The proliferation of electronic systems that process information is a driving force behind the soaring growth of the electronics industry. These computing systems constantly require new technological innovations to keep up with the demand for faster computing and larger storage.
The situation is particularly acute for the IC manufacturer. It’s a constant struggle for them to produce highly complex devices and yet contend with skyrocketing production costs as well as shorter product life cycles, said Adam Rhoads, vice president of product marketing for Optical Specialties. Strategies must be developed in all areas of IC manufacturing, including inspection, to solve these technological and economic issues.
The more dense and complex devices also have defects that are more difficult to locate. Inspection product manufacturers have, in turn, responded with improvements in defect detection and review technologies to find these imperfections.
For example, to inspect circuitry with five traces, some companies such as Automated Optical Inspection, use charged-couple devices (CCDs) with 10-micron rather than 13-micron detectors. This new detector size helps you inspect features as small as 4 mils.
IC manufacturers also are relying on confocal optics and Fourier optics to detect and review defects with higher sensitivity and better repeatability, said Mr. Rhoads. These optics are prompting equipment suppliers to use ultraviolet and scanning electron microscope technologies.
Cleaner manufacturing equipment and processes are other requirements affecting the inspection industry, said Tom Sherby, CEO of Knights Technology. Wafer manufacturers need more than defect data information. They require tools such as spatial pattern recognition software that not only summarize defect data but also identify defect patterns automatically from wafer maps.
The electrical characteristics of wafers are also becoming more important to IC inspection, said Mr. Sherby. But the data from parametric and electrical tests must be analyzed and correlated with the process and final test information to help improve yield and device performance. Integration of information from design through process to final test will be necessary to improve the operation for the newest submicron devices.
Recent cooperation among many companies supplying tools to IC manufacturers is producing an integrated approach to data management, continued Mr. Sherby. Together, with IC manufacturers, a yield management team can effectively define data integration requirements across the whole fab. Solutions will encompass software, hardware, applications and consulting services.
PCB Inspection System Offers
The AOI-2500 Series of automated PCB inspection systems transports boards through the inspection cycles, detects artwork and board defects and provides process-control data. It views PCBs with a minimum line width of 2 mils and detects flaws as small as 0.0004″. The 2500ST checks 18″ ´ 24″ panels in 3 s or 9,700 panels per shift, and the 2500S performs inspection at a rate of 600 panels per shift. The systems can be used in-line to inspect both sides of PCBs. AOI International, (508) 937-5400.
Video System Has Measurement
Statistics for Display
The VIA-170® Video Image Marker-Measurement System has measurement statistics available for display including count, mean, standard deviation, range and high/low values. A security feature allows a password holder to lock graphic markers in place and to protect system calibrations from being changed. The equipment is installed between a video camera and a video monitor. Features include the capability to measure X and Y dimensions, point-to-point measurements, angles, circumference and area. Boeckeler Instruments, (800) 552-2262.
Vision Processor Inspects
Ball Grid Arrays
The BGA Inspection Package is a PCI-bus plug-in vision processor with accompanying software for the inspection of BGAs. It inspects BGAs for missing, misplaced or improperly formed solder balls at a rate up to 4,000/s. A Windows™-based software package to help users describe the proper ball pattern is included. The system also performs calibration to convert training and measurement parameters from pixels to physical units and to correct for camera skew, optical distortion and scaling. Cognex, (508) 650-3000.
2-D Profiler Provides
The CyberScan® Cobra is a portable 2-D profiler that provides noncontact inspection of fragile or pliable parts including solder paste, BGAs, epoxy dots and flex circuits. The sensor is mounted on a Y-directional traveling arm which moves over the stationary object. Cobra can be connected on-line to provide dimensional information for process control. The profiler collects data on height, length, slope, area and surface roughness with resolutions of 0.4 microns. CyberOptics, (800) 746-6315.
Color Frame Grabber
Has Digital I/O On-Board
The DT3153 Color Frame Grabber generates horizontal and vertical drive signals to allow genlocking of multiple cameras. The board is designed for the PCI bus and handles composite and S-video signals. It improves degraded VCR-captured images by ignoring extra sync pulses and inserting them where missing. The frame-grabber board transfers images in real time to system memory without intervention from the CPU. It uses the PC system memory and video card for image storage and display, respectively. Data Translation, (800) 525-8528.
Reverse Geometry Probe
Finds PCB Flaws
The Reverse Geometry X-Ray Miniprobe (RGM) is a transportable imaging system that measures features as small as 20 m m. It operates at 160 kV, enabling it to see through a variety of materials. Data from the probe is fed to a computer which produces a video image. Two miniprobes generate a 3-D image and an array of probes produce laminographic views. Digiray, (510) 838-1510.
Inspection Stations Provide
In-Line Process Monitoring
The DualBeam 820i and 825i FIB/SEM Workstations are clean-room compatible and provide in-line process monitoring and defect characterization. The systems also have characterization capabilities in the Z direction to help identify the source and the sequence of a defect. The 825i features cassette-to-cassette wafer loading; the 820i uses manual wafer loading. The FIB sample stage is automatically moved to defects on the inspection-tool wafer maps through an integrated interface. Additional features include auto-wafer sensing, noncontact pre-alignment and 200-mm wafer coverage. FEI, (503) 640-7500.
Infrared Camera Provides
4,096 Levels of Resolution
The Prism DS Infrared Camera has 78,080 detector elements in its focal plane array and captures images with 12-bit dynamic range for 4,096 levels of thermal resolution for each point in the image. It features configuration storage with preset values for camera settings such as emissivity, background temperature, isotherms and high- temperature operation. Images are stored digitally on removable PC cards. The company’s AnalyzIR™ software helps perform thermal analyses. FLIR Systems, (800) 322-3731.
Portable X-Ray System
The RTX Mini Real-Time X-Ray System fits on a desktop, is portable and inspects BGAs, multilayers or leaded components. It has a 16″ ´ 5″ footprint and weighs 59 lb. The system incorporates the company’s patented X-ray camera that reveals defects as small as 0.001″. Systems may be upgraded with image processors and customized to accept any board. Glenbrook Technologies, (201) 361-8866.
Emission Microscope System
Performs Backside Inspection
The Backside Emission Analysis Microscope System (BEAMS®) pinpoints the location of IC defects. It is a comprehensive package of sensors, illuminators, filters, software and sample preparation instruments. The system produces high-resolution reflected illuminated images of backside metallization to locate embedded failures. The hardware and software are integrated into the company’s emission microscope and linked to programmable probers. Hypervision, (510) 651-7768.
Helps Predict Yield Problems
The Spatial Pattern Recognition Module for the company’s YieldManager™ software helps you predict and prevent potential yield loss by using defect distribution characteristics to identify developing problems in the wafer-manufacturing process. It uses statistical and morphological techniques to correlate defect maps from inspection equipment. The module helps pinpoint the sources of known defects and to identify the spatial distribution patterns of equipment processes. When defect signatures are identified, you are alerted and directed to the problem-causing tool or process. Knights Technology, (408) 988-0600.
Records up to 600 Frames/s
The Model 1000 MotionCorder Analyzer is a digital, motion analysis system that records from 240 frames/s, to 600 frames/s, views, measures and stores information in a production environment. The system records from 215 to 1,950 frames in RAM. The maximum image resolution is 640 ´ 240 pixels at 256 gray-scale levels. The video- system trigger mode is programmable to start and stop at specific points in a production cycle or it can record continuously. The portable system has a detachable camera head measuring 1.4″ ´ 1.4″ ´ 3″, and connects to the main unit with a 6’ flexible cable. Eastman Kodak, (619) 481-8182.
Solder-Paste Inspection System
Integrates 3-D Capabilities
The 1820/L Inspection System checks solder paste as well as components on PCBs. An integrated laser adds a 3-D inspection capability to the existing system. The system features a statistical process control package and a user-defined procedure for a variety of inspection needs, including 100% checking of all components in 3-D. Machine Vision Products, (800) 260-4MVP.
Mini Mirrors Help Inspect
Solder Under Pin-Grid Arrays
The Mini Mirror is a hand-held mirror that helps you see the solder joints on surface- mount devices with J leads and pin-grid arrays. The mirrors have diameters of £ 0.25″, are available in any shape mounted on a flexible wire shaft, and offer a variety of handles including an adjustable-length version. Mirrors vary from 0.006″ to 0.045″ in thickness. A diamond coating helps protect the mirror from scratching. Metron Optics, (619) 755-4477.
Thermal Imagers Are Sensitive
From -50° C to 2,000° C
The TH3100 Modular Thermo Tracer Systems are portable thermal-imagers with electronic detector cooling techniques, 12-bit A/D conversion of user-suppressible temperature spans and 12-VDC operation. They are used for periodic or long-term process monitoring and PCB performance evaluation. The TH3102 is sensitive to temperatures from -50° C to +250° C, the TH3104 spans temperatures from 0° C to +300° C and the TH3114 from +200° C to +2,000° C. The units are sensitive to infrared energy in the spectral bands ranging from 13 microns to 3 microns. Mikron Instrument, (201) 405-0900.
Video Measuring System
Stage Moves at 100 mm/s
The VM-250 Measuring System has a working envelope of 10″ ´ 8″ and a steel stage that moves at 100 mm/s and uses the company’s 0.4 micron linear scale. The main stand is constructed of steel with Y-axis rails integrated into the base for added stability. The system consists of a measuring microscope with zoom optics, a stage, integral CCD camera, measuring software and a video monitor. The optical system has computer-controlled 10:1 zoom capability with parcentric and parfocal optics. The system provides video edge-detection capabilities and three-axis computerized numerical control. Nikon, (800) 52-NIKON, ext. P617.
Video Measurement System
Has 12″/s Transport Speed
The OPTEK V-Series of Video Inspection and Measurement Systems provides transport speeds to 12″/s, a 5-micron measurement accuracy and a throughput rate of one feature measured per second. The new V-3000 offers a 30″ ´ 26″ X-Y transport; the V-3400 has a 34″ ´ 26″ transport. The inspection systems use a multitasking computer with a hard drive and 17″ monitor. Automatic skew alignment, distance, radius, diameter, roundness, Cartesian and true-position tolerancing, and an angle measurement capability are provided. Operations Technology, (908) 362-6200.
Optical Monitor Detects
Planar and Trench Defects
The IQ-156 In-Line Array Defect Monitor provides in-line monitoring of bare wafers for planar and trench defects. The system uses a 5× magnification version of the company’s patented optical-pattern filtering technology, allowing it to perform array inspection and detect subsurface defects, residue and water spots. It inspects more than twenty-five 200-mm wafers/h and has ±4-m m defect-location accuracy. Optical Specialties, (510) 490-6400.
In-Tray Lead Scanner Provides
Dual Inspection Sites
The LS-3900 DB In-Tray Lead Scanning System has enhanced sensor electronics and more streamlined software than previous versions in the LS-3000 Series. It provides dual inspection sites to eliminate tray-to-tray handling time. Throughput of quad flat packs is up to 2,800 units/h. Options include automatic Z adjustment, solder- flake detection and mark inspection. RVSI, (516) 273-9700.
Scanning Electron Microscope
Automatically Measures Wafers
The MI-3080 CD Scanning Electron Microscope automatically measures and inspects critical dimensions of submicron features on semiconductor wafers. The patented Retarding Field Column provides 3-nm resolution at 800 V with greater than 3-nm repeatability. The resolution capabilities are coupled with six measuring algorithms. Throughput is 25 wafers/h. Topcon Technologies, (201) 261-5410.
Wafer Bump Inspection System
Accommodates 4″ to 8″ Wafers
The Model 890 Wafer Bump Inspection System provides automated inspection of 4″ to 8″ silicon wafers. It features a 4.5×-resolution 3-D scanning laser and acquires multiple images of device features for real-time statistical process control. The software allows you to monitor process measurement histograms, trend plotting of individual balls, and percent yield, pass, fail and rework. Measurements include ball height, missing ball, position, volume, coplanarity, regression plane and ball diameter. View Engineering, (313) 677-8439.
45° and 60° Viewing Angles
The Leica GZ6E Stereomicroscope has rotatable eyepieces that allow the viewing angle to be changed from 45° to 60° . The working distance ranges from 40 mm to 350 mm and the magnification extends from 2× to 160×. The microscope also provides a 6:1 zoom with pre-centered optical mounting, a 360° rotatable body and a variety of stands for 3-D viewing or polarized light applications. Leica, (800) 248-0123.
SPM Features High-Temperature
Imaging in Vacuum
The AutoProbe® VP2 is a scanning probe microscope designed for atomic-scale surface analysis in an ultra-high vacuum. It combines high-temperature imaging with 3-D probe positioning, spectroscopy functions and self-sensing atomic force microscope probes. The AutoProbe is available in a standard, extended Y-translation and high- temperature configurations. It provides atomic force microscopy images to 300° C and scanning tunneling images to 600° C. Applications include high-temperature analysis of surface absorbates, semiconductor compounds and atomistic studies of chemical interaction. Park Scientific Instruments, (800) SPM-1602.
X-Ray System Inspects
Solder Joints to 0.008″ Pitch
The Model 5400 X-Ray Inspection System for PCB assemblies verifies the integrity of solder joints with a pitch as small as 0.008″. It is part of the company’s 5DX Series and can inspect flip-chip components and assemblies in one pass of the system. The 5400 has an enhanced X-ray tube and beam and a new camera that captures more data than previous versions. It provides a throughput rate of 25 joints/s. The system detects defective solder joints on gullwings, J leads, resistors, capacitors, TABs and BGAs. Hewlett-Packard, (800) 452-4844.
Copyright 1997 Nelson Publishing Inc.