5.2 Protective Packaging Selection

ESD-safe, cushioning, move and impact protection.

Packaging is the last engineering step, not gift wrap. It has two jobs: stop ESD (electrostatic discharge) from zapping electronics and cushion real-world drops so nothing dents or scuffs. The right choice depends on the journey—bench to test, van to site, or conveyors and pallets—not habit or whatever foam is nearby. A shielding bag acts like a tiny Faraday cage, while sized foam and solid cartons keep mass from meeting corners. Done well, accessories don’t wander, labels arrive readable, and boxes stack without crushing. A quick shake-and-drop check closes the loop, so the product that ships is the product that arrives.

5.2.1 The job (in one line)

Get each unit from your bench to the customer with zero zaps and zero dents—by pairing the right ESD barrier with the right cushion for the route it travels.

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

5.2.3 ESD basics (what must touch what)

Surface resistivity:
- Conductive < 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/boxes need a metal-in shielding bag (Faraday cage).
Stack order (inside→out): product → dissipative layer (tray/foam) → shielding bag (closed) → cushion → carton.
Ground path: totes/carts must bond to ESD floor; operators still strap until the bag is sealed.

5.2.4 Cushion material cheat sheet (choose by weight & fragility)

Material	Best for	Pros	Watch-outs
EPE foam (expanded PE)	General electronics (light–med)	Inexpensive, cuttable, rebounds	Not great 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 grade
XLPE plank	Heavier units, edge blocks	Strong, clean edges	Knife work; cost
Thermoformed trays (ESD)	WIP, light products	Precise nests, stackable	One orientation; custom tool
Corrugated inserts	Low-cost spacers	Recyclable, light	Not a cushion by itself
Inflatables/air cells (ESD)	Retail packs	Light, clean look	Temp/altitude sensitivity
Molded pulp	Eco-forward	Recyclable, stiff	Needs good design; check dust

Rule of thumb: Fragile electronics behave like 15–50 g items (need gentle landings). Heavier, stiff boxes need thicker, stiffer blocks.

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

Know the drop: parcel sees ~0.75 m (30”) face/edge/corner; palletized sees lower drops but stack compression.
Weight class:
- ≤ 2 kg → 20–30 mm foam each side
- 2–8 kg → 30–50 mm
- 8 kg → 50–75 mm + edge blocks
Float the product: ≥ 25 mm clearance to every wall (≥ 50 mm if 8 kg+).
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 foam and target g-limit.

5.2.6 Unit pack architecture (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.
Accessory bay (cables, PSU, manual) isolated so nothing presses the product.

Tertiary

Corrugated carton (board grade matched to weight), edge blocks, top pad.
Master carton for multiples: honeycomb divider or individual inners.
Pallet: no overhang, corner boards, top cap, strap + stretch wrap with rope band at base.

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.

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 peanuts and thin bubbles—static and collapse.
Retail finish: use film bags only over the shielding bag; keep fingerprints off before sealing.

5.2.9 Quick test plan (right-sized confidence)

Fit check: shake test—no product rattle.
Drop: 5–10 drops (faces/edges/corners) from route height; product and carton must pass cosmetics & function.
Vibration: random vibe for route type; look for fretting or foam dusting.
Compression/stack: simulate pallet stack time/weight; no wall bow, no crush into product.
ESD: bag continuity/shield verification; tote resistivity spot-check.

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

5.2.10 Acceptance cues (fast eyes)

Area	Accept	Reject
ESD barrier	Sealed shielding bag, correct label	Pink bag only; bag open or torn
Fit	No rattle; product centered with ≥25 mm float	Contact to wall; accessory presses product
Cushion	Even thickness, covers heavy ends	Thin spots; foam cuts exposing edges
Carton	Board grade correct; no overhang; clean print	Soft walls; crushed corners
Pallet	Square on deck; straps & wrap tight	Overhang; loose wrap; no corner boards
Labels	Orientation/fragile/regulatory correct	Wrong SKU/region; missing UP/CE/etc.

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

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

Bottom line: seal the electronics in a true shielding bag, float them on right-sized foam, and lock the load so it can’t shift. Choose materials for the route and weight, not habit. Test with a few drops and shakes, and your products arrive looking as good as they left.