Changeover control: understanding capabilities and managing changes can help to optimize your new equipment.Problem A customer's employee recently visited our factory to accept a new placement machine. As a requirement of acceptance, the machine would need to run one of their current products--one that was also running in their factory on earlier-generation equipment. The application was an aggressive blend of flip chip A chip packaging technique in which the active area of the chip is "flipped over" facing downward. Instead of facing up and bonded to the package leads with wires from the outside edges of the chip, any surface area of the flip chip can be used for interconnection, which is typically done and surface-mount component placement. On the manufacturing floor with our vintage equipment, the customer achieved a cycle rate of approximately 26 seconds. By taking product data provided by the customer to generate a program for the new machine, cycle time was reduced to 13 seconds. While the customer was impressed im·press 1 tr.v. im·pressed, im·press·ing, im·press·es 1. To affect strongly, often favorably: with placement quality, he was only moderately pleased by the reduced cycle time. After reviewing the new machine's specification, he wondered why the cycle time was not less. Investigation The machine was fully qualified and met all internal measurements, including tests for speed and accuracy. Therefore, we took our investigation to a different level. When asked where the program data came from, the customer said he had copied the files directly from the vintage machines in production at his facility. We analyzed an·a·lyze tr.v. an·a·lyzed, an·a·lyz·ing, an·a·lyz·es 1. To examine methodically by separating into parts and studying their interrelations. 2. Chemistry To make a chemical analysis of. 3. the data and found that special handling parameters had been activated activated a state of being more than usually active. In biological systems this is usually brought about by chemical or electrical means. Commonly said of pharmaceutical and chemical products. for many of the components in the program. We frequently find that in production text analysis computing computing - computer tools (TACT TACT Tuned aperature computed tomography Imaging A technology used to study ambiguous breast images, display 2-D images in 3-D and ↓ false negative mammograms. See Mammography. ) control and special handling parameters are activated to mask problems or overcome short-term Short-term Any investments with a maturity of one year or less. short-term 1. Of or relating to a gain or loss on the value of an asset that has been held less than a specified period of time. issues. These settings are sometimes required based on the capability of the gear set or if the process demands the settings to be activated. Often, the values are not returned to their default settings once the issues are resolved. [ILLUSTRATION OMITTED] We were also able to determine that other global features on the new machine could be enabled to enhance machine output while maintaining the required placement accuracy. [ILLUSTRATION OMITTED] Problem Solved By understanding that the new machine had increased capability, component-specific parameters were set back to the high-speed default settings. New features that had not been considered were activated to increase the machine's output capability. Process capability and metrology metrology Science of measurement. Measuring a quantity means establishing its ratio to another fixed quantity of the same kind, known as the unit of that kind of quantity. equipment were also available to assure that the changes did not negatively affect process yields. Metrology equipment can verify (1) To prove the correctness of data. (2) In data entry operations, to compare the keystrokes of a second operator with the data entered by the first operator to ensure that the data were typed in accurately. See validate. that equipment is optimized to provide a balance of speed and accuracy. In the end, product cycle time was further reduced from 13 seconds to 7 seconds. Lessons Learned When assessing a new piece of placement equipment, understand what features and functions can be leveraged. Your supplier should provide you with a solid understanding of the new gear's capability. Managing change control and using tools that assure machine performance are critical to achieve optimal performance. Equipment can easily become inefficient because of component-specific programming parameters. Such changes are typically made under times of duress duress (dy  `rĭs, d`–, d or
stopped production, and, while they allow production to continue, they
decrease efficiency. Often, these parameters mask the true issue and are
not reset to their default values after the cause has been identified
and resolved. Many suppliers offer line-level software tools to manage
component databases and programs to assure that official change request
procedures are followed.
Understanding process demands and equipment capabilities, as well as maintaining effective change control processes, can assure that equipment runs at maximum efficiency to produce high yields while maximizing return of your capital equipment investment. Richard Boulanger (boulange@uic.com) is vice president of the Advanced Semiconductor Assembly Division, and Shawn Robinson (robinson@uic.com) is manager, GSM (Global System for Mobile Communications) A digital cellular phone technology based on TDMA that is the predominant system in Europe, but also used worldwide. Developed in the 1980s, GSM was first deployed in seven European countries in 1992. Product Sales--both with Universal Instruments Corp., Binghamton, NY. |
|
||||||||||||||||
Printer friendly
Cite/link
Email
Feedback
Reader Opinion