User talk:Neil Breeden

From Spare Time Gizmos' Wiki

Notes to aid in successful builds (Per NeilB):

• Plan the build
  • Read the doc's fully at least twice before the soldering pencil touches the board. Check for errata (component changes, traces needing cut etc.) before you start assembly.
  • Do you have all the necessary tools?
    • A quality soldering station is an excellent investment, it must be temp controlled. Using a cheap soldering pencil will destroy your kit. I use a Hako 936 myself.
    • Use high quality solder; Kester ROSIN core works well; the thinner the solder the better; trying to use large diameter solder will lead to solder bridges. Never use acid paste solder (this is what you use to solder copper pipes) it will destroy your kit.
    • Use quality flush cutters; you cash get by with cheap ones HOWEVER replace them as soon as they become dull or pitted. A quality pair will last much longer and I find it is a cheaper long term investment.
    • Needlenose pliers, tweezers
    • Desoldering tool
    • Good lighting
    • Magnification and a flash light can really help when something looks odd or you are unsure.
    • Clean organized work area
  • Do you have all the necessary parts?
    • I tend to sort the parts into storage organizers, some people use cupcake pans; anything to help organize is useful.
  • Can you confirm they are the right parts?
    • Use a DVM to verify resistors as some of the colors in color codes can look the same.
    • If your DVM can measure capacitance it can be used to help confirm you have the right capacitor.
• Use HIGH quality sockets for ICs. Machined Pin sockets are more expensive but are worth it for a quality build.
• How will you power it; trying to kludge a power source last minute usually leads to disaster.
• Ventilate the work area; breathing solder fumes is an irritant.
• Take your time; use good lighting, inspect your work often. If your eyes are tired or your back hurts from bending over take a break.
• Start with the smallest profile components and work your way up. My typical build order is: Resistors; IC sockets, despiking caps (0.1uF disc caps), header pins, LEDs, larger caps such as electrolytic and tantalums. This is a general guideline; as you plan your build (you do plan it) the order will be clearer.
• Sockets - I install the largest ones first (typically 40 pin), I use blue painters tape (leaves no adhesive residue when removed) to hold them in place then flip the board over. The weight of the board tends to help set the sockets. I solder two corners, remove the tape and inspect them. If they are not seated properly against the board it is easy to reheat the solder joint in one corner and set the socket. I count the pins as I solder them. A 40 pin socket will have 19 unsoldered pins left on each side. 1, 2, 3 etc. It helps me make sure every pin is soldered. Sockets have a marking to indicate the ICs orientation on the board; align them to the silk screen; do NOT assume all parts face the same way.
  • More on sockets - I move on to the next biggest socket and repeat the steps above. By going from largest pin count to smallest pin count you will not accidentally solder a 14-pin socket in a position that uses a 16-pin socket. Everyone has done this; it is a MAJOR pain to fix and for the inexperienced builder will result in lifted traces on the PCB.
• Pin headers - I hold them in place with blue tape and solder only one pin. I then remove the tape and inspect them. Often they will not be straight. I use a long plastic pin jumper; i install it on 2 pins and reheat the one pin I soldered pressing the part in straight. With as bit of practice you can have perfect pins every time.
• I tend to mount LEDs, resistors, resistor networks, capacitors etc. using the same process: Install; tape to hold in place; solder one pin; align and solder remaining pins
• If you need to remove something with multiple pins (an IC soldered directly to the board or a bad socket for example) do not try too salvage the part UNLESS you have the proper tools to do so. Cut the body away if you can. The idea is to get to the point where you can head each solder joint and with a pair of tweezers or quality needle nose pliers pluck the individual pin out. Use a good quality solder sucker to clean out each hole.
• Sometimes the solder sucker fails; often adding a little solder then trying the solder sucker again will result in a successful removal of the solder.
  • Solder wick can be useful; it is braded copper with flux; it tends to suck up the solder, Try the solder sucker first!
• DO NOT try to pry components out while trying to heat a solder join. This can remove the plate through (the lining in the hole connecting the pad on the top of the PCB to the pad on the bottom. This is a MAJOR pain to troubleshoot.
• When if doubt ask.
• Take your time, plan ahead, keep notes, use checklists.