Small Pitch BGA Package Assembly for Burn-In Testing

Solution Overview

Problem

The high cost and manufacturing challenges of burn-in apparatuses that accommodate higher density ball grid array (BGA) devices with pitches less than 1.0 mm, due to size limitations and structural constraints, make it difficult to reliably test and sort defective components.

Innovation Solution

A package assembly with a pin-out configuration that includes a set of first contacts for direct contact with the burn-in apparatus and a set of second contacts that do not contact the apparatus, allowing for a smaller pitch without modifying the burn-in apparatus structure, enabling compatibility with standard burn-in equipment and facilitating self-testing during the burn-in process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the pitch of BGA devices is decreased to increase contact density, then the functional density of the package assembly is improved, but the compatibility with conventional burn-in apparatuses deteriorates

Engineering Contradiction:

Improvecontact densityVSAvoidburn-in apparatus compatibility

Core Design Contradiction:

Quantity of substanceVSAdaptability or versatility

Solution Approach 1:

The contact array is segmented into two distinct sets: first contacts arranged at a larger pitch for burn-in testing, and second contacts arranged at a smaller pitch for normal operation. This segmentation allows the package assembly to interface with conventional burn-in apparatuses through the first contacts while maintaining high-density second contacts for functional use.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the contact array have different pitch characteristics. The first contacts are positioned and spaced to match conventional burn-in apparatus pitch requirements, while the second contacts are positioned and spaced at higher density for normal operation. This local variation in pitch quality enables dual functionality.

Inventive Principle:

Principle #3Local quality

2Quantity of substance

If the pitch of BGA devices is decreased to increase contact density, then the functional density of the package assembly is improved, but the manufacturing cost of burn-in apparatuses increases

Engineering Contradiction:

Improvecontact densityVSAvoidburn-in apparatus manufacturing cost

Core Design Contradiction:

Quantity of substanceVSEase of manufacture

Solution Approach 1:

The contact array is segmented into two distinct sets: first contacts arranged at a larger pitch for burn-in testing, and second contacts arranged at a smaller pitch for normal operation. This segmentation allows the package assembly to interface with conventional burn-in apparatuses through the first contacts while maintaining high-density second contacts for functional use.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first contacts serve dual purposes: they enable high-density packaging overall while simultaneously providing compatibility with conventional burn-in apparatuses. This multi-functionality allows existing burn-in equipment to test high-density packages without modification, avoiding increased manufacturing costs.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Quantity of substance

If the pitch of BGA devices is decreased to increase contact density, then the functional density of the package assembly is improved, but the reliability of burn-in testing deteriorates

Engineering Contradiction:

Improvecontact densityVSAvoidburn-in testing reliability

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The contact array is segmented into two distinct sets: first contacts arranged at a larger pitch for burn-in testing, and second contacts arranged at a smaller pitch for normal operation. This segmentation allows the package assembly to interface with conventional burn-in apparatuses through the first contacts while maintaining high-density second contacts for functional use.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first contacts are positioned and configured to replicate the pitch and arrangement requirements of conventional burn-in apparatuses. This copying approach ensures that high-density packages can be reliably tested on existing equipment, maintaining testing reliability while achieving higher overall contact density.

Inventive Principle:

Principle #26Copying

Data Source

PatentUS7705619B2Small pitch ball grid array of a package assembly for use with conventional burn-in sockets

Publication Date: 2010.04.27 INTEGRATED DEVICE TECH INC

AI summary

A package assembly (18) that is selectively coupled to a burn-in apparatus (228P) during a burn-in process includes a pin-out (20) having an array of contacts (22) including a set of first contacts (222F) and a set of second contacts (222S). The first contacts (222F) are required for the burn-in process, and are each adapted to be in contact with a corresponding contact member (232P) of the burn-in apparatus (228P) during the burn-in process. The second contacts (222S) are not required for the burn-in process. The second contacts (222S) do not contact any of the contact members (232P) during the burn-in process. The contact members (232P) are arranged at a first pitch. In various embodiments, the array of contacts (22) is arranged at a second pitch that is smaller than the first pitch.