Chapter 31 An Optical Character Reader can be used with the IVS 155 to scan wafer ID s. The OCR Reader scans the ID on a wafer, and the AccuVision software reports the wafer ID character string to GEM. The Reader and new software provide you with a fully automated way to start and run job plans based on wafer ID numbers. There are a number of scenarios for running the job plan and reporting the wafer mark when the Reader is installed. These scenarios are listed below. GEM requests the wafer ID and selects a job plan. 1. The operator puts a cassette on a platform. 2. GEM is sent the letter of the platform the cassette is on (this part of IVS optical tool software is already functional). 3. GEM requests the wafer ID (character string). A wafer is loaded from the slot designated in the new menu on the optical tool (see page 401). The new software directs the robot and prealigner to load and align the wafer correctly under the reader for scanning. 4. The reader scans the ID. The character string is sent to GEM, and the wafer is returned to the cassette. 5. Based on the wafer ID, GEM can request a particular job plan to run as described in the next scenario, and the optical tool runs the job. GEM downloads job plan and wafer ID s are reported with data 1. The operator puts a cassette on the platform. 2. GEM downloads a job plan to the tool by using the PP-SELECT command. 3. GEM sends the START command to the tool. 4. For each wafer that is loaded onto the prealigner, the tool will perform an OCR reading and send the character string to GEM. 395
CHAPTER 31 5. In addition, the tool displays the character string, along with the reading status and will write the character string to any data files that are enabled (.c,.r,.w,.s, or.z). The character string is written to data file(s) when individual wafer information is stored, but not for lot statistics Operator selects job plan and wafer ID s are reported with data 1. The operator selects a job plan, and selects Execute Job Plan from the menu system. 2. For each wafer that is loaded onto the prealigner, the tool will perform an OCR reading. 3. The tool will display the character string, along with the reading status, and will write the character string to any data files that are enabled (.c,.r,.w,.s, or.z). The character string is written to data file(s) when individual wafer information is stored, but not for lot statistics. Installation and operation This section describes how to: Install the Reader and connect cables. Enable the GEM portion of OCR software. Use the new AccuVision menus to set wafer loading parameters and test operation. OCR reader Installation Installation of the Reader is straightforward. All the hardware comes in a kit with the required bolts and screws. You install the base plate to the isolation table, attach the top plate to the base plate, mount the OCR arm to the top plate, and mount the Reader on the arm. Follow these instructions. To install the Reader: 1. Mount the base plate to the isolation table. See photos below for proper positioning. The bolt hole on the isolation table to use for proper positioning is the bolt hole right next to the table alignment screw under Cassette C as shown. Orient the base plate as 396
IVS 155 User Guide shown below before mounting. One set of holes on the base plate are blocked out. Mount top plate to base plate using holes shown. 2. Bolt OCR arm to top plate so arrow on arm points to the correct size for the wafers you plan to run on the tool. See photo on page 398. 3. Before bolting the Reader to the OCR arm, make sure the Reader is set to read from the bottom and not from the front (right side when mounted and you are looking from the front of the tool). If you see a glass plate on the right side, you must remove the cover plate from the bottom of the Reader and mount it over the glass plate on the 397
CHAPTER 31 side. Remove the two screws from the cover plate on bottom to remove it. Replace the screws. Then remove the two screws at the sides of the glass plate to be covered. Set the cover plate over the glass plate and replace screws. If the cover plate was already mounted on the side, skip this step. 4. Bolt OCR reader to OCR arm. Use the correct holes for mounting depending on your prealigner (Model 2831 or Model 3000). See photo on page 398. Marker for cross reference Connecting the Reader to the optical tool The Reader gets its signals through port 8 of the Multiport serial interface board. This board is at slot 13 of the System Controller. Power to the reader is from a previously unused connector on the Multifunction Controller. Cables are supplied in the Reader kit. Connect the Reader as shown. The RJ-45 connectors on the cable shown below are keyed so the cable can only be plugged into the one notched port on the Reader shown below. 398
IVS 155 User Guide System controller Connector to Multiport serial interface board (slot 13) Connector has 8 cables (Ports 1-8) Multifunction controller back panel STAGE VAC SYS VAC CASS A CASS B CASS C P8 Cable no: 0001-01286-00 P8 OCR RS-232 9-pin D connector R J45 to DB9 adapter Connector for power cable RJ45 Cable no: 0001-01255-00 Bracket side OCR Reader Read window is on bottom Enabling the OCR Reader in software To use the Reader, the feature must be turned on in the Configuration Editor before opening the AccuVision program to run job plans. The Configuration Editor is operated independently of IVS 155 software and should be set only by qualified Soluris service staff. In order to enable the GEM portion of the OCR software, you must enter the following line in the STR- CUST.000 start-up file: set ocr_enable 1 The default value for ocr_enable is 0. When the value is zero, the tool will not perform any OCR readings when in GEM Remote mode or while running a job plan. However, the OCR menus on page 401 will still be functional. 399
CHAPTER 31 When the tool is in GEM Remote mode Place the tool in GEM Remote mode from the main menu by selecting: GEM >Enable Remote Mode There are two ways in which the Host can enable the tool to take OCR readings. 1. The Host issues the OCR-SELECT command. When this command is issued, the tool uses the wafer parameters specified in the Manual OCR > Wafer Parameters menu (see page 401) to load the wafer to the prealigner, and perform an OCR reading. After the reading is taken, the wafer is placed back into the cassette. If the specified cassette/ slot is empty, the software will prompt the operator for an alternate slot from which to load a wafer. 2. The Host issues a PP-SELECT command, followed by a START command. Assuming a valid job plan was specified, the tool will perform an OCR reading for each wafer that is loaded to the prealigner. If the specified cassette/slot is empty, the software will not prompt the operator for an alternate slot from which to load a wafer. Instead, the software will attempt to load the next wafer, if any, from the handler sequence. Regardless of which of the two methods above are used, when the tool is in GEM Remote mode, the following applies: Immediately before a wafer is taken from the cassette, the software assigns the GEM VID #103 (GEI_VID_SLOTID) with the slot number. After an OCR reading has been performed, the software updates two GEM variables: VID # 691 (GEI_VID_OCR_READING) is assigned the character string, and VID # 692 (GEI_VID_OCR_READ_RESULT) is the read result value. The Read Result value can be examined to determine the success or failure of the most recent reading. It s valid values can be 0, 1, 5, or 9, where: 0 = successful reading 1 = a reading was taken, but the results are invalid 5 = a time-out occurred while attempting a reading 9 = the wafer failed to load When a reading is taken, the tool sends GEM event #139 (GEI_CEID_OCR_READING_AVAILABLE) to the Host. If the tool attempts to take a wafer from an empty slot, it issues GEM event #141 (GEI_CEID_WAFER_NOT_FOUND) to the Host. Operators can send an OCR Reading Request to the host by selecting Send OCR Reading Request from the menu while in GEM Remote mode. When this occurs, the tool issues GEM event #140 (GEI_CEID_OCR_READING_REQUEST) to the 400
IVS 155 User Guide Host. This will NOT initiate an OCR reading; its purpose is to inform the host that the operator has requested a reading. Refer to documents V1.79 GEM Host Requirements, Rev 2 and SECS/GEM Interface Guide for the IVS 120/130/135, Rev J for further details. When the operator selects Execute Job Plan OCR readings will be taken for each wafer when a job plan is run from the main menu, by selecting the Execute Job Plan menu option. Regardless of how an OCR reading was initiated, the resulting character string will be displayed on the screen, as well as a SUCCESS or FAILURE indication. When a reading is taken while a job plan is being executed, the character string will be written to any data file that is enabled, as outlined on page 395. Using the AccuVision menus for the Reader Setting up and adjusting the reader for scanning requires the use of new menus in the AccuVision software to set wafer size and loading parameters and the use of the In-Sight 1700 software to initially set up the reader to properly read the wafer ID. The AccuVision menus are displayed using the Manual menu. The In-Sight window can be displayed by plugging into the reader and entering the program s address on the address line of Internet Explorer (just as you would call up a web page). You can connect directly to your laptop. Before trying to use the new AccuVision Reader menus, make sure the feature is turned on in the Configuration Editor. Setting up so the wafer is loaded properly under the reader You need to make certain settings using the Manual menus to ensure the wafer is properly loaded under the reader. To make these settings: 1. Start AccuVision. Manual OCR 1 Load Wafer 2. Go to the OCR menu by selecting 8 (Manual) from the 2 Re-align Wafer AccuVision menu, then 3 (OCR) from the Manual menu. 3 Abort Handler You will see the Manual OCR menu. 4 Read Mark 5 S et O nline 3. Select 9 (Wafer Parameters) to see the OCR Wafer Parameters menu. (All menu choices on the Manual OCR menu 7 Read Status 6 S et O ffline 8 Reset Reader are described at the end of this section). 9 W afer P aram eters 401
CHAPTER 31 4. You now need to make the proper wafer settings. NOTICE The settings in this menu are important because the IVS 155 must know the wafer characteristics to properly position the wafer under the OCR reader. Remember that the wafer is scanned before any job plan is begun so the tool does not know the characteristics of the wafer that are defined in the job plan. Wafer Size Enter the size (100 mm, 150 mm, 200 mm, etc.) Wafer Fiducial Choose flat or notch. OCR Wafer Parameters 1 Wafer Size 2 Wafer Fiducial 3 Wafer Angle 4 Sender Cassette Slot Wafer Angle The default is 15 but you can enter a range of 15 ±5. The exact angle will be determined when you set up a Configuration). The correct wafer angle ensures the wafer ID is loaded correctly under the reader. (0 is the wafer position on the prealigner when it finds the flat or notch.) Sender Cassette Select A, B, or C. Slot Sets the slot in the cassette for the wafer to be scanned. GEM can issue a command to override the slot set here but cannot change this default setting. Say a GEM command was issued to request a wafer from another slot. Once that command was executed, the slot number would revert back to what is set here the next time a wafer ID is requested. Once you make the correct settings on the OCR Wafer Parameters menu for the wafer, it can be properly loaded under the reader. Description of all Manual OCR menu choices You can load the wafer under the reader, read the mark and check pattern recognition scores and perform other operations using the OCR Manual menu. Here is a description of each item in the menu: 1 Load wafer Loads the wafer under the reader. 2 Re-align wafer Wafer spins so it is realigned under the reader. 3 Abort Handler Returns wafer to cassette. 4 Read Mark Reads the wafer ID number and reports back the items as shown in the example displayed below. 5 Set Online Enables reading. 402
IVS 155 User Guide 6 Set Offline Disables reading. 7 Read Status Sends back a 1 if online, 0 if offline. 8 Reset Reader Resets the reader. This is similar to physically recycling power on the Reader. 9 Wafer Parameters This choice has been described earlier. See page 402. Connecting to your laptop for OCR setup, alignment, and training This section explains: How to connect the Reader to your laptop and bring up the Insight 1700 windows through Internet Explorer. Correct settings for the In-Sight 1700 Options windows. Acquiring an image and setting up a mark using the In-Sight 1700 windows. Connecting the Reader to your laptop You can connect the Reader to your laptop s Ethernet port to set up the Wafer ID mark to be scanned. You can also use the displays you will see for adjustment and troubleshooting. Do not try to connect the reader directly to a company network since this could cause an IP address conflict. In other words, don t plug the cable from your laptop into a wall Ethernet 403
CHAPTER 31 port but plug in directly from your laptop CAT 5 port to the Reader port shown below. Use a Cat 5 crossover cable (nonkeyed) supplied in the Reader kit or a Cat 5 regular cable with an Ethernet hub or switch. You can communicate with the Reader, see the scanned image, and set up a mark once connected. Bracket side Cat 5 Ethernet crossover cable (can also use straight Cat 5 cable with an Ethernet hub or switch) Cat 5 Ethernet crossover cable (can also use straight Cat 5 cable with an Ethernet hub or switch) OCR Reader To laptop computer Ethernet port Read window is on bottom Internet browser requirements The Reader is platform-independent and can be controlled using a standard Java-enabled Internet browser. Microsoft Internet Explorer 5.0 or later must be used on a laptop running Windows XP, 2000, NT 4.0, Me, or 98SE. Using Windows XP, 2000, or NT is strongly recommended. To connect the Reader to your laptop: 1. Plug into the OCR reader as shown above. 2. Open Internet Explorer. 3. Type this address on the address line: http://163.185.212.151 4. You will be asked for an ID and password. Type in: Type: Admin Password: [hit the return key--no password necessary] If you see another password screen once the software loads, type in ID and password again. You will see the In-Sight 1700 main screen. CAUTION The Reader s IP address is fixed and has been factory set. The login and password must not be changed. 404
IVS 155 User Guide In-Sight 1700 screen shown when you log on Correct settings for the In-Sight 1700 displays The In-Sight displays allow you to adjust the scan for each mark you set up. For new marks, the color of the wafer may change, or its size, along with the font of the wafer ID, the number of characters or the exact area to be scanned. You can select and adjust the image area and see pattern recognition scores to aid in adjustments. Settings in the In-Sight Options window, Systems Settings window and Native Mode Details window must be set correctly for the OCR reader to operate properly. These settings have been factory-set and should not be changed. If you are troubleshooting a problem, make sure the windows shown below are set as shown. NOTICE If the tabs are dimmed on the Main window, uncheck the Online checkbox at the upper right hand corner of the window by clicking on it. Click on the box again when done to return the system back to Online. 405
CHAPTER 31 Click the Options tab on the Main setup screen to see the Options window shown below. Settings should be as shown below. 406
IVS 155 User Guide Click System at the upper right hand corner of the Options screen to see the System Settings window. Settings should be as shown below. 407
CHAPTER 31 Click the Serial tab on the System Settings screen to see the Native Mode Details window. Settings should be as shown below. Setting up a wafer mark You set up the wafer mark using the In-Sight 1700 displays. The settings for one mark, or a series of marks, is called a job in the In-Sight software. Each job can contain up to 10 unique reading configurations, called Configs. Each Config specifies a type of wafer mark, a checksum, the string field, light settings and other information. By setting up a Config, you are training the Reader to properly read the mark. As part of setup you need to load the wafer using the AccuVision Manual OCR menu, then drag and size a blue box over the wafer ID number to define the area where the mark is expected to appear. You can automatically tune the software to optimize Config settings to get the best scans. When the job runs, each Config will be tried if a read fails for the first Config. Creating more than one Config is not necessary but is useful when the mark is different from wafer to wafer. You only need to use the Insight displays when adding new Wafer ID numbers. Once a mark is setup, you won t need to use the In-Sight displays. Referring to the In-Sight 1700 Series Wafer Reader manual The In-Sight 1700 Series manual provided with the reader has detailed instructions for using the In-Sight displays, so see the manual if you need more information to set up a new wafer ID number than is given below. If the manual is not available, you can download it from the Cognex website (http://www.cognex.com/support/in-sight.asp). To set up a wafer mark follow the steps below. Acquire an image 1. In the Run tab, disable the Online checkbox. 408
IVS 155 User Guide 2. Click the Setup tab. You will see the Setup widow. Setup window 3. Load the wafer under the Reader using the AccuVision OCR Menu described in the previous section. 4. Click the Live button. Position the wafer mark horizontally (or best you can) in the field of view, making sure the entire mark is visible in the image. The mark will appear in the Setup screen above. You may need to adjust the wafer using choice 3 of the OCR Wafer Parameters menu if positioning is off. See Setting up so the wafer is loaded properly under the reader on page 401. 5. When the mark is properly positioned in the image, double-click the image or click the Manual button to exit Live mode. Set the region The region sets the area where the wafer mark should appear each time in the field of view. 1. Click the Config 0 tab if not already highlighted to designate Config 0 as your first Config. 2. Click the Edit Region button in the Setup window. 409
CHAPTER 31 3. Adjust the region as necessary to encompass the entire mark. The image coordinates and the size of the region are displayed below the box. To move the region, position the cursor anywhere inside the box, then click and hold the left mouse button while dragging. To resize the region, position the cursor over an edge or corner of the region, then click and hold the left mouse button while dragging. Set the character information 1. You can leave the Mark and Checksum settings at the default setting as shown in the window on page 409. See the In-Sight 1700 manual if you need more information on these settings. 2. Set the Field String so it represents the number of characters in the mark to be scanned. The Field String specifies the number of characters in the character string or encoded in a barcode, including alphanumerics (A-Z, 0-9), dashes (-), dots (.), and spaces. You use the * (asterisk) to indicate how many characters are in a string. 3. For instance, the field string entry shown on page 409 means there are 14 characters in the string (including the dash). The symbol (-) is used where the dash occurs in the character string to tell the software to only look for a dash in that slot. Limiting a position in a string like this can improve performance. Asterisks represent either characters or numbers. You can use other field definitions to limit the types of characters in a certain position in a string. See the In-Sight 1700 manual for a detailed description. Setting other fields All other settings in the setup window can be left as they appear in the Setup screen shown on page 409. You do not need to set Light Mode or Light Power or enter any value for Field Definition. The tuning process will handle this. Tuning The Tune button starts the automated tuning process used to optimize the Config settings. 1. To tune, click the Tune button at the bottom right of the Setup window. You can leave the boxes checked for Bright Field, Dark Field, and Size in the Tuning window. These are the defaults. Tuning will start. During tuning an exhaustive read test is performed on the mark using many combinations of Light Mode, Light Power, Size, and Color settings and the current definitions for the Mark, Checksum, Accept, Field String/Definition, Character Spacing and Region settings. 410
IVS 155 User Guide After each iteration, the string and score results for the last read are displayed. The best string and score result achieved so far is shown along with counts of the total number of reads attempted and the number of successful reads. When tuning is done, the combination of settings that correctly read the mark with the highest score is retained and can be applied to the Config or discarded. 2. Click Accept to apply the tuned settings to the Config. About the score With the Checksum set to SEMI with Virtual, which is the default, the maximum score is 400 points. The minimum passed score is 300 plus the Accept threshold (default is 50) Taking a Read Clicking the Read button at the lower left of the Setup window acquires an image and performs a test read on the wafer mark using the current Config. The String and Score results are reported to the right of the Read button. If the read passes, the String appears on a green background. If it fails, the string appears on a red background. You can take a read at any time to check the setup. Note that you can also take a read and get a score using the AccuVision OCR Manual Menu described earlier. Creating another Config Once you are done with your Config, you can create other configs if necessary by clicking the next Config tab. For instance, if you just set up Config 0, click the Config 1 tab in the Setup window to set up Config 2. Once you have set up the number of Configs needed, you do not need to do anything more in the In-Sight 1700 windows unless wafer marks change or new ones are added. Save your settings After making all your settings, you must save them. Don t forget to save. Otherwise new settings will be lost. 1. To save the tuned settings, click the File tab. 2. Click the Save button. The settings will be saved under the default file name WAFID00.JOB. To save the job to a new job file: 1. Enter a file name in the Save As...dialog box. A name for a job can contain up to 15 characters. The job extension is automatically added. 411
CHAPTER 31 2. Click OK to save. You have saved your settings (either one or more Configs). The whole setup (all 10 Configs, if used), are stored in a new file. To open a Job: The Reader is configured to load the WAFID00JOB automatically after receiving power. To load a different job: 1. Click on the File tab 2. Save changes made to the current job, if needed. 3. Highlight a job file in the list. 4. Click the Open button. 5. Click OK in the Open File dialog to load the job, or Cancel. Changing the startup job The Reader automatically loads and runs the WAFID00.JOB when powered up. To change the startup job. 1. Click on the Options tab. 2. Click on the System link in the upper right to access System Settings. 3. Click the Startup tab. 4. Select a new job file to load on startup from the Job list. 5. Click the Save button. 412