Technical Library | 2019-05-21 17:34:08.0
Flip chip components have been gaining popularity in the electronics industry since their introduction in the 1960s. Advances in attach methods and adhesives, as well as the drive for smaller and faster electronic devices made the technology take off. The basic premise of the flip chip is that the chip (semiconductor device) is mounted flipped from the traditional position. The traditional method of mounting a die is to mount it on a lead frame with the circuit and bond pads face up. The bond pads then receive a bond wire which then connects to the proper lead on the lead frame. Flip chips are mounted face down onto a substrate using small bumps on the bond pads to make direct electrical connection to their respective pads on the substrate. Stay tuned for more information on attachment techniques next month. This article will focus on how to rework flip chips.
Technical Library | 2015-08-27 15:32:16.0
Ever since there has been a widespread usage of surface mount parts, the trend of continued shrinkage of devices with ever finer pitches has continued to challenge PCB assemblers for the rework of same. Todays' pitches are commonly 0.5 to 0.4mm with packages of tiny outline sizes, 5 -10mm square, making the rework of such devices a challenge. In addition to the handling and inspection challenges comes the board density. Spacing to neighboring components continues to be compressed so the rework techniques should not damage neighboring components.
Technical Library | 2010-03-18 14:02:03.0
Selecting products that have been qualified by industry standards for use in printed circuit board assembly processes is an accepted best practice. That products which have been qualified, when used in combinations not specifically qualified, may have resultant properties detrimental to assembly function though, is often not adequately understood. Printed circuit boards, solder masks, soldering materials (flux, paste, cored wire, rework flux, paste flux, etc.), adhesives, and inks, when qualified per industry standards, are qualified using very specific test methods which may not adequately mimic the assembly process ultimately used.
Technical Library | 2016-01-08 11:56:03.0
Solder joint encapsulant adhesives have been successfully used to enhance the strength of solder joints and improve thermal cycling as well as drop performance in finished products. The use of solder joint encapsulant adhesives can eliminate the need for underfill materials and the underfill process altogether, thus simplifying rework, which results in a lower cost of ownership.Solder joint encapsulant adhesives include: low temperature and high temperature solder joint encapsulant adhesives, and their derivatives. Each solder joint encapsulant adhesive has: unfilled and filled solder joint encapsulant adhesives, and solder joint encapsulant paste. Each solder joint encapsulant product has been designed for different applications. In this paper, we are going to discuss the details and future of solder joint encapsulant adhesives.
Technical Library | 2014-05-12 09:24:11.0
With the advancement of the electronic industry, Package on package (POP) has become increasingly popular IC package for electronic devices, particularly in mobile devices due to its benefits of miniaturization, design flexibility and cost efficiency. However, there are some issues that have been reported such as SIR drop due to small gap between top and bottom components, difficulty underfilling and rework due to stacked IC components and process yield issues. Some suppliers have reported using some methods such as dipping epoxy paste or epoxy flux to address these issues, but so far, no customer has reported using these methods or materials in their mass production. In order to address these issues for POP assembly, YINCAE has successfully developed a first individual solder joint encapsulant adhesive.
Technical Library | 2014-06-02 11:03:45.0
With the advancement of the electronic industry, package on package (POP) has become increasingly popular IC package for electronic devices, particularly POP TMV (Through Mold Vials) in mobile devices due to its benefits of miniaturization, design flexibility and cost efficiency. However, there are some issues that have been reported such as SIR drop due to small gap between top and bottom components, difficulty underfilling and rework due to stacked IC components and process yield issues. Some suppliers have reported using some methods such as dipping epoxy paste or epoxy flux to address these issues, but so far no customer has reported using these methods or materials in their mass production. In order to address these issues for POP TMV assembly, YINCAE has successfully developed and commercialized the first individual solder joint encapsulant adhesive for mass production for years.
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.
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