Technical Library | 2021-11-03 16:49:59.0
Ultrathin bare die chips were soldered using a novel soldering technology. Using homogeneous flash light generated by high-power xenon flash lamp the dummy components and the bare die NFC chips were successfully soldered to copper tracks on polyimide (PI) and polyethylene terephthalate (PET) flex foils by using industry standard Sn-Ag-Cu lead free alloys. Due to the selectivity of light absorption, a limited temperature increase was observed in the PET substrates while the chip and copper tracks were rapidly heated to a temperatures above the solder melting temperature. This allowed to successfully soldered components onto the delicate polyethylene foil substrates using lead-free alloys with liquidus temperatures above 200 °C. It was shown that by preheating components above the decomposition temperature of solder paste flux with a set of short low intensity pulses the processing window could be significantly extended compared to the process with direct illumination of chips with high intensity flash pulse. Furthermore, it was demonstrated that with localized tuning of pulse intensity components having different heat capacity could be simultaneously soldered using a single flash pulse.
Technical Library | 2017-02-23 17:23:16.0
Managing the environmental performance of products is an increasingly complicated challenge for manufacturers today. These companies face a complex tangle of requirements and mandates from regulators, consumers and customers to manage the toxicity, recycleability and overall environmental impact of their products. Not only have governments, business-to-business customers and consumers demonstrated a clear preference for better environmentally performing and "greener" brands, but investors are now pressuring manufacturers, as well. For example, the Dow Jones Sustainability Index identifies and tracks leading sustainability-driven companies around the world. This paper focuses on the challenges companies face and the best practices they can employ when collecting substance, material and compliance data from their suppliers and supply chain.
Technical Library | 2021-06-02 19:39:14.0
With an estimated value creation potential for manufacturers and suppliers of USD 3.7 trillion in 2025,1 high hopes are set on Industry 4.0 to bring the next industrial revolution to discrete manufacturing. Yet, only about 30 percent of companies are capturing value from Industry 4.0 solutions at scale today. Approaches are dominated by envisioning technology development going forward rather than identifying areas of largest impact and tracking it back to Industry 4.0 value drivers. Further governance and organizational anchoring are often unclear. Resulting hurdles related to a lack of clarity regarding business value, limited resources, and an overwhelming number of potential use cases leave the majority of companies stuck in "pilot purgatory."
Technical Library | 2008-04-15 14:43:08.0
The increasing demands for miniaturization and better functionality of electronic components and devices have a significant effect on the requirements facing the printed circuit board (PCB) industry. PCB manufactures are driving for producing high density interconnect (HDI) boards at significantly reduced cost and reduced implementation time. The interconnection complexity of the PCB is still growing and today calls for 50/50 μm or 25/25 μm technology are real. Existing technologies are unable to offer acceptable solution. Recently the Laser Direct Imaging (LDI) technology is considered as an answer for these challenges.
Unipress - Institute of High Pressure Physics of the Polish Academy of Sciences
Technical Library | 2017-12-21 11:24:05.0
The present work concerns on the use of sensors to monitor the structural health of wind turbine . Conventionally the inspection was made using non-contact sensing during the turbine’s inoperable period hence loss occurred. A real -time monitoring system via embedded wireless sensor is preferred but the sensor could only be implanted using non-contact printing method due to most turbine blade s’ curved surface. Conductive ink associate d with non-contact printing method via fluid dispensing system are proposed since conductive inks are proven stretchable and fluid dispensing system enables printing on various substrates and works well with any materials...
Technical Library | 2022-09-12 14:07:47.0
Unique component handling issues can arise when an assembly factory uses highly-moisture sensitive surface mount devices (SMDs). This work describes how the distribution of moisture within the molded plastic body of a SMD is an important variable for survivability. JEDEC/IPC [1] moisture level rated packages classified as Levels 4-5a are shown to require additional handling constraints beyond the typical out-of-bag exposure time tracking. Nitrogen or desiccated cabinet containment is shown as a safe and effective means for long-term storage provided the effects of prior out-of-bag exposure conditions are taken into account. Moisture diffusion analyses coupled with experimental verification studies show that time in storage is as important a variable as floor-life exposure for highly-moisture sensitive devices. Improvements in floor-life survivability can be obtained by a handling procedure that includes cyclic storage in low humidity containment. SMDs that have exceeded their floor-life limits are analyzed for proper baking schedules. Optimized baking schedules can be adopted depending on a knowledge of the exposure conditions and the moisture sensitivity level of the device.
Technical Library | 2019-03-15 16:26:50.0
While there have been quite dramatic and evident improvements in almost every facet of manufacturing over the last several decades owing to the advent and mass adoption of computer automation and networking, there is one aspect of production that remains stubbornly unaffected. Massive databases track everything from orders, to inventory, to personnel. CAD systems allow for interactive and dynamic 3D rendering and testing, digital troubleshooting, and simulation and analysis prior to mass production. Yet, with all of this computational power and all of this networking capability, one element of production has remained thoroughly and firmly planted in the past. Nearly all manufacturing or assembly procedures are created, deployed, and stored using methodologies derived from a set of assumptions that ceased to be relevant fifty years ago. This set of assumptions, referred to below as the “Paper Paradigm” has been, and continues as the dominant paradigm for manufacturing procedures to this day. It is time for a new paradigm, one that accounts for the vastly different technological landscape of this era, one that provides a simple, efficient interface, deep traceability, and dynamic response to rapidly changing economic forces.This paper seeks to present an alternative. Instead of enhancing and improving on systems that became irrelevant with the invention of a database, instead of propping up an outdated, outmoded and inefficient system with incremental improvements; rewrite the paradigm. Change the underlying assertions to more accurately reflect our current technological capability. Instead of relying on evolutionary improvements, it is time for a revolution in manufacturing instructions.
Technical Library | 2019-09-24 15:41:53.0
This paper focuses on three different coating material groups which were formulated to operate under high thermal stress and are applied at printed circuit board manufacturing level. While used for principally different applications, these coatings have in common that they can be key to a successful thermal management concept especially in e-mobility and lighting applications. The coatings consist of: Specialty (green transparent) liquid photoimageable solder masks (LPiSM) compatible with long-term thermal storage/stress in excess of 150°C. Combined with the appropriate high-temperature base material, and along with a suitable copper pre-treatment, these solder resists are capable of fulfilling higher thermal demands. In this context, long-term storage tests as well as temperature cycling tests were conducted. Moreover, the effect of various Cu pre-treatment methods on the adhesion of the solder masks was examined following 150, 175 and 200°C ageing processes. For this purpose, test panels were conditioned for 2000 hours at the respective temperatures and were submitted to a cross-cut test every 500 h. Within this test set-up, it was found that a multi-level chemical pre-treatment gives significantly better adhesion results, in particular at 175°C and 200°C, compared with a pre-treatment by brush or pumice brush. Also, breakdown voltage as well as tracking resistance were investigated. For an application in LED technology, the light reflectivity and white colour stability of the printed circuit board are of major importance, especially when high-power LEDs are used which can generate larger amounts of heat. For this reason, a very high coverage power and an intense white colour with high reflectivity values are essential for white solder masks. These "ultra-white" and largely non-yellowing LPiSM need to be able to withstand specific thermal loads, especially in combination with high-power LED lighting applications. The topic of thermal performance of coatings for electronics will also be discussed in view of printed heatsink paste (HSP) and thermal interface paste (TIP) coatings which are used for a growing number of applications. They are processed at the printed circuit board manufacturing level for thermal-coupling and heat-spreading purposes in various thermal management-sensitive fields, especially in the automotive and LED lighting industries. Besides giving an overview of the principle functionality, it will be discussed what makes these ceramic-filled epoxy- or silicone-based materials special compared to using "thermal greases" and "thermal pads" for heat dissipation purposes.
