Die-Attach Pad Monitoring for Backside IC Tamper Detection

Solution Overview

Problem

Integrated circuits (ICs) are vulnerable to security attacks through the die-attach pad, particularly in leadframe packages, where attackers can easily access the IC from the backside, compromising stored secrets.

Innovation Solution

Implement a measurement circuit to measure electrical characteristics of the die-attach pad, such as resistance or capacitance, and a security control circuit to compare these measurements against stored reference values, initiating protective actions if deviations exceed a threshold, including erasing stored secrets.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional IC packaging is used without additional security structures, then manufacturing cost and device complexity are low, but security against backside attacks is poor

Engineering Contradiction:

Improvesecurity protectionVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The die-attach pad structure is made to serve dual purposes: its original function of mechanically and electrically connecting the IC to the package, and a secondary security function of detecting tampering attempts through measurements of its electrical characteristics. This eliminates the need for separate security structures.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The IC's existing measurement circuits and control logic are utilized to perform security monitoring functions. The measurement circuit measures electrical characteristics of the die-attach pad, and the control circuit compares these measurements against reference values to detect attacks, all using components already present in the IC.

Inventive Principle:

Principle #25Self-service

2Reliability

If conventional IC packaging is used without additional security structures, then manufacturing process is simple, but security against backside attacks is poor

Engineering Contradiction:

Improvesecurity protectionVSAvoidmanufacturing process

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The die-attach pad structure is made to serve dual purposes: its original function of mechanically and electrically connecting the IC to the package, and a secondary security function of detecting tampering attempts through measurements of its electrical characteristics. This eliminates the need for separate security structures.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If measurement circuit and security control circuit are added to detect die-attach pad tampering, then security protection is improved, but device complexity increases

Engineering Contradiction:

Improvesecurity protectionVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The die-attach pad structure is made to serve dual purposes: its original function of mechanically and electrically connecting the IC to the package, and a secondary security function of detecting tampering attempts through measurements of its electrical characteristics. This eliminates the need for separate security structures.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The IC's existing measurement circuits and control logic are utilized to perform security monitoring functions. The measurement circuit measures electrical characteristics of the die-attach pad, and the control circuit compares these measurements against reference values to detect attacks, all using components already present in the IC.

Inventive Principle:

Principle #25Self-service

4Reliability

If additional IC fabrication steps are used to implement security features, then security protection is improved, but manufacturing complexity and cost increase

Engineering Contradiction:

Improvesecurity protectionVSAvoidmanufacturing process

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The die-attach pad structure is made to serve dual purposes: its original function of mechanically and electrically connecting the IC to the package, and a secondary security function of detecting tampering attempts through measurements of its electrical characteristics. This eliminates the need for separate security structures.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Provides reliable and cost-effective protection against die-attach tampering by detecting changes in electrical characteristics, ensuring the security of stored data without additional IC fabrication steps.

Implementation Method 1

the electrical characteristic of the die-attach pad includes a resistance between at least two wires that are bonded to the die-attach pad

Methodology Applied

Scientific EffectElectrical Resistance: Electrical Resistance

Implementation Method 2

the electrical characteristic of the die-attach pad includes a capacitance between the die-attach pad and an electrical junction in the IC

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS12614004B2Detection of security attacks through die-attach pad

Publication Date: 2026.04.28 NUVOTON

AI summary

An electronic device includes an Integrated Circuit (IC) and a package including a die-attach pad for connecting the IC. The IC includes (i) a measurement circuit configured to measure an electrical characteristic of the die-attach pad, and (ii) a security control circuit configured to initiate a responsive action responsively to detecting a deviation of the measured electrical characteristic of the die-attach pad from an initial measurement of the electrical characteristic.