Coaxial Pad Probe Structure for Shielded RF S-Parameter Testing
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Solution Overview
Problem
Conventional methods for interconnecting semiconductor packages and probing RF signal connections face challenges such as increased size and complexity, difficulty in testing bond pads, and high costs due to inadequate shielding and frequency range limitations of coaxial probes.
Innovation Solution
The semiconductor package includes metal sections directly engaged via wafer bonding, compliant support structures, and electromagnetic interference fences to shield RF connections, along with a coaxial pad probe for efficient S-parameter measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional interconnection methods (wiring bonding, solder balls, copper pillars) are used to connect semiconductor dies, then electrical interconnection is achieved, but package size and complexity increase
Solution Approach 1:
The patent merges multiple separate interconnection structures (wiring bonding, solder balls, copper pillars, silicon bridges) into a single integrated interposer substrate that performs all these functions simultaneously. This consolidation reduces the number of discrete components and assembly steps while maintaining electrical interconnection capability between semiconductor dies.
Solution Approach 2:
The interposer substrate serves as an intermediary component between semiconductor dies and the PCB. It provides a unified interface that handles electrical connections, mechanical support, and thermal management, eliminating the need for multiple separate interconnection methods and reducing overall package complexity.
2Difficulty of detecting and measuring
If conventional coaxial probes with spring fingers are used to test bond pads, then RF signal measurement is possible, but shielding is inadequate and frequency range is limited
Solution Approach 1:
The probe tip incorporates a localized electromagnetic shield structure that provides frequency-selective shielding specifically at the measurement interface. This local shielding enhancement protects the bond pad measurements from external RF interference without affecting the overall probe design or requiring complete redesign of the coaxial structure.
Solution Approach 2:
The probe tip uses a composite structure combining conductive materials for shielding with dielectric materials for signal isolation. This composite approach enables effective RF shielding and broad frequency operation while maintaining the mechanical and electrical properties needed for reliable bond pad testing.
3Adaptability or versatility
If conventional probe tips with coplanar wavelength configuration are used, then general RF connections can be tested, but specific bond pad characteristics are not properly addressed
Solution Approach 1:
The probe tip features a localized coaxial structure at the measurement interface that matches the specific geometry and electrical characteristics of bond pads. This local coaxial configuration provides precise electrical coupling with bond pads while the rest of the probe maintains general RF testing capability through its coaxial cable structure.
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 configuration reduces package size and complexity while providing effective RF signal integrity testing at a lower cost, with improved frequency range capabilities and reduced probing time.
Implementation Method 1
The at least one section and the at least another section directly engage with one another via wafer bonding of the at least one electrical structure and the at least another electrical structure
Implementation Method 2
electromagnetic interference fences to shield RF connections
Data Source
AI summary
A coaxial pad probe for coupling with a preexisting coaxial cable having a first end and a second end opposite to the first end and remote from an analyzing device. The coaxial pad probe includes a probe operably engaged with the second end of the preexisting coaxial cable. The probe is configured to directly contact a coaxial input/output (IO) connection provided on a mixed signal die or a coplanar IO connection provided on the mixed signal die for measuring an S-parameter measurement of the mixed signal die. The probe may include a support structure operably engaged with second end of the preexisting coaxial cable. The probe may also include a probe tip operably engaged with the support structure and configured to directly contact with the selected coaxial IO connection provided on the mixed signal die or the coplanar IO connection provided on the mixed signal die.