5.2 Protective Packaging Selection

ProtectiveFinal protective packaging is the finalcritical layerdefense against the hazards of engineering that ensures carefully built electronics survive the journeylogistics intact.chain. It must solve two invisible but critical threats: electrostatic discharge that can silently damage circuitry, andprotect the bluntfinished forceproduct offrom drops,shock, vibration, and stackingenvironmental thatdegradation canduring crush or scuff. The challenge lies in matching barrierstransit and cushioningstorage. notPackaging by tradition but byis the product’slast realcontrol route—whethergate, acrossvalidating athe plant floor, in a service van, or stacked high on a pallet. Done with intent, packaging turns fragile assemblies into robust shipments that reach customers exactly as designed, both insidephysical and out.electrical integrity of the entire assembly against abuse beyond the factory floor.

5.2.1 TheESD jobBarrier (inand oneLayering line)Mandate

GetPackaging eachmust unitprovide fromboth your bench to the customer with zero zapselectrical and zeromechanical dents—byprotection pairingthrough thespecific rightmaterial layering.

A) ESD barrierProtection with the right cushion for the route it travels.

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5.2.2 Pick by journey (not by habit)

Lane	Typical trip	What it needs
WIP / in-plant	Cell ↔ test ↔ pack	Reusable dissipative totes + ESD trays, minimal cushioning, dividers
Service/field kit	Van → site	Shielding bag + light foam/clamshell, hard case optional
Direct ship (parcel)	Conveyors, drops, vibration	Shielding bag, engineered foam in corrugated, accessory cradle
Freight/pallet	Stacks, compression, fork hits	Double-wall cartons, corner boards, pallet pattern, strap/wrap

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5.2.3 ESD basics (what must touch what)

Protocol

• SurfaceShielding resistivity:
• • ConductiveBag Mandate: < 10⁴ Ω/sq (trays, totes)
  • Dissipative 10⁴–10¹¹ Ω/sq (bags, foams)
  • Insulative > 10¹¹ Ω/sq (raw bubble/peanuts—avoid)
• Shielding bag ≠ pink bag: pink “anti-static” only reduces tribocharge; it does not shield. Finished PCBAs/boxesassemblies needmust be sealed inside a metal-in shielding bag (Faraday cage). to prevent external static events from damaging sensitive components. Standard "pink anti-static" bags are insufficient for shielding.
• Stack orderOrder (inside→out)Inside – Out): productThe →required layering is: dissipativeProduct layer– Dissipative Layer (tray/foam)foam/tray) →– shieldingShielding bagBag (closed) →– cushionCushion →– carton.Carton.
• Dissipative Materials: Only materials with dissipative surface resistivity (10⁴ – 10¹¹ Ω/sq) are permitted to touch the product. Insulative materials (raw bubble, plain plastics) are prohibited.
• Ground pathPath:: totes/cartsCarts and totes carrying WIP (Work In Progress) must bond to the ESD floor;floor; operators must still strap until the shielding bag is fully sealed.
  

B) Moisture and Climate Control

• Long Haul/Humid Routes: For ocean freight or long-term storage, add a calculated amount of desiccant (silica gel) and a Humidity Indicator Card (HIC) inside the carton.
• Prohibition: Avoid materials prone to shedding (e.g., specific PU foams) near windows or vents, as this introduces FOD.

5.2.2 Mechanical Integrity and Cushioning Selection

Cushioning must be engineered based on the product's weight and fragility rating (G-rating).

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A)

Cushioning Sizing (Floating Mandate)

• 5.2.4Float the Product: The product must be centered within the carton, maintaining a minimum clearance of ≥ 25 mm to every wall. For heavier units (≥ 8 kg), float clearance must be increased (≥ 50 mm).
• Weight-Based Sizing (Rule of Thumb):
  • ≤ 2 kg: 20 – 30 mm foam each side.
  • 8 kg+: ≥ 50 mm foam + edge blocks.
• Center of Gravity (CG): Packaging must support the heaviest ends; use drop bridges so corners and structural elements absorb impact energy, not the bezel or sensitive panels.

B) Cushion materialMaterial cheat sheet (choose by weight & fragility)

Choices

Material	Best for	Pros	Watch-outs
EPE foamFoam (expandedExpanded PE)	General electronics (light–med)med weight).	Inexpensive, cuttable, reboundsgood rebound.	Not greatsuitable for heavy point loads
EPP foam	Reusable dunnage	Tough, long life	Higher cost upfront
PU foam (polyurethane)	Light cosmetic pads	Conforms to shapes	Can shed; check ESD gradeloads.
XLPE plankPlank	Heavier units, edge blocksblocks.	Strong, clean edgesedges, excellent shock resistance.	KnifeRequires work;specialized costtooling for cutting; higher cost.
Thermoformed traysTrays (ESD)	WIP, high-volume light productsproducts.	Precise nests, stackablestackable, repeatable.	OneCustom orientation;tooling customrequired; tool
Corrugatedlimited inserts	Low-costto spacers	Recyclable,one light	Not a cushion by itself
Inflatables/air cells (ESD)	Retail packs	Light, clean look	Temp/altitude sensitivityorientation.
Molded pulpPulp	Eco-forwardforward, single-use.	Recyclable, stiff structure.	NeedsDust potential; requires good design; check dustdesign.

5.2.3 Final Pack Architecture and Verification

The final carton architecture and labeling must ensure safety, stacking, and compliance.

A) Unit Pack Architecture

• RulePrimary of thumb:Protection: FragileShielding electronicsbag behavesealed; likeconnector 15–50caps gand itemsplugs (need gentle landings). Heavier, stiff boxes need thicker, stiffer blocks.

  
  

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  5.2.5 How much cushion? (fast sizing without a PhD)

  1. Know the drop: parcel sees ~0.75 m (30”) face/edge/corner; palletized sees lower drops but stack compression.fitted.
  2. WeightSecondary class:
  3. • ≤ 2 kg → 20–30 mm foam each side
     • 2–8 kg → 30–50 mm
     • 8 kg → 50–75 mm + edge blocks
  3. FloatProtection: theCushioning product:material ≥(foam, 25corrugated) mm clearanceplaced to everycontrol wall (≥ 50 mm if 8 kg+).
  4. Center of gravity: support heavy ends; add drop bridges so corners take the hit, not the bezel.

  Need more rigor? Ask packaging to use cushion curves for your foamorientation and targetprevent g-limit.

  
  

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  5.2.6 Unit pack architectureabrasion (what goes where)

  Primary protection

  • Shielding bag sealed (fold + label or zip).
  • Connector caps, screw/vent plugs, dust film on windows if customer expects.

  Secondary / dunnage

  • Cradle or clamshell that controls orientation; no rubbing on labels or gaskets.gaskets).
  • Accessory bayAccessories (cables,must PSU,be manual)placed in an isolated bay so nothingthey pressesdo not press against the product.
• Carton

  TertiaryIntegrity:

  • Corrugated carton (boardBoard grade matched(ECT/double-wall) tomust weight),match the weight and stack height. edge blocks, top pad.
  • Master cartonProhibited: for multiples: honeycomb divider or individual inners.
  • Pallet: no overhang, corner boards, top cap, strap + stretch wrap with rope band at base.
    

  
  

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  5.2.7 Corrugated & cartons (don’t cheap out on paper)

  • Board grade/ECT sized to weight + stack (double-wall for tall stacks or export).
  • No overhang past pallet edges—corners crush first in transit.
  • Orientation marks: UP arrows, CG label if needed; Do Not Stack cones if required by design.edges.

  
  

  B)

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  5.2.8 Moisture, climate & clean looks

  • Ocean/long humid routes: add desiccant + humidity card inside the carton (not bare on product).
  • Hot/cold swings: avoid peanutsVerification and thinAcceptance bubbles—static and collapse.
  • Retail finish: use film bags only over the shielding bag; keep fingerprints off before sealing.

  
  

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  5.2.9 Quick test plan (right-sized confidence)

  Cues
  • Fit checkCheck:: shakeShake test—test must result in no product rattle.rattle.
  • DropQuick Test:: Perform the Drop Test (5–10 drops (faces/edges/corners) from route height;height) on a sample to verify the product and carton must passsurvive cosmetics &and function.
  • VibrationAcceptance Cues:: randomCarton vibemust forbe route type; look forclean; frettingUP arrows orand foamfragile dusting.labels (if needed) must be correct; pallet pattern must be square on deck with corner boards installed.
  • Compression/stackData Linkage:: simulateAll palletpackaging stacklabels time/weight;mirroring noidentity wall(SN, bow,MAC) nomust crushbe intoprinted product.
  • ESD:from bagthe continuity/shieldMES verification; tote resistivity spot-check.only.

  (Your

  Final lab may quote ISTA/ASTM names later; the above is the spirit.)

  
  

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  5.2.10 Acceptance cues (fast eyes)Checklist

  AreaMandate	AcceptCriteria	RejectVerification Action
  ESD barrierBarrier	Unit sealed in a Sealedmetal-in shielding bag, correct label.	Pink baganti-static only;bags bagare openprohibited oras tornthe sole barrier.
  FitCushioning	No rattle; productProduct centered with ≥ 25 mm floatfloat; zero internal rattle.	Shake testContact toconfirms wall; accessory pressesno product movement or abrasion risk.
  Moisture Control	DesiccantCushion and HIC included in the MBB (Moisture Barrier Bag).	EvenMBB thickness,must coversbe heavyfully ends	Thinsealed; spots;HIC foamcolor cutsverified exposingprior edgesto closure.
  Material Usage	Only dissipative/conductive materials permitted to touch the product.	Insulative materials (raw bubble/peanuts) are prohibited.
  Carton Integrity	Board gradegrade/ECT correct;sized to weight; no overhang;overhang cleanon printthe pallet.	SoftCorner walls;boards crushedinstalled cornersfor vertical stack protection.
  Labeling	PalletOrientation, fragile, and regulatory marks are correct and aligned.	SquarePrinted onlabels deck;(SN/MAC) strapsmust &match wrapdata tight	Overhang;pulled loosefrom wrap;the no corner boards
  Labels	Orientation/fragile/regulatory correct	Wrong SKU/region; missing UP/CE/etc.MES.

  
  

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  5.2.11 Common traps → smallest reliable fix

  Trap	Symptom	Fix
  Pink bubble as only protection	Zapped boards	Use shielding bag; pink only as inside pad
  Accessories loose in box	Scratches, cracked bezels	Add accessory bay; band with sleeve
  Too little float	Corner dings	Increase clearance; add edge blocks
  One foam fits all SKUs	Over/under protection	Size foam by weight & drop; keep 2–3 standard sets
  Overhang on pallet	Crushed corners	Use right pallet; no overhang; corner boards
  Foam that sheds	Dust in windows/vents	Switch to closed-cell EPE/EPP; vacuum test
  ESD totes with plain dividers	Charge build-up	Dissipative dividers; ground carts to ESD floor

  
  

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  5.2.12 Pocket checklists

  Designing the pack

  • Journey picked (WIP / parcel / pallet); drop height known
  • Shielding bag chosen; connectors capped; labels planned
  • Foam type & thickness sized to weight and fragility
  • Accessory bay defined; CG supported; ≥ 25 mm float all sides
  • Carton board grade & master carton/pallet plan set
    

  At the pack cell

  • Gloves on; product bagged & sealed; labels correct
  • Cradle/clamshell engaged; no rattle; accessory bay filled
  • Carton square; edge blocks in; tape pattern complete
  • Master carton & pallet: no overhang; wrap + strap + corners
  • Ship labels & orientation marks applied; photos if customer wants

  Audit (sample)

  • One box drop-tested per lot; product passes cosmetic & function
  • ESD spot-check on bags/totes; resistivity in range
  • Pallet compression OK after 24 h; no wall bow

  
  

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  By sealing units in shielding bags, sizing cushions to weight and fragility, and testing against real transit stresses, packaging prevents hidden failures and visible damage alike. Consistent choices and disciplined checks transform shipping from a gamble into a controlled extension of the build process, delivering reliability all the way to the customer’s hands.