Relevant SMT electronic components welding techniques
Along with the era and the progress of science and technology, now more and more of the circuit board used SMT components. SMT components with its small size and easy to maintain more and more get of everybody love. But for many people, to SMT components was "afraid", especially for some beginners, because they think they don't have the welding element ability, think it is not like the traditional straight inserted element that is easy to grasp the welding, but in fact these worry is completely unnecessary. Readers can use the right tools and master some hand welding SMT knowledge, will soon become welding SMT components of experts.
A, use SMT components benefits
First of all, we come to understand the benefits of patch element. Compared with lead element, SMT components have many benefits. The first hand: small volume, light weight, easy to preserve and mail. Such as common SMT resistance 0805 package or 0603 package than before we use straight cutting resistance to little many. Dozens of straight cutting resistance can fill a bag but with SMD resistor words enough to put thousands or even tens of thousands. Of course, this is not consider its can withstand the maximum current situation. Second: SMT components than straight inserted element easily welding and remove. SMT components don't via, with less tin. Straight inserted element the most trouble and most concern is to remove; do and friends have this experience, in two or more layers of PCB board, even if it is only two tube feet, down and not too easy and is easy to damage the circuit board, the pin is not to mention the. And remove the SMT components would be easier, not only two pin down easy, even if a, two hundred a pin components and more than a few times can also don't damage the circuit board. The third aspect: SMT components, as well as a very important advantages, that is to improve the stability and reliability of the circuit to make it is to raise the success rate of the production.
This is because the patch element is small in size and don't need a hole, and thereby reducing the stray electric field and stray magnetic field, the high frequency simulation circuit and the high speed digital circuit is particularly important. Review said, the author can negative "responsibility", as long as you once adapt to and accept the SMT components, unless necessary, you might never want to use straight inserted element the.
Second, the welding SMT components need commonly used tool
By understanding the SMT components after good, let's learn some common welding SMT components needed some basic tools (see chart 1).
Figure 1 hand welding SMT components used commonly used tool
1. Solder iron
Hand welding components, this certainly is not less. Here recommend all welding head is pointed that, because in welded tube feet intensive SMT chip, accurate and convenient to one or a few pin for welding.
2. Solder wire
Good solder wire to patch welding is also very important, if the condition allows, in welding SMT components, as far as possible to use thin solder wire, such easy to control to tin quantity, and don't waste solder and suction tin of trouble.
The main function of tweezers is convenient clamp up and placed SMT components, such as welding SMT resistance, can be used tweezers clamping resistance on the circuit board on the welding. Tweezers requirements front end point and flat so that the clamp element. In addition, for some need to prevent electrostatic chip, the use of anti-static tweezers.
4. Suction tin belt
Welding SMT components, it is easy to appear on the tin too much.
Especially in weld intensive much pin SMT chip, it is easy to cause the chip adjacent feet even more feet are solder short circuit. At this time, the traditional suction tinware is no matter use, at this time will need to use knitted suction tin belt.
Suction tin belt can sell welding equipment place to buy, if not can also take wire of copper wire to replace, the article will tell.
Rosin is the most commonly used during welding flux, because it can separate out solder of oxide, protect the solder not oxidation, increase the fluidity of solder. In welding straight inserted element, if element rust should blow first light, in rosin with iron ironed, again on the tin. And in welding SMT components, rosin in addition to run-off role outside can also cooperate with copper wire can be used as a suction tin belt.
6. Solder paste
In welding, it is hard to tin iron piece goods such as, can use the solder paste, it can remove the metal surface oxide, its corrosive.
In welding SMT components, sometimes can use its to "eat" solder, let spot shine and firm.
7. Hot air gun
Hot air gun is the use of the gun core blown hot air to element for welding and remove the tool. The use of the process requirement is relative taller.
From the take off or install small element to the large integrated circuit can use hot air gun. In different occasions, the hot air gun temperature and volume etc have special requirements, the temperature is too low will cause element virtual welding, higher temperature can damage components and circuit board. Air will blow away small element. For ordinary SMT welding, can need not to hot air gun, in this not to do detailed narration.
8. A magnifying glass
For some pin special tiny intensive SMT chip, welding after the need to check pin is welding normal, for short circuit phenomenon, now employing eye is very arduous, so can use a magnifying glass, which is convenient and reliable view each pin welding conditions.
In the use of rosin as flux, it is easy to leave in the circuit board redundant rosin. In order to beautiful, then can use alcohol cotton ball will circuit boards have residual rosin place clean 10. Other patch welding the common tools in addition to the above said, but also some such as sponges, wash plate water, hard brush, glue, etc. In this not do say, conditional friend can go to understanding and practical use.