![]() High peak temperature can cause the damage of the component, damage of the assembly or detach of the pervious soldered components. REFLOW PROFILES ALPHA OM-340 SAC305 & Innolot Typical Reflow Profile Recommendation. Each solder paste defines the heating slopes and time and temperature limits within each slope. This three step profiling approach has been commonly used since the early days of SMT. Reflow Profile SupplementsTin/Lead Solder Paste Reflow Profile SupplementLead-Free Solder Paste Reflow Profile SupplementWave Profile SupplementWave Profile Supplement. ALPHA OM-340 SOLDER PASTE Technical Bulletin Issue: 19 October 2021 of 7. A typical profile consists of three heating slopes (the time vs temperature relationship or rate of temperature rise) defined by Figure 3-1. Typical paste manufacturer specifications require a three-to-four minute heat-ing profile (lead free solder paste: 4-6 minutes). This setting will determine the time that the PCB will spend in the heated tunnel. Since larger components normally reach lower maximum temperatures during reflow than smaller ones, because of the different heat capacities, keeping them below their ratings may not be difficult, as long as 250 ☌ is used as the maximum temperature for the joints of smaller components. If you are searching for a reflow profile that you cannot find here, please contact us. The first parameter to be considered in creating a profile is the conveyor speed setting. This means that 250 ☌ may not be usable as the maximum joint temperature for some components a lower temperature may be required. Although Intel BGAs are generally rated at 260 ☌, other components, especially large ones, may be rated at 250 ☌ or 245 ☌. Solder paste is approximately 50 flux by volume and not all of this flux can be evacuated from the solder joint during reflow. The temperatures shown for the reflow profile above are typical for the solder pastes in use most often by PCB contract manufacturers (CMs), with the peak for leaded solder at approximately 210-220☌ and lead-free solder about 30☌ higher. Components are typically rated as per J-STD-020C (or later), based on their package thickness and volume. Higher T g material is not necessarily more resistant to this damage, and must be tested for compatibility. If maximum solder joint temperatures exceed 250 ☌, PCB damage such as delamination and warpage may result when standard FR4 (T g =130 ☌) material is used. For 63Sn/37Pb solder paste with a melting point of 183☌, the peak temperature is generally 210-230☌, and the reflow time should not be too long to prevent adverse effects. Generally, it is recommended to add 20-40☌ to the melting point of the solder paste. 250 ☌ is recommended as the maximum temperature for all solder joints on the board, except for components with temperature ratings lower than 250 ☌. The soldering peak temperature varies with all solder pastes in the reflow section.
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