X-ray computed tomography for nano packaging - a progressive NDE method

Abstract

The challenge of nano-packaging requires new nondestructive evaluation (NDE) techniques to detect and characterize very small defects like transportation phenomenon, Kirkendall voids or micro cracks. Imaging technologies with resolutions in the sub-micron range are the desire.High end semiconductor industries today deal with functional structures down to 32 nm and below. ITRS roadmap predicts an ongoing decrease of the "DRAM half pitch" over the next decade. Nano-packaging of course is not intended to realize pitches at the nanometer scale, but has to face the challenges of integrating such semiconductor devices with smallest pitch and high pin counts into systems. System integration (SiP, SoP, Hetero System Integration etc.) into the third dimension is the only way to reduce the gap between semiconductor level and packaging level interconnection.To control the necessary technologies a selection of suitable and effective non-destructive evaluation methods is absolutely vital. The task of these methods is not only to identify any impurities on the package surface, but also to look as deep as possible into the package volume. Available non-destructive evaluation methods (NDE) for such kind of packaging are for example X-ray microscopy, X-ray computed tomography, ultrasonic microscopy and thermal microscopy.The paper will focus on X-ray nano focus computed tomography. It will discuss the potentials and limits of X-ray NDE techniques and the sample preparation, illustrated by the investigation of a complete system in package device (SiP).

Multi-scale radiographic applications in microelectronic industry

“…Figure3 shows some usual interface constructions and the ZVEI commitment to the beginning of nano-scaled interfaces (ZVEI -German abbreviation of the electronics industry association). So nano packaging is defined beginning with ball diameters of 150 μm and smaller (see [2] and [3]). …”

“…It is necessary to develop evaluation techniques to find out the possibilities and limitations of different inspection technologies. Some ways like the use of so called reference objects and defect samples are described in [3] and [4]. Later on in this paper a case study of such an inspection task is described.…”

“…To evaluate the inside structure X-ray radiography and X-ray computed tomography (CT) have been used amongst others (see [3]). X-ray radiography results showed the inside components but only poor information about the 3 rd dimension (Fig.…”

A Compact High-Resolution Resonance-Based Capacitive Sensor for Defects Detection on PCBAs

“…Besides, for such an evaluation on PCBAs, a 1D spatial resolution of around 0.15 mm is needed to distinguish different pins of a package for example [5]. In recent years, different potential sensing technologies have been advanced with the development of different probing techniques [6]- [13] to evaluate the fabrication quality of a PCBA, i.e. the device under test (DUT).…”

“…the device under test (DUT). For example, the Xray methods have long penetration depth and high spatial resolution, but it needs high cost and possibly result with the radiation hazards [6], [7]. An alternative inspection technique for high density PCBAs is the thermography methods [8], [9].…”