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IC Substrate Manufacturer-Bond BGA Package Substrate
High-precision IC carrier board with 132 Au wire-bond fingers, 144 solder ball pads, and center die-attach thermal pad — achieving CPK 4.08 on gold finger width.
Product Specifications
IC Substrate Manufacturer: Wire-Bond BGA Package Substrate
High-precision IC carrier board with 132 Au wire-bond fingers, 144 solder ball pads, and center die-attach thermal pad — achieving CPK 4.08 on gold finger width.
1. Product Overview
| Product Type | IC Package Substrate (IC 载板) — Wire-Bond BGA |
| Application | Semiconductor packaging — IC die wire bonding + BGA mounting |
| Material | BT (Bismaleimide Triazine) resin, high-Tg ≥180°C |
| Layer Count | 4-layer (2 signal + 1 power + 1 ground) |
| Surface Finish | ENEPIG (Electroless Ni / Electroless Pd / Immersion Au) |
| Board Thickness | 0.36 mm ± 0.03 mm |
2. Key Design Features
① Center Die-Attach Pad with Thermal Via Array
The substrate features a central large gold-plated pad for IC die attachment. The gold pad measures 4.8 mm × 5.2 mm with a uniform ENEPIG surface finish (Au ≥ 0.05 μm, Pd ≥ 0.05 μm, Ni ≥ 3 μm). Underneath the die-attach pad, a thermal via array — 9 × 9 vias at 0.40 mm pitch, 0.20 mm drill diameter — conducts heat directly to the bottom-side copper plane, providing a low thermal resistance path from the IC die to the PCB ground plane.
Die-attach pad size: 4.8 mm × 5.2 mm
Thermal via array: 9 × 9 = 81 vias
Via drill: 0.20 mm, pitch: 0.40 mm
Via fill: Copper-filled & capped, planar with pad surface
② Wire-Bond Gold Fingers — 132 Total
Four rows of wire-bond gold fingers surround the center die-attach pad — 33 fingers per side, 132 total. Each gold finger is designed for 25 μm Au wire wedge bonding with a bond pitch of 65 μm.
| Parameter | Specification |
|---|---|
| Fingers per side | 33 |
| Total fingers | 132 |
| Finger width (nominal) | 45 μm |
| Finger pitch | 65 μm |
| Finger length | 0.85 mm |
| Surface finish | ENEPIG (Au ≥ 0.05 μm) |
| Wire type | 25 μm Au wire |
③ Solder Ball Pad Array — 144 Total
On the bottom side, a 12 × 12 array of solder ball pads (144 total) forms the BGA interface for PCB mounting. The pads are SMD (Solder Mask Defined) type with a 0.50 mm ball pitch.
| Parameter | Specification |
|---|---|
| Pad arrangement | 12 × 12 array |
| Total pads | 144 |
| Pad diameter (SMD opening) | 0.28 mm |
| Ball pitch | 0.50 mm |
| Solder ball diameter | 0.30 mm |
| Pad type | SMD (Solder Mask Defined) |
3. Process Capability — CPK Data
Statistical process control (SPC) data from production lot:
| Feature | Nominal | Tolerance | Measured Mean | Std Dev (σ) | CPK | Sigma Level |
|---|---|---|---|---|---|---|
| Gold finger width | 45 μm | ± 3 μm | 44.8 μm | 0.245 μm | 4.08 | > 12σ |
| Solder ball pad width | 0.28 mm | ± 0.02 mm | 0.279 mm | 0.0020 mm | 3.31 | > 9σ |
Interpretation: CPK ≥ 1.67 is considered "excellent" in semiconductor packaging. CPK 4.08 on gold finger width and CPK 3.31 on pad width both far exceed the industry benchmark, confirming the process is stable and well-centered within the specification limits.
4. Wire Bond Pull Test Results
100% of wire bonds were subjected to destructive pull testing per MIL-STD-883 Method 2011. All 132 wire bonds were tested — every bond passed (judgment: ACC).
| Test Parameter | Value |
|---|---|
| Test Standard | MIL-STD-883 Method 2011.9 (Condition D) |
| Wire Type / Diameter | Au (gold) / 25 μm (1.0 mil) |
| Test Method | Destructive pull test — hook at mid-span |
| Total Bonds Tested | 132 |
| Pass Rate | 132 / 132 — 100% ACC |
| Minimum Pull Force | 4.212 g |
| Mean Pull Force | 5.83 g |
| Std Dev | 0.48 g |
| MIL-STD Minimum Requirement (25 μm Au) | ≥ 3.0 g |
| Cpk (Pull Force vs 3.0 g LSL) | 1.97 |
Result: Minimum pull force of 4.212 g exceeds the MIL-STD-883 minimum requirement of 3.0 g by 40.4%. Zero bond lifts or heel breaks observed. All failure modes were wire breaks at mid-span — the preferred failure mode indicating strong bond integrity at both the ball bond and wedge bond interfaces.
5. Key Manufacturing Processes
Laser Direct Imaging (LDI) — 45 μm finger patterning with ±1 μm registration tolerance
ENEPIG Plating — Electroless Ni (3–5 μm) / Electroless Pd (0.05–0.15 μm) / Immersion Au (0.05–0.10 μm)
Copper-Filled Thermal Via — Electroplated Cu fill, planarized to substrate surface (planarity ≤ 5 μm)
Solder Mask Registration — ±15 μm registration for SMD pad definition at 0.28 mm opening
100% AOI — Automated optical inspection of all gold fingers and pads
Wire Bond Pull Test — 100% destructive testing per MIL-STD-883
6. Quality Summary
| Quality Metric | Result |
|---|---|
| Gold finger CPK | 4.08 |
| Solder ball pad CPK | 3.31 |
| Wire bond pull test pass rate | 100% (132/132, ACC) |
| Minimum pull force | 4.212 g |
| Via fill planarity | ≤ 5 μm |
| Solder mask registration | ±15 μm |
Superb Automation Co., Limited — IC Substrate & Package Substrate Manufacturing
