Shorter dwell time at peak temperature (3 min instead of 10)
Parts complete processeing in 15 minutes instead of 45
Cool product to ambient without thermal shock
Use same furnace for both drying and sintering
Thick Film Processing with Near-Infrared
TF Series infrared furnaces have been specifically engineered for thick film and hybrid circuit applications. Processes include curing and/or firing of advanced Noble metal, copper, ceramic or glass ink, firing dielectrics, conductors and resistors on ceramic, porcelain and metallic substrates in air, nitrogen or forming gas (mixture of hydrogen/nitrogen) atmospheres. Unique technology provides outstanding performance and low cost of ownership.
As a result of the high equilibrium heat transfer of the near-infrared (NIR) lamps in the furnace, dwell time in a near infrared furnace can be quite short compared to a conventional convection furnace. The physical structure of thick film materials is developed very quickly, and the overall time/temperature product is relatively small. Dwell time at peak tempeartures can be as short as 3 to 4 minutes instead of 10 minutes. Limiting time at peak temperatures avoids materials migration and diffusion issues.
Because of the penetrating power of high intensity near infrared radiation, the organic volatiles within thick film inks and pastes essentially sublime completely from the structure without eruption.
Typically parts can complete processing in 15 minutes instead of 45 minutes required by a convection furnace and shorter production time means higher production output per furnace.
With TF-series furnace high efficiency controlled cooling system the cooling system is designed to provide cooling rates consistent with high yield and throughput without promoting cracking. Product is returned to room temperature, avoiding structural failure due to stress and strain resulting from excessive thermal gradients.
Use of burnout venturi exhaust after first chamber to eliminate volatiles combined with TF-series zone isolation and precise control allows for both drying and sintering operations in a single furnace.
The largest savings in energy consumption comes from three primary features of the TF-Series near-infrared furnaces:
1. Radiant near infrared heat focuses energy on the product in the furnace rather than heating the furnace itself.
2. TF-series furnaces require much shorter stabilization time (minutes instead of hours) so little energy is spent in bringing the furnace to "Process Ready."
3. SCR fired heating elements optimize power use by clipping the incoming sine wave providing full voltage to the heating elements at extremely low power levels.
Thick Film Profiling in a NIR Furnace
For most thick film processes in these infrared furnaces, the rate of temperature rise in the product can be made quite fast, the volatilization and sublimation of organic binders being completed long before sintering temperatures are attained. To achieve this result, the first zone should be driven as hard as practical to maintain the highest intensity near infrared radiation, reaching process temperature at the beginning of subsequent holding zone(s). The holding zones are set to maintain sintering temperatures in the product. Dwell time in these zones should be just sufficient to drive the pyrolysis or polymerization to completion. By limiting the time at temperature in this manner, unacceptable materials migrations or diffusions can be avoided.
Exacting Temperature and Atmosphere Control
The fastest and most efficient production furnaces available for thick film processing. High production yields and through put are achievable due to the design's quick start-up and changeover time, precise and repeatable temperature profiles up to 1000°C. The process gas atmosphere is uniform and ultra-clean.
The TF-Series infrared furnaces achieve exacting temperature profiles with rapid heat rise and no overshoot. The rapid heat rise of these furnaces is of particular advantage in the final lid sealing or die attach process since the semiconductor is not exposed to prolonged high temperature. The systems require only minutes to come up to temperature and stabilize.
Motorized Chamber Lift. TF-Series furnaces include TPS's unique motorized chamber lift. This feature allows users to open the furnace chamber, separating the chamber top and bottom for inspection, cleaning and maintenance of chamber internals.
Computer Controlled. The furnace is operated via the lasted TPS Furnace control software installed on a robust managed platform industrial furnace computer. The process engineer can easily vary process parameters using the sophisticated PID and power control parameters in the software. An almost infinite number of recipes and profiles can be labeled and stored for ready access on the furnace computer. The software includes multiple levels of password protected control and logs each change in recipe load or furnace state useful for troubleshooting product and process performance.
The furnace software operates on a Microsoft Windows Professional computer system. The program and all settings and recipes are stored on the local hard drives. The computer is complete with 19" LCD 1280x1024 high resolution color graphic screen, full size keyboard/mouse interface and Ethernet high-speed network connections to facilitate view and control of the furnace by managers and process engineers from any location. The furnace includes two (2) local USB ports for connecting profilers and jump drive storage devices.
Low cost of ownership results from the furnace versatility, high throughput, quick readiness, and low utility consumption. Small zones and high temperature differentials enable broad profile flexibility. Profiles with peak temperatures from 150°C to 1000°C are possible. The furnace can be turned on, turned off, or re-profiled in minutes, saving time and money.
Made in USA. TPS TF-serices furnaces are fabricated and assembled in Paramount, California, USA.
All models include universal transformers which accommodate 208-480 Vac and 50/60 Hz frequency anywhere in the world, allowing furnace relocation without external equipment. All furnace systems are phase balanced to improve facility efficiency. IR lamp controls automatically keep IR spectrum constant.