Socketless Test Board Using Pneumatic Membrane for Thermal Locking

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Solution Overview

Problem

Current test systems for electronic devices are complex and costly, with inefficient thermal conditioning and high operational complexity, particularly during the burn-in test process at the package level, which affects the quality and reliability of electronic devices.

Innovation Solution

A test system utilizing a fluid to both mechanically lock and thermally condition electronic devices, featuring expandable chambers with thermally conductive membranes and a pneumatic system for uniform temperature distribution, eliminating the need for sockets and bulky air conditioning structures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If sockets are used to mechanically lock and electrically connect electronic devices on test boards, then reliable electrical connection and mechanical stability are achieved, but device complexity and manufacturing cost increase due to complex socket structures and multiple assembly operations

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidtest board structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the socket component from the test board system. Instead of using sockets to interface electronic devices, the test board directly receives and contacts the device terminals through recesses formed in the board substrate, thereby simplifying the overall structure while maintaining reliable electrical connection.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The test board is designed to perform multiple functions directly: it provides mechanical support, electrical connection, and thermal conditioning through integrated structures. The recesses in the test board serve both as mechanical receivers for device terminals and as pathways for thermal contact, eliminating the need for separate socket components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Strength

If sockets are soldered or snap mounted on test boards, then mechanical locking and electrical connection are achieved, but manufacturing cost and assembly time increase due to multiple assembly operations

Engineering Contradiction:
Improvemechanical locking strengthVSAvoidtest board manufacturing ease
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The invention merges the mechanical locking function and electrical connection function into the test board substrate itself. The recesses are formed directly in the board during manufacturing, eliminating the need for separate socket assembly operations such as soldering or snap mounting, thereby simplifying the manufacturing process while maintaining strong mechanical and electrical connections.

Inventive Principle:
Principle #5Merging (Combining)

3Temperature

If hot or cold air is forced towards test boards for thermal conditioning of electronic devices, then thermal conditioning is achieved, but system size and cost increase due to bulky air conditioning structures

Engineering Contradiction:
Improveelectronic device temperature controlVSAvoidthermal conditioning system complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The invention uses a fluid (liquid or gas) delivered through channels formed in the test board substrate to condition the electronic devices thermally. This pneumatic/hydraulic approach replaces bulky air conditioning structures with integrated fluid delivery systems, reducing overall system size while maintaining effective temperature control.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The thermal conditioning is achieved by delivering fluid through channels within the plane of the test board substrate rather than using external bulky structures. This two-dimensional integration of thermal management pathways within the board itself reduces the third-dimensional footprint of the system.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Use of energy by stationary object

If forced air is used for thermal conditioning, then temperature control is achieved, but temperature uniformity across different electronic devices deteriorates due to difficult heat distribution

Engineering Contradiction:
Improvethermal energy deliveryVSAvoidtemperature distribution uniformity
Core Design Contradiction:
Use of energy by stationary objectVSManufacturing precision

Solution Approach 1:

The invention provides localized thermal conditioning by delivering fluid through individually configured channels in the test board substrate. Each channel can be optimized to deliver thermal energy directly to specific electronic devices, ensuring uniform temperature distribution across different devices while efficiently using thermal energy.

Inventive Principle:
Principle #3Local quality

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 simplifies the test board structure, reduces manufacturing costs, and ensures uniform thermal conditioning, shortening the test process while enhancing the quality and reliability of electronic devices.

Implementation Method 1

A first expandable chamber is arranged above the test board and is expandable under the action of a fluid under pressure

Methodology Applied
Scientific EffectPneumatic pressure: Pressurisation

Implementation Method 2

a second expandable chamber arranged below the test board, said second expandable chamber having a base formed by a membrane of a thermally conductive material

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

The test system further includes means for forcing the conditioning fluid to circulate under pressure through the chambers

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP2115480B1Test of electronic devices at package level using test boards without sockets
Publication Date: 2011.05.25 ELES SEMICON EQUIP
  • EP2115480B1 patent drawingFigure 1
  • EP2115480B1 patent drawingFigure 2A~2B
  • EP2115480B1 patent drawingFigure 3A

AI summary

A test system (100) is proposed; the test system is used to test electronic devices (105;105 ) each one having a case (205;205 ) with a plurality of terminals (210;210 ) for example, of the BGA type. The test system includes a set of (one or more) test boards (125;125 ). Each test board includes a plurality of banks of electrically conductive receptacles (225;225 ), each one for resting a corresponding electronic device; each receptacle is adapted to receive a terminal (210;210 ) of the corresponding electronic device. A set of (one or more) boxes (230) is arranged in operation above the test boards. Each box defines an expandable chamber (235) for a conditioning fluid; particularly, the box includes a rigid body (240), a flexible membrane (245) of a thermally conductive material facing the test boards, an inlet (330), and an outlet (335). Means (350) is provided for controlling a temperature of the conditioning fluid (for example, a heat exchanger). The test system further includes means (345) for forcing the conditioning fluid to circulate under pressure through the chambers, so as to expand the flexible membranes downwardly; the expanded flexible membranes press the electronic devices against the test boards to lock the electronic devices mechanically on the test boards and to condition the electronic devices thermally.