A Comprehensive Guide to SMT Machines: What They Are and How to Choose

  • 2023-08-08
  • Home » TECHNICAL Blog » A Comprehensive Guide to SMT Machines: What They Are and How to Choose

Nowadays, people’s life is inseparable from electronic products. And printed circuit boards, as the brain of electronic products, their demand is also increasing correspondingly. As a result, PCB manufacturers have tried their best to increase their output, and one of the effective ways is to introduce advanced SMT machines to their production lines. With these machines, even tiny electronic components can be assembled with fast speed and high precision.

In this blog, we will introduce different types of SMT machines and their functions, and also provide some tips for selecting the right machines for your production line.

Different SMT Machines Used in PCB Assembly Process

According to the sequence of the SMT PCB assembly process, we will list the equipment used one by one as follows:

  1. The Solder Paste Printing Machine

The first machine used in SMT PCB assembly is the Solder Paste Printing Machine, which holds the PCB in position in an automated paste printer, where a squeegee applies the correct amount of solder paste onto the pads. Subsequently, a blade scrapes the stencil, evenly distributing the solder paste in the designated areas where components will be affixed, leaving the remaining areas untouched. Finally, the machine removes the stencil. If everything has proceeded smoothly, the solder paste should now be in the appropriate locations for the later placement of components.

  1.  The Solder Paste Inspection (SPI) Machine

Once the solder paste has been applied to the board, the following important step is to inspect whether the paste has been printed onto the board correctly. Poor solder paste printing is frequently the cause of SMD soldering issues, so this stage is critical. This is where an SPI machine steps in. This kind of machine can capture 3D images with cameras, and then evaluate the solder paste according to its volume, alignment, and height. It can also recognize unsuitable sizes and imperfections.

  1.  Pick-and-Place Machine

A pick-and-place machine is the primary and most critical type of SMT machine. Its function is to pick up components and position them in their designated locations. There are three varieties of pick-and-place machines:

4.Reflow Soldering Machine

Despite the precision and care that goes into the soldering process, there is always the possibility of flux and excess solder remaining on the PCB. This is where Solvent Cleaning Equipment comes in handy. The purpose of this specialized SMT Machine is to eliminate any leftover flux and solder from the PCB following the soldering process, thereby guaranteeing that the PCB is thoroughly cleaned and prepared for the next stage in the manufacturing process.

  1. Repair and Inspection Equipment

The PCB Inspection Equipment is a highly sophisticated SMT Machine designed for inspecting and repairing printed circuit boards. The machine not only identifies any potential defects or faults on the circuit board but also aids in repairing and fixing them. The thorough inspection of the PCB is guaranteed by its highly precise and accurate measurements, which enable the identification and resolution of any issues before delivery of the final product.

How to Choose the Best SMT Machines

Choosing a suitable SMT machine for your assembly line is not an easy task, there are several factors you should consider before making the decision:

  • Component Placement Speed

The placement speed of the SMT placement machine is the focus of the initial research on the purchase of the placement machine. These placement machines vary in placement speed and it is important to choose one based on your production needs and budget. You can check them against the IPC 9850 standard, which defines the placement speed of their pick-and-place machines.

  • Placement Accuracy

Placement Accuracy is another important aspect one should consider. Machines with higher accuracy tend to perform better, leading to high-quality yields. The optimal SMT machine should have an accuracy of 0.0001″ and a fine pitch lead of 12mil to achieve the best accuracy.

  • Machine repeatability

When selecting an SMT machine, it’s important to not only consider its accuracy but also its ability to produce consistent results. This is known as repeatability and is a critical feature to look for, especially in machines that use programmed software solutions to operate.

  • Parts Size

Another important factor to consider is the part size. For example, a pick-and-place machine should be able to handle parts of sizes 0402, 0201, and 01005. If the machine you have selected meets your other requirements but does not support these sizes, you can purchase an additional nozzle or feeder to enable the production of circuit boards with these sizes.

Top 4 SMT Machines Manufacturers 

Final Thoughts

Now you have a better understanding of what SMT equipment is needed to assemble electronic boards, including how to choose suitable machines and which brands you can go for. But it may not be cost-efficient to purchase these expensive machines if you are producing small quantities of boards. In such cases, partnering with a dependable PCB manufacturer can be a superior option as they can provide quicker and more dependable services. Qtech Technology is equipped with industry-leading equipment to offer customers one-stop PCB assembly services from PCB manufacturing to assembly and inspection. Contact us today to learn more!


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