Technical Library | 2019-09-17 02:37:31.0
1.PET carrier tape. It has outstanding mechanical function, and the impact strength is 3~5 times that of other films, and the folding resistance is good.
Technical Library | 2009-11-05 11:17:32.0
Head-in-pillow (HiP), also known as ball-and-socket, is a solder joint defect where the solder paste deposit wets the pad, but does not fully wet the ball. This results in a solder joint with enough of a connection to have electrical integrity, but lacking sufficient mechanical strength. Due to the lack of solder joint strength, these components may fail with very little mechanical or thermal stress. This potentially costly defect is not usually detected in functional testing, and only shows up as a failure in the field after the assembly has been exposed to some physical or thermal stress.
Technical Library | 2016-01-12 11:01:25.0
More and more Land Grid Array (LGA) components are being used in electronic devices such as smartphones, tablets and computers. In order to enhance LGA mechanical strength and reliability, capillary flow underfill is used to improve reliability. However, due to the small gap, it is difficult for capillary underfill to flow into the LGA at SMT level. Due to cost considerations, there are usually no pre-heating underfill or cleaning flux residue processes at the SMT assembly line. YINCAE solder joint encapsulant SMT256 has been successfully used with solder paste for LGA assembly. Solder joint encapsulant is used in in-line LGA soldering process with enhanced reliability. It eliminates the underfilling process and provides excellent reworkability. The shear st rength of solder joint is stronger than that of underfilled components. The thermal cycling performance using solder joint encapsulant is much better than that using underfill. Bottom IC of POP has been studied for further understanding of LGA assembly process parameters. All details such as assembly process, drop test and thermal cycling test will be discussed in this paper.
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.
Technical Library | 2019-10-29 02:55:33.0
For every 10 ℃ increase in temperature, the reaction rate is twice to three times. This means that for every 10 ℃ increase in temperature, the life span of the product will be halved, and when the temperature rises by 20 ℃, the life span of the product will be reduced to 1/4. High temperature will lead to aging, oxidation, evaporation, physical deformation and so on. Low temperature will lead to embrittlement, ice formation, viscosity and solidification degree, loss of mechanical strength, physical shrinkage and so on. When the product is shipped, stored and operated in the environment, it will be endangered. In addition, each product has regulatory and certification requirements, and it is important to evaluate reliability and durability before it is put on the market. In general, according to the IEC60068 test standard, it requires the volume of the laboratory to be at least five times the total volume of the sample under test. Haida constant temperature and humidity box can help you meet this demand. So with the fast developmement of manufacturing industry,test becomes a necessity to see wether the product is able to meet regulated standards in R&D satge,Climatest Symor specializes in handling temperature and humidity,we supply environmental test chamber to China State-owned Research Institutes and laboratories,and obtain excellent reputation from international cllients,our company put much efforts on chamber R&D ,striving to supply best-quality climate simulation equipment and after-sale service. For details,pls visit our official website www.climatechambers.com
Technical Library | 2016-01-07 19:13:23.0
The purpose of this study is to investigate the effect of plasma surface modification to improve adhesion strength between polytetrafluoroethylene (PTFE) and electroless copper plating. PTFE is widely used in many industries because of its unique electrical, thermal, and mechanical characteristics. However, because of its low surface energy, it is difficult to acquire enough adhesion strength between PTFE and other substances without surface modification. Plasma is well known as one of the surface modification techniques that improve adhesion strength.
Technical Library | 2016-01-12 11:05:28.0
The electronic industry is currently very interested in low temperature soldering processes such as using Sn/Bi alloy to improve process yield, eliminate the head-in-pillow effect, and enhance rework yield. However, Sn/Bi alloy is not strong enough to replace lead-free (SAC) and eutectic Sn/Pb alloys in most applications. In order to improve the strength of Sn/Bi solder joints, enhance mechanical performance, and improve reliability properties such as thermal cycling performance of soldered electronic devices, YINCAE has developed a low temperature solder joint encapsulant for Sn/Bi soldering applications. This low temperature solder joint encapsulant can be dipped, dispensed, or printed. After reflow with Sn/Bi solder paste or alloy, solder joint encapsulant encapsulates the solder joint. As a result, the strength of solder joints is enhanced by several times, and thermal cycling performance is significantly improved. All details will be discussed in this paper.
Technical Library | 2020-10-14 14:49:14.0
In this study, the modification of an epoxy matrix with different amounts of cube-like and rod-like CaCO3 nanoparticles was investigated. The effects of variations in the morphology of CaCO3 on the mechanical properties and thermal stability of the CaCO3/epoxy composites were studied. The rod-like CaCO3/epoxy composites (EP-rod) showed a higher degradation temperature (4.5 _C) than neat epoxy. The results showed that the mechanical properties, such as the flexural strength, flexural modulus, and fracture toughness of the epoxy composites with CaCO3 were enhanced by the addition of cube-like and rod-like CaCO3 nanoparticles. Moreover, the mechanical properties of the composites were enhanced by increasing the amount of CaCO3 added but decreased when the filler content reached 2%. The fracture toughness Kic and fracture energy release rate Gic of cube-like and rod-like CaCO3/epoxy composites (0.85/0.74 MPa m1/2 and 318.7/229.5 J m
Technical Library | 2015-12-31 15:19:28.0
Today's consumer electronic product are characterized by miniatuization, portability and light weight with high performance, especially for 3G mobile products. In the future more fine pitch CSPs (0.4mm) component will be required. However, the product reliability has been a big challenge with the fine pitch CSP. Firstly, the fine pitch CSPs are with smaller solder balls of 0.25mm diameter or even smaller. The small solder ball and pad size do weaken the solder connection and the adhesion of the pad and substrate, thus the pad will peel off easily from the PCB substrate. In addition, miniature solder joint reduce the strength during mechanical vibration, thermal shock, fatigue failure, etc. Secondly, applying sufficient solder paste evenly on the small pad of the CSP is difficult because stencil opening is only 0.25mm or less. This issue can be solved using the high end type of stencil such as Electroforming which will increase the cost.
Technical Library | 2015-02-19 16:54:34.0
Pad cratering is an important failure mode besides crack of solder joint as it’ll pass the regular test but have impact on the long term reliability of the product. A new pin pull test method with solder ball attached and positioning the test board at an angle of 30º is employed to study the strength of pad cratering. This new method clearly reveals the failure mechanism. And a proper way to interpret the finite element analysis (FEA) result is discussed. Impact of pad dimension, width and angle of copper trace on the strength is included. Some findings not included in previous research could help to guide the design for better performance
