For many people,the requirement for the PCB assembly production line is not very clear,and we will show you about this
First, temperature
The SMT print machine required a temperature 23 degree and tolerance is 3 degree,so the working environment temperature should between this range.Generally,the working temperature between 17-28 degree is ok,if it can’t reach this,it can over 15-35 degree.
Second, humidity
Humidity has a great influence on product quality in the production environment. If too high ,some element is easy to absorb moisture, it’s not good to moisture sensitive components, and if solder paste exposed to humid air ,it is easy to absorb moisture, cause welding defects. If the humidity is too low and the air is dry, it is easy to produce static electricity, which is unfavorable to the electrostatic sensitive element (ESD). Therefore, the environmental humidity must be controlled. Generally, the relative humidity between 45% to 70 % RH is good.And there are also some rules is 30% to 55%RH,and some not very district rule is 40%-80% RH.
First, temperature
The SMT print machine required a temperature 23 degree and tolerance is 3 degree,so the working environment temperature should between this range.Generally,the working temperature between 17-28 degree is ok,if it can’t reach this,it can over 15-35 degree.
Second, humidity
Humidity has a great influence on product quality in the production environment. If too high ,some element is easy to absorb moisture, it’s not good to moisture sensitive components, and if solder paste exposed to humid air ,it is easy to absorb moisture, cause welding defects. If the humidity is too low and the air is dry, it is easy to produce static electricity, which is unfavorable to the electrostatic sensitive element (ESD). Therefore, the environmental humidity must be controlled. Generally, the relative humidity between 45% to 70 % RH is good.And there are also some rules is 30% to 55%RH,and some not very district rule is 40%-80% RH.
Third,Air cleanliness
If there are too much dust in the workshop,it will have very serious influence for the small components,like 0201 and 01005 and the small pitch(0.3mm)SMT components,and it will speed up the attrition of the equipment,and it can even cause the equipment fault,increase some extra work for equipment repaid and maintenance.In the SMT assembly environment,except the dust,there maybe some chemical gas,if there is harmful thing in the gas,it will bring some harm for the workers;if the gas have corrosivity,it will influence the reliability of the product a lot.So the work environment need to be clean,no dust,no corrosivity,and no smell gas.Then it can make use the PCB assembly products quality,the equipment can work well,and the worker’s health.
And the workshop cleanliness should reach 100 thousand grade(BGJ73－84).If under the air conditioner,there need be a certain of wind,and try the best to control the CO2 below 1000PPM,and to make sure the worker’s health.
To make sure the factory cleanliness reach 100 thousand grade(BGJ73－84),the factory should pay for a lot of money for that.And the normal factory can’t get that.In order to get this kind of environment,when the workers come to the workshop,they have to extract to vacuum,and there are negative pressure in the whole workshop.In today's highly competitive market environment,the companies’ profit is very small,if you can’t reach this requirement,you have to have some rules with the air cleanliness,such as the carton which can brought a lot of dust can’t get to the SMT workshop.
