In the next part of the chips story I brought up the topic of desoldering and gave some general info about solder. On the picture one sees the nice chips but covered… with epoxy. I bet that this is Devil himself’s creation. Read on below.
🌟Chip photography 🌟
🔶 Getting a chip off the circuit board 🔶
The journey of the chip starts here. Chips are usually enclosed in black epoxy coating. On the bottom side is the metal base of the chip which is soldered to the circuit board and connects it to the rest of the components.
Solder used to contain 60% tin and 40% lead. Well, there are many possible alloys, other metals added to improve the properties of the solder but the tin-lead solder was the most common. After the use of lead was banned due to its toxicity, tin became the major component of commonly used solder. Silver, copper and bismuth are possible additional metals. Lead-free solder melts at a somewhat higher temperature, which can reach 220 °C or more (traditional solder melts at 183 °C).
Desoldering can be easily done using a hot-air gun.
‼️ It might sound tempting to put the circuit board on a hot plate… don’t! It starts smoking and smell horrible… as a bonus – those fumes are toxic. 😱
Once the chips are desoldered, comes the trickiest part of the process – getting rid of the epoxy. More on that in the next post.
(originally posted on 25.9.2020 on my Instagram account)
