Backside Tamper Protection via Substrate Light Reflection

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Solution Overview

Problem

Existing tamper-resistant semiconductor devices restrict application range and are cost-inefficient due to the requirement for transparent encapsulants and reflective outer coverings that surround the entire IC, limiting packaging flexibility and increasing costs.

Innovation Solution

A tamper-resistant semiconductor device with light-emitting and light-sensing devices on the circuitry side, emitting light into the substrate and sensing reflections at the backside, allowing for detection of tampering attempts without the need for a transparent encapsulant or reflective covering, enabling flexible packaging and cost-effective production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a transparent encapsulant and reflective outer covering are used to protect the backside of the IC, then tamper protection is achieved, but packaging flexibility is restricted and costs increase

Engineering Contradiction:
Improvetamper protectionVSAvoidpackaging flexibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The invention extracts the light-emitting and light-sensing devices from the traditional encapsulation structure and integrates them directly into the IC substrate. This removes the requirement for transparent encapsulants and reflective outer coverings, thereby maintaining tamper protection capability while restoring packaging flexibility and reducing costs.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention merges the light-emitting device and light-sensing device into a single integrated structure on the IC substrate. By combining these functional elements directly into the chip, the patent eliminates the need for separate encapsulation layers and external reflective coverings, achieving both tamper protection and packaging versatility.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If a transparent encapsulant and reflective outer covering are used to protect the backside of the IC, then tamper protection is achieved, but manufacturing costs increase

Engineering Contradiction:
Improvetamper protectionVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention extracts the light-emitting and light-sensing devices from the traditional encapsulation structure and integrates them directly into the IC substrate. This removes the requirement for transparent encapsulants and reflective outer coverings, thereby maintaining tamper protection capability while restoring packaging flexibility and reducing costs.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention uses standard semiconductor fabrication processes to create the light-emitting and light-sensing devices directly on the substrate, replacing expensive custom encapsulation and assembly processes. This approach uses conventional, cost-effective manufacturing techniques to achieve the same security function.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Reliability

If the entire IC is surrounded by transparent encapsulant and reflective covering, then backside protection is achieved, but device complexity increases

Engineering Contradiction:
Improvebackside protectionVSAvoidpackage structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts the light-emitting and light-sensing devices from the traditional encapsulation structure and integrates them directly into the IC substrate. This removes the requirement for transparent encapsulants and reflective outer coverings, thereby maintaining tamper protection capability while restoring packaging flexibility and reducing costs.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention merges the light-emitting device and light-sensing device into a single integrated structure on the IC substrate. By combining these functional elements directly into the chip, the patent eliminates the need for separate encapsulation layers and external reflective coverings, achieving both tamper protection and packaging versatility.

Inventive Principle:
Principle #5Merging (Combining)

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

This solution provides effective backside tamper protection without restricting application range or increasing costs, allowing for detection of tampering attempts while maintaining packaging flexibility and reducing manufacturing complexity.

Implementation Method 1

The light-sensing device is arranged to sense at least a fraction of the emitted light following passage through the substrate and reflection at the backside

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP2115652B1Semiconductor device with backside tamper protection
Publication Date: 2019.04.10 NXP BV
  • EP2115652B1 patent drawingFigure 1a~2
  • EP2115652B1 patent drawingFigure 3~4b
  • EP2115652B1 patent drawingFigure 5~7

AI summary

A tamper-resistant semiconductor device (5;20;30;40;50;60) which includes a plurality of electronic circuits formed on a circuitry side (6) of a substrate (7) having an opposite side which is a backside (8) of the semiconductor device, and comprises at least one light-emitting device (9a-f;21) and at least one light-sensing device (10a-f;22a-b) provided on the circuitry side (6) of the semiconductor device. The light-emitting device (9a-f;21) is arranged to emit light, including a wavelength range for which the substrate (7) is transparent, into the substrate towards the backside (8), and the light- sensing device (10a-f;22a-b) is arranged to sense at least a fraction of the emitted light following passage through the substrate (7) and reflection at the backside (8), and configured to output a signal indicative of a reflecting state of the backside, thereby enabling detection of an attempt to tamper with the backside (8) of the semiconductor device (5;20;30;40;50;60). Through the present invention, a semiconductor device can be equipped with a backside tamper protection which neither restricts the field of application of the semiconductor device, nor the choice of packaging of the device.