SMT Assembly

Surface Mount PCB Assembly

Surface Mount PCB Assembly

At MOKO Technology, we have a wide range of cutting-edge technology that creates a medium to large series of electronic gadgets to meet the SMT assembly needs of our all-round clients.

Our optimized processes, great level of standardization, high assembly performance and quality assurance as well as automated soldering and physical assessment, meet the diverse requirements of our increasing clients.

Surface Mount PCB Assembly

On our state-of-the-art SMT assembly lines, we make electronic products from small-sized to large series. The great PCB assembly performance, repeatability, availability, and population, and soldering quality, as well as the automated optical inspection, meet the highest demands of our demanding clients.

Our SMT electronic assembly capabilities are far superior to those of our competitors and we take pride in this fact. We have a highly-trained staff who are very skilled at manufacturing a wide range of PCB boards through SMT assembly.

Our SMT Assembly Line and Our Equipment for PCBA Production

MOKO Technology has five SMT assembly lines. These lines are well-equipped for manufacturing a wide range of PCBA. Our assembly lines have the capability to rapidly change as per the requirements. Hence, our lines offer very high flexibility. This allows us to effectively engage in all of our customer requests. Therefore, we always manufacture and deliver electronic products ahead of deadlines.

Main PCBA equipment list
We have very sophisticated and advanced equipment at every SMT PCBA set up.

Main PCBA equipment list

PCB SMT assembly capacity
5 SMT Lines (10 million chips per day (0402, 0201 with 8 million per day)
DIP production capacity
3 Production Lines (1.2 million pcs per day)
Enclosure assembly
3 Production Lines for enclosure assembly (Each line has 15 assemblers and 2 quality control engineers)

Enclosure assembly

SMT Types That We Can Assemble

We have a sophisticated setup and that coupled with our innovative environment allows us to indulge in a variety of technological endeavors. Our highly-skilled resource and our advanced equipment allow us to claim that we can work on all sorts of SMT assembly service:


The Processes Involved in SMT Assembly

1. Material examination and preparation
The first step involves examining the PCB and the electronic components. We look for the flaws and then prepare the PCB and components accordingly. Usually, the PCB is very flat. On top of that, it includes lead-, gold-, silver, or copper-plated pads. These pads don’t have any holes and we refer to them as solder pads.
2. Stencil preparation
We use a stencil in PCB SMT assembly so that we can perform solder paste printing at a fixed position. So, we prepare the stencil as per our placements of solder pads.
3. Solder paste printing
Solder paste is basically a mixture of tin and flux. We use it for connecting the solder pads and the electronic components on the PCB. We use the stencil for applying the solder paste to the PCB. Hence, the positioning can vary between angles of 45° and 60°.
4. SMT placement
We then use automated machines for picking and placing the PCB. So, these machines then carry the PCB boards over to a conveyor belt. After that, we can place the electronic components on them.
5. Reflow soldering
After placing the components on the PCB, we place them in a reflow soldering oven. The heating is done in various stages. And each stage refers to a specific heating zone. So, these stages are as follows:
Pre-heat Zone
Soaking Zone
Reflow Zone
Cooling Zone

If the PCB is double-sided then we might have to repeat all of these processes for the other side as well.
6. Cleaning and Inspecting
Then we clean the PCBs and look for any inherent defects. If no defects are found then the PCB is good to go. Otherwise, we will have to perform repair or rework. Therefore, we use various equipment for performing the inspection. These include AXI, X-ray machine, Automated Optical Inspection, etc.

pcb assembly process moko

Difference Between SMT Assembly and SMD Assembly

SMT assembly
It is the technology that allows us to mount various electronic components and modules on a PCB board. It involves various processes such as stencil preparation, solder pasting, and reflow. So, SMT involves extensive use of sophisticated machinery such as automated pick and place machines, X-ray machines, and machines for AOI.
Advantages of SMT assembly
The biggest advantage of SMT is that it allows us to significantly reduce various costs. So, these costs include board costs, material costs, handling costs, manufacturing costs, and distribution costs.

SMT also allows us to reduce the traces of routing. It enables us to reduce the size of the PCB and the number of holes that we might have to drill.

The process design of SMT is very economical. This is because it allows us to reduce weight, lease less real estate, and eliminate any sorts of electrical noise.

SMT components weigh only a fraction of their counterparts from other conventional technologies. Hence, the final surface mount assembly is much lighter than alternative electronic products.

So, it is possible for us to pack surface mount PCB assembly into limited spaces. Hence, we save a lot in terms of packaging costs as well.

In the modern electronics, we tend to prefer denser products because they are more efficient. Hence, SMT allows us to easily achieve this goal.

Disadvantages of SMT assembly
The small space between adjacent electronic components makes it difficult for subsequent repairs.

We cannot use SMT for mounting electronic components which generate a lot of heat.

The solder we use in SMT might weaken if we expose the assembly to high mechanical stresses. Hence, we have to practice caution during handling.

SMD assembly
SMD refers to any small electronic device or electronic component that we can mount on a PCB board. So, we specifically design them so that we can mount them on PCB boards in later stages.

Hence, SMD assembly is ideal for microelectronic applications only. Typical example of SMD includes a process mounted on a computer’s motherboard.

Advantages of SMD assembly
It involves much smaller electronic components. Hence, we are able to achieve much higher component densities. Therefore, we are able to achieve more electronic connections through each component.

Disadvantages of SMD assembly
We cannot use SMD directly with the breadboards. So, we have to look for alternatives.
If we use materials that go through thermal cycling then the solder connections of SMD might get damaged.

Deciding Between SMT PCB Assembly and SMD PCB Assembly

Whether you choose to go with SMT or SMD entirely depends on your needs and requirements. It also depends on what kind of applications you are looking for. However, there is a general rule of thumb that you should go with SMT when you are working with Micro-electronics and go with SMD when dealing with Micro-electronics.

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