Apr09
Selective Mask Wave Soldering Process: The Optimal Timing and Limitations

Selective Mask Wave Soldering Process: The Optimal Timing and LimitationsWorkingbear initially thought that wave soldering machines should have been relegated to museums by now! However, despite the decades-long development of Surface Mount Technology (SMT), many PCBs still undergo wave soldering processes. But nowadays, most wave soldering processes employ Selective Mask Wave Soldering, rather than the old method of immersing entire boards into solder baths.

In Selective Mask Wave Soldering, the original wave soldering machine is still used, but the PCB is placed in a wave soldering carrier. Only the pins or solder joints of components requiring wave soldering (typically through-hole components) are exposed to the solder, while other components are shielded with a mask of carrier. It’s a bit like wearing a lifebuoy in a swimming pool – the parts covered by the lifebuoy won’t get wet. Similarly, in the wave soldering process, the areas covered by the carrier won’t get soldered, eliminating the risk of re-melting solder or components falling off.

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Apr02
Can Surface Mount Devices Run Through the Wave Soldering Without Falling Into the Pot?

Can Surface Mount Devices Run Through the Wave Soldering Without Falling Into the Pot?

In previous discussions, Workingbear introduced the “wave soldering” process, which was used in early day of PCBA soldering. SMT assembly, on the other hand, emerged later. Can wave soldering be used for Surface Mount Devices (SMDs) after SMT placement? Workingbear noticed that many people still seem confused about the relationship between wave soldering and SMDs. So, this article aims to explain the key process of making SMDs  compatible with wave soldering.

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Mar26
What is AOI? What Defects Can 2D AOI Detect in PCB Assembly?

What is AOI (Auto Optical Inspection)What Defects Can AOI Detect on PCB Assembly?

AOI (Auto Optical Inspection) is an automated optical recognition system that has become widely used in the electronics industry for inspecting the quality of soldering, component placement accuracy and the presence of missing components on PCBA (Printed Circuit Board Assembly) production lines, replacing human visual inspection processes.

(Please note: The AOI mentioned in this article refers to 2D AOI. Nowadays, there are 3D AOIs available on the market that provide more detailed three-dimensional image inspection, improving the detection rate of AOI.)

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Mar19
The Purpose of Nickel (Ni) Plating on Components or Circuit Boards in the Electronics Industry

The Purpose of Nickel (Ni) Plating on Components or Circuit Boards in the Electronics Industry

Firstly, let’s clarify that Workingbear is not a metallurgy expert. The content of this article is based purely on personal experience and information gathered from the internet. If there are any errors, feel free to point them out for correction. However, Workingbear takes no responsibility for any consequences.

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Mar12
Why Do PCBs Have Those Small Circles? What purpose of Test Points on PCBs?

Why Do PCBs Have Those Small Circles? What purpose of Test Points on PCBs?

Have you ever noticed those tiny circles on PCBs and wondered why they’re there? They don’t seem to have any parts soldered onto them, and some don’t even have solder paste. Well, those small circles are called test points, and they play a crucial role in ensuring that the electronics on the PCB are working correctly during the assembly process.

For those who know about electronics, having test points on a PCB is common knowledge. However, for those with a background in mechanics or other fields, the term “test point” might be a bit confusing.

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