Technical Library | 2021-01-03 19:24:52.0
Reflow soldering is the primary method for interconnecting surface mount technology (SMT) applications. Successful implementation of this process depends on whether a low defect rate can be achieved. In general, defects often can be attributed to causes rooted in all three aspects, including materials, processes, and designs. Troubleshooting of reflow soldering requires identification and elimination of root causes. Where correcting these causes may be beyond the reach of manufacturers, further optimizing the other relevant factors becomes the next best option in order to minimize the defect rate.
Technical Library | 2019-06-07 14:49:54.0
ACI Technologies was contacted in regards to poor solder joint reliability. The customer submitted an assembly that was exhibiting intermittent opens at multiple locations on a ball grid array (BGA) component. The assembly’s functionality did not survive international shipping, essentially shock and vibration failures, immediately making the quality of the solder joints suspect. The customer was asked about the contract manufacturer and the reflow oven profile as well as the solder paste and surface finish used. The ACI engineering staff evaluated the contract manufacturer’s technique and determined that they were competent in the methods they used for placing thermocouples in the proper locations and developing the reflow oven profile. The surface finish was unusual, but not unheard of, in that it was hard gold over hard nickel, rather than electroless nickel immersion gold (ENIG). The customer was able to supply boundary scan testing data which showed a diagonal row of troublesome BGA pins.
Technical Library | 2019-08-14 08:27:46.0
There are five forms of carrier tape sealing cracking. In particular, it is more important to seal products such as IC components (IC tape carriers) and lighter and thinner LED components (LED tape carriers).
Technical Library | 2014-06-19 18:13:23.0
For high-density electronic packaging,the application of flip-chip solder joints has been well received in the microelectronics industry. High-lead(Pb) solders such as Sn5Pb95 are presently granted immunity from the RoHS requirements for their use in high-end flip-chip devices, especially in military applications. In flip-chip technology for consumer electronic products, organic substrates have replaced ceramic substrates due to the demand for less weight and low cost. However, the liquidus temperatures of high-Pb solders are over 300°C which would damage organic substrates during reflow because of the low glass transition temperature. To overcome this difficulty, the composite solder approach was developed...
Technical Library | 2019-04-11 05:59:57.0
Are your MSD safely stored? As humidity is found to be one of the key reasons for rejected products, many manufacturers are taking measures to control the humidity to increase their production efficiency and save the cost. In the industries of semi-conductor and electronics, the key section in which the rejected products are most probably to be made is that during the heating process of SMT, the IC(e.g.,PBGA,BGA,or TQFD) is likely to crack and thus cause non-effective welding because of the humidity. Climatest Symor® auto dry cabinet is the best solution to avoid the cracking and non#2;effective welding by dehumidifying the surface of your components. The dry unit can be used for 20 years without replacement,and controller is calibration free within 5 years.We attach dry cabinet application with different humidity range,welcome to download.
Technical Library | 2017-06-22 17:11:53.0
C-mode scanning acoustic microscopy (C-SAM) is a non-destructive inspection technique showing the internal features of a specimen by ultrasound. The C-SAM is the preferred method for finding “air gaps” such as delamination, cracks, voids, and porosity. This paper presents evaluations performed on various advanced packages/assemblies especially flip-chip die version of ball grid array/column grid array (BGA/CGA) using C-SAM equipment. For comparison, representative x-ray images of the assemblies were also gathered to show key defect detection features of the two non-destructive techniques.
Technical Library | 2015-12-23 16:57:27.0
The onset of copper barrel cracks is typically induced by the presence of manufacturing defects. In the absence of discernible manufacturing defects, the causes of copper barrel cracks in printed circuit board (PCB) plated through holes is not well understood. Accordingly, there is a need to determine what affects the onset of barrel cracks and then control those causes to mitigate their initiation.The objective of this research is to conduct a design of experiment (DOE) to determine if there is a relationship between PCB fabrication processes and the prevalence of fine barrel cracks. The test vehicle used will be a 16-layer epoxy-based PCB that has two different sized plated through holes as well as buried vias.
Technical Library | 2013-01-03 20:27:54.0
Electronics assemblies with large flip-chip BGA packages can be prone to either pad cratering or brittle intermetallic (IMC) failures under excessive PCB bending. Pad cratering cracks are not detected by electrical testing or non-destructive inspection methods, yet they pose a long term reliability risk since the cracks may propagate under subsequent loads to cause electrical failure. Since the initiation of pad cratering does not result in an instantaneous electrical signature, detecting the onset of this failure has been challenging. An acoustic emission methodology was recently developed by the authors to detect the onset of pad cratering. The instantaneous release of elastic energy associated with the initiation of an internal crack, i.e., Acoustic Emission (AE), can be monitored to accurately determine the onset of both pad cratering and brittle intermetallic (IMC) failures.
Technical Library | 2021-08-11 01:00:37.0
Conformal coatings and potting materials continue to create issues for the electronics industry. This webinar will dig deeper into the failure modes of these materials, specifically issues with Coefficient of Thermal Expansion (CTE), delamination, cracking, de-wetting, pinholes/bubbles and orange peel issues with conformal coatings and what mitigation techniques are available. Similarly, this webinar will look at the failure modes of potting materials, (e.g Glass Transition Temperature (Tg), PCB warpage, the effects of improper curing and potential methods for correcting these situations.
Technical Library | 2018-11-07 03:31:04.0
Generally speaking, there are not many cases of insufficient solder and solder short in BGA soldering, but it is not impossible. Here we discuss some elements may cause it
