ECE Projects Lab

1
ECE Projects Lab

• Surface Mount Technology
• Kip Coonley - kcoonley_at_ee.duke.edu
• Willie Du w.du_at_duke.edu

2
What is SMT?

• Surface Mount Technology
• Used primarily in industry
• Same circuitry with much smaller components
• Was not intended for individual soldering, but
  gaining popularity

3
SMT Components

• Resistors
• 555 IC

4
SMT Board
5
Why SMT (advantages)?

• Much smaller size
• Components on both sides of board
• Leads can be much shorter reducing inductance and
  resistance there by increasing performance
• Prototyping is more indicative of the final
  product

6
How to SMT (techniques)

• Fine tip soldering
• Uses conventional soldering techniques on a much
  smaller scale
• Hot air reflow
• Uses soldering paste and hot air to reflow the
  soldering paste with components preset
• Oven reflow
• Uses soldering paste and reflows entire board

7
Fine Tip Soldering

• Conventional equipment
• Causes eye strain
• Requires a steady hand

8
Hot air reflow

• Hot-Air Rework Station AM6500 by JBC
• Fine tip solder tools
• Desoldering tools
• Hot tweezers
• Hot air gun

9
How hot air reflow works

• Hot air used to desolder IC
• Vacuum extractor pulls IC after solder flows

10
Oven reflow

• Typical Reflow oven
• Large and bulky
• Expensive ?
• Cuisinart TOB 165
• Just as good
• A small fraction of the cost

11
Oven Reflow Overview

• After applying solder paste and setting
  components, the board is inserted to be cooked
• End result is a perfectly soldered board for a
  fraction of the cost (no eye strain either)

12
Reflow Caution

• The temperature of the reflow process must be
  precise enough as to not damage the ICs through
  excess heat and sufficient for reflow of the
  solder.

13
Oven Reflow Steps

• Apply soldering paste
• Set ICs and components
• Cook!
• Touch up using soldering wick to remove excess
  solder

14
Toaster Oven Reflow Steps
15
Movie time

• Silicon runs II

16
Summary

• Fine tip soldering is hard, but essential
  sometimes
• Hot air reflow is more convenient for reworking
  of components
• Oven reflow is great for creating a whole board
  at once
• ECE Projects Lab will do it all.

17
Credits/Work cited

• http//en.wikipedia.org/wiki/Surface-mount_technol
  ogy
• General SMT info
• http//www.heinc.com/jbc/repair.html
• Hot air reflow station website
• http//www.bidservice.com/Browses/NF_Detailed_Item
  _View_new.asp?ProductID20069
• Place to purchase typical reflow oven
• http//www.seattlerobotics.org/encoder/200006/oven
  _art.htm
• Another group that has done a similar project
  with a toaster oven
• http//www.circuitcellar.com/library/print/0704/La
  coste_168/
• Thermal profile for a toaster oven

18
Laboratory Hours

• Monday 1115AM-145PM
• Tuesday none
• Wednesday 1115AM-145PM
• Thursday 600PM-800PM
• Friday 1115AM-145PM
• For other times please contact Kip Coonley at
  kcoonley_at_ee.duke.edu

19
Design Lab Website

• Presentations available
• Online Reflow Tutorial
• http//www.ee.duke.edu/DesignLab/
• Useful Contact Info
• Me w.du_at_duke.edu
• Kip kcoonley_at_ee.duke.edu

20
The End