Technical Library | 2019-05-06 23:13:09.0
Temperature and humidity test chamber has brought a lot of help to many industrial enterprises, but while it brings convenience to us, we should also take good care of them, otherwise they may be brought into the end-of-life phase ahead of time. The way of maintenance is also very simple. After daily use, the equipment is cleaned regularly, but the cleaning of the test chamber is also very skillful. If the operation is wrong, it may also lead to equipment failure. Let‘s learn how to extend the service life of the temperature and humidity test box together. 1, Pls clean the working room with water after each use, then dry the interior with dry cotton cloth. 2, Pls regularly remove dust from the evaporator inside the equipment, and periodically wipe the equipment to ensure clean and tidy. 3, When doing the test, the sample should be uniformly placed onto sample shelves,and the vent should not be blocked to prevent the influence of the test 4, It is necessary to pay attention to the cleaning of water tanks in peacetime, after the test or when the equipment is not intended to be used for a long time, all the water in the tank should be discharged, otherwise it will lead to the formation of scale inside the tank. The water used in the temperature and humidity test chamber must be pure or distilled water, or long-term use may result in a humidifier or internal pipe clogging. Above are the usual use notice of temperature and humidity test chamber, if customer adhere to the above several points,it is really able to prolong the service life of the equipment.
Technical Library | 2022-05-02 21:35:53.0
Testing of electronic assemblies involves three elements: the device under test, test equipment, and fixturing to make the connections between them. The challenge for a test engineer building a sophisticated test system is that instrumentation may need to measure thousands of test points through the mechanical interconnect.
Technical Library | 2015-08-20 15:18:38.0
Increasing system integration and component densities continue to significantly reduce the opportunity to access nets using standard test points. Over time the size of test points has been drastically reduced (as small as 0.5 mm in diameter) but current product design parameters have created space and access limitations that remove even the option for these test points. Many high speed signal lines have now been restricted to inner layers only. Where surface traces are still available for access, bead probe technology is an option that reduces test point space requirements as well as their effects on high speed nets and distributes mechanical loading away from BGA footprints enabling test access and reducing the risk of mechanical defects associated with the concentration of ICT spring forces under BGA devices. Building on Celestica's previous work characterizing contact resistance associated with Pr-free compatible surface finishes and process chemistry; this paper will describe experimentation to define a robust process window for the implementation of bead probe and similar bump technology that is compatible with standard Pb-free assembly processes. Test Vehicle assembly process, test methods and "Design of Experiments" will be described. Bead Probe formation and deformation under use will also be presented along with selected results.
Technical Library | 2013-04-04 15:28:39.0
This paper will outline and define what requirements must be adhered to for the OEM community to truly achieve the IPC class product from the Electrical Test standpoint. This will include the test point optimization matrix, Isolation (shorts) parameters and Continuity (opens) parameters. This paper will also address the IPC Class III/A additional requirements for Aerospace and Military Avionics. The disconnect exists between OEMs understanding the requirements of their specific IPC class design versus the signature that will be presented from their design. This results in many Class III builds failing at Electrical Test... First published in the 2012 IPC APEX EXPO technical conference proceedings
Technical Library | 2021-02-25 14:19:00.0
This study proposes a new design of lightweight and cost-e#14;cient composite materials for the aeronautic industry utilizing recycled fresh scrap rubber, epoxy resin, and graphene nanoplatelets (GnPs). After manufacturing the composites, their bending strength and fracture characteristics were investigated by three-point bending (3PB) tests. Halpin–Tsai homogenization adapted to composites containing GnPs was used to estimate the moduli of the composites, and satisfactory agreement with the 3PB test results was observed.
Technical Library | 2015-08-13 15:52:40.0
Pad cratering has become more prevalent with the switch to lead free solders and lead free compatible laminates. This mainly is due to the use of higher reflow temperature, stiffer Pb-free solder alloys, and the more brittle Pb-free compatible laminates. However, pad cratering is difficult to detect by monitoring electric resistance since pad cratering initiates before an electrical failure occurs. Several methods have been developed to evaluate laminate materials' resistance to pad cratering. Pad-solder level tests include ball shear, ball pull and pin pull. The detailed methods for ball shear, ball pull, and pin pull testing are documented in an industry standard IPC-9708. Bansal, et al. proposed to use acoustic emission (AE) sensors to detect pad cratering during four-point bend test. Currently there is an industry-working group working on test guidelines for acoustic emission measurement during mechanical testing.
Technical Library | 2020-01-02 12:16:02.0
A customer contacted the Helpline with the concern that parts being used in their assembly may possibly be counterfeit components. The counterfeiting of electronics components is a world-wide problem, and the threat today is even more evident than ever before. Any company, large or small, that manufactures assemblies using electronics components is equally susceptible to using counterfeit devices in their assemblies. In most cases, counterfeit components aren't discovered until after the component has already been placed on a printed circuit board (PCB), usually during first article electrical test. At this point, the only recourse is to debug the circuit to determine the faulty component and rework each PCB already in production to replace the faulty component. As one might easily surmise, this is a rather costly process; world-wide, counterfeit components account for over $15B loss in sales annually!
Technical Library | 2016-02-04 19:11:47.0
In a typical mechatronic manufacturing functional test setup, actual load simulations are usually done by connecting the DUT outputs to power or ground in order to establish either a high or low side driver. Each output is connected with different load and the test will either be sequential or concurrent. At lower power levels, these can usually be managed with general purpose switches. However, when it comes to higher power levels of currents more than 5 amps, such switching and loading might pose a greater challenge. Furthermore, critically in the manufacturing line, the tradeoff between cost and test time would have a great influence on the test strategy.This paper will present some key points to design a cost effective high power switching and load management solution.
Technical Library | 2019-11-12 02:09:22.0
Thermal shock test chamber can be used for testing the chemical change or physical damage on composite materials caused by the thermal expansion and contraction of the sample in the shortest time,which is subjected to extremely and continuous high and low temperature environment.so how to check the temperature recovery time of this chamber? Normally we take following steps to inspect the temepratuire recovering time: 1.Install the temperature sensor at the specified position, and adjust the temperature controller of hot zone and cold zone to the required nominal temperature respectively. 2.The temperature increases and reduces respectively,30min after temperature in two zones reach stable status,record temperature value of the measuring point,pls set the temperature value of two zones to be required nominal temperature. 3.The temperature shock test chamber automatically places the inspected load into theh ot zone,select the corresponding retention time according to regulated standard. 4.Set the transfer time,then the inspection load is transferred from hot zone to cold zone, and the temperature of the measuring point is observed and recorded, and then the reverse conversion of the load from cold zone to hot zone is carried out according to the same method, and the temperature of the measuring point is observed and recorded. www.climatechambers.com
Technical Library | 2013-01-24 19:16:35.0
The electronics industry has mainly adopted the higher melting point Sn3Ag0.5Cu solder alloys for lead-free reflow soldering applications. For applications where temperature sensitive components and boards are used this has created a need to develop low melting point lead-free alloy solder pastes. Tin-bismuth and tin-bismuth-silver containing alloys were used to address the temperature issue with development done on Sn58Bi, Sn57.6Bi0.4Ag, Sn57Bi1Ag lead-free solder alloy pastes. Investigations included paste printing studies, reflow and wetting analysis on different substrates and board surface finishes and head-in-pillow paste performance in addition to paste-in-hole reflow tests. Voiding was also investigated on tin-bismuth and tin-bismuth-silver versus Sn3Ag0.5Cu soldered QFN/MLF/BTC components. Mechanical bond strength testing was also done comparing Sn58Bi, Sn37Pb and Sn3Ag0.5Cu soldered components. The results of the work are reported.
