The Centre for NanoHealth at Swansea University has recently purchased an electrical wafer probe station from microelectronics assembly equipment specialist Inseto (www.inseto.co.uk), to assist them with their electrical probing of micro and nano devices for bio sensors.
Dr Owen Guy, Senior Lecturer explains why the University chose the Inseto prober. “We were on the search for a low cost probe station to assist in our research and development work here at the Centre for NanoHealth (CNH), where we are collaborating with local companies. We are involved in the probing of micro and nano devices in bio sensors that are typically used in disease markers such as glucose markers. The funds for the prober have been made available to the CNH’s new Nano & Micro Technologies for Healthcare project, through the European Regional Development Fund via the Welsh Government. The tendering process involves the submission of three quotes but it isn’t typically just cost that drives the purchase. We knew of Inseto as we had been in touch with them previously regarding some other equipment we had looked to purchase. We also know their Technical Support Team, led by Jim Rhodes, as they had provided us with some process and equipment training and therefore trusted them and knew they fully understood the Universities requirements and demands. Location was also a factor, we weren’t necessarily insisting that we had a UK supplier but we felt it was a distinct advantage and it has proved to be invaluable, as Inseto are available for service and support as and when we require, which has been a real bonus.
The delivery of the prober has also been very seamless as the whole process only took a few weeks to go through”. Dr Guy concludes, “We have been very impressed all round with the product, service and support we have received from Inseto and are already talking to them about future equipment purchases”.
The SemiProbe range of manual probe systems are ideally suited to Universities, Research & Development facilities, Laboratories and for facilities where low volume testing is required. The range includes the cost-effective LAB Assistant and modular Probe System For Life (PS4L). The low-cost LAB Assistant is available in either DC or HF configurations for 100, 150 or 200mm wafers- devices and includes all the options required to start testing, out-of-the-box, whereas the PS4L is available in 100 to 450mm versions, with an extensive range of options
For Chip-On-Board (COB) applications, some form of protection is necessary for the bare silicon Integrated Circuit (IC) and its wire bonds. Typically, COB consists predominantly of surface-mount components, which by their very nature do not require any extra protection against environmental stresses. However, the bare silicon, and the wire bonds that connect the IC to the tracks on the PCB, are fragile by nature, and some form of protection is required.
This is provided in the form of a hard black epoxy. For small ICs, a single process is sufficient to ensure this protection. The epoxy is dispensed onto the surface of the IC and flows in a controlled manner to form a dome over the IC and the wire bonds. Heat is then applied to cure the adhesive, forming a hard protective surface over the IC. However, larger ICs require a two-stage process: A high-viscosity epoxy is dispensed to form a wall, or Dam, around the area to be protected, and a chemically-compatible, lower-viscosity epoxy is then dispensed into the cavity to complete the protective covering. This process is known as Dam & Fill, and ideally the Dam and the Fill are cured simultaneously.
In addition to mechanical protection, these epoxies provide excellent resistance to aggressive chemicals such as motor oil & diesel, aqueous, UV & solvent-based printing inks, and also vibration and temperature extremes. Typical applications include automotive electronic sensors, bio-medical device protection, aerospace and military mixed technology programs. The adhesives are one-part, solvent-free epoxies, optimised for easy dispensing and fast, low-temperature curing. They provide maximum moisture protection, successfully meeting the requirements of JEDEC MSL 1, and have an operating temperature range of -60C to +180C.
Full details can be found our web site: http://www.inseto.co.uk/products/encapsulationadhesives.htm
Why Plasma Clean?
Plasma cleaning is primarily used in a diverse range of industries to modify materials surfaces prior to bonding (adhesion). Plasma cleaning can replace chemical treatment and etching processes (leaving no organic residue and requiring no subsequent solvent clean) and mechanical abrasion methodologies such as sand blasting. Surface modification uniformity is significantly improved with plasma cleaning with respect to other techniques; observed in the improved uniformity of adhesion results after cleaning.
Typical applications which routinely employ plasma cleaning include:
Surface modification of a wide range of materials for improved bonding
What is a Plasma?
The plasma state is generated when a gas is subjected to sufficient energy to brake down its molecular integrity and dissociate it into ions, electrons and other sub atomic species. During recombination, photons are released.
In a plasma cleaning system, the plasma is generated by a high energy discharge (from an RF source) between two (or three) electrodes. Positive ions are accelerated in one direction, while electrons (negative polarity) are accelerated in the opposite direction.
Ideally, the materials to be cleaned are positioned on a sample tray that is parallel to the electrode sets such that the plasma action is evenly distributed across the sample plane, ensuring uniformity and consistent cleaning results. This is an improvement over traditional “Barrel” cleaning systems as the generated plasma has an even distribution over each of the parallel electrodes within the processing chamber – while cylindrical samples are well suited to the traditional barrel electrode setup; planar samples, such as chips or substrates in the semiconductor industry will achieve improved levels of cleaning uniformity.
Appropriate gas(es) are selected accordingly to the specific contaminants to be removed, or the nature of the surface modification.
“Molecular Sandblasting” or surface ablation is achieved by bombarding the material surface with high energy plasma particles which dislodge molecules from the sample surface. The surface area of any given planar dimension is thus increased by the molecular peaks and troughs produced. Obviously to prevent any chemical reaction taking place, the gases employed for ablation alone must be inert such as Argon and Nitrogen.
A further mechanism by which surfaces can be modified occurs when the plasma generation chemically react with the surface of the sample being treated. Gases such as Oxygen and Carbon Tetraflouride provide a chemical plasma clean.
For the removal of organic contaminants, an oxygen plasma in commonly employed. Oxygen plasma will crack the organic (hydrocarbon) contaminant molecules generating H2O, CO2 and CO. An inert gas, such as Argon can then be employed to remove any latent oxide layers in a subsequent treatment.
ATV, the thermal transfer specialists have announced the release of a “Perfect Soldering”, tabletop model at the forthcoming Productronica exhibition. The perfect soldering systems, solder reflow ovens (SRO) with rapid thermal annealing and brazing capability are IR lamp heated multi-purpose “cold wall” process ovens. The SRO is ideal for R&D, process development as well for low to high volume production.
Applications include: Die attachment, IGBT/DBC, high vacuum encapsulation, MEMS package sealing, IR sensor/Crystal package sealing, wafer level packaging, thermo electric cooler/Peltier, low moisture package sealing, high power LED, laser bar, Getter activation, alloying, wafer bump/solder ball reflow, pin fin heat sink, backing, flip chip, 3 D-CSP, diffusion bonding, CPV, thermo compression bonding, pin fins, Hybrid assembly, MMIC die attachment, power modules, electric vehicle controls and power solar cells etc.
The system is ready to use, out-of-the-box, incorporating a formic acid capability and diaphram vacuum pump. The operating temperature range is 450 to 750°C with a heated area of 230 x 217mm.
More information can be found on our website: http://www.inseto.co.uk/products/atv-solderprocessing.htm
Inseto is pleased to announce the signing of an agreement to distribute Plasma Etch products in the UK, Ireland & Scandinavia.
Plasma Etch are leading manufacturers of plasma treatment, etching and cleaning systems, including entry level bench-top models through industrial to high-volume continuous feed production equipment, used in electronic, medical, industrial & research applications.
Inseto is an ISO accredited technical distributor, providing manufacturing equipment, assembly materials and related consumable products for advanced electronic research & production, in addition to adhesives for technology-led industries.
According to Tony Brown – Managing Director of Inseto, “Besides producing an excellent range of equipment, which compliments our existing product lines, Plasma Etch also share our customer support philosophy, ensuring that each customer is completely satisfied with our products and services”.
Further information on Plasma Etch Inc., is available on Inseto’s website www.inseto.co.uk.
SemiProbe, a global supplier of manual to fully automatic probing and testing solutions for microelectronics, MEMS, nanotechnology, chemistry, microfluidics, optoelectronics, photovoltaics and more have introduced a free-to-download Glossary of Probing Terms & Acronyms.
Click HERE to download your copy.