Long time no see, today we continue our knowledge of the LED are discussed.
A friend asked what is LED a glue?
What are the detailed information about LED a glue?
LED curing patch can use syringe glue, needle transfer or template printing method to impose on PCB.
We did a explained below.
Needle transfer method using less than 10% of all applications, it is to use a needle array is arranged in the plastic tray.
Then hang gum drops transfer to the board as a whole.
These systems require a low viscosity adhesive, and has good resistance to moisture absorption, because it is exposed to indoor environment.
Control needle transfer glue of the key factors including the needle diameter and style, the temperature of the glue, needle immersed depth and glue cycle length (
Including needle contact PCB before and during the delay time)
Pool tank temperature should be between 25 to 30 ° C, it controls the number of plastic viscosity and gel point and form.
Model is widely used for solder paste printing, also can use glue and distribution.
Although it is less than 2% of the SMA is a sample with printing, but the increase in the interest in this method, a new device is overcome some of the limitations of earlier.
The correct template parameter is the key to achieve good effect.
For example, a contact printing (
Zero from plate height)
May require a delay period, allowing good glue point form.
In addition, the polymer template of non-contact printing (
About 1 mm gap)
Request the best scraper speed and pressure.
The thickness of the metal template is commonly 0.
15 ~ 2.
00 mm, should be slightly greater than (
The gap between components and PCB.
The temperature will affect the viscosity and gel point shape, most modern glue machine depending on the needle mouth or let room temperature control device to keep the temperature of the glue is higher than the room temperature.
But, if PCB temperature was improved from the previous process, glue point outline may be damaged.
LED a glue to above problem,, if you already have the answer?
So the next exciting problem, we are looking forward to you will watch again, see you in tomorrow night!