Lighting Device Pad Segmentation for IC Testing
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Solution Overview
Problem
Conventional lighting devices have a design that prevents functional testing of the integrated circuit chip before installation on a printed circuit board, due to the common connection of input power supply voltage and anodes of light emitting diode chips to the same pad.
Innovation Solution
The lighting device includes a carrier with configuration pads, light emitting diode chips, an integrated circuit chip, five external pads, and a connection component. The connection component passes through the substrates to electrically couple the configuration pads and external pads, allowing for individual detection of the integrated circuit chip before installation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the input power supply voltage and anodes of light emitting diode chips are connected to the same pad, then the device complexity is reduced, but the ability to perform functional testing on the integrated circuit chip is lost
Solution Approach 1:
The invention segments the power supply connection by separating the input power supply voltage (VDD) connection from the anodes of light emitting diode chips connection. Specifically, VDD is connected to a first external pad while the anodes are connected to a second external pad, allowing independent access to each connection for testing purposes without requiring complex internal routing.
Solution Approach 2:
The invention introduces an intermediary substrate structure (carrier) that provides separate connection pathways between the integrated circuit chip and external pads. The carrier includes configuration pads and connection components that mediate the electrical connections, enabling functional testing through dedicated test pads while maintaining the simplified overall device structure.
2Reliability
If separate external pads are used for input power supply voltage and anodes of light emitting diode chips, then functional testing capability is improved, but the device complexity increases
Solution Approach 1:
The external pads are designed with multi-functionality: they serve both as electrical connection terminals for normal device operation and as test access points for functional testing. The first external pad connects to VDD for both power supply and testing, while the second external pad connects to anodes for both LED operation and testing, eliminating the need for separate dedicated test pads.
Solution Approach 2:
The invention maintains equipotential connections through the carrier substrate, ensuring that the separate external pads provide the same electrical potential and connection quality as a unified pad would, while enabling separate access for testing purposes. The connection components on the carrier ensure equal electrical characteristics for both testing and operational modes.
Data Source
AI summary
A lighting device includes a carrier, a plurality of configuration pads, a plurality of light emitting diode chips, an integrated circuit chip, five external pads, and a connection component. The carrier includes a first substrate, a second substrate, and a third substrate. The second substrate is located between the first substrate and the third substrate. The configuration pads are disposed on the first substrate and are spaced apart from each other. The light emitting diode chips and the integrated circuit chips are electrically connected to the configuration pads. The five external pads are disposed on the third substrate and are spaced apart from each other. A portion of the connection component passes through the first substrate and the third substrate, so as to be electrically coupled to the configuration pads and the five external pads.