A Handy Novel Impedance Standard Substrate for Calibration of both Horizontal and Vertical Interconnects by Radio Frequency and Microwave Probes

This article proposes a novel impedance standard substrate, as known as calibration kit, 17 for the calibration using radio frequency (RF) and microwave probes, especially the through 18 substrate which is able to calibrate not only the conventional horizontal but also the vertical 19 interconnects on the basis of the short-open-load-through (SOLT) standardized calibration 20 approach. In the measurement of a vertical connection where the probing ports are located on the 21 opposite surfaces of devices, a location change or rotate with the probes is required after the 22 calibration based on the conventional coplanar kit which only allows the probing in the same 23 plane. The location change or rotation of the probes and corresponding connected cables 24 inevitably affects the precision of the calibration since the probes and cables are sensitive to the 25 surroundings. Our proposed calibration kit can overcome the aforementioned shortcomings, and 26 the comparison of calibrated results between conventional and proposed through impedance 27 standard substrate is demonstrated. Validation of the proposed kit based on the coplanar meander 28 lines and vertical couplings by via arrays is also discussed.

A Handy Novel Impedance Standard Substrate for Calibration of both Horizontal and Vertical Interconnects by Radio Frequency and Microwave Probes

This article proposes a novel impedance standard substrate, as known as calibration kit, 17 for the calibration using radio frequency (RF) and microwave probes, especially the through 18 substrate which is able to calibrate not only the conventional horizontal but also the vertical 19 interconnects on the basis of the short-open-load-through (SOLT) standardized calibration 20 approach. In the measurement of a vertical connection where the probing ports are located on the 21 opposite surfaces of devices, a location change or rotate with the probes is required after the 22 calibration based on the conventional coplanar kit which only allows the probing in the same 23 plane. The location change or rotation of the probes and corresponding connected cables 24 inevitably affects the precision of the calibration since the probes and cables are sensitive to the 25 surroundings. Our proposed calibration kit can overcome the aforementioned shortcomings, and 26 the comparison of calibrated results between conventional and proposed through impedance 27 standard substrate is demonstrated. Validation of the proposed kit based on the coplanar meander 28 lines and vertical couplings by via arrays is also discussed.

Non-destructive In-line IMC Thickness Measurement Using Acoustic Metrology for 3D Stacking

The constant demand for small-feature-size, high performance and dense I/O applications have necessitated the development of fine-pitch vertical interconnects for 3-D integration. Microbumps and through silicon vias enable the high-density vertical interconnects. As microbumps scale, intermetallic compound formation during thermocompression bonding and its impact on reliability is a concern. In this paper, we describe the application of picosecond acoustic metrology technology as a viable option for non-destructive characterization of the intermetallic compounds. The small spot size technology allows measurement on small bumps, with very good accuracy and repeatability.