Engineering worksheet

MATERIAL SELECTION / STARTING POINT

Start with the operating conditions.

Build a shortlist for a supplier discussion. A material family is not a qualified construction.

Enter requirements in order of consequence

Begin with assembly method and service movement, then add electrical priorities and environment. State what is fixed by the product and what can change. For example, distinguish a fixed connector interface from a preferred film brand. The materials overview explains the constituent choices. A candidate that fails a mandatory process or interface requirement should not remain preferred because of an unrelated attractive property.

Material shortlist worksheet

DecisionDefineReview
Assembly requirementProcess, profile and reworkCandidate evidence or unanswered question
Mechanical dutyInstallation and service movementRepresentative geometry and test plan
Electrical priorityLoss, insulation, power or impedanceGrade and complete-stack model
Supply decisionExact construction and alternativesApproved substitution process

Record evidence beside each candidate

For every shortlisted grade, list the source sheet, relevant test conditions, available construction, and open supplier questions. Use ‘unknown’ where evidence is absent. Compare complete constructions at the same functional boundary; do not compare raw film data on one side with assembled-board results on the other. Link the result to your proposed stack drawing so changes in thickness or bonding remain visible.

Convert the shortlist into a next step

Ask the fabricator to confirm proposed constructions and material availability, and identify what a prototype must demonstrate. Assign a decision owner and a closure condition to each open question. If the material change affects electrical geometry, assembly exposure, or qualification, resolve those consequences before releasing layout. Save the final assumptions with the quote brief for later comparison and production transfer.

Before you release the design

  • Enter real operating conditions.
  • Separate mandatory limits from preferences.
  • Attach source revisions to data.
  • Keep unknowns visible.
  • Choose a prototype decision criterion.

Watch points

  • A worksheet cannot determine fatigue life or certify compatibility from a few dropdown selections.

Practical questions

What if no candidate has complete data?

Prioritize the missing facts that could reject a candidate. Request those first and plan testing where supplier data cannot answer the product question.

Can a shortlisted material be quoted?

Yes, as a clearly identified proposal with unresolved requirements. Final release should reference the reviewed construction and accepted assumptions.

Technical references

References support the material or design context. Check the exact grade, part number, document revision and project conditions before release.

Updated 27 September 2026 · Technical content policy · Engineering guidance supports project review; the agreed drawing defines the build.