SMT PCB assembly

SMT PCB assembly meaning

SMT PCB assembly is one method of PCB assembly, which would involve using a stainless steel stencil to print solder paste and using pick and place automatic machine to attach components to PCB board surface and using reflow soldering to solidified components on the PCB.

Why you should use SMT PCB assembly?

Compare with other type of PCB assembly methods, SMT PCB assembly are more cost efficient and time efficient. Beside, it can make out higher reliable quality PCB board. It can help you to make out lower cost of products. That would help you to market share you know.

when you need the SMT PCB assembly?

Consider SMT PCB Assembling technology if your PCB design calls for no lead components and a PCB board without drilling holes.
Soldering PCB components onto the substrate of the PCB is done using surface mount technology (SMT). Surface mount components (SMCs) are directly soldered onto the board using this technique, which involves reflow soldering.

Because of this, the SMT technique is far speedier than THT assembly, which entails connecting your components’ conductive “legs” to pads on the opposite face after guiding them through tiny openings.

SMT PCB Assembly is something to think about if you need your product to be produced more effectively. 

A pick and place PCB assembly machine can help the SMT process become even more effective. 

this machine can be used to quickly and properly arrange all of the components.

You need SMT PCB Assembly if you require additional small-sized products. 

Additionally, it’s important to keep in mind that components created for SMT layouts frequently tend to be more compact and affordable than those created for THT builds. 

Because of this, people frequently choose our SMT assembly service when they wish to save expenses and conserve space.

SMT PCB assembly process

The SMT procedure begins during the design stage, when the PCB is created and the components are chosen. The procedure can be started early enough to take into account every aspect of assembly. Starting the SMT procedure at this stage also simplifies production.

The assembly can start once the PCB has been created and you’ve determined the SMT technique is the best option for your requirements. There are three processes (and numerous inspection stations) involved in this.

Step 1. Solder paste printing

To ensure accuracy and speed, the solder paste printing process is automated.

Using a pre-made PCB stencil and squeegees, a printer applies solder paste at this stage of assembly. The SMC and solder pads on the PCB are connected using this solder paste, which is often a flux and tin mixture.

It’s crucial that the appropriate quantity of paste be applied to each pad during this stage of the procedure. If not, when the solder melts in the reflow oven, a connection won’t be made.

Controlling the solder paste printing process’ quality is essential. This is due to the fact that any printing flaws that are not discovered at this stage will result in more flaws later. In order to make the process repeatable and reliable, the assembly crew must pay close attention to the stencil’s design. Thankfully, most solder paste printers have the option of integrating an automatic inspection to speed up the procedure.

But occasionally, other tools are employed to evaluate the printing’s quality. These inspection devices for solder printers employ 3D technology and provide a more thorough inspection. This is due to the fact that they examine other factors outside the print area, such as the solder paste volume per pad.

Step 2. PLACING THE Components

The PCB enters the SMT assembly process’ component placement stage after passing inspection.

Using a vacuum or a gripper nozzle, each component that will be installed on the PCB is extracted from its package during this stage. Then a machine places it in the predetermined spot. The machines that do this operation are not only extremely speedy, but also extremely accurate. Some of the most sophisticated machines have an hourly capacity of 80,000 individual component placements.

Once every component has been positioned on the PCB, it is necessary to check that everything has been done correctly. This is a crucial phase in the process since any placement mistakes could result in a large amount of time- and money-consuming rework if the parts are soldered into the incorrect position and go unnoticed.

Step 3. Reflow soldering

The method advances to the reflow soldering stage after the placed components have passed their inspection. The PCB is put into a reflow soldering machine during this stage of the SMT procedure (some people refer to them as reflow ovens).

All of the electrical solder connections between the components and the PCB are created in this area. The solder paste that was previously placed is transformed into solder using heat. Again, precision is essential at this point of the procedure because if the PCB is heated to a temperature that is too high, the parts or assembly may be damaged and the PCB won’t perform as planned. An establishment of a link could fail if the temperature is too low.

All of the PCBs in the soldering equipment are put on a conveyor belt to provide the greatest results. After that, they undergo a series of zones of gradual heating before passing through a zone of cooling.

The PCBs must remain in each zone for the appropriate amount of time in order to prevent joint problems. The PCBs must then completely cool before handling or moving them. Otherwise, they might warp.

Step 4. Inspection

All of the PCBs in the soldering equipment are put on a conveyor belt to provide the greatest results. 

After that, they undergo a series of zones of gradual heating before passing through a zone of cooling.

The PCBs must remain in each zone for the appropriate amount of time in order to prevent joint problems. 

The PCBs must then completely cool before handling or moving them. Otherwise, they might warp.

How to select a reliable SMT PCB assembly manufacturer?

When you want to choose a good SMT PCB assembly manufacturer, below factors you should consider.

The PCB assembly manufacturer should have advanced of SMT machine line.

PCB assembler should have ISO9001 quality control system.

The manufacturer should be with a good reputation.

Besides, the SMT PCB manufacturer should can provide your best price and short lead time.

We, INTOPCB, are a professional SMT PCB assembly manufacturer since 2000. We have certitfication of ISO 9001, TS16949, UL, Rohs, IPC 2, IPC 3 and serve over 10000 customers all around the world, 99% customer satisfaction. Welcome to contact us to request a quotation of SMT PCB assembling now.

our customers service email: sales@intopcb.com