Technical Library | 2023-01-17 17:37:45.0
Various international market trends drive electronics manufacturers and their mate- rials and equipment suppliers to develop new assembly techniques to reduce the industry's environmental impact. Two pri- mary forces in this drive are the movements to lead-free assembly and ISO 14000 cer- tification. In response to these factors, reflow technology advances are enabling manufacturers to meet or anticipate the new environmental mandates.
Technical Library | 2023-01-17 17:22:28.0
The impact of voiding on the solder joint integrity of ball grid arrays (BGAs)/chip scale packages (CSPs) can be a topic of lengthy and energetic discussion. Detailed industry investigations have shown that voids have little effect on solder joint integrity unless they fall into specific location/geometry configurations. These investigations have focused on thermal cycle testing at 0°C-100°C, which is typically used to evaluate commercial electronic products. This paper documents an investigation to determine the impact of voids in BGA and CSP components using thermal cycle testing (-55°C to +125°C) in accordance with the IPC- 9701 specification for tin/lead solder alloys. This temperature range is more typical of military and other high performance product use environments. A proposed BGA void requirement revision for the IPC-JSTD-001 specification will be extracted from the results analysis.
Technical Library | 2019-06-19 11:06:46.0
Tin (Sn) metal displays the characteristic of growing “tin whiskers” from pure tin coatings (most actively on relatively thin, electrodeposited or immersion tin coatings), usually months or years from the initial deposition of the tin. Tin whiskers are electrically conductive, filamentary, single crystals of white (beta phase) tin. These filaments of single crystal tin are usually one to five microns in diameter, and a few microns up to several tens of millimeters long, that grow spontaneously from the tin coatings. Alloying additions of several percent (by weight) of lead (Pb) prevents these electrically conductive tin whiskers from growing. Pb alloyed into the Sn was discovered to prevent the occurrence of tin whiskers in electronic assemblies in the 1950s as the Bell Laboratories solution to the problem of tin whiskers. The alloying of the tin with lead has thus quietly averted incalculable losses from short circuits in electronic equipment for the last 60 years.
Technical Library | 2020-06-02 15:16:51.0
A commercial systems manufacturer working on a major defense program contacted the Helpline for urgent assistance with an issue of failed parts during reliability testing. They were attempting to incorporate commercial off-the-shelf (COTS) computer-related hardware into a battlefield system and were experiencing reliability issues. It was noted that the parts were labeled by the vendor as "compliant to military (or MIL) standards" but not clearly identified as tin-lead or lead-free. ACI Technologies has supported a number of customers with lead-free issues and we assisted the customer in developing a short term and long-term solution to their problem.
Technical Library | 2019-06-20 07:45:19.0
One of the two basic risks of employing the commercially accepted, Restriction of Hazardous Substances (RoHS) compliant, lead-free (Pb-free) electronics is the threat to the electronics reliability from the growth of tin whiskers. The other basic risk deals with Pb-free solder joint reliability.
Technical Library | 2020-07-01 19:45:04.0
A company approached ACI Technologies (ACI) for assistance with a new product that was about to undergo its initial proof-of-concept prototype build. This product was an item that was being furnished to the Department of Defense for a program designed to increase the technical capabilities of computer equipment issued to the war fighter. The requirements for this item specified the use of tin-lead solder during assembly of production units. One of the main responsibilities for ACI during this project was to assist the client in mitigating the risk introduced using commercial off-the-shelf materials that may be lead-free.
Technical Library | 2019-05-24 09:22:59.0
There is a smaller process window and a much narrower margin of error when creating and using lead-free reflow profiles for surface mount parts on printed circuit boards (PCBs). Solder balls, dewetting, tombstones, voids, and head-on-pillow problems will occur much more frequently because lead-free alloys behave differently than eutectic pastes. Problems are compounded due to the extra heat necessary for some lead-free pastes to reach their melting points.
Technical Library | 2020-05-08 18:22:31.0
A customer contacted the Helpline to perform analysis on a lead-free assembly which exhibited intermittent functionality. The lead-free assembly exhibiting intermittent functionality when pressure was applied to the ball grid array (BGA) packages. Industrial adaptation of a Restriction of Hazardous Substances (RoHS) compliant solder standard has created a new host of failure modes observed in lead-free assemblies. Pad cratering occurs when fractures propagate along the epoxy resin layer on the underside of the BGA connecting pads. While originating from process, design, and end use conditions, it is the combination of a rigid lead-free solder with inflexible printed circuit board (PCB) laminates that has advanced the prevalence of this condition. Pad cratering is simply the result of mechanical stress exceeding material limitations.
Technical Library | 2024-02-26 09:08:23.0
Precision Control in Electronic Assembly: Selective Wave Soldering Machine Discover the technical features of I.C.T's Selective Wave Soldering Machines, including precision flux application and innovative preheating systems. Learn how these machines redefine efficiency and reliability in electronic assembly. Introduction: Enhancing Precision Soldering: Technical Features of Selective Wave Soldering Machines by I.C.T Explore the innovative design and operation of I.C.T's Selective Wave Soldering Machines, featuring a seamless PCB handling system and modular design for enhanced assembly line flexibility. Experience precision control and efficiency with comprehensive PC controls, allowing easy adjustment of solder parameters like temperature and flux type. Automatic calibration and CCD mark positioning ensure consistent soldering quality. Detail Excellence: Enhancing Selective Wave Soldering Technology Flux System Mastery German high-frequency pulse injection valve ensures precise flux application. Optional flux nozzle jam detection simplifies maintenance. Pressure tank and precision pressure flow meter ensure consistent flux control. Preheat System Excellence Bottom IR preheating system ensures stability and efficiency. Maintenance is simplified with a tool-free mode and plug-in design. Soldering System Innovation Swedish "PRECIMETER" electromagnetic pump coil ensures stability. Stainless steel soldering pot prevents tin liquid leakage. N2 online heating system reduces solder dross. Transmission System Mastery Specially designed material profiles ensure operational stability. Thickened customized rails guarantee flawless operation. Control and Intelligence Keyence PLC+module high-end bus control system ensures stability. Industry 4.0 compliance allows guided programming and real-time data visualization. Market Promotion and Success Stories: Elevating Selective Wave Soldering Machine I.C.T's strategic market positioning has led to global success across diverse industries. Success stories from European clients highlight reliability and trust in the machine. Over 70 units sold across 20+ countries since 2022, establishing its industry-leading position. Conclusion Conclusion: I.C.T's Selective Wave Soldering Machine combines technical excellence with global market success, solidifying its leadership in precision soldering technology.
Technical Library | 2019-10-21 09:58:50.0
An ACI Technologies customer inquired regarding printed circuit board(PCB) failures that were becoming increasingly prevalent after the SMT (surface mount technology) manufacturing process. The failures were detected by electrical testing, but were undetermined as to the location and specific devices causing the failures. The failures were suspected to be caused predominately in the BGA (ball grid array) devices located on specific sites on this 16 layer construction. Information that was provided on the nature of the failures (i.e., opens or shorts) included high resistance shorts that were occurring in those specified areas. The surface finish was a eutectic HASL (hot air solder leveling) and the solder paste used was a water soluble Sn/Pb(tin/lead).
