6th Day - 12 July Thursday

SOLDERING PROCESS

This company more uses microcontroller and PLC for the project. So, we have to know about microcontroller and PLC. Engineer Siva also gives us a task to remember how to read value of components and we also must sort the components next week. We also must learn about how to read value from SMD component because the component that we always use and learn is type of through hole. Engineer Siva told us about project that maybe we will involved on our practical. After briefing by Engineer Siva, we need to accomplished task by note that Mr Mazran gave to us to complete soldering process on the PIC by using the new components that he already buy.

Some of these size of components very small and do not have any leg so we need to be more careful when soldering. Mr Mazran teaches us how to solder the components in easy way and soldering must only use a small amount of tin-lead alloy. For this soldering, we use tin-lead alloy and not lead-free alloy. After lunch break, Mr.Mazran gave us module about IPC and we have to read the standard for soldering that must be follow. In module 4 and module 7 explain about the acceptance soldering or defect soldering by Class 1, Class 2 and Class 3. If class 1 defect, class 2 and 3 also defect. If class 2 defect, class 3 also defect but class 1 is acceptance. by reading this book, we must compare to our PIC soldering with the standard and we saw a lot of fault on our soldering. This module we can keep it to study more about IPC.

SOLDERING STEPS

Step 1: Surface Preparation

A clean surface is very important if you want a strong, low resistance solder joint. All surfaces to be soldered should be cleaned well.

Step2: Component Placement

After the component and board have been cleaned, we are ready to place the components onto the board. Most likely you will be soldering a few components at a time before turning the board over and placing more. In general it is best to start with the smallest. It is also best to save sensitive components until the end to lessen the chance of damaging them during assembly of the rest of the circuit.

Step 3: Apply Heat

Apply a very small amount of solder to the tip of the iron. The small amount of solder we applied to the tip before heating the joint will help make contact between the board and the lead. If we see the area under the pad starting to bubble, stop heating and remove the soldering iron.

Step 4: Apply Solder To The Joint

Once the component lead and solder pad has heated up, we are ready to apply solder. Touch the tip of the strand of solder to the component lead and solder pad, but not the tip of the iron. If everything is hot enough, the solder should flow freely around the lead and pad. Once the joint that is made we should inspect it. It is good practice to clean the entire excess flux residue from the board.