Meeting Minutes and Actions

Teledyne, LAT QA, & NASA QA, Oct. 1, 2004

 

 

PARTICIPANTS:

Rhonda Santiago

Lupe Villegas

Darren Marsh

Evon Bennett

Brian Caplen

Tracy Shepard

Jim Lohr

Don Knaepple

David Rich

 

 

DISCUSSION:

Reviewed Non-Conformances.

 

Brian said that Teledyne has reviewed final draft wording for LAT-DS-00898 & -00899 and approves of wording.

 

Teledyne was informed of NCR #190, Conformal Coating on connector mating interface.

Don Knaepple did not forward NCR #190 to Teledyne.Darren said that process going forward would be that Richard Gobin will forward NCRs to Rhonda Santiago and copy others.Don requested that LAT QA keep a record of which type of connector saver is involved with each non-conformance noted to see if there was a correlation.Tracy explained that it appears that conformal coating is wicking from bottom side of connector interface into mating interface area.Brian noted that Teledyne is not permitted to demate connector saver w/o written authorization.The driver for this is limiting number of cycles of mate/demate of connectors and that Teledyne does not wish to have to keep mate/demate log.Brian asked if SLAC or INFN currently use Ionizers.The answer is currently-No.

 

ESD Procedure-Evon Bennett of Teledyne presented that their work stations for MCM production after ASIC installation is 100V.MCM susceptibility is 200V.Evon also reported that Teledyne does have a higher level of ESD protection 30V at ultra sensitive areas.Jim Lohr requested that Teledyne implement bench top ionization units are every work station after ASIC installation.Note:We have not reported a single ESD failure to date.David Rich agreed to request for quote to implement ionization units as requested by Jim Lohr.I was noted that Ionizers are presently used during kapton masking and removal operations.

 

David Rich forwarded to Teledyne prior to this meeting Fred Grossís issue with use of silicon adhesive Kapton tape used for masking operations.Also forwarded was NASA Advisory Bulletin on this subject.Teledyne is to investigate immediately all process steps where this silicon adhesive Kapton tape is being used.Brian will need to investigate alternative materials.Acrylic adhesive substitutions have been supplied to Teledyne to consider as replacements.

 

The question was raised what is the adhesive used on the Kapton sheet on the backside of the MCMs.David Rich confirmed with Jerry Clinton after the meeting that an acrylic adhesive is used to bond the Kapton sheet on the backside of the MCMs.

 

Discussed recommendation of performing a bake-out of polyimide PWB prior to conducting the reflow process.This step is recommended by the polyimide manufacturer as researched by Tom Himel as part of the PWB leakage current investigation he is performing.††† Prior to the start of flight production, it was believed that the Pitch Adapter epoxy curing operation (1 Ĺ hrs at 85C) would be sufficient to drive off the moisture absorbed by the PWB prior to reflow step.NASA recommends 2 hr bake-out at 93C.The polyimide manufacturer recommends 2 hr bake-out at 120C.Jim Lohr requested that MCM production not start until the PWB bake-out was implemented.David Rich objected to a constraint of not restarting production without the new PWB bake-out step implemented but agreed to request a quote from Teledyne to implement the recommended bake-out.

Subsequently, test results from Tom Himel suggest that bake-out should be four (4) hrs @ 120C.An RFQ will be requested to perform a bake-out for 4 hrs at 120C. The reflow process step is to be performed within 48 hours of completion of PWB bake-out.

 


 

RETURN TO PRODUCTION:

The following represents a summary of items which need to be closed and a closure plan for each to return to production of MCMs:

 

Item

Description

Responsible

Action

Status

1

PWB, Kapton on back side extends to Italian edge

 

 

D. Rich

Ref. NCR #194-

2)Disposition NCR to have Teledyne adjust trim tool to compensate for Kapton and verify trim results

3)Fix note on drawings

Per telcon, Brian recommended 2 good parts off each of 4 trim tools.

D. Rich to find out how many tall/short ratio for remaining PWBs & report to Brian.

2

Masking of holes

A. Nguyen

Finalize dimension of mask area with Brian, update drawings, release, transmit to Teledyne

 

3

Conformal Coating on connector interface

R. Gobin

Ref. NCR #190-

Transmit NCR to Teledyne.

Teledyne to investigate cause & if improved masking can resolve issue.

 

4

Silicon Adhesive Kapton Tape

R. Santiago

 

 

 

 

 

 

 

 

 

 

D.Rich

1) Teledyne to generate an NCR.

Document all locations and associated process steps where silicone adhesive Kapton tape has been used.

2) Purge all silicone adhesive Kapton tape from MCM production.

2) Investigate replacement Kapton tape & procure.

3) Run process validation units with replacement tape.

4)Evaluate contamination risk of residue silicone adhesive on MCMs.

Telcon w/Fred Gross scheduled for 10/5/04.

5

Localized damage to PWBs under mounting screws

B.Caplen

1)Review accept/reject criteria with Tracy, Richard, Don, Lupe & Evon and capture in Teledyne inspection process.

2)Investigate if localized damage to PWB can be reduced or eliminated by change in process or improved education of production team.

Process Improvement, not a gate to restart of production.

6

Rust on mounting screws

A. Nguyen

Change drawings to call out corrosion resistant screws.Provide new screws to Teledyne.Teledyne to purge old screws from inventory & WIP.

Teledyne has ordered stainless steel screws and is installing these in PWBs in process.Temporary change documented on Teledyne AR.

7

Bake-out of PWBs before reflow

D. Rich

SLAC procurement to issue RFQ.

4 hrs. @ 120C.Reflow to be within 48 hrs of bake-out.(PWBs to be maintained in dry box after bake-out.Process change validation shall be required to qualify new process step.

Test sample of PWB with bonded Pitch Adapter tested at SLAC for 4 hrs. @ 120C.No visible damage per visual inspection.

8

ESD

D. Rich

SLAC procurement to issue RFQ.

 

9

Inspection criteria

D. Rich

 

R. Gobin & T. Shepard

 

B. Caplen

1) Send LAT-DS-04879 to Teledyne for review.

2) Travel to Teledyne and discuss details of inspection with Teledyne QA and Don K.

3) Incorp inspection criteria in Teledyne process.

 

 

 

 

 

 

 

 

 

 

 

 

ACTIONS ASSIGNED:

1)     Brian and Albert need to finalize on diameter of masking area around mounting screws.This item gates revision of LAT-DS-00898 & -00899.

2)     Richard Gobin is to transmit NCR #190 to Rhonda Santiago and copy Brian Caplen, Evon Bennett, Don, and Lupe.

3)     Richard Gobin and Tracy Shepard are to visit Teledyne and review inspection criteria with Don Knaepple, Brian, Lupe, and Evon.Date: TBD

4)     David Rich is to forward the (SLAC internal) MCM Inspection Procedure to Rhonda, Brian, Don, Lupe & Evon for review prior to Tracy and Richards visit to discuss inspection criteria.

5)     David Rich to work with SLAC procurement to issue RFQ to implement ionization units at each work station afterASICs are installed on MCMs.Will also request quote to bring work stations to 30v ultra sensitive standard (if more than addition of bench top ionizers is required.

6)     Brian Caplen is to review where silicon adhesive Kapton tape is used for MCM masking operation.Brian is to pick a replacement Kapton tape which does not use silicon adhesive.Brian is to conduct an engineering evaluation to ensure that process change is acceptable.Teledyne is to update their process specification to call-out explicitly no silicon adhesive to be used during MCM production.

7)     David Rich is to issue a written request for Teledyne to provide a 5-10 gm. Sample of Humiseal conformal coating, applied with same mix ratio used during MCM production.Conformal coating sample is to be cured at room temperature for 24 hours followed by bake-out at 85C for 168 hours.Sample is to be provided in clean Petri dish.This sample will be provided to Fred Gross (GSFC) for TML analysis.

8)     An RFQ will be requested to perform a bake-out for 4 hrs at 120C.The reflow process step is to be performed within 48 hours of completion of PWB bake-out.

9)     Dispo NCR to authorize Teledyne to adjust trimming tool to compensate for Kapton backing, run two MCMs per fixture.Provide ratio of short/tall for balance of MCMs (approx. Qty. 330).

10) Albert to revise LAT-DS-00898 & -00899 and release.Send revised document to Teledyne thru SLAC procurement.