Blogs
MTI Application Note: How to Achieve <1um Accuracy When Measuring Roller Gap
How to Achieve <1um Accuracy When Measuring Roller Gap Roller Gap Measurement with MTI Digital Accumeasure Capacitive Probes Many roll-to-roll finishing processes typically use a calender, or series of hard pressure rollers, to deliver smooth, high-quality products of plastic, textile, or paper (Fig 1). Ensuring a consistent material thickness, however, depends on the ability to monitor, and maintain, a precise gap between rollers. This application note describes a quick and easy means for roller gap measurement. Problem How to measure the small gap between rollers to keep track of product thickness. Typically, it’s not possible to [...]
A Comprehensive Guide to Non-Contact Sensors and Their Applications
A Comprehensive Guide to Non-Contact Sensors and Their Applications Sensors, both contact and non-contact, are crucial devices that allow the monitoring, detection, and reaction to conditions in an environment or within a process or piece of equipment. While myriad types of sensors exist and are designed to monitor varying conditions, all of them can be characterized as being one of two types — contact sensors and non-contact sensors. We’ll focus on the latter, diving into different technologies, types, and applications of non-contact sensor technology; but first, let’s explore what differentiates contact and non-contact sensors. Contact vs. Non-Contact Sensors: What’s [...]
The Benefits of Manual, Semi-Automated, and Fully-Automated Systems for Semiconductor Wafer Inspection and Metrology
This is the third of three articles in Semiconductor Wafer Measurement for Increased Profitability. The first article in this series explains why disc geometry matters. The second article examines the cost of failing to inspect semiconductor wafers. Fully automated systems that can load, scan, and unload wafers are fast, convenient, and efficient at high volumes. They’re useful for checking every wafer in every batch, but these systems are expensive. Semi-automated and manual systems cost significantly less and are generally used for lower volumes; however, they’re also easy-to-use and can make fast, accurate measurements that support production flow. Semi-automated and [...]
Why Disc Geometry Matters In Wafer Production
This is the first of three articles in Semiconductor Wafer Measurement for Increased Profitability. The second article examines the cost of failing to inspect semiconductor wafers. The third article describes the benefits of using semi-automated, fully-automated, and manual systems for wafer metrology and inspection. Semiconductor wafers are cut from cylindrical silicon crystals, or ingots. The flatness of these disc-shaped wafers is controlled to tight tolerances to ensure that the entire wafer surface is suitable for integrated circuit (IC) production. If disc geometry is out-of-spec after cutting, it may be possible to reprocess the wafer. Cutting is only the first [...]
Why Demand for SiC Wafers is Hot and Durable
Why Demand for SiC Wafers is Hot and Durable Pardon the pun, but SiC wafers are a hot item for high-temperature applications. Silicone carbide (SiC), a semiconductor containing both silicon and carbide, withstands temperatures up to 2700°C. Carborundum, as this durable ceramic is also known, finds additional applications in bulletproof vests, extrusion dies, sandpaper, and high-performance disc brakes. In electronics, SiC materials are used with light-emitting diodes (LEDs) and detectors. In the semiconductor industry, a market where interest is red-hot, SiC wafers are used in electronic devices that operate at high temperatures, high voltages, or both. Examples include electric [...]
Wafer Stress Analysis Using the 300iSA
Wafer Stress Analysis Using MTI Instruments Proforma 300iSAWafer processing involves several stages that may translate into mechanical alterations. Sometimes these alterations can cause deformities that render the wafer either unusable or that put it marginally close to not being usable. To determine this, stress analysis can be used.The Proforma 300iSA wafer characterization tool provides a software capability in which a wafer can be analyzed prior to processing and then after processing. The tool then evaluates how the wafer changed and hence, provides the resulting stress analysis.The software expects the customer to provide the material elasticity constants and to define them [...]
Wafer Backgrinding and Semiconductor Thickness Measurements
Wafer backgrinding is the first step in semiconductor packaging, the process of encasing one or more discrete semiconductor devices or integrated circuits (IC) for protection. Known also as wafer thinning or wafer lapping, backgrinding reduces wafer thickness to allow stacking and high-density IC packaging. Wafer thickness also determines package height, an important consideration as smartphones, laptops, and other electronic devices become thinner. With MEMS, wafer thinning also controls the proof mass for devices such as accelerometers or the diaphragm thickness for pressure sensors. Etching the surface of the wafer produces the IC but grinding the backside is what produces [...]
Transducer Selection for High Resolution Applications
High resolution applications do not always require an interferometer. If you want to make accurate measurements in the micron to picometer range, then an MTI Digital Accumeasure D100 HD or D200 system may be what you need. Laser interferometers can sell for more than $15,000 and be difficult to setup. For example, you may have to buy additional optics to guarantee a good return signal since the laser beam must reflect off a mirror surface or precision retro reflector in order for the beam to re-enter the interferometer’s optics at less than a degree of reflection angle. The downsides [...]