01Physical definitions of the three ESD types
The "ESD property" of SMD plastic reels refers to surface resistivity (unit: Ω/sq). Per ANSI/ESD S541, plastic materials are classified into three categories:
| ESD Type | Surface Resistivity (Ω/sq) | Material Principle | Color Convention |
|---|---|---|---|
| Anti-static | 10⁹ – 10¹¹ | PS/ABS + anti-static agent | Blue / White |
| Conductive | 10² – 10⁵ | PS/ABS + conductive carbon black | Black |
| Insulative | > 10¹² | Natural PS/ABS, unmodified | Natural / White |
The three ESD types are not "lower is always better". Selection should match the component's ESD sensitivity and packaging context — over-conductive materials can cause component short circuits or pick-and-place failures.
02Matching ESD sensitivity levels
Per ANSI/ESD S20.20, IC component ESD sensitivity classifications (HBM, Human Body Model):
- Class 0: <250V HBM — highly sensitive (high-frequency RF, MEMS sensors)
- Class 1A: 250–500V HBM — high sensitivity (high-speed ICs, MOSFETs)
- Class 1B: 500–1000V HBM — moderate sensitivity (general ICs)
- Class 1C: 1000–2000V HBM — less sensitive
- Class 2+: >2000V HBM — not sensitive (passive components, mechanical parts)
Selection logic
Class 0 / Class 1A ICs
- High-frequency RF / MEMS
- High-speed MOSFET
- BGA / WLCSP
- Surface resistivity ≤10⁵ Ω/sq
Class 1B / 1C / 2 ICs
- General SMT ICs
- Standard logic components
- SMT mass-production mainstream choice
- Surface resistivity ~10¹¹ Ω/sq
Non-ESD sensitive components
- Capacitors / resistors / inductors
- Mechanical parts / connectors
- Natural PS/ABS reel
- Lowest cost
03Practical procurement checklist
When a procurement engineer faces a BOM, evaluate in this order:
- Check the IC datasheet's ESD rating — look at HBM/MM/CDM values
- Match your factory's ESD zone classification — EPA (ESD Protected Area) standards
- Confirm customer specifications — major semiconductor IDM/OSAT customers typically specify in their procurement requirements
- Check your current line's reel spec — align with existing BOM to avoid mixing different ESD types on the same line
- Confirm with trial samples — for custom specs, run a small batch first
"Conductive = anti-static but better" is wrong. Conductive materials actively conduct electricity — in some IC packaging scenarios this can cause accidental short circuits. The principle is to choose the level that best matches component specifications; over-specifying is not necessary.
04Pricing and availability
Guann-Ming's stock is primarily anti-static (blue), comprising 80%+ of inventory. Conductive and insulative types are mostly produced on custom schedules.
05FAQ
Does anti-static performance degrade over time?
Yes. PS/ABS anti-static agents are migratory additives — their effectiveness gradually decreases in dry environments below 30% RH. Reel storage should be maintained at 40–60% RH. Guann-Ming anti-static reels retain effective performance for 1–2 years under standard conditions.
Can conductive reels short-circuit component leads?
Not under correct packaging. The EIA-481 carrier tape design keeps component lead frames from directly contacting the reel body. However, improper use (e.g., placing components directly against the reel flange) can cause shorts. Conductive reels should be used with anti-static bags and grounding wrist straps.
How is surface resistivity measured?
Per ANSI/ESD STM 11.11, a Surface Resistivity Meter is used with probe spacing of 10 cm, applying 10V or 100V DC and reading after 15 seconds. Guann-Ming can provide a Certificate of Analysis (COA) with test data for each material batch.
Is there a Dissipative classification?
Yes. Some customers use the term Static Dissipative, referring to surface resistivity of 10⁵–10⁹ Ω/sq — between conductive and anti-static. G.M Reels anti-static reels typically measure within this range in high-frequency testing. Refer to the COA for specific values.
Have product needs or technical questions?
Our sales team will have the appropriate engineer or sales person reply directly.