Engineering & DFM — aperture, appearance, FPC.

1. Golden Aperture (shared datum)

Customer bezel window, cover outer contour, silk-screen viewing window (VA), LCD active area (AA), touch sensor active area (TP AA), gasket, and rear clearance should reference one shared coordinate datum.

Cover VA

Cover VA window = LCD AA + (0.5–1.0 mm per side)

TP AA

Touch Active Area (TP AA) = LCD AA + (0.3–0.5 mm per side)

Rear clearance

Rear LCD clearance ≥ 0.5 mm

Worst-case stack-up early prevents BM encroachment into LCD AA, weak edge-touch near metal bezels, pinched FPC loops, or unsupported cover edges.

2. Ink step & optical bond (OCA / OCR)

Silk-screen border (BM) ink creates a step at the viewing-window edge. For full optical bonding:

• OCA thickness should be roughly 5×–7× the ink step height to reduce perimeter delay bubbles
• Or use OCR / LOCA when ink step or metal raised features exceed practical OCA fill
• Typical organic ink step ≈ 8–20 μm; ceramic ink often thicker — measure the actual cover print

3. Appearance inspection zones A / B / C

Zones follow human-interaction viewing geometry. Accept/reject criteria follow the signed inspection plan / Golden Sample for the project — not a public SKU table.

Zone A — Active / central viewing

LCD AA plus ~1.0 mm outward into the core viewing window. Strictest: under ~500–1000 lux, viewing ~30–50 cm at 45°/90°; foreign matter, fibers, pinholes, micro-bubbles, linear scratches, dark spots, bright dots — very low allowance (project-confirmed).

Zone B — Viewing border / BM

Black BM border, icon windows, visible glass edge. Control BM light leak, jagged print edge, local pinholes, ink scuffs, minor edge chips within agreed chamfer; color vs master ΔE < 1.0 (project-confirmed).

Zone C — Non-visible structure

Metal rear, adhesive bond areas, concealed FPC tail. Cosmetic non-critical defects allowed if they do not hurt fit, glass impact strength, seal, or electrical function.

4. FPC routing & bend rules

Design-rule envelopes for static routing after FOG / sensor exit. Final radii and stack thickness are project-confirmed on the signed drawing.

• Static min bend radius — single-sided Cu FPC: R ≥ 3×–5× FPC thickness
• Static min bend radius — double-sided Cu FPC: R ≥ 6×–10× FPC thickness
• FOG exit stress relief: after leaving the glass/sensor bond area, keep 1.5–2.0 mm straight unbent buffer; neutral silicone strain-relief dot preferred; no sharp fold at root
• Stiffener / coverlay edge offset: PI or steel stiffener edge vs coverlay opening offset ≥ 0.5 mm (avoid single-trace shear)

Pinched FPC loops are a common DFM fail when rear clearance / exit path is ignored — see Golden Aperture rear clearance above.

5. Manufacturing scope (quick envelope)

• Sensor structures: G+G / G+F+F / G+F (G+F self-capacitive / key use typically 0.96–5.0″)
• Not offered: consumer-grade OGS smartphone panels
• In-house LCM customization: 0.71–10.1″
• Tier-1 display integration: AUO / BOE / Tianma / Innolux / IVO / CSOT + high-bright backlight adaptation (project-confirmed)
• Full optical bonding (OCA/OCR): up to ≈32″; project touch assemblies up to ≈55″

6. What to send with the first RFQ

Use the Interactive Engineering RFQ fields (Application Sector, In-house vs Tier-1, Touch Interface, Glove/Water, Target EAU) plus cover OD/VA or a housing opening photo. Prefer email for drawings.

Open Engineering RFQ How a reply works Back to Knowledge hub

Honesty: no invented millimetre tables as public SKUs; process numbers stay project-confirmed on the signed drawing.