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temperature Electronics Forums search results

2680 results found for temperature in 4s.
Showing matching items 1 - 50

98% Batch Ovens - 11/4/05 -
... to profile. If we program an air temperature ramp up of 4 degrees C/second to a soak temperature of 180C, stay there for 60 seconds then ramp up at the same rate to 240C and stay there for 50 seconds whether its the first or the tenth profile, the air temperature curve will be the same regardless of temperature of the metal inside . . . heater will turn on and off intermittently to maintain your profile settings. I will say that the starting air temperature inside the oven during your second and ...

97% Air Bath Rework System - 12/22/04 -
... a leading supplier and may claim increased power in response to lead free solders that require higher temperatures to reflow, coupling the power and velocity in a carefully controlled manner is crytical in ensuring that lead free and eutectic solders are reflowed using a reflow pattern that is at an optimum temperature in all segments, never having to increase the ramp rate or temperature above that recommended for the component. The 1200Watt phenomenon (The importance of not ?going over the top ...

97% Reflow Specs. - 8/13/01 -
... four distinct temperature ramp rates in ovens that are primarily convection. TENT: two distinct temperature ramp rates in ovens that are primarily convection. You appear to be using a traditional profile. Typical temperature control times of a reflow profile are: PREHEAT TIME: Time from when the profile starts and the beginning of the ramp to peak temperature. SOAK TIME: Portion of Preheat Time prior to the beginning of the ramp to peak temperature when the temperature change is small. LIQUIDOUS ...

97% Military Lamina bake-out - 8/3/02 -
... the laminate be elevated to a temperature above the glass transition temperature of the resin. Stress relief may well be accomplished at the same time as increased cure is being effected, as long as a slow cool down is used. In order to prevent bow and twist, the bake and cool down should be done under low pressure or under a uniform weight. Typical bake times and temperatures for the various laminate resins are shown below: Resin Type||Tg*||Bake Temperature||Time Difunctional Expoxy||130?C||160 ...

96% Reflow Oven Selection - 8/27/05 -
... still a good read. I was actually surprised that to test temperature uniformity across the zone, they attached T/C's to the substrate rather than measure the air temperature. By reading the temperature values on the board, it seems that they are getting closer tolerances than if they were reading the air temperature of the zone. I think they advertise/d temperature uniformity within 2 degrees. Always thought that's the air temperature tolerance within the zone . . . guess not. As far as them ...

96% Solder reflow temperatures too high - 1/14/07 -
... cures the problem just enough to clean the old solder off or remove the component in question. R: This makes sense. Mixing an alloy with a lower liquidus temperature to a high melting temperature will lower the liquidus temperature of the higher melt alloy, because the new melting temperature is combination of the two liquidus temperatures of the solder alloys. ----> Yes, this is great, I just need to figure out how to get (for example sake) a "liquid form of solder" to add to the BGA's solder ...

96% Solder reflow temperatures too high - 1/11/07 -
Solder reflow temperatures too high Joe: I know this is not the correct forum to post chip "reworking" questions. Reply: Rework questions are as appropriate as the next topic here on SMTnet J: BGA will not reflow at any normal temperature level. I believe these chips may have been generating high operating temperatures and thus possibly raising the reflow threshold of the solder below it? Does this sound right? R: No, the reflow temperature is governed by: * Alloy of the solder * Thermal mass of ...

96% Soldering - 12/5/01 -
... high"? As a side, the temperature on the temperature sensor is: * Inaccurate. * Not the temperature at the solder. Listen, operators are smart people. They have figured-out that they can solder faster with a hotter iron that they can with a cooler iron. There are many different working temperatures. Our operators determine working temperatures according to the alloy of the solder and the size of the joint being soldered. Typically a smaller tip and a lower temperature can be used for small ...

95% Baking components at 70 degree - 12/19/07 -
... carriers of low temperature material will disfigure and become useless at 125*C bake temperatures. The reason you can not find 70*C bake data is: J-STD033B, "4.2.2 Low Temperature Carriers. SMD packages shipped in low temperature carriers may not be baked in the carriers at any temperature higher than 40?C. If a higher bake temperature is required, SMD packages must be removed from the low temperature carriers to thermally safe carriers, baked, and returned to the low temperature carriers. Note ...

95% Specific Gravity - 11/4/03 -
... supplier. Temperature Correction All hydrometer readings must be corrected from the temperature they were read at, to the temperature the hydrometer was designed for. Most hydrometers are set to 15.6*C (60*F). Some hydrometers calibrated are to 20*C. Check any hydrometer prior to use! The difference each degree of temperature makes to the specific gravity is not constant, however approximate corrections are: For every degree the sample is above the hydrometer's calibrated temperature, add 0.001 ...

95% Batch Ovens - 11/29/05 -
... Y axis represents temperature in Celsius (5 degrees between 2 dashed horizontal lines and 20 degrees between solid lines). Results: ProfileCycle1- a)25C to 120C in 50 seconds b)120C to 160C in 65 seconds c)160C to 219C in 60 seconds d)Peak temperature - 219C e)5 seconds at peak temperature f)Time above 183C - 90 seconds ProfileCycle10- a)25C to 120C in 50 seconds b)120C to 160C in 50 seconds c)160C to 224C in 60 seconds d)Peak temperature - 224C e)5 seconds at peak temperature f)Time above 183C ...

95% Re: Help... Need new or used SOIC-16 metal tubes - Do You Really?? - 5/5/98 -
... temperature and faster, but requires handling components and metal tubes and reels 2. Lower temperature and slower, but can be done with the supplers tubes and reels As an expample, page from Intel's "Packaging Databook," page 8-21 8.5.2 Rebaking of PSMCs ? High Temp Bake. If the HIC indicates that the contents of the MBB have expired, then the components can be baked to desorb moisture. Two bake temperature profiles are recommended, High and Low temperature. The higher temperature ...

94% Reflow oven profiling - frequency ??? - 5/17/07 -
... since it is able to have fluid temperature (air) and mass temperature; I tried to implement this instead of plot just the peak temperature but quited due to lack of time. I think there's a little of misunderstanding about "profiling" you just profile once (well or one session of profiling iterations) and then you just track behavior of the oven to see how much variation on temperatures you have inside the oven. Regards

94% Type K thermocouple for Super M.O.L.E - 11/5/01 -
... results of these profiles seem inaccurate and unreliable Returning to your comment that Type K thermocouples ?suffer from temperature cycling hysteresis at above 250? C? ? * Certainly all thermocouples exhibit measurement hysteresis [A lack of voltage retraceability as the temperature decreases], what is temperature cycling hysteresis? * What happens with this temperature cycling hysteresis upon reaching the 250?C? * What are the references for these articles? * What are the implications of this ...

93% J-STD-001 Par 4.2.2 Temperature and Humidity - 7/19/07 -
... a shelf. Stainless steel shelves providing endurance and rigidity. No rust or corrosion! ? Humidity Set Range 1%- 50 % Rh 3 and temperature set range 20?C - 45?C4 (Optional 60?C) provide versatility for different applications. Accurately calibrated humidity and temperature sensors ensure correct measurements. 0.1 %Rh and 0.1?C resolution of humidity and temperature display. Optional Calibration Software or precisely calibrated sensors are available for customers even hard to please. ? Ready to ...

93% Baking components at 70 degree - 12/19/07 -
... as the low temperature carrier that you want bake at a higher temperature. One of the these extra carriers needs to be high temperature material that you'll use last. * Place the low temperature material carrier on the table so that you can see the components. * Place one of the extra carriers with cavities down, pin one notation aligned, bla bla bla on top of the low temperature material carrier. * Holding both carriers, turn them upside down. When you take the low temperature material carrier ...

93% adhesive for thermocouple - 4/30/04 -
... in reflow, and are more commonly used for wave solder applications. Special high temperature, two part epoxies are rated up to 260*C, but require several hours at elevated temperature to cure. PRO: ? These products are easier to use than high temperature solder. ? The accelerator and UV activated products set quickly, to speed installation. ? High temperature, two part epoxies will withstand reflow temperatures for many cycles. ? Both products can attach thermocouples to unsolderable surfaces ...

92% Solder Paste Reflow Profiling - 7/23/01 -
Solder Paste Reflow Profiling Responding to your questions: (1) The greater the temperature the greater intermetallic layer growth, the thicker the intermetallic layer, the weaker the solder connection. (2) If your components are affected by higher temperatures, you should limit their exposure to high temperatures. Further, the more temperature cycles through Tg, the more stress on PTH and via of a board. (3) Yupper!!! (3a) Consider that you probably are not repairing [overcoming] your ?micro ...

92% Thermocouple attachment on fine pitch component. - 4/11/01 -
... used for wave solder applications. Special high temperature, two part epoxies are rated up to 260?C, but require several hours at elevated temperature to cure. A thermocouple is properly installed with a small amount of adhesive. PRO: * These products are easier to use than high temperature solder. * The accelerator and UV activated products set quickly, to speed installation. * High temperature, two part epoxies will withstand reflow temperatures for many cycles. * Both products can attach ...

92% Reflow - 6/9/03 -
Reflow Welcome. You have selected a fascinating area to work. "What is delta temperature? Depends on what someone is talking about. Here's some possibilities: * In process equipment definition, the difference in temperature from one side of conveyor to the other. * In reflow temperature recipe development, the change in temperature between the preheat and soldering. * In soldering temperature recipe development, the difference in temperature from one side of component to the other ...

92% PCB lamination issues - 2/12/07 -
... oven Spec. says that to put PCBs in these temperatures for preheat, activation and reflow zone but these temperatures are not in the range (doesn?t mingle) of my solder paste temperatures so when I put my temperatures according to oven then soldering is good but if I put temperature according to solder paste specification it is not. Is that effect on my soldering process? A3. What ever works is the proper way to determine the proper temperatures in a reflow oven. Oven manufacturer and paste ...

92% Batch Ovens - 11/4/05 -
... ovens where the heaters cannot ramp up at the desired rate. In our oven, you may program the ramp up rate up to 4 degC/second to a specific soak and reflow temperatures, the time you stay at those temperatures and the time at the cooling phase. The principle is that the board is stationary . . . the heater will ramp up to set temperatures. Cooling is achieved with a built in exhaust system that pulls out the hot air from the heating chamber (at a rate of 140 CFM) while ambient room air is cycled ...

92% About temperature sensitive component - 9/24/04 -
About temperature sensitive component We're not sure what you mean by temperature sensitive components. From an assembly process stand-point, every component we use is temperature sensitive to one level or another. More specifically, some of our products use polyphenylene sulfide (PPS) capacitors, and we see delamination after going through water wash. There are many layers of the plastic film to protect the dielectric layers underneath. We had similar concerns about the delam so we have run ...

92% Re: Board Warp And Twist - 8/10/00 -
... considerations to be borne in mind is the glass transition temperature of the basic material, for example traditional FR4 glass epoxy laminate has a glass transition temperature between 115-135oC. During recent years more attention has been paid to the use of higher stability materials which cost more. If during the processing stages, this temperature is exceeded the material changes its state and becomes pliable, when the temperature drops the board becomes rigid again. There are a number of ...

92% Reflow Temperatures and speed for a 7 zone top/bot for conceptro - 6/16/03 -
Reflow Temperatures and speed for a 7 zone top/bot for conceptro The second one is typical. The important temperature is the temperature of the joint, not the setting of the oven. The oven setting are only important because they determine the temperature of the joint. If you set the oven to 150, that will be the temperature of the oven thermocouple, and the board itself will be less than that. How much less depends on many factors. You will need to put thermocouples on the board itself to ...

91% Baking time for PCBA rework - 4/24/02 -
... temperatures are: Baking Temperature [?C]||Baking Time [Hrs] 120||3.5 to 7 100||8 to 16 80||18 to 48 Longer bake-out times and higher temperatures are not recommend, as this can degrade PWB and component solderability. So if people bake to remove moisture from a board at 80?C, then it might ne possible to damage a component at that temperature. Have you considered: * Shielding moisture sensitive parts from the heat? * Impact of the temperature change on the bare board ...

91% Low humidity dry cabinets for MSD - 7/19/07 -
... a shelf. Stainless steel shelves providing endurance and rigidity. No rust or corrosion! ? Humidity Set Range 1%- 50 % Rh 3 and temperature set range 20?C - 45?C4 (Optional 60?C) provide versatility for different applications. Accurately calibrated humidity and temperature sensors ensure correct measurements. 0.1 %Rh and 0.1?C resolution of humidity and temperature display. Optional Calibration Software or precisely calibrated sensors are available for customers even hard to please. ? Ready to ...

91% Drying & Storage of Moisture Sensitive Devices - 7/19/07 -
... a shelf. Stainless steel shelves providing endurance and rigidity. No rust or corrosion! ? Humidity Set Range 1%- 50 % Rh 3 and temperature set range 20?C - 45?C4 (Optional 60?C) provide versatility for different applications. Accurately calibrated humidity and temperature sensors ensure correct measurements. 0.1 %Rh and 0.1?C resolution of humidity and temperature display. Optional Calibration Software or precisely calibrated sensors are available for customers even hard to please. ? Ready to ...

91% PCB lamination issues - 2/11/07 -
... problem from my assembling process? 2. If SMT components are mounted on non-rigid FLEX PCBs, how it can be soldered? 3.Reflow oven Spec. says that to put PCBs in these temperatures for preheat, activation and reflow zone but these temperatures are not in the range (doesn?t mingle) of my solder paste temperatures so when I put my temperatures according to oven then soldering is good but if I put temperature according to solder paste specification it is not. Is that effect on my soldering process ...

91% Moisture sensitive components (MSC) - 2/20/01 -
... Depending on the material, some trays can take a high temperature bake, while other trays, in addition to tubes, and reels, require a low temperature bake. With this later group of carriers, long storage times at elevated temperatures can cause deformation of packaging, reduced solderability of components, and deterioration of the antistatic properties of the shipping carriers. The 40?C value you see quoted for low temperature baking is derived from properties of the material used to fabricate ...

91% Wave solder capability study - 7/17/08 -
... Contact length the greatest impact. * Control flux density, time through preheaters, top side temperature as the board reaches the wave, temperature of the solder pot while the board is being soldered, time the board is over the solder pot [K Kuhlow] * Flux specific gravity, preheater temperature, conveyer speed, solder temperature * Two most important parameters are: solder temperature & dwell time * The most extensive study ever conducted on wave solder process control, involving 384 wave ...

91% Crystalized Flux under BGA - 8/4/04 -
... in temperature can increase the water's rate of reaction with the flux. Sometimes, only a 5 degree change can make the cleaning difference. If the flux inconsistently presents itself, then the likely cause is something in the system which is varying. If temperature is varying, monitor the incoming DI water temperature. Likely the Final Rinse cascades to the wash reservoir. If the final rinse temperature drops, this will have an initial effect on the wash reservoir temperature. If it drops ...

91% temperature range - 11/20/00 -
temperature range Hello, I have to design a PCB for which the customer have the following temperature requirements: -55degC to +85degC operating temp. -61degC to +125degC storage temp. My question is: does the FR4 material meet this conditions? Which are the parameters that shall I look for when I read the specification for the FR4 materials and how are these parameters interpretated? If the FR4 material meet these temperature conditions and also the components mounted on my PCB meet these ...

91% Peak Temperature during Leadfree reflow - 5/28/08 -
Peak Temperature during Leadfree reflow Hi, AJ, In general, the peak PCB temperature is variable depending on the profile used. We try to keep our peak temperatures in line with the paste manufacturers recommended temperatures; ignoring the peak temps for the PCBs. For the peak temps you mentioned, I assume this is a lead free process. We profile all assemblies prior to production. Since we run lead free and leaded assemblies, we achieve different peak temperatures. For our leaded assemblies, we ...

91% BGA 1517 XLINX REFLOW PROFILE - 6/2/05 -
... max||3||3||3||3 Preheat - Temperature Min (Tsmin), *C||100||100||150||150 - Temperature Max (Tsmax), *C||150||150||200||200 - Tme (min to max) (ts), seconds||60-120||60-120||60-180||60-180 Tsmax to TL - Ramp-up Rate, *C/seconds max||3||3||3||3 Time maintained above: - Temperature (TL), *C ||183||183||217||217 - Time (tL), seconds||60-150||60-150||60-150||60-150 Peak Temperature, *C||225 +0/-5||240 +0/-5 ||245 +0/-5 ||250 +0/-5 Time within 5*C of actual Peak Temperature (tP), seconds||10-30||10 ...

90% Blowholes during wave soldering - 9/6/07 -
... Temperature Another approach is to increase preheat temperature to ensure that your flux?s solvent is removed in the preheaters, leaving only the flux?s solids to be removed by the solder wave. Be careful not to provoke too high a maximum preheat slope, as this can induce thermal shock to your components even before your board reaches the solder wave. Also, too high a preheat temperature can burn away flux solids as well. This can cause insufficients. Remember, preheat temperature is taken one ...

90% DI cleaner (washer) bath temperature - 2/27/07 -
DI cleaner (washer) bath temperature If you?re running chemistry in the wash, the wash temperature will be influenced by the chemical manufacturer?s recommendations. Typically, wash chemistries recommend operating temperatures between 130F and 150F. If your application is straight DI and the equipment is not closed looped, then 130F to 135 F is normal. If you are close-looping the wash solution, then I would not recommend wash temperatures above 120F for two reasons. First, most ion-exchange ...

90% Backing of Cards - 2/8/06 -
... to temperature (>100?C) the moisture changes in vapour/gas generating an internal pressure causing in the worst case damages like internal planes delamination, popcorn effects, degassing, ecc. So you can understand why before reflow it could be necessary to backe and not when you do adhesive curing. The reason is that temperature and PCB exposition to Temperature in Reflow is higher ( 230?C-240?C on hottest PCB point, even higher in case of Lead Free reflow)compared to adhesive Temperature ...

90% Calculating Reflow Slope - 10/5/04 -
... slope. Here's an approach to calculating slope: * Subtract the lower temperature from the upper temperature. [Temp|upper-Temp|lower] = Temp|change * Subtract the time when the lower temperature was measured from the time when the upper temperature was measured. [Time|upper-Time|lower] = Time|change * Divide Temp|change by Time|change to determine slope. Generally, people calculate slope over the entire time that the temperature is changing value, because doing that averages all the little ...

90% BGA voids - 1/13/03 -
... of investigations concerning solder joint voiding and BGA components. * Read EP&P 10/98 says something like: ** Number of small and large voids correlate. ** Reflow time (temperature) is (are) very significant in void formation. Soak time is not a factor. *** Increasing reflow temperature increases voiding. Temperature influences void formation 8.4X times greater than reflow time *** Increasing reflow time decreases voiding ** Small voids near the base (top) of the ball, increase reflow time (60 ...

90% Sn/Pb diffusion - 5/17/02 -
... oxidation occurs on the surface of the solder. * No, ?most intermetallic growth ? occurs at room temperature? is incorrect. IMC are an artifact of a successful solder connection. You are correct that they keep growing at temperatures above 0?K, but they grow faster at soldering temperature than at room temperature. * Similarly metals oxidize faster at higher temperatures than lower temperatures. Although oxides are not requisite to soldering, practically they are an element of the process ...

90% Wave Soldering and Through Hole Forums - 1/24/02 -
... didn?t tell us about your solder, wave temperature profile, or the distribution of the problem. So, let?s assume the solder is near eutectic and the problem is wide spread. Wolfgang makes good points. So, let's talk a different tact. When we talk ?orange peel? effect. It?s an uneven, pebbly surface somewhat resembling the skin of an orange. Temperature appears to significantly influence the appearance of solder. It seems, when the bath or reflow temperature is high, tin continues smelting longer ...

90% Profile - 1/8/02 -
... screws. The third is Temprobe, a mechanical thermocouple support device, designed expressly to provide quick, reliable temperature readings on any type of surface. PRO: *? Paper clips are certainly quick and easy and will repeatedly withstand oven temperatures. * Screws provide a very rugged and reliable thermocouple attachment and will repeatedly withstand oven temperatures. *? Temprobe is quick and easy to clip the mechanical thermocouple support device to the edge of a board, and to position ...

90% Non-wetting on QFP lead - 11/21/01 -
... on one corner, close to the edge ? don?t face this problem, and the temperature measure at all it?s leads were around 212 deg ? 221 Deg C. c) Temperature difference when profiles were taken with and without loading were about 5 Deg C. at the one mentioned above were with loading. d) Oven performance ? tip-top, all the temperature changed event has been logged and monitored. No deterioration either on the temperature as well as the conveyor?s speed. I?m running out of idea, anyone with suggestion ...

90% Accelerated testing to Service life conversion - 8/7/01 -
... reality Nft = Number of cycles to failure test dTr = Temperature swing reality dTt = Temperature swing test 2 From Process Sciences [512-259-7070], Arrhenius Product Life Calculator/Estimator: Tm2=Tm1*(10^(Ea/2.303R*(Tp2-Tp1)/(Tp1*Tp2)) ? where: Tm1 = Component's original life span in days Tp1 = Component's original operating temperature in Celsius (?C must be less than or equal to 95?C) Tp2 = Component's elevated test temperature in Celsius (?C must be less than or equal to 95?C) R = Universal ...

90% Batch Ovens - 11/5/05 -
... the actual air temperature and adjust the heater accordingly to maintain your profile settings. When the oven is cold, the heater stays on longer/uses more power to maintain your programmed temperature ramp. When the metal inside gets hot, the heater uses less power because it mainly heats up the air considering that metal does not absorb as much heat as before. The net result is that the air temperature still ramps up at the same rate regardless of the metal temperature. It looks like your oven ...

90% 25 mil QFP soldering issue - 7/19/04 -
... temperature to peak temperature of 210?-225?C at 1?C/second. Adjust ramp up rate to minimize the differential of temperature (∆T) and thermal shock to components - Time above liquidus: 45 - 75 seconds - Cool down at 1? - 3? C/second * Pre-heat time may be required for reflowing high thermal mass assemblies to minimize the T. - Ramp up from ambient temperature to 120?C at 1? - 2?C/second - Soak at 120? - 160?C for 1 - 2 minutes - Ramp up at 1 to 2 ?C/second from 160?C to peak temperature of ...

90% Problems about Profiling board with P5 socket - 1/12/04 -
... Delta T. and the socket temperature always the lowest one because of it's large ,partly metal composed body.is there anyone can share with me the profiling experince of P5 socket? or any suggestions will be greatly appreciated. Q2: Peak temperature issue: Intel indicates the peak temperature of it's chipset must be from 210~220C and if the profile meets intel's requirment ,peak temperure of P5 socket can't reach 205C,but from IPC,or solder paste datasheet,Peak temperature must range from 210 ...

90% BGA Picture Evaluation - 4/9/03 -
... is quick and easy to use. Thermocouples may be taped to any type of surface. CON: * Adhesive grip of tape weakens with increasing temperature. Consequently, at reflow temperature it relaxes the preload on the thermocouple. This can allow the thermocouple to lose contact with the surface being monitored, and read ambient temperature instead of surface temperature. * It can be difficult or impossible to tape a thermocouple down reliably in tight places, such as between components." KIC Thermal ...

90% PCB Laminate Materials - 7/18/01 -
... 250C glass transition temperature - K = natural color F resin with 110-150C glass transition temperature - L = natural color I resin with > 250C flass transition temperature - M = coloring agent or opacifier added to F resin with 110-150C glass transition temperature - N = natural color of resin - P = coloring agent or opacifier added to resin - T = natural color F resin blended with nonepoxy resins for high temperature integrity, with 170-220C glass transition temperature From the Handbook of ...


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