Soldering iron that can’t kill, mounter that can’t hurt

Recently, many hardware engineer friends complained in our background, saying that they had been pitted when they asked a manufacturer to make SMT patches, and a good board was soldered wrongly or damaged, which wasted a lot of money and time, and the project almost rolled over. I have to find a way to solve the problem myself. I am very disappointed with the domestic SMT process. Some people are even so angry that they welded 3 boards overnight.

Seeing this, I have to pull out that old-fashioned topic again:

Hand welding and SMT, how should you choose as a hardware engineer?



However, before making a choice, we might as well take a look at it. What is the difference between hand welding and SMT?

/Hand welding, the “traditional handicraft” that hardware engineers must know/
Just like a teacher can’t live without chalk, a doctor can’t live without a prescription, and a hardware engineer can’t play a soldering iron.

Hand soldering is to manually solder each component to the designed PCB with the help of an electric soldering iron and solder, and finally make the circuit run well.

Because of its long application time, hand welding is regarded as one of the “traditional handicrafts” in the hardware industry and is widely used in various segments of the hardware industry.

The electric soldering iron used for hand soldering can be called the “national tool in the electronic industry”. Its operation is straightforward, simple and convenient, and it occupies a small area. Usually, when there are not many materials and the size of the components is ideal, hand soldering has become a more important choice for many hardware engineers. customary welding method.


Although hand welding has many benefits, it is not “harmless to humans and animals”:

“The vision of the university is 4.9, and I have been doing hardware welding for two years. Now the astigmatism has been forced to 300 degrees”

“Keeping your head down for a long time in one position, it takes one or two hours after welding, and now I can’t straighten my waist.”

“When I was studying before, I didn’t get dizzy at all in 3D. I welded the board for more than three years, and I didn’t dare to play with chicken. It was too dizzy.”

These cases are not alarmist.

Manual hand welding inevitably has objective disadvantages such as low efficiency, low precision, high time cost, and unsightly appearance, and the cervical and lumbar vertebrae strains, vision loss and other problems caused by long-term use of hand welding, as well as the heavy metals caused by the volatilized gas of the solder. Hazards also plague a large number of hardware engineers.

This also makes a considerable scale of hardware engineers gradually switch to SMT and continue to reduce the use of hand welding. However, in the field of digital maintenance and some hardware DIY scenarios, hand welding is still the mainstream operation method for many engineers.


/SMT, the productivity tool that hardware engineers love and hate/

SMT, which now mostly refers to machine automated placement, is one of the processes of modern PCBA. At this stage, it coexists and complements manual soldering.

The advantages of SMT over hand welding are obvious:
1. The entire process of component placement is carried out by automated machinery and computer programs, with high efficiency and high precision;

2. It can precisely process extremely tiny components such as 0201, which are difficult to solder by hand, and can paste a 10cm² PCB board in just a few minutes;

3. Theoretically, the PCB board that has been patched can play the best design performance;

4. At the same time, the cost of batch processing is lower;

It can be said to be one of the absolute productivity tools in the field of modern hardware.


However, the advantages of SMT are so obvious, why do hardware engineers frequently love and hate it?

“I placed an order for SMT from a certain manufacturer, 10 boards, and 6 boards were blankly posted. When I placed the order, it clearly showed that there was material, but when I went online, I didn’t expect to post it to me. If I didn’t expect it, forget it. I didn’t tell me in advance. I have to wait for me to take the initiative to report it to them, I’m really speechless.”

“Some of the materials in a batch of boards were manually welded by the workers in their factory. The one that was welded was called a piece of water. The welding was wrong and the welding was broken. I haven’t washed the boards yet!!!”

“The price is relatively cheap and fast, but the manufacturer’s components are too few, and they are not fully attached at all. In the end, you have to hand-solder them yourself.”

“There is no transparent quotation when placing an order, and the price is increased in confusion in the middle, alas”

“The first time I sampled 5 boards, 2 boards were already bent.”

There are many similar cases that users broke out in the background and forums, and it is inconvenient to list them one by one.

As a PCBA process, there is no doubt that SMT is convenient for hardware engineers. However, in the past ten years, while the domestic SMT industry has developed rapidly, there have also been frequent occurrences of “biased subjects”. As a user, it is very “injured”.


Just open the browser and search for “SMT proofing”, you will see a large number of advertisements of SMT manufacturers.

The propaganda words such as “one piece of stickers, imported equipment from Japan, no stencil fee, no start-up fee, 1 cent per solder joint, 10 years of experience” can be described as overwhelming, as if every manufacturer’s promise gives users no reason to refuse. Especially in terms of sample processing price, “low price” has become an excellent means for manufacturers to “capture” users.

However, in many cases, the beautiful price does not bring the beautiful harvest to the user. The efficiency of SMT is indeed much faster than that of hand welding. It takes a whole day for hand welding of the board, and the machine sticks it in a few minutes. However, empty stickers, missing soldering, poor service, and inadequate craftsmanship…become the ruthless charm of the sugar-coated shell of “low price”, making hardware engineers and users “manually make up the remaining 30% of SMT” by themselves. A reality that people can’t help laughing at.


In other words, some SMT manufacturers blindly seek speed and equipment, ignoring services and supporting measures. Even more advertising and marketing are not conducive to the healthy development of the SMT market.

Just like a user on Electronic said bluntly: The domestic SMT industry is mixed, and some manufacturers think that a few imported equipment can be done once and for all.

However, although there are still many flaws in the domestic SMT industry, under the active guidance of national policies, the positive support of local governments, and the effective supervision and feedback of users, the overall situation of the domestic SMT industry is still optimistic.

Many manufacturers are constantly improving their processes, optimizing management, and improving services to provide hardware engineers and the hardware industry with more complete and cost-effective business solutions.

Of course, as a hardware engineer, always being responsible for your own board is the first priority. Therefore, whether you choose hand welding or SMT, you need to consider it according to your own needs. There is no perfect solution, only the most suitable solution for you.

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