Questionnaire Application of Equipment

The vacuum process systems and reflow solder systems contain long term engineering know how at highest level. By continued advancement and improvements the systems comply with all technical requirements. By use of high quality components (stainless steel, quartz glass, graphite) semiconductor requirements are completely met.
Nearly all parts are manufactured in our own workshop. Software development is controlled by us. These prerequisites provide highest flexibility with regard to lead time and customer specific requirements.

A long life time of vacuum process ovens and reflow solder systems is reached by clever consumption of resources (electric power, cooling water, process gases, CDA). Regular maintenance and a sophisticated system design ensure trouble free operation for a long term.

All vacuum process ovens and reflow solder systems are cold wall oven in which only a small thermal mass has to be heated up and cooled down. For operation of these systems a cooling water supply (15…20 °C, 5 bar, deionised water without copper particles) is required. For reduction of cooling water consumption and for protection of cooling channels the chassis temperature is permanently monitored. Cooling water will be used only if required.

Reflow solder systems: The heating plate is heated by IR radiation. Thermocouples integrated into heating plate provide the temperature value to process control so that the defined temperatur profile can be performed.

RTP systems: The single wafer or susceptor (graphite plate) absorbs a fraction of radiation emitted by IR heater. The pulsed operation of IR heater allows for an extended life time when compared to systems running at full-load operation.

Compact reflow solder systems with small heated area are heated by heater cartridge. By doing so tabletop units with single phase power supply (230 V, 16 A) can be produced.

Inert gases like nitrogen or Argon are used in order to perform thermal process in a reproducible environment (free of oxygen gas). In addition to MFC controlled standard process gas line for nitrogen (N2) gas our systems can be upgraded with up to three MFC controlled process gas lines.

Formic acid (FA) is used for flux free (flux less) solder processes. Nitrogen (N2) gas serves as carrier gas which absorbs traces of FA in a dedicated FA module. In process chamber formic acid causes reduction (removal) of native oxide layer as well as improved wetting of solder material.

All standard systems can be evacuated down to a pressure of 10-3 hPa. Evacuation of process chamber causes removal of air constituents (nitrogen gas, oxygen gas) and humidity (water vapor). In this way reproducible process conditions can be realised.

Reflow solder processes can be observed through the viewing window (in hinged cover or at front side). The observation allows determining melting point of lot (liquidus) and - if necessary - interaction on program run.

Overpressure (p > 1 bar) can assist the reflow solder process for reduction of voids (area between metal surfaces not covered by solder). Simultaneously splashing of solder material will be drastically reduced.

Pure hydrogen gas (100% H2) is an effective way for reduction of native oxide layers. UniTemp GmbH offers suitable H2 modules as well as safety devices for proper and safe operation with pure hydrogen gas.