PCB screen printing screen production process can be roughly divided into two aspects: pull the net, net drying.
There are many small operation methods in these two aspects, let’s take a look together as below.
Pull The Net
Steps of pulling the net: cleaning the screen frame-level inspection-applying the bottom layer glue-pulling the net-measuring the tension-applying glue-removing the net, sealing the edge-storing.
Specific operation instructions:
Due to the repeated use of the screen frame, there are residual viscose, net yarn and other debris around the screen frame, which must be removed to avoid affecting the adhesion between the net yarn and the screen frame.
Place the screen frame on the platform (need to be level) to check whether the screen frame is deformed, if it is deformed, it needs to be leveled.
After cleaning, the undeformed screen frame and the net yarn are then spread and evenly coated with a layer of Nanbao right grease (without adding hardener) to enhance the adhesion between the net yarn and the screen frame after the screen is drawn.
After the first application of glue for about 10 minutes, place the screen frame on the drawing table, and adjust the relative position and height.
Select the mesh, loosen the surrounding gripper, spread the mesh on the frame, and then evenly clamp the mesh into the gripper without wrinkles. Note that the four corners should have looser mesh and the gripper must be locked tight, there can be no gap between the clamp and the clamp (for example, automatic lifting frame and manual netting).
Pulling the net: The first tension is 26, and the tension is 24 after standing for 5 minutes. The second tension is 28, and the tension is 26 when standing for 5 minutes. The third tension is 32, and the tension is 30 when standing for 5 minutes. The fourth time is adjusted to 5 points, the tension is 32, the gluing tension is 30 after standing for 20 minutes. The gluing tension is 28 after 15 minutes of curing, and the screen can be made after 72 hours of standing (take the use of a one-meter x one-meter full-automatic production line as an example).
Use a small brush to evenly brush the adjusted glue on the surface of the screen frame and the mesh. Do not drop the glue into the middle part of the screen. After the glue is dry for 8 minutes, you can use a spatula to apply the glue on the glued surface. After the glue is completely dried (open air blower should be used to strengthen the drying), then the net can be installed.
Remove the excess mesh around the screen, and indicate the date, mesh and tension of the screen (to observe the tension change) in the frame of the screen to prevent the penetration of white water, seal the inner corner of the screen frame with red glue, and then use the waterproof tape seal the mesh frame and the surface of the mesh, which also prevents the penetration of the medicine.
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