Why Use Surface Mount Devices?

SMDs have improved performance over through-hole components due to their smaller size, shorter internal leads, and smaller board layouts. SMDs can also be more cost effective than traditional through-hole components due to the smaller board size, fewer board layers, and fewer holes. Besides, they are easier for people to replace than through-hole components on multilayer boards. The reason is because it is very difficult to heat the long hole on a multilayer board, but much easier to heat just the pad and component terminal of an SMD on the surface of a board. SMD components have a variety of advantages than through-hole components. 

1.The cost of surface-mount devices can lower 30%~50% than other technologies from saving materials, energy, equipment, labor, time, etc.

2.SMD has good high-frequency performance which can largely reduce the interference of radio-frequency and electromagnetism. 

3.SMD is more reliable that it has high resistance capability, and low soldering defect rate. 

4.Products are always 40%~60% smaller and 60%~80% lighter than using other methods.

For more info. about surface mount articles, pls visit Shanghai EPCB.

Soldering a Surface Mount Resistor

There are several ways to successfully solder SMD components on a circuit board. Some are easier to learn, and some require using special materials (like solder paste, which is a mixture of powdered solder and flux) or special equipment (like SMD solder stations). Actually, you don’t need fancy equipment to do SMD soldering at home. You can easily do it with a soldering iron.

Soldering a resistor is the simplest way for freshmen. At the beginning, you should apply flux to one pad on the circuit board in order to clean the pad and make it easier for the solder to fasten properly. And then touch the circuit board pad with the tip which covers some solder to let them pass on to the pad. Next, place the resistor on its ideal location, and fix it by soldering. The resistor should now be fastened on one side. Apply solder to the soldering tip again and touch the iron tip on the other side. Finally, you’d better to use a loupe to check the solder joints to make sure the connection is good. 

More info. about soldering, pls visit Shanghai EPCB

Soldering Surface Mount Chips

There are several ways to successfully solder SMD components on a circuit board. Some are easier to learn, and some require using special materials (like solder paste, which is a mixture of powdered solder and flux) or special equipment (like SMD solder stations). Actually, you don’t need fancy equipment to do SMD soldering at home. You can easily do it with a soldering iron. 

If you are able to solder a resistor, it won’t be difficult for you to solder a surface mount chip as the method is similar. Start by applying some solder to one of the chip’s corner pads. Secondly, hold the chip in place while touching the corner pad with the tip of the soldering iron so that the heated solder can combine the pin with the pad. Next, check the alignment of the chip. If it is not in its place, then relocate it. Only you’re sure the chip place is perfect, can you move to the next step. Then you can solder on the opposite corner just like the one you have fixed. Finally, after all the pins have been soldered, you should inspect all the solder joints carefully with a loupe to check if there exist any bad joints or solder bridges. 

For more info., pls visit Shanghai EPCB.

ICT Disadvantages

Every coin has two sides, though in-circuit test is a very powerful tool for testing PCBs, the in-circuit test also has some disadvantages which are listed as following. 

1. As the fixtures are mechanical and require general and wiring assembly for each printed circuit board, they can be a costly item.

2. As the fixture is a fixed mechanical item, with the probes or "nails" mechanically fixed, any updates to the board changing the position of the contact points can be costly to change.

3. Electrolytic components can be tested for polarity only in specific configurations (e.g. if not parallel connected to power rails) or with a specific sensor

4. The quality of electrical contacts cannot be tested unless extra test points or a dedicated extra cable harness are provided.

5. It is only as good as the design of the PCB. If no test access has been provided by the PCB designer then some tests will not be possible. 

Foe more info., pls visit Shanghai EPCB.

ICT Advantages

In-circuit test is a very powerful tool for testing custom PCBs which has several advantages. When determining the best form of test for any given application, it is necessary to investigate the advantages of each system carefully.

Easily detect manufacturing defects: It is that most board faults arise from problems in manufacture - incorrect component inserted, a wrong value component, diodes, transistors or ICs inserted with incorrect orientation, short circuits and open circuits. These are very easily and quickly located using ICT as the in circuit tester checks components, continuity, etc.

Programme generation is easy: An In-Circuit tester is very easy to programme - files can be taken from the PCB layout to generate much of the programme required.

Test results easy to interpret: As the system will flag a particular node as having a short of open, or a particular component as being faulty, location of a problem in a board is normally very easy - and do not require the application of the most highly skilled test staff.

For more info., pls visit Shanghai EPCB. 

Capacitance and Resistance Tests

To guarantee the high-quality of finished printed circuit boards produced by us, Shanghai EPCB will test capacitance and resistance of PCBs before shipping them for you to use. Capacitance testing for bare circuit boards involves charging a net or plane before probing each net to measure the induced capacity. Inaccuracies do occur with this method due to inherent variability in producing PCBs. Resistance testing measures the resistance found in the net, which is proportional to length and inversely proportional to the cross-sectional area of a conductor. A good conductor will have a low resistance. Only all PCBs pass the capacitance and resistance test can we deliver goods to you.

Potential Applications for Soluble Printed Circuit Boards

Though soluble printed circuit boards can greatly protect our environment, product designers and engineers in all industries must find ways to integrate the technology into our daily applications, so they can enter the market and accept by people all around the world. Potential uses for this new technology that could be seen in the coming years include: 

Medicine – Brain monitors and other medical devices that need to be implanted can be made from these components so that once they have served their purpose they do not need to be removed.

Cell Phones – Most cell phones and other portable electronics end up in landfills when people stop using them, but it really does severe harm to our environment. If we use soluble printed circuit boards, they will be able to safely and responsibly recycle.

Machinery – Machines that rely on PCBs can have their parts easily swapped out as needed without needing to start from scratch, saving time and money. 

For more info.,  pls visit the website of  Shanghai EPCB.

PCB Depanelization

Depanelization is the removal of the PCBs from the panel itself. In order to increase the throughput of printed circuit boards manufacturing, PCBs are often designed so that they consist of many smaller individual PCBs that will be used in the final product. This PCB cluster is called a panel. The large panel is broken up or "depaneled" as a certain step in the process - depending on the product, it may happen right after SMT process, after soldering of through-hole elements, etc., but it often occurs before final assembly and testing takes place. There are six main depanelization cutting techniques currently in use: hand break, pizza cutter (also known as V-cut), punch, router, saw, and laser. For more information, please contact a representative of Shanghai EPCB. 

Soluble Printed Circuit Boards

The mobile devices are so common in people’s daily life as the economy picks up. It is said that Ringing Bells in India has launched a $4 mobile phone which indicates a dramatic growth in PCBs use. But we cannot ignore a serious question about how to tackle those consumer electronics and other products when they are no longer in use? Of course, they can’t be dropped in landfills which have a drastic bad effect on our environment. Researchers are working to tackle this problem by developing printed circuit boards that are soluble and will essentially dissolve completely over time. This technology is primarily aimed to assist the medical industry, but would also do wonders for the world of consumer electronics. There is still much to be developed and worked out in terms of ensuring that components work the same, if not better, than what is available now.

To protect our environment, Shanghai EPCB always firmly comply with the requirements of RoHS compliant and IPC-A-600H-2010 in PCB manufacturing process, as well as any other requirement of the relevant authority related to E-waste disposal.