Inspection Industry Accepts Challenges to Increase Yield

The electronic inspection industry is in an age of ever-increasing density and complexity of devices, where semiconductor manufacturers need to probe closer than ever before and make nondestructive measurements down to the nanometer level. Scanning probe microscopes are meeting this need by providing the capabilities to measure below the wavelength of visible light (about 400 nm).

The increased complexity of devices also increases the time it takes to develop inspection test routines. These lengthy test-development times are a major impediment to automated inspection lines, especially if the routine is tweaked often. Some inspection-equipment manufacturers offset this problem by providing special tools to shorten the test-development time. For example, Hewlett-Packard offers a module to convert CAD data into its 5DX X-ray system test files.

Inspection systems generate a significant amount of data, and converting raw data into useful information for real-time, yield-related decision-making can be very time- consuming. To handle the enormous amount of data efficiently, it’s best to automate the tasks.

Automated inspection also helps manufacturing companies catch defects immediately so they can use the data to identify process problems and prioritize efforts to improve yield. One method to improve yield is to use software tools such as YieldManager from Knights Technology. YieldManager brings together data from design inspection, electrical test, failure analysis and factory information systems to make yield-related decisions.

Improving productivity through an increase in manufacturing yield requires controlling the process, a responsibility placed squarely on the shoulders of the inspection industry. By focusing on controlling the process, defects are reduced and manufacturing productivity improves.

Reducing the cost of inspection is another significant challenge. Savings can occur by increasing throughput and inspection capability and connecting other process steps with inspection. For instance, a significant cost-savings occurs by combining steps such as lead conditioning or tape-and-reel operations with inspection.

Today’s more powerful PC-based inspection systems also can reduce costs. PC-based computers with a PCI bus, a Pentium™ or PowerPC™ processor and a 32-bit operating system are less expensive than dedicated controllers yet provide similar performance capabilities. The PC also provides a wide selection of optional hardware and software not readily available on other platforms.

Whatever platform you choose, you need one that meets the increasing demand for quality and the stiff competition caused by a global market. To help you find the right system for your application, EE presents a showcase of the best inspection equipment on the market today.

Inspection Products

OCR Module

Recognizes 6,000 cpm

Powervision™ OCR is a neural network-based optical character-recognition module for the company’s machine vision system. It performs character recognition on an image captured by a CCD camera and identifies up to 45 characters or symbols at one time at 6,000 characters per minute (cpm). Noncontiguous or segmented characters are read at 3,000 cpm. System software Version 8.3 enables processing of 600 ppm and supports 256 levels of gray-scale images. The operator interface supports two levels of password protection. Acuity Imaging, (603) 598-8400.

Microscope Module Provides

Confocal Imaging

The Confocal Scan Module (CSM) is an attachment for the company’s Axiotron 2 microscope. The confocal imaging mode is selected from the microscope keypad. A 100-W mercury bulb provides illumination. Light intensity is controlled by a variable power supply. Brightfield and differential interference contrast scan modes are offered. An autofocus system is integrated into the module and operates in the confocal mode. Three camera ports are provided on the CSM. Carl Zeiss, (800) 233-2343.

Inspection System Performs

Noncontact Profiling

The CyberScan™ LV is a laser-based, noncontact workstation for inspecting solder paste, pin connectors, IC leads, thick-film resistors, BGA devices and ceramic substrates. Features include a menu and an icon-based graphical interface, a monochrome camera for capturing the magnified image of the laser beam location, a color camera for taking snapshots, and software that converts data into a 3-D profile. The workstation has a laser sensor, servo-controlled three-axes stages with linear encoders, and a Pentium-based PC with all required software. CyberOptics, (800) 746- 6315

Frame Grabber Supports

RS-170 or CCIR Video Inputs

The DT3152 Variable-Scan Frame Grabber provides a scanning capability from 0 to 20 MHz. The software-programmable input timing and spatial resolution help support a wide variety of video inputs, including RS-170 and CCIR devices as well as progressive-scan and line-scan cameras. The frame grabber can transfer an unlimited number of consecutive frames across the PCI bus and store consecutive images up to the amount of available system RAM. The digital clock has ± 4-ns jitter to allow operation with asynchronous input devices. It supports four monochrome inputs and is Windows® 95 plug-and-play compatible. Data Translation, (800) 525-8528

FIB Integrates Defect Review

And Failure Analysis

The DualBeam™ 820 Focused Ion Beam/Scanning Electron Microscope (FIB/SEM) Workstation integrates defect review, failure analysis and device modification capabilities of a FIB with the imaging of a field-emission SEM. The FIB capabilities are optimized for 3-D defect review and characterization, providing the information needed to detect the cause of a problem. Computer-aided design information is overlaid on FIB or SEM images to help navigate to buried features. The system eliminates transfer time between FIB and SEM systems and combines complimentary imaging information. FEI, (503) 640-7500.

New Model Added to

Cross-Sectional Imaging Series

The 5DX Model 5000 is an automatic cross-sectional X-ray inspection system that detects solder joint defects on 20-mil pitch components and on hidden solder joints of BGA packages. It can be upgraded to perform inspection on very-fine-pitch technology. Four Pi/Hewlett-Packard, (970) 679-5700.

System Does X-Ray and Vision

Inspection Simultaneously

Dual-VU™ is an inspection system that simultaneously performs X-ray and vision examinations of BGAs, dies and other components on assembled PCBs. The system presents a 15X magnified view of the surface on one monitor and an X-ray of the same area on a second monitor. It incorporates a mirror that permits the X-ray and vision images to correspond exactly. The system reveals defects as small as 0.001″. Glenbrook Technologies, (201) 361-8866.

Software Links Inspection and

Failure Analysis Tools

Defect Wafer Map™ software provides a link between semiconductor inspection defect data and the characterization equipment. Engineers can correlate defect-coordinate data from inspection equipment and the IC design data base by combining the company’s Defect Wafer Map and CAD Navigation software. Users can view defect locations relative to the physical layout, net list and schematic of the chip. The software sorts and filters defect data by size, class, die and wafer layer. Knights Technology, (408) 988-0600.

Monoscope Offers 3-D Effect

With 8″ Working Distance

The Super 3-D Monoscope provides a resolution of 1.2 line pairs/mm at 5X magnification and a depth of field of 15 mm at an 8″ working distance. The working distance allows room for soldering and assembly. Metron Optics, (619) 755-4477.

X-Ray System Stores

50 Motion Programs

The NXR 1400P X-Ray Inspection System offers X-Y table control for up to 50 motion programs. Table locations and dwell times are entered from the front panel. A single program can have up to 300 views. The system operates in the manual or the programmed mode. A choice of X-ray sources and detectors is available. The platform movement area is 16″ x 24″. Nicolet Imaging Systems, (619) 635-8600.

Confocal Microscope Provides

Sub-Half-Micron Resolution

The Optiphot 200C is a confocal microscope system that enables high-contrast, high-resolution imaging of 3-D specimens in real time. The microscope offers sub-half-micron resolution using the company’s chromatic-aberration-free optics. A built-in aperture slider with various diameter pinholes helps adjust the lighting, which is provided by a mercury or halogen illuminator. The microscope handles wafers up to 8″. Nikon, (516) 547-8531.

Zoom Attachment Has

Right-Angle Design

The MS-507 Right-Angle Zoom Tube has a 6:1 zoom ratio, a zoom range from 0.75X to 4.5X and a working distance of 90 mm. Conversion objectives range from 0.25X to 3X. Relay lenses from 1.5X to 4X adjust magnification, field of view and working distance. Optro-Mechanics (USA), (800) 890-3333.

Option Combines Conditioning

And Lead Inspection

The AT4165 programmable option for the company’s AT4070 and AT4060 lead inspection systems inspects, conditions and reinspects components at one station. It moves in the X, Y and Z axes and corrects the coplanarity of gullwing leads. The programmability of the inspection system option eliminates the need for dedicated tooling. Texas Instruments, (214) 917-4030.

Closed-Loop Scanner Aids

Measurements of SPMs

TrueMetrix™, a closed-loop scan linearizer, aids scanning probe microscopes to perform 3-D measurements. Movement is based on an inherently linear sensor which improves scan linearity and reduces hysteresis in the X, Y and Z axes. The scanner enables nanoscale measurements. TopoMetrix, (408) 982-9700.

Inspection Station Has

0.6X to 3.3X Zoom Objective

The MZV-1 Macrozoom Video Inspection Station consists of a zoom objective ranging from 0.6X to 3.3X, a stand, a rack-and-pinion focusing arm, a photomonocular body and a TV-C mount adapter. A 10X widefield eyepiece is provided for macroscope viewing. A color CCTV camera and a black-and-white CCTV unit accompany the system. Options include a mechanical stage, a spotlight, and a fiber-optic and a ring illuminator. Unitron, (516) 589-6666.

System Measures Device

Coplanarity, Bump Position

The Model 890 Bump/Die Measurement System performs 3-D measurements for inspecting features on semiconductor wafers, dies, flip chips and BGA devices. It performs device coplanarity, bump position and bump absence/presence measurements. The system includes a 4X-resolution laser and obtains more than 1 million data-points-per-second. An on-line statistical process control capability generates data in graphs and histogram plots. View Engineering, (313) 665-1140.

Laser-Based Lead Scanner

Targets High-Pin Count Devices

The LS-3700 DB Lead Scanner is a laser-based, dual-bed in-tray inspection system. The two-tray assembly holds one tray for scanning while the other is loaded with devices. It enables BGA and QFP inspection on the same system. It features a coplanarity accuracy of 0.0002″, a lead angle accuracy of 1.0° and automatic calibration. Software packages are available for QFP, TSOP, SOIC, PLCC and BGA devices. Robotic Vision Systems, (516) 273-9700

Optical Inspection System

Has Interactive Screens

The MVP 1820/40 AutoInspector inspects leads in-line of SMTs and mixed-component technologies. It has a color monitor, interactive operator control windows, help screens, file-management functions, backup capabilities, statistical processing and an Ethernet connection. The system uses a SunSparc Workstation front end connected to the system’s memory bus. Machine Vision Products, (619) 438-1138.

Copyright 1996 Nelson Publishing Inc.

February 1996

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