Your cart is currently empty!
DFSS Instructor Prep · Module 5
Layer B — Engineering Substance · Tier 2 Domain Depth
Connectors, Terminals & Crimping Science
Where Yazaki’s reputation lives or dies. The crimp is the single most-scrutinised engineering detail in the wiring-harness industry — and the convergence point of mechanical, electrical, materials, and process engineering. This module gives you full literacy in contact physics, terminal design, plating selection, sealing classes, and the crimping science governed by USCAR-21.
What’s in this module
- What a connector actually does — the seven functions
- Contact physics — how electrons actually cross the interface
- Terminal anatomy — male/female, blade sizes, retention features
- Plating selection — tin vs silver vs gold
- Sealing classes & the IP rating system
- Connector position assurance (CPA) & terminal position assurance (TPA)
- The crimp — anatomy, the four critical dimensions
- Crimp validation — pull force, cross-section, the USCAR-21 framework
- Production process control — CFM (Crimp Force Monitoring)
- Standards landscape — USCAR-2, -21, -25, -38; JASO; LV-214
- DFSS linkage — where this lands in DMADV
- Instructor facilitation pattern
- Self-check (10 questions)
1. What a connector actually does — the seven functions
Most people think a connector “just connects wires”. A senior engineering audience will appreciate that a modern automotive connector is a multi-function electromechanical assembly. Listing the seven functions explicitly makes the design space visible.
- Establish electrical contact — between male and female terminals, with low and stable resistance.
- Retain the mated connection — under vibration, thermal cycling, and pull loads over the vehicle’s service life.
- Provide polarisation — physically prevents the wrong connectors mating to each other (keying).
- Allow controlled mating/unmating — with defined insertion force, audible/tactile lock confirmation, and serviceable disconnection.
- Seal against the environment — moisture, dust, fluids, salt; IP rating defines the class.
- Protect against partial mate & mis-assembly — TPA / CPA features force-complete the assembly.
- (HV only) Provide safety interlock — HVIL loop ensures HV is dead during mate/unmate.
Why this list is instructor gold
Each function is a candidate function statement in a DFMEA (Module 3). When you see a DFMEA that lists only “carries current” as the terminal function, you immediately know it’s incomplete. The seven-function list is your auditing tool.
2. Contact physics — how electrons actually cross the interface
The thing most field failures actually attack. Get this right and the rest of the module makes sense.
2.1 The a-spot model
When two metallic surfaces are pressed together, they don’t actually touch over the full apparent area. They touch only at microscopic asperities — surface high points. The real contact area is a tiny fraction of the apparent area (often < 1%). Electrical current flows through these tiny contact spots, called a-spots.
Three things follow from this picture, and each one is a design lever:
- Contact resistance is dominated by constriction at the a-spots. More a-spots, larger a-spots → lower resistance. Driven by normal force, surface finish, and material softness.
- Plating exists to make a-spots reliable. Oxidation, corrosion, and adsorbed films on bare metal make a-spots unreliable; noble or oxide-stable platings keep them clean.
- Wipe length matters. When terminals slide during mating, the wipe action breaks through surface films and creates fresh a-spots. Too little wipe = unreliable contact; too much = plating wear.
2.2 The four design levers
| Design lever | What it controls | Typical value (LV signal terminal) |
|---|---|---|
| Normal force | How hard the spring presses contacts together. More force = more a-spots = lower R, but more mating force and plating wear. | 1.5 — 4 N typical |
| Wipe length | How far the contacts slide during mating. Establishes fresh a-spots. | 1 — 3 mm |
| Plating choice & thickness | Surface conductivity and corrosion resistance. See §4. | 3 µm matte tin typical |
| Geometry / contact pressure distribution | Hertzian stress at a-spots; symmetry of contact (front/back, top/bottom). | Designed for > 100 MPa local stress |
Why this maps so well to DFSS
These four levers are the control factors in a P-diagram of contact reliability. Noise factors are the same five stress drivers from Module 2: temperature, vibration (creates fretting), humidity (corrodes a-spots), and so on. A robust-design DOE around contact reliability has these inputs and outputs almost ready-made.
3. Terminal anatomy — male/female, blade sizes, retention
3.1 The standard terminal families and where they’re used
| Terminal series | Blade size | Typical current | Typical use |
|---|---|---|---|
| 0.5 mm / 0.64 mm (micro) | 0.5 — 0.64 mm | up to ~2 A | ECU pins, sensor signals, high-density connectors |
| 1.5 mm (mini) | 1.5 mm | up to ~10 A | Body wiring, lights, LIN sensors |
| 2.8 mm | 2.8 mm | up to ~25 A | Body main harness, switches, fuses |
| 4.8 mm / 6.3 mm | 4.8 — 6.3 mm | up to ~50 A | Engine bay, headlamps, fans, blower motors |
| 9.5 mm and bolt-down | ≥ 9.5 mm or bolt M5/M6/M8 | 50 — 400 A+ | Battery, starter, HV bus, ground stud |
| HV-specific (Yazaki YESC HV, e.g. HV01) | 4.8 mm tabs to bolt-down | 27 A @ 3 sq, 40 A @ 5 sq | HV battery, inverter, motor, charger |
Naming convention to keep in mind
Connector terminal families are usually named by the blade thickness or width in mm (or sometimes inches: 0.025″ ≈ 0.64 mm). When a participant says “this is a 2.8 series terminal”, they mean the male tab is 2.8 mm wide. The OEM specifies the terminal series for each application based on current rating, vibration class, and packaging space.
3.2 The seven parts of a typical female terminal
Reading a terminal drawing requires knowing what to look for. A typical female terminal has seven distinct regions, from front to back:
- Mouth / entry chamfer — guides the male blade in.
- Contact zone — where the contact springs touch the male blade. This is where the a-spots live.
- Contact springs / dimples — provide normal force. Often a “twin-beam” or single dimple design.
- Lance / lock tab — engages the connector cavity to retain the terminal.
- Transition zone — connects contact section to crimp section.
- Wire (core) crimp — grips the bare conductor.
- Insulation crimp — grips the wire insulation; provides strain relief.
Female terminal — schematic anatomy
4. Plating selection — tin vs silver vs gold
Plating is one of the highest-leverage cost-versus-reliability decisions in connector design. Each plating choice has a known signature failure mechanism.
Tin (Sn) — matte or reflow
Use: Default for LV connectors; cost-driven.
Watch out: Fretting corrosion (Module 2 #1) — the dominant failure mechanism in the entire industry. Tin oxide is insulating and hard; micro-motion creates oxide buildup.
Pure tin: can grow whiskers — banned for fine pitch in some applications. Lead-bearing or satin tin preferred.
Silver (Ag) — flash or full
Use: High-current and HV applications where contact resistance stability matters; AR-HUD / EI signal connectors where tin’s resistance drift is unacceptable.
Watch out: Tarnishes in sulphur atmospheres; corrosion in marine/road-salt environments unless protected. Higher cost than tin.
Yazaki HV connectors often use silver-plated contacts for stable contact resistance under high current.
Gold (Au) — flash over nickel
Use: Low-level signals where any contact-resistance drift is catastrophic (ECU pins, ADAS sensors, low-current diagnostic). Also in mate-many-times applications.
Watch out: Cost — typically 5–20× tin. Used as a thin “flash” over nickel barrier to control cost.
Best fretting performance of the three.
A pattern in OEM choices
Premium European brands more readily specify silver/gold for safety and signal-integrity-critical connectors. Cost-focused programmes default to tin almost everywhere. India/SE-Asia OEM programmes increasingly mandate silver flash for HV and ASIL-rated paths. Knowing this pattern means you can ask a participant: “what’s the plating spec on your customer’s reference connector?” — and follow their answer.
The nickel underlayer matters
Almost all noble-metal platings (gold, silver) use a nickel underlayer to prevent copper diffusion from the substrate. Without nickel, copper migrates through the gold over time and oxidises at the surface, raising contact resistance. A drawing that specifies “gold over copper” without nickel is a problem; the standard is “gold over nickel over copper alloy substrate”.
5. Sealing classes & the IP rating system
The IP (Ingress Protection) rating, defined by IEC 60529, classifies a connector’s resistance to solids and liquids. Two digits: first = solids, second = liquids.
| IP code | Solids (1st digit) | Liquids (2nd digit) | Yazaki use case |
|---|---|---|---|
| IP00 | None | None | Unsealed cabin connectors (under dashboard, behind interior trim) |
| IP54 | Dust-protected | Splash from any direction | Under-seat, door-internal |
| IP67 | Dust-tight | Immersion up to 1 m for 30 min | Under-bonnet, underbody, exposed exterior connectors |
| IP69K or IP6K9K | Dust-tight | Withstands high-temperature, high-pressure water jets (e.g. car-wash spray) | Engine bay, EV powertrain, exterior charging inlet |
The “K” suffix
You’ll see IP6K9K as well as IP69K. The “K” denotes German DIN 40050-9 (now ISO 20653) test methods — used heavily in automotive. The two digits both have “K” because both are tested using the road-vehicle-specific test variant. This is a very common automotive spec.
IP ratings degrade over time
Module 2’s seal compression set mechanism — rubber seals harden and lose elasticity over ~10–15 years — means a connector that ships at IP6K9K may drop to IP54 in service. DFMEA should reflect this with a time-bounded function statement: “maintain IP6K9K for 15 years through 5000 thermal cycles.”
6. Connector Position Assurance (CPA) & Terminal Position Assurance (TPA)
Two features that exist specifically because of assembly-error failure modes.
6.1 What they do and why they exist
| Feature | Function | Failure it prevents |
|---|---|---|
| TPA (Terminal Position Assurance) | A secondary lock — typically a separate plastic insert that engages each terminal independently after they’re loaded into the connector. Cannot be closed if any terminal is not fully seated. | Partially-seated terminals — would otherwise back out under vibration and cause intermittent open, very hard to diagnose |
| CPA (Connector Position Assurance) | A secondary lock on the connector-to-connector mate — typically a slider that cannot be closed unless the primary latch is fully engaged. | Partial-mate connectors that look mated but aren’t fully locked, would back out under vibration |
The poka-yoke principle
TPA and CPA are pure error-proofing devices (poka-yoke) — they exist because operators and service technicians WILL get assembly wrong, so the design refuses to accept incorrect assembly. Both are explicit features on most modern automotive connectors. When a participant’s DFMEA discusses “partial mating” or “terminal back-out” as a failure mode, the natural prevention is CPA / TPA — they should be in the design, not an afterthought.
7. The crimp — anatomy & the four critical dimensions
Now we arrive at the topic that earns the room. The crimp is where wire meets terminal — a mechanically formed, gas-tight, cold-welded joint that must conduct current and survive 15 years.
7.1 What a crimp physically is
A crimp is not soldering. It is a mechanical deformation of the terminal’s conductor wings around the bare wire strands, applied with enough force to (a) compress the strands tightly, (b) cold-weld strand surfaces together at the contact points, and (c) form a gas-tight seal that excludes oxygen.
The cold-welding action is the critical bit. Without compression sufficient to break through the oxide layers on individual copper strands and to create metallurgical bonds between them, the crimp is just a mechanical squeeze that will oxidise and corrode over time.
Crimp cross-section — schematic
7.2 The four critical dimensions every crimp engineer measures
| Dimension | What it controls | Typical value & tolerance |
|---|---|---|
| Crimp height (CH) | Vertical compression of the strands. The single most-monitored crimp dimension. Too high = under-crimp (loose, low pull-force); too low = over-crimp (cuts strands, brittle). | Specific to terminal+wire combination, tolerance typically ± 0.05 mm |
| Crimp width (CW) | Lateral compression. Less commonly measured than height but matters for sealing the wings. | Driven by tooling geometry |
| Compaction ratio | The ratio of theoretical conductor cross-section (all strands solid) to the actual cross-section after crimping. The fundamental quality metric. | USCAR-21 Rev 4 specifies a compaction range of 15–20% (which corresponds to ~80–85% of theoretical density) |
| Bell-mouth & brush length | Bell-mouth = the flared opening at the front of the crimp (good — relieves stress); brush length = how much wire protrudes past the crimp front. Both must be within spec. | Per terminal-maker drawing |
Why compaction ratio matters more than height
Crimp height alone doesn’t tell you everything — different wire types (more strands vs fewer, thicker vs thinner) at the same height will have different compaction. Compaction ratio is the universal measure because it normalises for wire construction. Modern crimp validation moved from “crimp height ± X” to “compaction ratio Y%”. USCAR-21 Rev 4 codified this shift.
8. Crimp validation — pull force & cross-section
Two tests every Yazaki engineer references constantly. Both are USCAR-21 standardised.
8.1 Pull-force test (the mechanical proof)
The terminal is gripped, the wire is gripped, and the joint is pulled apart on a tensile testing machine. The force at which the joint fails is the pull force.
USCAR-21 specifies minimum pull-force requirements by wire size. A representative subset:
| Wire cross-section (sq mm) | Minimum pull force (USCAR-21) |
|---|---|
| 0.22 | ~ 30 N |
| 0.35 | ~ 50 N |
| 0.50 | ~ 70 N |
| 0.75 — 3.0 | ~ 100 N+ |
| ≥ 4.0 | ~ 120 N+ |
The required ratio is roughly: pull force should approach the wire’s own tensile strength. In a well-designed crimp, the wire breaks before the joint slips.
A subtlety for instructors
The mode of failure in pull testing matters as much as the force. A good crimp fails by wire break outside the joint (the joint is stronger than the wire). A bad crimp fails by strand pull-out — strands slide out of the joint, often at lower force. The mode is often more diagnostic than the number.
8.2 Cross-section analysis (the metallurgical proof)
The crimp is cut perpendicular to the wire axis, polished, etched, and viewed under microscope. The cross-section reveals whether the strands are properly compacted, whether the wings are “locked”, and whether the geometry meets USCAR-21 criteria.
USCAR-21 Rev 4 explicitly categorises cross-sections into three verdicts:
✓ Ideal
- Symmetric compaction of all strands
- No round strands remaining
- Wings touch only conductor
- Wings “locked” — no gap at top
- Terminal stock free of cracks
~ Acceptable
- Some overlapping wings
- Extreme “ram-horning” present
- Otherwise meeting all spec
- Acceptable but not ideal
✗ Unacceptable
- Open wings — core exposed
- Wings folded down but not touching conductor (not locked)
- Wings “crash” through to terminal floor or wall
- Low or no strand compaction
- Cracks in terminal stock
Why this is DFSS gold
The Ideal/Acceptable/Unacceptable framework is exactly the kind of operationalised CTQ a DMADV team should aspire to. Every CTQ in a project should have a similarly clear pass/marginal/fail definition — not just “good crimp” or “bad crimp”. When you see a vague CTQ in a participant’s project, point at this USCAR-21 example as the standard.
9. Production process control — Crimp Force Monitoring (CFM)
Pull-force and cross-section testing are destructive — they can’t be done on every crimp. So how do you ensure quality on millions of crimps per year? Crimp Force Monitoring — a real-time measurement of the force-time signature of every single crimp.
9.1 How CFM works
A load cell on the crimping tool measures the compression force as the ram descends. The resulting force-vs-position curve (or force-vs-time) is unique to a good crimp. The system compares each actual curve to a reference and flags deviations.
Common CFM faults that get detected:
- Missing wire strands (lower peak force — operator stripped too long)
- Extra strands or wrong wire (higher peak force)
- No wire inserted (very low force)
- Mis-aligned terminal (asymmetric force curve)
- Tool wear (gradual drift in peak force)
- Wrong terminal or wrong wire combination (different curve shape)
The DFSS interpretation
CFM is a 100% in-line detection control. In DFMEA language, it converts a Detection rating from D=7 (sample-only post-process inspection) to D=2 or 3 (100% in-line). Adding CFM is one of the most impactful detection actions available — and a great example of what “good detection” looks like under the AIAG-VDA framework.
10. The standards landscape
USCAR (US), JASO (Japan), LV (Germany) — three regional standards bodies dominate. Most connector validation references one of these.
| Standard | Scope | Used most by |
|---|---|---|
| SAE/USCAR-2 | Performance specification for automotive electrical connectors (the system-level test) | US OEMs (GM, Ford, Stellantis) and global suppliers |
| SAE/USCAR-21 | Cable-to-terminal crimp performance specification (the crimp-level test). Revision 4 is current (2020). | Global crimp validation |
| SAE/USCAR-25 | Electrical connector system header thermal cycling | Header connectors (e.g., on ECU housings) |
| SAE/USCAR-38 | Voltage-temperature-humidity-load (VTHL) testing of connectors | Premium and safety-relevant connectors |
| USCAR-25/USCAR-37 | HV-specific connector validation | EV programmes |
| JASO D 611 | Japanese standard for automotive connector design — used heavily in Japanese OEM programmes | Toyota, Honda, Nissan, Suzuki, etc. |
| LV 214 / LV 215 | German VDA connector specification (LV 214) and HV-specific (LV 215) | VW, BMW, MB, Audi |
| ISO 8092 family | International connector terminology and basic dimensions | Reference / baseline |
What you actually need to remember
You don’t need to memorise every clause. You need to know:
- USCAR-2 = connector system, USCAR-21 = crimp.
- LV 214 is the European/VW equivalent.
- JASO is the Japanese family.
- Every Yazaki spec references one of these.
11. DFSS linkage — where this lands in DMADV
| DMADV Phase | Connector/crimp content that lands here |
|---|---|
| Define | Specify connector family, terminal series, current rating, IP class, vibration class, life target. CSR alignment. |
| Measure | Operationalised CTQs — e.g., “contact resistance stable below 10 mΩ for 15 years through 5000 thermal cycles + USCAR-2 vibration”; “USCAR-21 pull force ≥ 100 N”; “compaction ratio 15–20%”; “IP6K9K retained for 15 years”. |
| Analyze | Concept selection across plating options (cost vs reliability), connector family selection, terminal series. DFMEA failure modes anchored in Module 2 mechanisms (fretting, fatigue, corrosion). |
| Design | P-diagram with four design levers (normal force, wipe length, plating, geometry) as control factors. Tolerance design on crimp height ±0.05 mm. Robust design DOE across plating × normal force × thermal cycle range. |
| Verify | USCAR-2 / USCAR-21 / LV 214 testing per CSR. ALT design (Module 2) for fretting under combined vibration + thermal cycle. Pull-force capability study (Ppk ≥ 1.67). CFM implementation as a production detection control. |
A complete worked example you can use in class
Take a tin-plated 2.8 mm female terminal for a 0.5 sq mm wire used on an ECM-to-airbag wakeup line (the example from Module 3). The end-to-end story now:
- CTQ: contact resistance < 10 mΩ for 15 years, USCAR-21 pull force ≥ 70 N, compaction 15–20%, IP54.
- DFMEA failure mode: contact resistance rises > 100 mΩ due to fretting (Module 2).
- Preventive action options: upgrade to silver flash plating (Module 5 §4); raise normal force from 2.5 N to 3.0 N (Module 5 §2).
- Detection action: add CFM in production (Module 5 §9); expand DV test sample size.
- Validation: USCAR-21 Rev 4 pull/cross-section, USCAR-2 vibration + thermal cycle, ALT per Module 2 acceleration models.
12. Instructor facilitation by function
| Function | Connector/crimp angle that lands |
|---|---|
| Testing Center Manager | This is their daily world — crimp validation, USCAR-21, pull-force testing. Treat as a key SME ally in the room. |
| WH (LV/HV) Manager / Deputy | Crimping is the highest reject-rate operation on the WH line. Their pain points are here. Ask: “What’s your current CFM coverage? What % of crimps go through 100% force monitoring?” |
| CDDC — Connectors / JB / BMS / PDU AGM | Owns the entire CDDC component family. Engage strategically on plating selection, IP rating evolution for EVs, HV connector roadmap. |
| CDDC — Grommet/Protector Sr Manager | Sealing class, compression set, polymer ageing (Module 2 #10). Their products are the IP boundary. |
| CDDC — Fuse/JB/Relay Box Manager | Bus-bar joints, terminal-to-PCB interfaces, contact welding in relays. Different failure physics from plug connectors. |
| EI — Sensor Developer | Sensor internal connectors are usually gold or silver plated — low-current signal integrity is paramount. |
| EI — AR HUD / System Engineer Lead | HUD connectors carry Ethernet-class signals — return loss, impedance, special connector families (Mate-Q, H-MTD). Different physics from regular automotive connectors. |
| Shared Service — Advance Materials | Plating selection, copper alloy substrates, contact lubricants. Owns the materials roadmap for connectors. |
| Shared Service — Thermal/EMI/CFD | Joule heating in terminals at high current; CFD around connector geometries for cooling-flow design. |
| SD Coordination / Project Mgmt | Connector family selection at RFQ stage drives the entire harness BoM cost. They are upstream of the engineering choices. |
A single high-leverage question
For any harness/connector project, ask: “What’s your compaction ratio target, and which USCAR-21 cross-section verdict do your validated samples land in?” A team that can answer fluently is operating at the right level of engineering rigour. A team that can’t has work to do. This is the connector-equivalent of the architectural question from Module 1.
Instructor self-check
Ten questions calibrated to the level of crimp / connector conversation you’ll be in.
Q1. A participant says, “Our crimp height is 1.25 mm and it passes USCAR-21.” Your most important follow-up question is:
A. “Is 1.25 mm bigger than 1.0 mm?”
B. “What colour is the terminal?”
C. “What’s the compaction ratio at that height, and which cross-section verdict — Ideal, Acceptable, or Unacceptable — do your samples show?”
D. “How long is the wire?”
Correct — crimp height alone is incomplete; compaction ratio (USCAR-21 target 15–20%) and the cross-section verdict are the real engineering measures.
Q2. Why is gold plating used for ECU pin contacts despite costing 5–20× tin?
A. Gold is heavier and reduces vibration
B. Gold doesn’t oxidise — contact resistance stays stable for low-current signals where any drift would be intolerable
C. Gold is cheaper at scale
D. Gold conducts better than copper
Correct — for low-current signals, contact-resistance stability over 15 years matters more than initial bulk conductivity. Tin’s fretting/oxidation drift is unacceptable.
Q3. A team says their connector is “IP67 sealed” — for a charging inlet on an EV. What’s wrong?
A. IP67 is fictional
B. The colour code is wrong
C. EVs don’t have charging inlets
D. IP67 covers immersion but not high-pressure / high-temperature jets — a charging inlet exposed to car-wash spray needs IP6K9K (or IP69K)
Correct — IP67 is immersion; IP6K9K covers the high-pressure, high-temperature water-jet test that road-vehicle exterior connectors must withstand.
Q4. What is the function of Terminal Position Assurance (TPA)?
A. A secondary lock that prevents partially-seated terminals — cannot be closed if any terminal is not fully seated, preventing terminal back-out under vibration
B. To set the crimp height
C. To carry HV current
D. To seal against moisture
Correct — TPA is a poka-yoke device that error-proofs terminal seating, eliminating one of the most common assembly faults.
Q5. In contact physics, “a-spots” refer to:
A. The active contacts in a relay
B. The American notation for terminals
C. Microscopic points where two metallic surfaces actually touch — the real contact area is a small fraction of the apparent area
D. A specific plating compound
Correct — a-spots are the actual current-conducting micro-contacts; understanding them is the basis of contact physics.
Q6. A “good” crimp pull-force failure mode is:
A. Strand pull-out at low force
B. Wire break outside the joint — the joint is stronger than the wire itself
C. Terminal stock cracking
D. Wing opening
Correct — in a well-designed crimp, the wire is the weak link, not the joint. Strand pull-out at low force is a clear failure mode signature.
Q7. The DFSS interpretation of adding Crimp Force Monitoring (CFM) is:
A. It reduces Severity in DFMEA
B. It is a 100% in-line detection control — it converts a sample-based detection (high D rating) to a 100% screening (low D rating)
C. It reduces Occurrence to zero
D. It eliminates the need for pull-force testing
Correct — CFM is one of the highest-leverage detection actions available for crimp processes. It does not reduce occurrence; it dramatically improves detection.
Q8. The USCAR-21 cross-section verdict “Unacceptable” includes which of the following?
A. Symmetric strand compaction
B. Wings locked at top with no gap
C. Wings touching only conductor
D. Wings “crash” through to the terminal floor, or open wings with core exposed, or no strand compaction
Correct — the unacceptable verdict has specific named criteria from the USCAR-21 Rev 4 spec.
Q9. In a P-diagram of contact reliability, “vibration-induced micro-motion under thermal cycling” is best classified as:
A. A control factor
B. A signal factor
C. A noise factor (external stress driving fretting corrosion)
D. A response variable
Correct — vibration + ΔT are environmental noise factors. Plating, normal force, and wipe length are the control factors that make the design robust against them.
Q10. Aside from “carries current”, what’s the simplest test of whether a DFMEA function statement for a connector terminal is complete?
A. Does it address all seven connector functions — contact, retention, polarisation, mating control, sealing, error-proofing, and (HV only) interlock?
B. Does it have at least 100 words?
C. Is it written in capital letters?
D. Does it mention copper?
Correct — the seven-function checklist (§1) is your auditing tool for DFMEA function statements on connector products.