There are three basic types of printers on the market. - Flood Systems - Have reflectors as large as the exposure frame that contain the lamp. The reflectors are made from a number of flat facets of aluminum that are mirror, brush, or dimple finish. The lamps are mercury capillary, or medium pressure arc. These systems produce soft illumination. They are the least sensitive to dust and debris but are limited in resolution, are very sensitive to vacuum contact and have a significant difference in performance across the exposure plane. This is due to the differences from the center compared with the reverse light angles caused by the side reflectors. Capillary lamps have from 10 - 15k exposures life. - Collimated Systems - Have high pressure short arc lamps in an elliptical reflector that refocuses the lamp on an optical integrator, the rays are then bounced from a parabolic collimating mirror before striking the exposure plane. The system has the least sensitivity to out of contact exposures. The tight optical angles tends to reproduce flaws in the glass, and the artwork. There is also a high sensitivity to dust and debris. These systems are the more costly to purchase, and have a higher operating cost due to lamp cost and life, power consumption, air conditioning load and the required cleanliness of the environment. Yields are often a trade of shorts for opens. Lamps have a 750h to 1000h life, there is an explosion possibility if lamps are run too long. - Point Source Systems - Have a compact optical system, lamp plus reflector that is typically 25 cm square. These systems use medium pressure additive lamps that can be manufactured with a spectrum which optimizes the resolution of the photoresist. They provide a compromise between flood and collimation in optical sharpness. On a scale of 1 to 10 with collimation being 1 and flood systems rating a 10, the optical sharpness of the point source is 3. The higher intensity and favorable spectrum enhance the resolution. As a result of the increased resolution over flood systems in combination with a reduced sensitivity to flaws and debris of collimated system, the point system tends to produce at higher yields. Lamps are the least costly and have a 1000 - 2500 hour life. Bert Ohlig ---------- From: [log in to unmask] Sent: Thursday, February 20, 1997 12:47 AM To: [log in to unmask] Subject: Collimation or not? \0 TO: I4235700 IBMMAIL IBM Mail exchange FROM: DWALLACE EX2 D.Wallace - Process Control Mngr Dunsdale DATE: 20 February 1997 SUBJECT: Collimation or not? I am interested in some user input regarding collimated light source exposure units for imaging multilayer innerlayers. Currently, we use ORC (Japan) point light source units in combination with a glass to glass vacuumed print frame and we are able to achieve very acceptable yields on 100 micron track / gap technology. We wish to improve this capability down to 50 micron track / gap. Is collimation the only practical way of achieving this? Are there any other benefits in using this type of light source? What, if any, are the drawbacks? Thanks in advance for any imput. David H Wallace Process Control Manager Exacta Circuits Limited. *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * *************************************************************************** *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************