Al.

If it helps here's a section from our customer guide for handling
& storing drypacked SMDs. I reckon 8.2 sounds like the likely option
unless you have the luxury of a 3-week wait!

8.0 DRY-OUT PROCEDURES
  SMDs that are not handled or stored within specification must
  undergo one of the following dry-out procedures prior to reflow:

8.1 125°C Dry-Out Bake
  Bake SMDs at 125°C (± 5°C) for 24 hours (± 1 hour).
  CAUTION: Do not bake SMDs in shipping trays with a temperature
  rating of less than 130°C. Do not bake SMDs in plastic tubes or
  Tape and Reel (T&R) packaging. Use care in handling SMDs out of
  their shipping container to maintain lead coplanarity.

8.2. 40°C Dry-Out Bake
  Bake SMDs at 40°C (+5°C/-0°C) in an atmosphere of less than 5% RH
  for 192 hours (± 8 hours).
  NOTE: This bake is designed for SMDs in plastic tubes or T&R, and
  is best achieved in a dry nitrogen purge oven. Higher
  temperatures warp or melt plastic tubes and T&R cover tape
  separates from carrier tape at 60°C.

8.3 Room Temperature Dry-Out
  Store units at less than 20% RH for a minimum of 500 hours. This
  drying method is designed for SMDs in plastic tubes or T&R when a
  40°C Dry-Out bake is not possible or desirable.
  NOTE: The customer must apply the same storage requirements and
  time limits specified in Section 6.0 to all "dried" SMDs.

--
Thx & best regards . . .
------------------------------------------------------------------------
Norman S. Robinson             Tel. No.: (44) 1355 355349
Snr. Assy. Engr.               Fax. No.: (44) 13552 65201
TSG BE/OS PE                   Email: [log in to unmask]
MOTOROLA EKB, SCOTLAND, U.K.   Email: [log in to unmask]
------------------------------------------------------------------------

John Brewer wrote:

Al Writes:
I have 5 year old plastic SOIC packages on reels and want to dry them out
in an oven rather than leave it to the pre-heat of the reflow solder machine.
Production asked for temperature and time for the SOIC to be in the oven.
My initial thoughts are to put them in a cold oven and set the thermostat
to 110'C and leave them baking for 4 hours.

Al, make sure that they need baking.... if they're low pin count SOIC's
they likely don't.
Large >28 Pin PQFPs, TSOPs etc likely DO.

110C in tape will likely melt things. I believe the profile for in-tape
bake is something like 40C for a week, or something close to that. IC vendor
websites will have the appropriate profile. Beware that hi temp bakes can
tend to oxidize the leads, so that only one high temp bake should be done
(if done in air) to avoid creating solderability probs.
Some contract vendors can perform bake in a dry nitrogen environment at
high temps avoiding the oxidation issues (or so they say...does anyone have
experience with this?).

Rgds, John

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