3.2 NPI Component Handling: MSL Hygiene and Feeder Readiness

In Mass Production, components arrive in factory-sealed, vacuum-packed reels. In NPI, components arrive in cut strips, opened bags from engineering labs, or generic packaging labeled with a sharpie. This lack of pedigree creates two distinct risks: Popcorning (hidden moisture damage during reflow) and Feeder Starvation (machine inability to pick the part). This chapter establishes the protocols to transform "loose parts" into "process-ready" inputs.

The MSL "Reset" Protocol

NPI components frequently arrive with unknown moisture history. A bag secured with a stapler is not a moisture barrier. If a moisture-sensitive device (MSL 2A - 5a) absorbs humidity, the rapid expansion of water vapor during reflow will delaminate the die or crack the package ("Popcorning").

1. The "Unknown History" Rule

• Assumption: Treat any open, non-vacuum-sealed bag of MSL components as "Floor Life Exceeded" (Saturation).
• Action: You must Bake the components to reset the floor life before reflow.
  • Standard: Follow IPC/J-STD-033.
  • Typical Reset: 125˚C for 24 hours (High Temp carriers) or 40˚C for <5% RH (Low Temp carriers/Paper Tape).
• Warning: Do not bake plastic reels or paper tape at 125˚C. They will warp or burn, destroying the components inside. Use Low-Temp bake or transfer parts to metal trays.

2. Time-to-Reflow Tracking

Once the bag is opened or baked, the clock starts ticking.

• Labeling: Apply a temporary label to the reel/tray indicating "Opened: [Date/Time]" and "Max Floor Life: [Hours]."
• Pause Rule: If the NPI build is paused for > 24 hours, Then return MSL parts to a Dry Cabinet (< 5% RH) or vacuum seal them immediately. Leaving them on the feeder cart over the weekend is prohibited.

Feeder Compatibility: Making Parts Runnable

A component is only "present" if the machine can feed it. NPI kits are notorious for failing physical feeder constraints.

1. Cut Tape & Leader Requirements

Splicing is the #1 cause of feeder jams in NPI.

• The Leader Constraint: Feeders require a specific length of tape to engage the sprocket and peel back the cover tape before the pick-point reaches the nozzle.
  • Rule: If the strip length is < 150 mm (approx. 6 inches), you must attach a Leader Extender (dummy tape).
  • Cover Tape: Ensure the cover tape is securely attached to the leader. If the cover tape peels off prematurely, the components will vibrate out of the pockets before the nozzle arrives.

2. Pocket Depth & Component Fit

Just because the tape width (8mm, 12mm) is correct, it does not mean the part fits.

• Check: Verify pocket depth vs. component height.
  • Risk: Thick inductors or capacitors placed in shallow embossing will stick up, causing the nozzle to crash or the feeder to jam.
  • NPI Fix: If the pocket is too shallow or tight, Then transfer to a Matrix Tray or authorize Manual Placement. Do not force the feeder.

3. Tray vs. Tape (The BGA Rule)

• If you are prototyping with expensive BGAs/FPGAs, Then prefer Matrix Trays over Cut Tape.
  • Reasoning: Cut tape for large components often has "memory" (curvature) from being wound on a reel. This curvature causes the component to sit tilted in the pocket, leading to vacuum errors or placement shift. Trays are planar and stable.

ESD Discipline in NPI

NPI involves high-touch manual handling (counting, splicing, hand-loading). This increases ESD risk significantly compared to automated volume production.

• The 1-Meter Rule: No static-generating plastics (Pink Poly, Styrofoam cups, clear tape) within 1 meter of open components.
• Manual Counting: Never count pins or components by touching the leads. Use vacuum pens or tweezers. Finger oils cause solderability issues (non-wetting) as much as ESD causes latent damage.

Final Checklist