Technical Library | 2023-01-17 18:07:31.0
To achieve higher levels of consistency in PCB output, process engineers are able to maintain tighter controls and reduce process-related defects by using closed-loop process controls. At every stage of assembly, from screen printing through placement to reflow, closed-loop systems help control the variable factors that can have adverse effects on the process.
Technical Library | 2010-01-13 12:34:10.0
Micro-sectioning (sometimes referred to as cross-sectioning)is a technique, used to characterize materials or to perform a failure mode analysis, for exposing an internal section of a PCB or package. Destructive in nature, cross-sectioning requires encapsulation of the specimen in order to provide support, stability, and protection. Failures that can be investigated through micro-sectional analysis include component defects, thermo-mechanical failures, processing failures related to solder reflow, opens or shorts, voiding and raw material evaluations.
Technical Library | 2019-04-07 22:47:46.0
How to protect your PCB from moisture related damage? J-STD-033 put forward stricter regulation on the MSD exposure environment,when the exposure time exceed the tolerated,the moisture will penetrate into electronics,Moreover, the newest RoHS regulation will rise soldering temperature,the sudden high temperature will lead to expansion and cracking on electronic components. In order to decrease the moisture defect on PCB for the manufacturers in China,Climatest Symor® begin to concentrated on electronic dry cabinet R&D since early 1990s,we specialize in handling temperature and humidity for 20 years,and we provide best solution for PCB storage.
Technical Library | 2017-09-07 13:56:11.0
As a surface finish for PCBs, Electroless Nickel/Electroless Palladium/Immersion Gold (ENEPIG) was selected over Electroless Nickel/Immersion Gold (ENIG) for CMOS image sensor applications with both surface mount technology (SMT) and gold ball bonding processes in mind based on the research available on-line. Challenges in the wire bonding process on ENEPIG with regards to bondability and other plating related issues are summarized.
Technical Library | 2016-11-09 19:22:54.0
Nordson MARCH found a solution for a manufacturer of PCBAs used in ruggedized environments. Read how plasma prior to conformal coating reduced defects and virtually eliminated coating-related failures.
Technical Library | 2023-01-06 16:09:03.0
The 4-14 IPC Standards Committee recently created a revision to the IPC4552 specification for Electroless Nickel/Immersion Gold (ENIG) finished Printed Circuit Boards (PCB). Revision A brings a more comprehensive evaluation of metal layer thicknesses measurement, composition and introduces, for the first time, a quality aspect for nickel corrosion which has been historically connected to a defect called black line nickel or black pad.
Technical Library | 2018-05-09 22:15:29.0
Creep corrosion on printed circuit boards (PCBs) is the corrosion of copper metallization and the spreading of the copper corrosion products across the PCB surfaces to the extent that they may electrically short circuit neighboring features on the PCB. The iNEMI technical subcommittee on creep corrosion has developed a flowers-of-sulfur (FOS) based test that is sufficiently well developed for consideration as an industry standard qualification test for creep corrosion. This paper will address the important question of how relative humidity affects creep corrosion. A creep corrosion tendency that is inversely proportional to relative humidity may allow data center administrators to eliminate creep corrosion simply by controlling the relative humidity in the data center,thus, avoiding the high cost of gas-phase filtration of gaseous contamination. The creep corrosion relative humidity dependence will be studied using a modified version of the iNEMI FOS test chamber. The design modification allows the achievement of relative humidity as low as 15% in the presence of the chlorine-releasing bleach aqueous solution. The paper will report on the dependence of creep corrosion on humidity in the 15 to 80% relative humidity range by testing ENIG (gold on electroless nickel), ImAg (immersion silver) and OSP (organic surface preservative) finished PCBs, soldered with organic acid flux.
Technical Library | 2019-05-17 01:50:39.0
Dry cabinet is especially designed with fully automatic humidity control to prevent moisture related defects. This cabinet is the optimal storage expert for SMT/BGA/PCB/IC electronic components.Our newly developed design greatly increases dehumidifying system which runs faster and more reliable compare to those traditional dry cabinets. it decreases the defective rate at production line.
Technical Library | 2013-12-27 10:39:21.0
The head-in-pillow defect has become a relatively common failure mode in the industry since the implementation of Pb-free technologies, generating much concern. A head-in-pillow defect is the incomplete wetting of the entire solder joint of a Ball-Grid Array (BGA), Chip-Scale Package (CSP), or even a Package-On-Package (PoP) and is characterized as a process anomaly, where the solder paste and BGA ball both reflow but do not coalesce. When looking at a cross-section, it actually looks like a head has pressed into a soft pillow. There are two main sources of head-in-pillow defects: poor wetting and PWB or package warpage. Poor wetting can result from a variety of sources, such as solder ball oxidation, an inappropriate thermal reflow profile or poor fluxing action. This paper addresses the three sources or contributing issues (supply, process & material) of the head-in-pillow defects. It will thoroughly review these three issues and how they relate to result in head-in pillow defects. In addition, a head-in-pillow elimination plan will be presented with real life examples will be to illustrate these head-in-pillow solutions.
Technical Library | 2016-07-07 15:37:18.0
How susceptible are the metals used in modern electronics manufacturing to corrosion by common beverages? This is a question of interest, especially to manufacturers, retailers and to a certain extent end customers. In this study the dissolution of aluminum, copper, gold, iron, lead, nickel, SAC305 solder, silver, tin and zinc was examined. Individual foils of these materials were fully immersed in one of sixteen chosen beverages and heated for 3 days at 40°C. The resulting solutions were analyzed using ICP-OES. The data were examined in light of the known pH, conductivity and ionic contents of the beverages, determined in previous work. Conclusions about the relative susceptibility to corrosion of the various metals and the corrosive power of the different beverages are made.
.gif)
