# WIA Advanced Packaging Standard Specification v1.0

**WIA-SEMI-003**

> 弘益人間 (홍익인간) · Benefit All Humanity

---

## Document Information

- **Standard ID**: WIA-SEMI-003
- **Version**: 1.0.0
- **Status**: Final
- **Date**: 2025-01-15
- **Category**: Semiconductor Manufacturing
- **Maintainer**: WIA Standards Committee

---

## Table of Contents

1. [Introduction](#1-introduction)
2. [Scope](#2-scope)
3. [Normative References](#3-normative-references)
4. [Terms and Definitions](#4-terms-and-definitions)
5. [Data Format Specification](#5-data-format-specification)
6. [2.5D Packaging Standard](#6-25d-packaging-standard)
7. [3D IC Stacking Standard](#7-3d-ic-stacking-standard)
8. [Chiplet Integration Standard](#8-chiplet-integration-standard)
9. [Interconnect Specification](#9-interconnect-specification)
10. [Thermal Management](#10-thermal-management)
11. [Power Delivery](#11-power-delivery)
12. [Signal Integrity](#12-signal-integrity)
13. [API Specification](#13-api-specification)
14. [Manufacturing Guidelines](#14-manufacturing-guidelines)
15. [Testing and Validation](#15-testing-and-validation)

---

## 1. Introduction

### 1.1 Purpose

This specification defines the WIA Advanced Packaging Standard (WIA-SEMI-003), providing a comprehensive framework for the design, simulation, manufacturing, and validation of advanced semiconductor packages including 2.5D interposer-based designs, 3D IC stacking with Through-Silicon Vias (TSVs), and heterogeneous chiplet integration.

### 1.2 Background

As semiconductor technology nodes approach fundamental physical limits, advanced packaging has emerged as a critical enabler for continued system performance improvements. The disaggregation of monolithic system-on-chip (SoC) designs into multiple chiplets connected through advanced packaging technologies offers significant advantages in terms of cost, yield, performance, and time-to-market.

### 1.3 Philosophy

Following the WIA philosophy of 弘益人間 (홍익인간) - Benefit All Humanity, this standard is designed to:

- Enable widespread adoption of advanced packaging technologies
- Reduce barriers to entry for new market participants
- Promote interoperability between different vendors and technologies
- Ensure reliability and safety in critical applications
- Support sustainable manufacturing practices

---

## 2. Scope

This standard covers:

- **2.5D Packaging**: Interposer-based multi-die integration
- **3D IC Stacking**: Vertical die stacking with TSVs
- **Chiplet Integration**: Heterogeneous die integration protocols
- **HBM Integration**: High Bandwidth Memory packaging guidelines
- **Thermal Management**: Design rules and simulation methodologies
- **Signal Integrity**: High-speed interconnect design
- **Power Delivery**: Multi-level PDN design
- **Manufacturing**: DFM rules and process guidelines

This standard does not cover:

- Traditional wire-bond packaging
- Single-die flip-chip packages (covered in WIA-SEMI-001)
- Wafer-level packaging (covered in WIA-SEMI-002)

---

## 3. Normative References

The following documents are referenced in this standard:

- JEDEC JESD229: Wide I/O
- JEDEC JESD235: High Bandwidth Memory (HBM)
- IEEE 1076: VHDL Language Reference Manual
- IPC-2221: Generic Standard on Printed Board Design
- SEMI P47: Specification for Carrier Wafers for Ultra-Thin Wafer Handling

---

## 4. Terms and Definitions

### 4.1 Advanced Packaging
Integration technology that enables heterogeneous dies to be connected with interconnect densities and performance approaching on-chip levels.

### 4.2 Interposer
An intermediate substrate containing fine-pitch routing that connects multiple dies to each other and to the package substrate.

### 4.3 Through-Silicon Via (TSV)
A vertical electrical connection passing through a silicon die or wafer.

### 4.4 Chiplet
A modular die designed to be integrated with other dies in an advanced package.

### 4.5 Micro-bump
A fine-pitch solder bump typically 20-40μm in diameter used for die-to-interposer connections.

### 4.6 HBM (High Bandwidth Memory)
A 3D-stacked DRAM technology providing high bandwidth through a wide memory interface.

### 4.7 2.5D Packaging
A packaging technology where multiple dies are placed side-by-side on an interposer.

### 4.8 3D IC
A packaging technology where multiple dies are stacked vertically and connected through TSVs.

---

## 5. Data Format Specification

### 5.1 Package Definition Format

All package designs SHALL be described using JSON format conforming to the following schema:

```json
{
  "package": {
    "id": "string",
    "type": "2.5D" | "3D" | "hybrid",
    "version": "string",
    "substrate": {
      "type": "silicon" | "organic",
      "dimensions": {
        "width": "number (mm)",
        "height": "number (mm)",
        "thickness": "number (μm)"
      },
      "layers": "number"
    },
    "dies": [
      {
        "id": "string",
        "position": {"x": "number", "y": "number", "z": "number"},
        "dimensions": {"width": "number", "height": "number"},
        "technology": "string (e.g., '5nm')",
        "power": "number (W)",
        "function": "string"
      }
    ],
    "interconnects": [
      {
        "type": "microbump" | "tsv" | "hybrid",
        "source": "die_id",
        "target": "die_id",
        "count": "number",
        "pitch": "number (μm)",
        "diameter": "number (μm)"
      }
    ]
  }
}
```

### 5.2 Thermal Map Format

Thermal analysis results SHALL be exported in the following format:

```json
{
  "thermal": {
    "timestamp": "ISO8601",
    "ambient": "number (°C)",
    "nodes": [
      {
        "id": "string",
        "position": {"x": "number", "y": "number", "z": "number"},
        "temperature": "number (°C)"
      }
    ],
    "hotspots": [
      {
        "location": {"x": "number", "y": "number", "z": "number"},
        "temperature": "number (°C)",
        "area": "number (mm²)"
      }
    ]
  }
}
```

---

## 6. 2.5D Packaging Standard

### 6.1 Interposer Specifications

#### 6.1.1 Silicon Interposer

Silicon interposers SHALL meet the following requirements:

- **Minimum feature size**: 2μm line/space
- **Metal layers**: 2-8 layers
- **Via diameter**: 5-20μm
- **Wafer thickness**: 100-750μm
- **CTE**: 2.6 ppm/°C

#### 6.1.2 Organic Interposer

Organic interposers SHALL meet:

- **Minimum feature size**: 10μm line/space
- **Metal layers**: 2-4 layers
- **Via diameter**: 50-100μm
- **Thickness**: 200-800μm
- **CTE**: Match to substrate (typically 17 ppm/°C)

### 6.2 Die Placement Rules

Dies on interposer SHALL be placed according to:

- **Minimum die-to-die spacing**: 500μm (silicon), 1000μm (organic)
- **Minimum die-to-edge spacing**: 1000μm
- **Maximum die area coverage**: 70% of interposer area
- **Thermal balance**: ±20% power density between quadrants

### 6.3 Micro-bump Specifications

Micro-bumps connecting dies to interposer SHALL meet:

- **Pitch**: 20-55μm
- **Diameter**: 15-40μm
- **Height**: 10-25μm
- **Material**: Copper pillar with solder cap or pure solder
- **Underfill**: Required for pitches <40μm

---

## 7. 3D IC Stacking Standard

### 7.1 TSV Specifications

TSVs SHALL meet the following requirements:

#### 7.1.1 Via-First TSVs
- **Diameter**: 5-10μm
- **Depth**: 50-100μm
- **Aspect ratio**: 8:1 to 15:1
- **Keep-out zone**: 3× diameter

#### 7.1.2 Via-Last TSVs
- **Diameter**: 10-30μm
- **Depth**: 20-100μm
- **Aspect ratio**: 3:1 to 8:1
- **Keep-out zone**: 2× diameter

### 7.2 Die Stacking Rules

Stacked dies SHALL comply with:

- **Maximum stack height**: 8 dies or 1000μm
- **Die thickness**: 20-100μm (thinned), 775μm (base die)
- **Die size variation**: ±5% within stack
- **Alignment tolerance**: ±2μm

### 7.3 Bonding Specifications

#### 7.3.1 Hybrid Bonding
- **Bond pitch**: 0.4-10μm
- **Bond pad size**: 0.3-8μm
- **Surface roughness**: <2nm Ra
- **Bonding force**: 20-100 kN
- **Bonding temperature**: 200-400°C

#### 7.3.2 Thermal Compression Bonding
- **Bump pitch**: 20-55μm
- **Bonding force**: 50-200 kN
- **Bonding temperature**: 220-280°C
- **Bonding time**: 1-30 seconds

---

## 8. Chiplet Integration Standard

### 8.1 Die-to-Die Interface Protocol

Standard die-to-die interfaces SHALL support:

- **Physical layer**: UCIe (Universal Chiplet Interconnect Express) or equivalent
- **Signaling**: Single-ended or differential
- **Data rate**: Up to 32 Gbps per pin
- **Protocols**: PCIe, CXL, AXI, or custom
- **Power modes**: Active, idle, sleep

### 8.2 Chiplet Design Rules

Chiplets SHALL include:

- **Standard edge placement**: Die-to-die interfaces on designated edges
- **Power/ground distribution**: Dedicated TSVs or micro-bumps
- **Test access**: Boundary scan (IEEE 1149.1) support
- **Thermal sensors**: On-die temperature monitoring
- **Redundancy**: Optional redundant interconnects for high-reliability applications

### 8.3 HBM Integration

HBM stacks SHALL be integrated according to:

- **Interface width**: 1024 bits per channel
- **Channels**: 8 or 16 per stack
- **Data rate**: 2.4-4.0 Gbps per pin (HBM2e/HBM3)
- **Stack height**: 4, 8, or 12 dies
- **Base die**: Logic die with PHY and controllers

---

## 9. Interconnect Specification

### 9.1 Signal Integrity Requirements

High-speed interconnects SHALL meet:

- **Insertion loss**: <3dB at Nyquist frequency
- **Return loss**: >10dB across operating band
- **Crosstalk**: <-30dB (near-end), <-40dB (far-end)
- **Jitter**: <15% UI (total jitter at BER 1e-12)
- **Eye height**: >200mV differential at receiver

### 9.2 Routing Guidelines

Signal routing SHALL follow:

- **Trace width**: Controlled impedance ±10%
- **Via stubs**: Minimized or back-drilled
- **Reference planes**: Continuous for high-speed signals
- **Differential pairs**: Matched to ±5% or ±1ps
- **Guard traces**: For sensitive signals

---

## 10. Thermal Management

### 10.1 Thermal Design Rules

Packages SHALL be designed to:

- **Junction temperature**: <125°C for automotive, <105°C for commercial
- **Thermal gradient**: <50°C across die
- **Hotspot temperature**: <10°C above average
- **Thermal cycling**: -40°C to +125°C for 1000 cycles

### 10.2 Thermal Interface Materials

TIMs SHALL meet:

- **Thermal conductivity**: >1 W/m·K (gap fillers), >3 W/m·K (thermal paste)
- **Thickness**: 50-200μm
- **Bond line thickness variation**: ±20μm
- **Pump-out resistance**: Stable after 1000 thermal cycles

### 10.3 Heat Spreader Design

Integrated heat spreaders SHALL:

- **Material**: Copper, aluminum, or composite
- **Thickness**: 0.5-3mm
- **Thermal conductivity**: >150 W/m·K
- **Flatness**: <50μm across surface

---

## 11. Power Delivery

### 11.1 Power Distribution Network

PDN SHALL be designed to:

- **IR drop**: <5% of supply voltage
- **Impedance**: <1mΩ at DC, <10mΩ at switching frequencies
- **Decoupling**: Multi-stage with on-die, package, and board capacitors
- **Resonance**: Avoid resonant peaks >10mΩ

### 11.2 Voltage Regulation

On-package regulation MAY include:

- **VR location**: On interposer or separate die
- **Efficiency**: >85% at nominal load
- **Response time**: <1μs for load transients
- **Ripple**: <50mV peak-to-peak

---

## 12. Signal Integrity

### 12.1 Simulation Requirements

Signal integrity analysis SHALL include:

- **S-parameters**: 4-port or higher extraction
- **Time-domain**: Eye diagram and BER analysis
- **Frequency-domain**: Insertion loss, return loss, crosstalk
- **Statistical**: Monte Carlo with process variations

### 12.2 Measurement and Validation

Manufactured packages SHALL be validated by:

- **TDR/TDT**: Time-domain reflectometry/transmission
- **VNA**: Vector network analyzer measurements
- **BERT**: Bit error rate testing at operating speed
- **Eye diagrams**: Sampled with real-time oscilloscope

---

## 13. API Specification

### 13.1 TypeScript/JavaScript SDK

The SDK SHALL provide:

```typescript
interface Package2D {
  id: string;
  interposer: Interposer;
  dies: Die[];
  simulate(): SimulationResult;
  optimize(): OptimizationResult;
  export(format: 'GDSII' | 'JSON' | 'LEF/DEF'): Buffer;
}

interface Package3D {
  id: string;
  dies: Die[];
  tsvs: TSV[];
  stack(): StackResult;
  thermalAnalysis(): ThermalResult;
}

interface Chiplet {
  id: string;
  interfaces: ChipletInterface[];
  connect(target: Chiplet): Connection;
}
```

### 13.2 REST API

HTTP endpoints SHALL be provided for:

- `POST /api/v1/package/create`: Create new package design
- `GET /api/v1/package/{id}`: Retrieve package design
- `POST /api/v1/package/{id}/simulate`: Run simulation
- `POST /api/v1/package/{id}/optimize`: Optimize design
- `GET /api/v1/package/{id}/thermal`: Get thermal analysis
- `POST /api/v1/package/{id}/export`: Export design

---

## 14. Manufacturing Guidelines

### 14.1 Design for Manufacturing

Designs SHALL comply with:

- **Wafer thinning**: Gradual thinning in multiple steps
- **TSV reveal**: Chemical mechanical polishing (CMP)
- **Alignment tolerance**: ±2μm for die bonding
- **Underfill**: Complete flow without voids
- **Warpage control**: <100μm for interposers

### 14.2 Process Integration

Manufacturing flow SHALL include:

1. Wafer fabrication and TSV formation
2. Wafer thinning and backside processing
3. Die singulation
4. Interposer preparation
5. Die placement and bonding
6. Underfill and cure
7. Final assembly and molding
8. Testing and qualification

---

## 15. Testing and Validation

### 15.1 Electrical Testing

SHALL include:

- **Continuity**: All interconnects
- **Resistance**: <10Ω per TSV, <1Ω per micro-bump
- **Capacitance**: Characterized per design
- **High-speed**: BER <1e-12 at operating speed

### 15.2 Reliability Testing

SHALL validate:

- **Thermal cycling**: -40°C to +125°C, 1000 cycles
- **Temperature humidity bias**: 85°C/85%RH, 1000 hours
- **High temperature storage**: 150°C, 1000 hours
- **Mechanical shock**: Per JESD22-B104
- **Vibration**: Per JESD22-B103

### 15.3 Compliance

Designs compliant with this specification MAY use:

**WIA-SEMI-003 Compliant** logo and certification

---

## Appendix A: Reference Designs

Reference implementations available at:
- https://github.com/WIA-Official/wia-standards/advanced-packaging

## Appendix B: Change History

| Version | Date | Changes |
|---------|------|---------|
| 1.0.0 | 2025-01-15 | Initial release |

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弘益人間 (홍익인간) · Benefit All Humanity