A typical profile consists of three heating slopes (the time vs temperature relationship or rate of temperature rise) defined by Figure 3-1. The Typical Profile The reflow profile is defined by the relationship of temperature versus time during heating. Save optimized parameters as per the target board’s reflow specification. words, the solder reflow profile must first be defined and then maintained.Adjust the parameter setup and test several times to find the upper limit and bottom line of the real-time reflow profile.Compare real-time thermal data with the virtual profile.Burn-in a test board with thermal shock and mechanical shock to check the board’s reliability.Check the solder joint quality, PCB and component status.Reflow the board and measure the real time thermal profile simultaneously.So, you must analyze your target board first before creating a unique reflow profile.Ī virtual reflow profile is based upon soldering theory, the recommended solder profile from the solder paste manufacturer, size, thickness, cooper weight, layers of the board and size, and the density of the components. The below temperature profile for moisture sensitivity characterization is based on the IPC/JEDEC. For the Sn63/Pb37 and Sn62/Pb36/Ag2 alloys, the typical profile length is 3 to 4 minutes from the time the assembly begins to heat up until it reaches its maximum temperature of 215C 10C. changing the reflow profile can cause other lder defects. While varying reflow profiles may be utilized to achieve optimum soldering results, in general these share many of the same details.
With that said, there are certainly instances where fine tuning the reflow profile will benefit. Big components may need more time to heat up than small ones. For instance, it is widely accepted that 60-70 of all solder defects can be traced back to the printer. It is also quite different when the components absorb the heat to warm up. We recommend using the solder profile as given in Section 2.1 Solder reflow profile for soldering QFN packages. IPC/JEDEC J-STD-020, which defines soldering conditions for. The PCB thermal capacity is different according to the material type, thickness, copper weight and even the shape of the board. Surface Mount Packages are qualified by simulating the solder reflow conditions specified in. Does it mean that every spot in this GREEN area should fit your board reflow application? The answer is absolutely NO!
The GREEN area is the acceptable range for the whole reflow process. Default values and weight-based estimations for these parameters are provided in the tool.Ĭlick here to go to the Reflow Profile calculator page.According to the recommendation by the IPC association, the generic Pb-free solder reflow profile is shown below. The IMC thicknesses of SAC305 soldered joints for different reflow profiles are summarized in Table II. The tool uses the thermal capacity and conductivity of components and the PCB as well as the convective heat transfer coefficient of the oven to determine the solder joint temperature obtained during the reflow process.
#Reflow profile Offline
Offline reflow profile prediction for a specific PBA and reflow oven, based on the Bill-of-Material and PCB build-up of the PBA and the oven heating characteristics.Ĭonvective heat transfer characterization of reflow ovens. TAIWAN SEMICONDUCTOR RECOMMENDED SOLDERING PROCESS FOR SURFACE MOUNTED. The Classification Profile (Not to scale) table in the IPC/JEDEC-020 shows the classification reflow profile to be used for the device MSL classification/. Offline reflow profile prediction based on reflow profiles obtained on a different PBA and/or in a different reflow oven. Offline reflow profile optimization for a specific PBA and reflow oven, based on a single reflow profile measurement. It supports the following applications that are related to convective reflow soldering of electronic assemblies: With tin lead eutectic composition one could easily get away by maintaining peak temperature between 190C to 225C. The 'Reflow Profile' calculator is now available in our Calculators section. Reflow Profile For Backward Compatibility.
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