Socket with Bended Portion for Warped IC Package Testing
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Solution Overview
Problem
Fan-out wafer level chip scale packages (WLCSPs) face challenges during testing due to warpage caused by elevated temperatures, leading to misjudgment of good packages as bad and potential damage from excessive force applied to ensure probe contact.
Innovation Solution
A testing apparatus with a socket and conductive pins that match the profile of the integrated circuit package, including a bended portion and conductive pillars to maintain stable contact and reduce the risk of damage, and an interposer with conductive joints and underfill for flexibility and ease of maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If excessive force is applied to press the probe cards against the DUTs to ensure contact, then the contact reliability between probe pins and solder balls is improved, but the package and probe cards may be damaged
Solution Approach 1:
The probe pins are designed with spherical tips instead of flat or pointed ends. This spherical shape allows the probe pins to conform to the curved warpage of the package surface while maintaining stable contact with the solder balls, eliminating the need for excessive pressing force that would cause damage.
Solution Approach 2:
The invention changes the geometric parameters of the probe pins by making them movable and spherical-tipped, allowing them to adapt to varying contact conditions. This parameter change enables reliable contact without requiring high contact force, thus preventing package damage while maintaining testing reliability.
2Reliability
If the profile of the socket and conductive pins matches the warped profile of the package, then stable contact is maintained during testing, but the device complexity increases
Solution Approach 1:
The socket is designed with a bended portion that has a curved profile matching the typical warpage of the package. This curvature allows the conductive pins to maintain stable contact with the solder balls across the warped surface without requiring complex active adjustment mechanisms.
Solution Approach 2:
The socket structure passively adapts to the package warpage through its pre-designed bended profile, eliminating the need for active sensing or adjustment systems. The geometry itself provides the adaptation function, simplifying the overall system while maintaining contact stability.
3Productivity
If fan-out WLCSP technology is used to increase the number of I/O pads, then the packaging capability is improved, but the package becomes more prone to warpage
Solution Approach 1:
The testing apparatus socket is designed with a bended portion that provides a curved contact surface. This curvature compensates for the warpage induced by fan-out WLCSP packaging, allowing stable electrical contact to be maintained despite the package's non-planar shape, thus enabling the use of high-density fan-out packaging.
Data Source
AI summary
A testing apparatus for testing an integrated circuit package having a plurality of electrical terminals includes a base, a socket, a plurality of conductive pins and a plurality of conductive pillars. The base includes a plurality of electrical contacts. The socket is disposed on the base and includes a bended portion bended away from the base and a plurality of through holes distributed in the socket. The conductive pins are disposed in the through holes respectively and electrically connected to the electrical contacts, wherein each of the conductive pins protrudes from an upper surface of the socket for forming temporary electrical connections with one of the electrical terminals. The conductive pillars are disposed on the base and connected to the bended portion, wherein each of the conductive pillars electrically connects one of the conductive pins and one of the electrical contacts.