Contactless Inductive Circuit Testing via Coil Probes
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Solution Overview
Problem
Conventional electronic circuit testing apparatuses have a short service life due to needle wear and require test pads, restricting design flexibility and necessitating electrostatic discharge protection, which hinders high-speed processing.
Innovation Solution
An electronic circuit testing apparatus using probes with transmitter and receiver coils that are two-dimensionally movable and coaxially disposed, allowing contact-free testing without test pads and eliminating the need for ESD protection circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If needle probes are used to touch pads for testing, then testing can be performed, but the needle tip wears away and service life is shortened
Solution Approach 1:
The patent replaces the mechanical needle-probe contact system with an electromagnetic induction system. Instead of using physical needles to touch pads, the invention uses transmitter coils to generate magnetic fields that induce currents in receiver coils on the chip, enabling contactless testing. This eliminates mechanical wear and extends service life.
Solution Approach 2:
The patent introduces magnetic fields as an intermediary medium for signal transmission during testing. The transmitter coil generates a magnetic field that couples with the receiver coil through inductive coupling, serving as a non-contact intermediary to transfer test signals without direct physical contact between the testing apparatus and the chip pads.
2Reliability
If test pads are provided for testing, then testing can be performed, but design flexibility is restricted
Solution Approach 1:
The patent replaces the requirement for physical test pads with electromagnetic coupling between transmitter and receiver coils. This allows testing functionality to be achieved through inductive coupling without dedicating specific pad locations, thereby maintaining full design flexibility for pad placement while preserving complete testing capability.
3Reliability
If ESD protection circuits are used for needle contact points, then electrostatic discharge is protected, but high-speed processing is hindered due to large electrostatic capacitance
Solution Approach 1:
The patent replaces the ESD protection circuit requirement by eliminating direct electrical contact. Since the testing is performed through inductive coupling without physical needle contact, there is no direct electrical path for electrostatic discharge, removing the need for ESD protection circuits and their associated capacitance that would slow down signal processing.
Solution Approach 2:
The magnetic field acts as an intermediary that isolates the testing apparatus from direct electrical contact with the chip. This electromagnetic coupling provides inherent protection against electrostatic discharge while maintaining high-speed signal transmission capability, as the magnetic field can transfer signals rapidly without the capacitance limitations of ESD protection circuits.
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
The solution extends the service life of testing apparatuses, enhances design flexibility, and enables faster input/output operations by avoiding needle wear and electrostatic discharge issues, while inductive coupling facilitates high-speed processing.
Implementation Method 1
communications between substrates such as IC (Integrated Circuit) bare chips, and PCBs (Printed Circuit Boards) by inductive coupling
Implementation Method 2
the respective coils are disposed on the first through the third LSI chips 31a, 31b and 31c so that the centers of the openings of the three pairs of transmitter and receiver coils 33 and 35 are made coincident with each other. Accordingly, the three pairs of transmitter and receiver coils 33 and 35 form inductive coupling, thereby enabling communications.
Data Source
AI summary
The present invention has an object to provide an electronic circuit testing apparatus that is preferable for testing an electronic circuit which carries out communications between substrates based on inductive coupling and is capable of testing the electronic circuit without using test pads, wherein a probe 15 is caused to intervene in a communications channel composed by inductive coupling based on the first and second transmitter coils 21a, 21b; and the first and second receiver coils 23a, 23b, and an LSI is tested by a tester 11, buffers 12 and 13, and a Tx/Rx switch 14. Accordingly, it is not be necessary for that the electronic circuit testing apparatus is provided with a needle that touches pads and leads of the electronic circuit, and the service life there can be lengthened.