Technical Library | 2023-01-17 17:27:13.0
Reflow profile has significant impact on solder joint performance because it influences wetting and microstructure of the solder joint. The degree of wetting, the microstructure (in particular the intermetallic layer), and the inherent strength of the solder all factor into the reliability of the solder joint. This paper presents experimental results on the effect of reflow profile on both 63%Sn 37%Pb (SnPb) and 96.5%Sn 3.0%Ag 0.5%Cu (SAC 305) solder joint shear force. Specifically, the effect of the reflow peak temperature and time above solder liquidus temperature are studied. Nine reflow profiles for SAC 305 and nine reflow profiles for SnPb have been developed with three levels of peak temperature (230 o C, 240 o C, and 250 o C for SAC 305; and 195 o C, 205 o C, and 215 o C for SnPb) and three levels of time above solder liquidus temperature (30 sec., 60 sec., and 90 sec.). The shear force data of four different sizes of chip resistors (1206, 0805, 0603, and 0402) are compared across the different profiles. The shear force of the resistors is measured at time 0 (right after assembly). The fracture surfaces have been studied using a scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS)
Technical Library | 2001-05-23 16:29:52.0
Management consultant R. Michael Donovan outlines the problems and opportunities of performance measurement as an "enabling force" for improving overall business performance...
Technical Library | 2013-05-30 17:33:26.0
This paper covers the following topics: The Measurement Application, Measurement Requirements, Measurement Problems, Measurement Results, Reference Samples, Conclusions
Technical Library | 1999-05-09 13:07:16.0
This paper will give the reader a general understanding of EOS and ESD phenomena. It specifically addresses hand soldering's role in EOS and ESD and how to protect against and test for potential problems. It discusses how Metcal Systems address EOS and ESD concerns and how they differ from conventional soldering systems.
Technical Library | 2013-01-05 22:21:01.0
More and more countries legislate to forbib lead usage in solder material. However, the lead-free solder wire has higher melting point and soldering temperature, increase soldering iron temperature may damage the PCB or components. How to solve this problem?
Technical Library | 2021-12-22 01:35:51.0
As a speed type air compressor, centrifugal compressor can generate air flow moving in radial direction. Centrifugal air compressors are used by a large number of companies today because of their high-pressure tightness. Therefore, common faults in the operation have become one of the most concerned issues for users. This article will discuss causes of centrifugal compressor failures and give corresponding maintenance measures. At the end, OKmarts has listed the problems and solutions in detail for your quick reference.
Technical Library | 2012-04-05 22:53:10.0
In this paper we show how hybrid control and modeling tech-niques can be put to work for solving a problem of industrial relevance in Surface Mount Technology (SMT) manufacturing. In particular, by closing the loop over the stencil printing process, we ob
Technical Library | 2022-04-27 01:34:43.0
SMD capacitors and resistors have small sizes and many models. Some manufacturers buy a lot of products and do not use them up in time. The problem of storage is always a headache. So how should chip capacitors and resistors be stored? There are also precautions when using chip capacitors. Please see the following information and hope it will help you.
Technical Library | 2019-05-06 23:04:05.0
The temperature and humidity test chamber simulate the temperature and humidity, so there are a lot of things customers shoud notice in the process of use, although there is detailed instruction when purchasing the equipment. But some users just know how the device works and start using it. This is very easy to cause problems in the use of the equipment, so Symor intends to describe the safety details during the use of temperature and humidity chamber. 1. Before the test, determine if the sample contains flammable and explosive substances to avoid combustion or explosion during the test. Of course, also make sure there is no flammable and explosive material around the test equipment, otherwise it may cause fire and other accidents. 2, Do not open the chamber door to operate during the experiment, or the gas in the studio may cause the operator to burn and so on. 3. At the end of the test or at the time of regular cleaning of the test chamber, power off the equipment to avoid electrocution accidents. Also, when cutting off the equipment power, pull the power cord to pull out the plug, otherwise it may lead to a rupture of the power cord and so on. You can contact manufacturers if there are some places you donnot understand, do not dismantle and repair the temperature and humidity test chamber without authorization, otherwise it may lead to more serious problems.
Technical Library | 2009-05-07 23:23:00.0
Thermal fatigue has been one of the most serious problems for solder joint reliability. Thermo-mechanical fatigue failure is considered to be closely related to micro-structural coarsening (grain/phase growth). Factors that influence the phase growth are studied and measurement methods are discussed, including the preparation of the eutectic solder sample for phase size measurement. Three categories of models used to predict grain growth in polycrystalline materials are presented. Finally, phase growth in solder during high temperature aging and temperature cycling and its use as a damage correlation factor are discussed.
