A thermal profile is a complex set of time-temperature data typically associated with the measurement of thermal temperatures in an oven (ex: reflow oven). The thermal profile is often measured along a variety of dimensions such as slope, soak, …

Solder reflow ovens control the temperature profile by adjustments to the zone temperature set points and the belt speed. Modern reflow ovens used for mass production also have the ability to control convection rate – the speed at which the hot gases hit the product.

• Time Above Liquidus (TAL) is a key to improved wetting, less chance of flux entrapment. • TAL and peak are two areas where there are the majority of changes to the profile, and therefore time given to experimentation. As we progress with these changes to the profile we MUST consider the rest of the PCB assembly.

temperature. The Lee Profile minimum TAL can be as short as 30 seconds. Some RPRD profiles suggest peak temperatures of 235°C and minimum TALs of 45 seconds. These types of profiles can cause charring of components or form intermetallics that are too thick. (See Figure 9.)

Dec 2, 2024 · The standard reflow profile has four zones: preheat, soak, reflow and cooling. The profile describes the ideal temperature curve of the top layer of the PCB.

Jan 2, 2024 · Choosing an oven that maintains a flat active temperature curve improves soldering effectiveness, especially in preventing tombstone defects, as it avoids significant differences in melting times and uneven stress on component ends.

Feb 21, 2025 · Reflow oven profiling can be a tedious, expensive, and time-consuming process. Reflow is a single-step procedure. If the oven is built correctly, planned, and maintained, the entire assembly will be subjected to the same oven settings regardless of …

In forming optimum intermetallics, two critical parameters are involved in the reflow phase: peak temperature and TAL (time-above-liquidus). The peak temperature is generally 20-30°C above the liquidus temperature of the alloy and the TAL is typically 30-90 seconds in order to form effective in termetallics.

Thermal profiling is the process of plotting temperature vs. time of the PCB as it travels through the oven. The PCB thermal profile is determined by temperature, time, and heat transfer rate. PCB temperature is typically measured by attaching thermocouples to different areas on the PCB.

Reflow zone: The reflow zone, also referred to as the “time above liquidus” (TAL), is the part of the process where the highest temperature is reached. A common peak temperature is 20–40 °C above liquidus.