Post by Dominic A on Apr 16, 2015 16:00:24 GMT -8
Soldering Workshop
Objective: Students will learn the basics of soldering chips and components
Things learned: How to use various soldering tools, how to solder and remove surface mount components, how to solder header pins.
I have had a fair amount of soldering experience so I could easily teach and correct student’s soldering technique. If you are unfamiliar with soldering, you need to practice before you try to teach the students!
Note: I taught this to a group of 3 students, which meant each one got a lot of time practicing soldering. If you have a large classroom, I’d call them over in groups of 3-4 to practice soldering while everyone else works on something else.
Materials needed
If you don’t have a specific board you plan to solder, you might consider buying practice soldering boards (like this one)
Optional Materials
Before Class
Set up a soldering station at one place. Be sure to dampen your sponge and plug in the soldering iron. You don’t want to wait for it to heat up when the students are there!
Then, put all the other tools on a separate table where the students will go first.
Stage 1: Show and explain the tools
Wire and Wire stripper: Wire comes in a spool, so it must be cut and stripped before it is used. Cut and strip some wire to show them how to do it.
Solder: this flexible metal will be used to bond the components to the board (like glue)
Soldering wick: this braid can remove excess solder from a point
Flux: used for cleaning up joints before soldering
Tweezers: used for holding components so you can accurately place them and not burn your fingers.
Needlenose pliers: can be helpful with placing components
Third hand: Useful for holding components when soldering them. One hand has the iron and the other has solder, so the third hand is really helpful!
Surface mount components and through hole components: surface mount components are small, but are great to make boards smaller
At this point, explain some safety with the soldering iron. It is hot, so you need to be careful around it, and not mess around with it.
Stage 2: Soldering surface mount components
If you don’t know how to solder surface mount components, see this tutorial or search Youtube for soldering surface mount components. For our purposes, we shouldn’t need the magnifying glass in the video, unless your vision is poor.
Show the basic steps while you solder on one component
Let each of your students practice soldering a surface mount component. As I helped them, I found it useful to use a piece of wire to point to places on the board. My finger was too large, and I didn’t want to get burned from the iron.
Stage 3: Removing surface mount components
If you don’t know how to remove surface mount components, see this tutorial or search Youtube for removing surface mount components
Show them the basic steps of removing a component
The method of applying extra solder is helpful for removing components with more than two pins. I’ve successfully used it to remove SOIC-8 packages.
Components usually have some heat threshold before they get damaged. I always assume that the component got damaged when I removed it and just pitch the component once it is removed. The components are very cheap and debugging a faulty chip on a PCB is a huge PAIN! It isn’t worth the few cents you save trying to reuse a piece.
Stage 4: Soldering on header pins
If you don’t know how to solder on header pins, check out this tutorial, or search Youtube for soldering header pins.
This was the highlight of my lesson as my students had accidentally fried two H-bridges by switching the positive and negative terminals. Here, we got to assemble the new devices from Pololu and use them!
Explain the basic process of soldering on the header pins
I gave each student 5-10 pins to solder.
Afterwards
Have your students wash their hands as they potentially dealt with lead (depending on what kind of solder you used).
Further Explorations:
Give them some PCB to solder that actually does something.
Objective: Students will learn the basics of soldering chips and components
Things learned: How to use various soldering tools, how to solder and remove surface mount components, how to solder header pins.
I have had a fair amount of soldering experience so I could easily teach and correct student’s soldering technique. If you are unfamiliar with soldering, you need to practice before you try to teach the students!
Note: I taught this to a group of 3 students, which meant each one got a lot of time practicing soldering. If you have a large classroom, I’d call them over in groups of 3-4 to practice soldering while everyone else works on something else.
Materials needed
- Soldering Iron
- Solder
- Soldering Wick
- Tweezers (preferably with a sharp point)
- Sponge (for wiping off solder)
- Something to place over area soldering (don’t burn a desk!)
- PCB board to solder
- Surface mount components to solder
- Header pins
If you don’t have a specific board you plan to solder, you might consider buying practice soldering boards (like this one)
Optional Materials
- Wire stripper/cutter
- Wire
- Third Hand tool
- Flux
- Needlenose pliers
Set up a soldering station at one place. Be sure to dampen your sponge and plug in the soldering iron. You don’t want to wait for it to heat up when the students are there!
Then, put all the other tools on a separate table where the students will go first.
Stage 1: Show and explain the tools
Wire and Wire stripper: Wire comes in a spool, so it must be cut and stripped before it is used. Cut and strip some wire to show them how to do it.
Solder: this flexible metal will be used to bond the components to the board (like glue)
Soldering wick: this braid can remove excess solder from a point
Flux: used for cleaning up joints before soldering
Tweezers: used for holding components so you can accurately place them and not burn your fingers.
Needlenose pliers: can be helpful with placing components
Third hand: Useful for holding components when soldering them. One hand has the iron and the other has solder, so the third hand is really helpful!
Surface mount components and through hole components: surface mount components are small, but are great to make boards smaller
At this point, explain some safety with the soldering iron. It is hot, so you need to be careful around it, and not mess around with it.
Stage 2: Soldering surface mount components
If you don’t know how to solder surface mount components, see this tutorial or search Youtube for soldering surface mount components. For our purposes, we shouldn’t need the magnifying glass in the video, unless your vision is poor.
Show the basic steps while you solder on one component
- Apply a small amount of solder to one of the pads
- Pick up the component with the tweezers in one hand, and heat the solder on the pad with the iron.
- Slide the component into the bead of solder.
- Once it is in place, remove the soldering iron and wait for the solder to solidify.
- Let go of the piece
- Apply some solder to the other pad, connecting the component’s other terminal
Let each of your students practice soldering a surface mount component. As I helped them, I found it useful to use a piece of wire to point to places on the board. My finger was too large, and I didn’t want to get burned from the iron.
Stage 3: Removing surface mount components
If you don’t know how to remove surface mount components, see this tutorial or search Youtube for removing surface mount components
Show them the basic steps of removing a component
- Apply extra solder to each terminal of the piece you are trying to remove
- Alternate heating each terminal for a few seconds until the piece easily slides off
- Use soldering wick to remove excess solder from the pads or surrounding areas.
The method of applying extra solder is helpful for removing components with more than two pins. I’ve successfully used it to remove SOIC-8 packages.
Components usually have some heat threshold before they get damaged. I always assume that the component got damaged when I removed it and just pitch the component once it is removed. The components are very cheap and debugging a faulty chip on a PCB is a huge PAIN! It isn’t worth the few cents you save trying to reuse a piece.
Stage 4: Soldering on header pins
If you don’t know how to solder on header pins, check out this tutorial, or search Youtube for soldering header pins.
This was the highlight of my lesson as my students had accidentally fried two H-bridges by switching the positive and negative terminals. Here, we got to assemble the new devices from Pololu and use them!
Explain the basic process of soldering on the header pins
- Break the header strip to the proper length
- Solder a single pin on the strip to each side. Check if they are straight
- Verify the chip fits into the breadboard, and adjust the strip angles if necessary
- Take it out of the breadboard and apply a bead of solder to each pin
I gave each student 5-10 pins to solder.
Afterwards
Have your students wash their hands as they potentially dealt with lead (depending on what kind of solder you used).
Further Explorations:
Give them some PCB to solder that actually does something.