MEL PICBASIC Forum - SMD Prototyping

  • SMD Prototyping

    Have you ever wanted to prototype with a part that only came in an SMD package but did not because it would not breadboard?

    Here is one way of getting around the problem.

    If you have experience with SMD parts you may laugh at this method, if you are new to using SMDs you might find this useful.
    Normally pre-sensitized boards, templates, and light boxes are use before etching. For the prototyping of a few parts the layout will be hand drawn on regular copper clad board.

    The part I want to test here is a SMD voltage regulator, AMA8800AEETZ, 3.3 volt output.
    Parts list:
    Item Quantity Package
    AMA8800AEETZ 1 SOT-23
    1 uf Capacitor 2 SM0805
    LED 1 SM0603
    470 Resistor 1 SM0603
    3 Pin Header 1 NA
    As usual a schematic and board layout are needed.

    The board is the same size as a TO-220 package. The traces are
    drawn with a permanent marker,"Sharpie". Allow the ink to dry
    before etching. Ink can be removed with isopropyl alcohol.

    Etch in a ferric-chloride solution and tin per manufactures instructions.
    Tinning is not needed but recommended as the finished part will be handled
    by hand.

    The parts will be soldered on to the board using a solder paste
    with a standard, un-modified toaster oven. The oven needs to
    maintain 300 to 350 degrees Fahrenheit.

    The solder paste I use is made by Chipquick, part #SMD 291AX10.
    The paste is packaged in a syringe, so you do not need a stencil.

    Be careful not to use more paste than needed as pictured here. It
    causes the parts to float. The board is assembled on a piece of thin
    aluminum plate to help with heat transfer and handling in the oven.
    The un-tinned board is holding the header level.

    As you can see, some of the parts "floated" a little but it works!
    Where else can you get a linear regulator with an "on LED"?