Recommended for high temperature lubricating wave soldering furnace
Lubricants are widely used to reduce the friction coefficient between the contact surface of the two relative motion that is indispensable to any mechanical movement, reflow oven conveyor chain plate width adjusting screw rod, hot wind motor bearings and other parts need to work in more than 200 DEG C temperature.
The specific area of welding furnace temperature of 250 DEG C or higher, this temperature is ordinary grease can not afford. To ensure the reflow furnace long-term trouble free operation, reduce unnecessary maintenance workload of welding furnace, high temperature lubricant must choose the appropriate.
What kind of lubricant for high temperature lubricating parts of reflow oven?
Reflow furnace temperature requirements
The use of reflow oven in printed circuit board assembly of surface mount components, to get high quality solder joint must use the appropriate reflow profile, follow the curve of solder paste data provided by the manufacturer. By using Sn63/Pb37 eutectic solder solder as an example, the liquefaction temperature is 183 DEG C, in order to ensure the quality of reflux to prevent defects, the reflux degree board must be higher than the liquefaction temperature of 20 DEG C. Under the influence of heat transfer rate, the actual temperature is always lower than the set plate thermometer welding furnace, so the welding furnace temperature in the reflow zone set at 250 C. The following is a typical set of reflow oven temperature value of each interval.
The interval interval at the end of the actual temperature setting plate temperature
Top hot 210 C 140 C 177 C 150 C 250 active return C 210 C
Used for a long time considering chain and other components are a good guide of heat, can be thought of as the interval of the mechanical movement parts temperature approximation to the set temperature, which is the highest for 250 DEG C, the temperature is the high temperature grease must be able to withstand the temperature.
It is necessary to point out that when using solder paste or different products does not at the same time, the actual welding furnace set temperature may be higher.
Cut into a society of environmental protection, focus on considering and welding furnace need to adapt to had the lowest cost of lead-free solder paste, and co melting point of the solder paste is roughly at about 200 DEG C, so the heat resistance of the welding furnace high temperature lubricating grease must leave some leeway, preferably high temperature grease, the long-term use can withstand temperature should be in more than 280 degrees.
Requirements for the maintenance of electronic industry
Competition is so fierce in the electronics industry, exert the maximum capacity of production line in order to create the largest profit is the basic criterion, so it is many factories of SMT line running 24 hours a day, a week run six days to six and a half days. The date of delivery in urgent cases, half a month of continuous driving time is also common. We know that the lubrication and maintenance of the high temperature parts of the reflow oven is in turn a hot air motor bearing,
Board wide adjustment of the wire rod and the chain, the first two kinds of maintenance to open the welding furnace interruption of production, manufacturers if the highly limited maintenance time to use the welding furnace once a week or three or four days once the lubrication is certainly not worth it,
However, it can not give up the maintenance of equipment to reduce life. Therefore, the high temperature grease used for the lubrication of the chain and the screw rod must have a lubrication cycle, which is difficult to take into account the lubrication and maintenance of the motor bearing.
In combination with other elements, the preferred reflow oven high temperature lubricant should meet the following requirements:
1, 280 high temperature under the effective lubrication
2, up to a month long lasting lubrication time, motor bearing grease lubrication cycle is not less than one year
3, do not pollute the environment, does not affect the health of the operator
SMT plant seal, air circulation is small. High temperature evaporation of a large amount of oil, the volatilization and thermal will solution components to wind through the welding furnace tube discharged in time, these ingredients and a variety of additive in lubricating oil for the air accumulated over a long period of time will adversely the health of operators. Lubricating oil with short lubricating period and frequent lubricating oil indicated that the volatile and thermal decomposition were much more than that of the oil.
4, does not affect the quality of the product
Grease adhesion strong, grease will not have a drop of oil at high temperature. High temperature adhesion is not strong oil will crawl along the chain, until the pollution of circuit board. When the hot air motor is positioned above the chain, circuit board bearing grease will drop of oil pollution.
5, prolong the service life of equipment
To ensure that the service life of the equipment. The lubricating oil in addition to formed on the surface of the metal oil wax need to have low friction coefficient and excellent load capacity, high temperature when used for a long time should be no coking and coking. Carbon accumulation allophone is issued, the adjusting plate width difficult, until the chain and wire rod stuck, locking, forcing the device downtime.
6, the grease flash temperature is over 300 DEG C, reduce fire hazards.
The flash point of oil should be higher than the temperature 20 to 30 DEG C, in case of fire, which is for welding furnace without nitrogen protection is especially important.
Meet the above 250 DEG C in long-term use and flash point in about 300 DEG C is not much, only a polyphenylene ether, perfluoro polyether, methyl silicone oil, methyl phenyl silicone oil lubricants, but the most suitable only NOKLUBE synthetic high temperature lubricating grease.
This is because the polyphenylene ether at room temperature is not easy to flow is not conducive to the use of. Silicone oil due to extremely low surface tension and high compressibility. Lead load capacity lubricating oil film formation is not strong and is only applicable to the lubrication instrument.