SMT Cost Breakdown and Factory Selection Tips

By Travis Zhang, Insight Solutions

If you have studied the process of SMT, you may regard it as a simple technology. Sure enough it has only four steps and described in one sentence, it’s just soldering components onto board.

However, when you consider all the failures during the SMT process, you may be amazed that so many different kinds of defects can occur. This is SMT – simple in principle and complex in technical details.

With that in mind, let’s take a look at the process of purchasing SMT manufacturing services.

Price

The basic factor influencing price of SMT is pin count on components and board. The more pins, the more soldering points to deal with, thus a more complicated stencil to design. The price of pins is open and transparent, and is often calculated on a group of two pins or four pins.

The second thing that influences the price is the alignment of components on the board. In other words, the complexity of the board. A complicated  alignment means close spacing of the components, which requires higher precision, resulting in a higher price. The same reasoning means the price of SMT for double-sided boards is generally higher.

Thirdly, if you’re going to mass produce your product, the SMT factory may request a share on the cost of the machine used. This is usually appears as a higher unit price of soldering points. Moreover, delivery time is also a factor that influences the price. It’s common sense that short delivery time requires more money.

Factory selection

Now you have some knowledge of the factors affecting price, then how do you choose a factory?

If you’re going to prototype your product or make a sample of your product, you should choose small factories. These factories are always flexible and can provide customized service in delivery time. Most of the placement work is done by human hands in these factories so the price is relatively low.
On the other hand, you need to spend more time on communication with the technicians in these factories to emphasize your needs. Don’t hesitate to switch to another factory if the current one isn’t willing to assist in testing. Though you have many choices in selecting these factories, you better settle down on one plant to finish your prototyping and sampling, since these two processes are highly related.

If  trial production and mass production is what you’re considering, you should choose a well known and large scale factory. Large plants will have a group of responsible and professional engineers. The automatic machines can provide a higher yield and better quality. QC (quality control) and inspection are usually emphasized and measured in large factories, and they generally offer a more disciplined schedule of delivery time. As with prototyping and sampling, for your trial production and mass production jobs, you should choose one factory for both as they are related.

Future trend

Generally, future SMT technology demands a higher level of integration, automation and precision. An important point of SMT technology is the ‘lead’. Lead is a component of solder paste. As a soldering material, tin-lead alloy is way better than pure tin, but lead is toxic to the human body and environment as we all know. Currently technology with lead is much cheaper than that without lead, and the performance of the product with lead is better too.

With the advancement of technology and the requirement of environmental protection, we’ll eventually find a substitution for lead and lead-free technology will eventually become mainstream.

 

For more information about supplier selection for SMT, contact Insight Solutions.