What exactly is SMD PCB Assembly

If you are not attached with electronic and electrical equipment manufacturing, you may not perhaps be aware of the phrase SMD PCB ASSEMBLY. The expansion for SMD is a Surface Mount Device It is basically an electronic device, the components for which is placed directly or mounted onto the PCB surfaces. This is a relatively new technology, but it is catching up quite fast amongst all major manufacturers of electronic equipment, appliances and devices, big and small. Over the years, SMT technology or Surface-mount technology has started replacing the old through-hole technology method of construction. This method was used and in fact is still being used for fitting various components in the PCB.

This is done with the help of wire leads that are fixed into the holes of the circuit boards. However, SMD PCB technology has still not caught up fully and it still is not a full replacement to the older through-hole technology of THT that still continues to be in vogue. The good thing about SMT technology is that it can be used alongside and both can co-exist at the same time. There are some components that are not suitable for surface mounting and in such cases the old THT method of PCB assembling still continues to be used. A few examples are power conductors that use heat-sink technology or PCB assembling for large transformers.

WHAT ARE THE SPECIAL FEATURES OF SMT COMPONENTS?

When we refer to any SMT component, we are talking about a component that is smaller when compared to through-hole counterparts. This is because it has much smaller leads and in some cases there are no leads all. In its place there could be short pins or lead that are of various other styles. These could include BGAs, better known as solder balls, flat contacts or even terminations that get attached to the body of the component.

WHAT ARE THE DIFFERENCES BETWEEN SMD AND THT?

Here is a look at the major differences between SMD PCB assembly and through-hole technology:

* Space is often a problem with the old through-hold mounting system. This can be easily addressed and prevented with the use of SMT method of PCB assembling.
* The absence of leads makes it easy to directly mount the components to the PCB which is not possible in a thorough-hole components. These require lead wires that have to be passed through drilled holes.
* The pin counts are much in SMT higher in through-hole technology.
* Since most of the components that are used in SMT technology are compact, you can expect to achieve a much better packing density when compared to through-hold mounting.
* When it comes to large scale production of PCB assembled sets, SMT components are preferred. This is because they are less expensive when compared to through-hole counterparts.
* If manufacturers are looking for assembly automation, SMT is the choice. Therefore, when volumes need to be ramped up at lower overall production costs, through-hold production may not be the answer and it may not be cost-effective.
* The turnaround process will be much higher because the circuit speeds are higher. This is possible because the circuit overall sizes are much smaller when compared to the conventional through-hole option.
* Though there are many scenarios where through-hole mounting technology could be a better option, there are many reasons for shifting towards SMT technology. Yes, the initial cost and investment is higher, but the long term returns and benefits will compensate for the higher investment quite easily.

SOME DOWNSIDES OF SMT PCB ASSEMBLY

However, there are some downsides as far as SMT technology is concerned. Here are a few of them:

* The initial capital investment required for SMT PCB assembly machinery is much higher when compared to through-hole technology.
* When you have bulky and large components, it may not be possible to go in for SMT technology. Through-hold mounting is the most suitable and desirable. This is because these bulky and large components are regularly subjected to mechanical stress. Hence when it comes to high-voltage and high-power parts, through-hole PCB assembly is the best way forward.
* You need much higher technology, human resources skills if you plan to switch over to SMT technology. The training cost is much higher and the overall maintenance and upkeep costs are also higher when you compare it with through-hole technology.

HOW TO SELECT THE RIGHT VENDOR FOR SMT PCB ASSEMBLY?

As mentioned above, the initial investment required towards purchase of machinery and equipment for SMT is quite high. This often becomes a deterrent and many small-sized electronic companies prefer to use the old through-hold technology. However, you have to start looking towards the future because in a few years from now through-hole technology will become obsolete except for some large sized components that cannot make use of SMT PCB assembly systems and methods.

There are many third-party companies who undertake manufacture of SMD PCB assembly for a cost. They have the required expertise, experience and most importantly, they also have the right technology, machineries, human resources and infrastructure to do the job for you at a pre-agreed and contracted cost. This will help you as an electronic equipment manufacturer to be in line with modern technologies. You will be able to sell more to more customers because these third-party manufacturers are capable of meeting your requirements if you are ready to enter into a legally-enforceable contract with them.

However, there are a few things that you must bear in mind before you select these third party manufacturers. We are listing down a few important points that you must bear in mind before selecting such manufacturers.

* CHOOSE A REPUTED VENDOR WHO HAS A PROVEN RECORD AND HAS THE BEST OF CREDENTIALS.
* MAKE SURE THAT THE VENDOR HAS THE MOST MODERN AND STATE-OF-THE-ART TECHNOLOGIES
* THEY SHOULD BE ABLE TO OFFER THE BEST PRACTICES AS FAR AS MANUFACTURING PROCESSES ARE CONCERNED.
* ENSURE THAT THEY HAVE REASONABLY FAST TURNAROUND TIMES WITHOUT COMPROMISING ON QUALITY UNDER ANY CIRCUMSTANCES.
* DO NOT ALWAYS BE DRIVEN BY LOWER COSTS WHEN IT COMES TO MAKING THESE SMD PCB ASSEMBLIES FROM THIRD PARTY MANUFACTURERS. FOCUS MORE ON QUALITY. LET IT NOT BE A CASE OF BEING PENNY WISE POUND FOOLISH.
* IF POSSIBLE HAVE MORE THAN ONE SUCH THIRD PARTY VENDOR SO THAT YOUR PRODUCTION SCHEDULES DO NOT GET DISTURBED BECAUSE OF PROBLEMS WITH ONE OF THE VENDORS.

CONCLUSION

To conclude, it is clearly evident from the above that the future belongs to SMT PCB technology and electronic equipment manufacturers have no other option but to make the shift from Through-Hole technology. You can have a combination of these two technologies right now but in the next four or five years you will have to move over to SMT PCB assembly methods. Yes, there will be some exceptions to the rule for large sized and bulky components where through-hole PCB assembly technology will continue to be used.