Technical Library | 2025-08-29 13:53:05.0
In electronics manufacturing, "underfill" refers to a material that is applied to fill the gap between a semiconductor device, such as flip-chip assemblies, Ball Grid Arrays (BGA), or Chip Scale Packages (CSP), and the substrate, such as a PCB or flex circuit. It is also important in 3D ICs and advanced packaging technologies that involve stacking multiple chips or integrating multiple functions into a single package.
Technical Library | 2011-01-20 18:43:39.0
PCB stack-up is an important factor in determining the EMC performance of a product. A good stack-up can be very effective in reducing radiation from the loops on the PCB (differential-mode emission), as well as the cables attached to the board (common-mo
Technical Library | 2015-05-14 15:45:45.0
The Printed Circuit Board industry has seen a steady reduction in pitch from 1.0mm to 0.4mm; a segment of the industry is even using or considering a 0.25mm pitch. This has increased the use of stacked microvias in these designs. The process of stacking microvias has been practiced for several years in handheld devices; however, the devices generally do not operate in harsh conditions. Type 1 and Type 2 microvias have been tested over the years and have been found to be very reliable. We do not have enough test data for 3 and 4 stack microvias when placed on and off buried via. The main objective of this study was to understand the reliability of 3 and 4 stack microvias placed on and off a buried via.
Technical Library | 2018-12-12 22:20:22.0
Numerous 3D stack packaging technologies have been implemented by industry for use in microelectronics memory applications. This paper presents a reliability evaluation of a particular package-on-package (PoP) that offers a reduction in overall PCB board area requirements while allowing for increases in functionality. It utilizes standard, readily available device packaging methods in which high-density packaging is achieved by: (1) using standard "packaged" memory devices, (2) using standard 3-dimensional (3-D) interconnect assembly. The stacking approach provides a high level of functional integration in well-established and already functionally tested packages. The stack packages are built from TSOP packages with 48 leads, stacked either 2-high or 4-high, and integrated into a single dual-flat-no-lead (DFN) package.
Technical Library | 2017-12-27 22:52:43.0
To compensate for the insufficiency and instability of solder paste dispensing and printing that are used in the SMT production process, a noncontact solder paste jetting system driven by a piezoelectric stack based on the principle of the nozzle-needle-system is introduced in this paper, in which a miniscule gap exists between the nozzle and needle during the jetting process.
Technical Library | 2007-08-02 13:24:23.0
This paper presents the results of a joint - three way study between Amkor Technology, Panasonic Factory Solutions and Spansion in the area of package on package (PoP) board level reliability (BLR) (...) The scope of this paper is to cover the already popular 14 x 14mm PoP package size that provides a 152 pin stacked interface which supports a high level of flexibility in the memory architecture for multimedia requirements.
Technical Library | 2008-02-26 15:02:19.0
More and more chip packages need multi-GHz RF structures to meet their performance targets. The ideal chip package needs to combine RF features with Digital features for these applications. They drive low-loss, controlled impedance transmission lines, flexibility in assigned signal and power layers, and clearances of various shapes in power layers. Building these features in a chip package is difficult without making the stack-up very thick or compromising the reliability of the product. In the present paper, we have designed and built a flip-chip package test vehicle (TV) to make new RF structures, using Z-axis interconnection (Zinterconnect) building blocks.
Technical Library | 2009-04-30 18:06:24.0
This presentation surveys the most significant via and via-related laminate failure mechanisms from past to present using data from current induced thermal cycling (CITC) testing, failure analysis, and other sources. The relative life and failure modes of thru vias, buried vias, and microvias (stacked vs. non-stacked) are compared, along with the affect of structure, materials, and peak temperatures on the above. The origin of via-induced laminate failures such as "eyebrow cracks" and Pb free related internal delamination is also explored.
Technical Library | 2014-02-27 15:30:20.0
Silicon dioxide is normally used as filler in underfill. The thermal conductivity of underfill is less than 1 w/mk, which is not able to meet the current flip chip application requirements such as 3D stacked multi-chips packaging. No matter which direction the heat will be dissipated through PCB or chip, the heat has to pass through the underfill in 3D stacked chips. Therefore the increase of thermal conductivity of underfill can significantly enhance the reliability of electronic devices, particularly in 3D package devices
Technical Library | 2021-12-16 01:33:11.0
Ball Grid Array devices, BGAs, are widely used in a vast range of products including consumer, telecommunications and office based systems. As an area array device of solder joints, it provides high packing density with a relatively easy introduction cycle. However, over the last couple of years engineers have started to experiment, and in some cases implement, stacked packages, of the type often called Package on Package, or POP. In simple terms, POP devices are the stacking of components, one on top of the other, either during the original component manufacture or during printed board assembly.
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