I. Humidity control
Bubbles in the solder joints with the raw materials have a great relationship with moisture, long exposure to the air PCB boards and components, to be baked in advance to prevent excessive moisture due to humidity. Can fire the PCB board in advance in the drying oven baking 2-4 hours, the temperature is set at 120 degrees, or let the PCB board supplier to re-bake - under the baking and then over the reflow soldering.
II. Use of solder paste
If the solder paste contains water, it is also easy to produce air bubbles, first of all, we should use good quality, finer particles of solder paste, the better the solder paste, the less air bubbles. Thaw the solder paste out of the refrigerator in advance, and leave it at room temperature for 2-4 hours before use, or you can bake the solder paste. The heating and melting of the solder paste, stirring should be operated according to the regulations, the solder paste should not be exposed to air for a long time, and the solder paste printing should be completed in time to complete the reflow soldering.
III. Optimize the furnace temperature curve
First of all, the temperature of the reflow soldering machine preheating zone can not be too low, the rate of temperature rise and the speed of the furnace can not be too fast, reduce the peak temperature, appropriate prolongation of the preheating time and the constant temperature time, shorten the reflow time, the constant temperature time is controlled at 10-105s or so, the reflow time is controlled at about 85s, so that the flux in the water can be fully evaporated. It is best to test the furnace temperature every day, and constantly optimize the reflow furnace temperature curve.
IV. Optimize the stencil opening
You can try to change the way of stencil opening and reduce the opening area.
Use vacuum reflow soldering:If the void rate of reflow soldering is required to be relatively high, you can use vacuum reflow soldering, which can effectively prevent air bubbles from arising, and can control the void rate of the soldered joints at less than 5%.
Features of NeoDen IN8C Reflow Oven
NeoDen IN8C is a new environmentally friendly, stable performance intelligent automatic orbital reflow soldering.
This reflow solder adopts the exclusive patented design of "even temperature heating plate" design, with excellent soldering performance.
with 8 temperature zones compact design, lightweight and compact.
to achieve intelligent temperature control, with high-sensitivity temperature sensor, with stable temperature in the furnace, the characteristics of small horizontal temperature difference.
While using Japan NSK hot air motor bearings and Switzerland imported Heating wire, durable and stable performance.
And through the CE certification, to provide authoritative quality assurance.