Technical Library | 2023-08-16 18:09:06.0
One of our customers involved with Electronics and Aerostructures requested a test to dispense Techspray Wondermask 2204 solder mask. The dispensing locations include large and small screw holes, single through-hole vias, and connector locations consisting of multiple through-hole vias. The process needed to run quickly and reliably.
Technical Library | 1999-05-06 15:36:33.0
The success of surface-mount technology has not meant the end of through-hole connectors. For reasons ranging from availability to user concerns over reliability, through-hole connectors remain widely used.
Technical Library | 2023-06-12 18:52:18.0
This paper will review stencil design requirements for printing solder paste around and in through-hole pads / openings. There is much interest in this procedure since full implementation allows the placement of both through-hole components as well as SMD's and the subsequent reflow of both simultaneously. This in turn eliminates the need to wave solder or hand solder through-hole components.
Technical Library | 2019-07-17 17:56:34.0
The increased demand for electronic devices in recent years has led to an extensive research in the field to meet the requirements of the industry. Electrolytic copper has been an important technology in the fabrication of PCBs and semiconductors. Aqueous sulfuric acid baths are explored for filling or building up with copper structures like blind micro vias (BMV), trenches, through holes (TH), and pillar bumps. As circuit miniaturization continues, developing a process that simultaneously fills vias and plates TH with various sizes and aspect ratios, while minimizing the surface copper thickness is critical. Filling BMV and plating TH at the same time, presents great difficulties for the PCB manufactures. The conventional copper plating processes that provide good via fill and leveling of the deposit tend to worsen the throwing power (TP) of the electroplating bath. TP is defined as the ratio of the deposit copper thickness in the center of the through hole to its thickness at the surface. In this paper an optimization of recently developed innovative, one step acid copper plating technology for filling vias with a minimal surface thickness and plating through holes is presented.
Technical Library | 2020-03-12 13:10:35.0
The electronics industry is further progressing in terms of smaller, faster, smarter and more efficient electronic devices. This continuous evolving environment caused the development on various electrolytic copper processes for different applications over the past several decades. (...) This paper describes the reasons for development and a roadmap of dimensions for copper filled through holes, microvias and other copper plated structures on PCBs.
Technical Library | 2020-03-01 23:06:45.0
For though hole soldering, no matter it's wave soldering or selective soldering, the process is same formed by fluxing,preheating,soldering. How these 3 process will change the soldering result? When you face the soldering defects, what could be the reasons caused these and how to debug them? With below information you may get some hints.
Technical Library | 2007-09-27 16:18:15.0
Considerable interest exists in the process known as the pinin- paste, or the Alternative Assembly and Reflow Technology (AART) process. The AART process allows for the simultaneous reflow of both odd-form and through hole devices as well as surface mount components. This process has several advantages over the typical mixed technology process sequence that includes wave soldering and/or hand soldering, often in addition to reflow soldering.
Technical Library | 2018-09-21 10:12:53.0
Moisture accumulates during storage and industry practice recommends specific levels of baking to avoid delamination. This paper will discuss the use of capacitance measurements to follow the absorption and desorption behaviour of moisture. The PCB design used in this work, focused on the issue of baking out moisture trapped between copper planes. The PCB was designed with different densities of plated through holes and drilled holes in external copper planes, with capacitance sensors located on the inner layers. For trapped volumes between copper planes, the distance between holes proved to be critical in affecting the desorption rate. For fully saturated PCBs, the desorption time at elevated temperatures was observed to be in the order of hundreds of hours. Finite difference diffusion modelling was carried out for moisture desorption behaviour for plated through holes and drilled holes in copper planes. A meshed copper plane was also modelled evaluating its effectiveness for assisting moisture removal and decreasing bake times. Results also showed, that in certain circumstances, regions of the PCB under copper planes initially increase in moisture during baking.
Technical Library | 2021-12-21 23:15:44.0
High Density Interconnect (HDI) technologies are being used widely in Asia and Europe in consumer electronics for portable wireless communication and computing, digital imaging, and chip packaging. Although North America lags behind in developing process capability for this technology, HDI will become a significant business segment for North America. For this to happen, the printed circuit board shops will have to become process capable in fabricating fine lines and spaces, and also be capable in forming and plating microvias.
Technical Library | 2007-06-06 15:25:30.0
Though today's microvias and high aspect plated through holes (PTH's) look nothing like the earliest through holes of 40 years ago, the PTH in its various forms remains the “weak link” and most critical element of printed wiring boards and laminate chip carriers (...) The paper outlines an approach to evaluating PTH reliability and quality that involves characterizing PTH life across a range of temperatures to reveal intricacies not seen by testing at a single delta-T, and certainly difficult to predict by modeling alone.
