Reflow profiling for next generation solder paste alloys smtai. Lead free specs are tighter and less forgiving than lead processes, often requiring ramp soak spike rss profiles and not just the straight ramp to spike rts that you are. Ramp soak spike on the left and ramp to spike reflow profile on the right. The ramp to spike rts profile is almost a linear graph, starting at the entrance of the process and ending at the peak segment, with a greater. For that same matter, no one sells bricks, so why do you put one through your reflow oven. Match solder paste specifications and oven configurations to provide robust. Some solder paste manufacturers will request that the profile use preheat and some will call for a soak period. The two most common types of reflow profiles are the ramptopeak profile, also called ramptospike or tent profile. Autoseeker reflow thermal profile optimisation software. Since different system, different components and different solder are used by different customer, the optimum soldering condition to insure the solder integrity and reliability can only be determined by user customer. A ramp profile also referred to as ramptospike profile, is a reflow profile that increases to the reflow temperature in a near linear fashion.
This document contains proprietary technical information which is the property of simcom limited, copying of this document and giving it to others and the using or. A ramp topeak profile is a linear ramp to the peak max temperature. In soldering, a thermal profile is a complex set of timetemperature values for a. As a general rule, temperature slopes in the range of 2 to 4 degrees c are desirable to prevent damage to the board andor components caused by heating or cooling too rapidly. Rather than increasing the temperature of the soak zone on the whole, an alternative profile is to make the soak zone temperature a slow ramp from 150 c to 180 c. Cr0 10zone smt convection reflow oven pcba soldering.
A typical reflow profile contains several different stagesinitial ramp, soak, spike to reflow, reflow and cool down of the product. This page lists the things you need to do to optimize a reflow profile of a target board, including making a virtual reflow profile, checking solder joint quality, testing the boards thermal shock and mechanical reliability, and adjusting parameter set up. Weaker joints form as a result of improper profiling. However, without the datasheet, we had neither the recommended. It is important to note that the soak zone generally is not needed to activate the flux chemistry of solder paste. Ramp, soak, and spike suggest the temperatures needed to change the structure of solder and the time it takes to occur. Therefore, because the soak zone is unneeded, the profile may be altered into a linear ramp to spike profile.
The recommended soldering profiles reflect the common range used by pcb. The purpose of the work was to determine the snagcu reflow profile. Because the soak zone is unneeded, the profile may be altered into a linear ramp to spike rts profile. Profile planner software is designed to allow you to easily develop robust. The lower relative peak of the reflow zone results in a more equalized temperature across the pcb and components. Lets not forget, the purpose of a reflow oven is to create a profile for your product. For leadfree reflow soldering, a disadvantage of the standard profile is the relative height of the peak of the reflow zone. Solder profile for lead free reflow process figure 1 classification reflow profile for smt components refer to ipcjedec jstd020e table 1 classification reflow profiles profile feature pbfree assembly average ramp up rate t smax to t p 3c second max. Preheat usually refers to increasing the temperature from normal temperature to 150 c and from 150 c to 180 c.
After the soak, the assembly will enter the spike area, where the assembly will be reflowed above 183c for a target time of 60 seconds, plusminus 15 seconds the entire profile should last between 3. There are four stepszones to this process preheating, soaking, reflow and cooling. The solder paste library of your profiling software provides several choices. Preheat temperature min t smin temperature max t smax time t smin to t smax 150. Best zone distribution between ramp, soak and spike regions. A soak profile also referred to as rampsoakspike profile, ramps to a. The ramp to spike rts profile is not a cureall for every reflow profile soldering issue. A ramp profile also referred to as ramp to spike profile, is a reflow profile that increases to the reflow temperature in a near linear fashion. Profile feature general profile ipc jedec1 2 no clean flux recommended starting point water soluble flux recommended starting point3 ramp up rate reflow profiles are the ramptopeak profile, also called ramptospike or tent profile see figure 1 and the soak profile, or ramp soak spike profile see figure 2. The solder paste library of your profiling software provides several. You can then see the profile that will be generated and how well it will conform to the paste manufacturers specification. Extended soak times andor high soak temperatures can cause pre mature loss of activity in the solder paste resulting in wetting and solder balling issues. Profile planner reflow profiling software description. May 21, 2015 autoseeker reflow optimises reflow profiles with the click of a mouse.
There are typically two types of reflow profiles, abbreviated rss and rts. A soak profile also referred to as rampsoakspike profile, ramps to a certain temperature at which point it levels off to a large degree before again ramping to the reflow temperature. Classic pcb thermal profiling of the reflow solder process. The measured reflow profile parameters for these are shown below table 2. Standard reflow profile for standard and leadfree packages. Reflow profiling the benefits of implementing a ramp to spike profile david suraskiaim introduction the issue of reflow profiling has been and continues to be a hot topic. Rss is the most common, having the temperature profile divided into 45 distinct sections.
The soak should bring the temperature of all parts of the assembly to equilibrium before the assembly reaches the solder reflow temperature so all parts of the assembly reflow simultaneously. Profile stages the smt reflow profile can be broken. With the soak zone at 150 c and the reflow zone at 245 c typical value for leadfree reflow soldering, the temperature rise from soak zone to reflow zone is 95 c. Find, read and cite all the research you need on researchgate. This document contains proprietary technical information which is the property of simcom limited, copying of this document and giving it to others and the using or communication of the contents thereof, are. The two most common types of reflow profiles are the ramp topeak profile, also called ramp to spike or tent profile see figure 1 and the soak profile, or ramp soak spike profile see figure 2. Best practices reflow profiling for leadfree smt assembly 98675. A soak profile displays some plateau within a limited temperature range, before the alloy reflows.
Why thermal characteristics of components are important for. I hope thats useful, the software supplied with solderstar thermal. This document contains proprietary technical information which is the property of simcom limited. We know already about the soak segment of reflow soldering. T of 2c across the pcb assembly due to the highspeed blower adjacent to each heat source. A soak profile displays some plateau within a limited. Linear ramp profiles provide enough time for the solder.
Reading your profile via profile software profiling guru. Inadequate temperature settings can damage components by heating and cooling at a rate that is too high. A thermal profile is a complex set of timetemperature data typically associated with the. Rampsoak spike on the left and ramptospike reflow profile on the. Match solder paste specifications and oven configurations to provide robust process profiles. Reflow soldering is the most widely used method of attaching surface mount components to printed circuit boards pcbs. Oct 11, 2009 tweet no one of course reflows bare boards, so why would you profile one. Fill the void v mitigation of voiding for bottom terminated. A ramptopeak profile is a linear ramp to the peak max temperature.
Introduction reflow process overview selection of solder paste. For some inputs, such as slope, preheat, soak and tal you can define multiples of the same input. Reflow soldering profile, per jstd020d, table 52, pbfree. The rts profile cannot also be used with all ovens or all assemblies. A range of reflow profiles were tested which included.
A soak profile also referred to as ramp soak spike profile, ramps to a certain temperature at which point it levels off to a large degree before again ramping to the reflow temperature. To accommodate this, our convection reflow ovens provide medium and highvolume manufacturers with reliable solutions. More commonly the initial ramp from ambient is called preheat and the relatively flat section from that initial ramp to the reflow spike is called soak. Profiler automatic profiling walkthrough profile simulation software. Standard reflow profile for standard and leadfree packages 2 table 3 classification reflow profile profile feature snpb eutectic assembly pbfree assembly preheat and soak temperature minimum tsmin temperature maximum tsmax time tsmin to tsmax ts 100c 150c 60120 seconds 150c 200c 60120 seconds average ramp up rate. While the ramp soak spike rss allows for about 4 cs, the requirements of the rts is about 12 cs. Best practices reflow profiling for leadfree smt assembly. Precise temperature profiling the cr0s heating zone temperature controllers can boast an accuracy of 1c and a. Ensuring proper reflow oven profiling can help to avoid costly. Short answer, greater number of zones give you greater control over your process.
A sample leadfree reflow profile download scientific diagram. The rts profile ramp zone serves as the preheat zone for the assembly, wherein the flux is activated, the volatiles are driven off, the assembly is prepared for reflow and thermal shock is prevented. Thermal profiling for pcb assembly explained sierra circuits. Reflow soldering is a process in which a solder paste a sticky mixture of powdered solder and flux is used to temporarily attach one or thousands of tiny electrical components to their contact pads, after which the entire assembly is subjected to controlled heat. Maximum rising slope ramp rate maximum falling slope cooling rate preheat. May 04, 2008 triggering your data run with your profiler, conveying through a reflow oven, uploading data to your software and software overview. Reflow was conducted in a 10zone convection reflow oven with an air atmosphere. They were just too complex and expensive to profile, so the solution instead of finding a scrap board or some other. If the assembly being soldered has a number of larger thermal mass components, it may be necessary to use a soakstyle profile, commonly referred to as rampsoakspike rss, which uses different heating rates in the different profile stages.