performed during SMT assembly?
-Automated Optical Inspection (AOI) helps to ensure correct arrangement of components and solder quality.
-X-Ray machine is used to control optically invisible components or locations. The inspection takes place in real time, and if necessary to save the report, X-ray pictures are taken, which show components invisible to the AOI device and soldering points.
- What information is usually required for the SMT assembly process?
-PCB production requires files in Gerber format (one of the most popular formats on the market), which are used for stencil manufacture;
-BOM (bill of materials) - component list, where specified all the necessary components for the assembly of the electronics product;
-PNP (pick and place) or CPL (component placement list) file. They provide a list of components with the coordinates of each component on the board. This data is used to program automatic SMT assembly machines;
-Assembly drawing with reference designators for components: rotations, directions, polarity.
Have You got more questions about SMT assembly technology or are You still hesitant to start realizing your electronics idea? Tell us about Your project!
sales@esemda.com