6 Layer PCB Display Screen Used Black Solder Mask
Printed Circuit Board Features:
1 6 Layer printed circuit board used in display screen.
2 FR4 substrate material, tg 150 degree and board thickness is
2.0mm.
3 Black solder mask and white silkscreen.
4 OSP Treatment
5 PCB size is 748mm*90.4mm/1pcs.
6 35 um copper thcikness on each layer.
7 PCB file or gerber file should be offered by customer.
8 Customized printed circuit board.
Packing Specifications:
1 One vacuum pcb package should not be over 25 panels based on
panel size.
2 The vacuum pcb package sealed must be free to tear, hole or any
defects that may cause leakage.
3 The pcb package must be suitable to ensure effective vacuum
sealing.
4 Every package must have desiccant and humidity indicator card on
the inside of vacuum package.
5 Humidity indicator card target less than 10%.
FAQ:
Q1:What is PCB Grid Testing or Bed of Nails Testing?
A1: Grid testing or Bed of Nails testing is a process used to check the
performance of components mounted on a PCB board. This test uses a
frame/fixture that contains various pins inserted into an epoxy
phenolic glass cloth laminated sheet (G-10) in order to access all
the PCB test points. These pins act as sensors which are aligned to
make contact with the test points on the PCB board and are also
connected with a measuring unit through wires. The position of the
pins is designed and customized for each PCB based on the
components or points on the board that need to be tested.
A grid testing machine has three building blocks - a fixture, a bed
of nails and software, to control the overall functionality of the
machine. It usually has two cameras which are placed on the top and
bottom of the machine in order to scan the whole board.
Advantages of PCB Grid Testing:
- Very Reliable method of PCB testing as all the points on the PCB
board can be tested simultaneously.
- Offers very good accuracy since it uses two cameras
- Can easily detect manufacturing defects
- An in-circuit tester is easy to program
- Interpretation of test results is quite easy
- It checks for Open, shorts, mission components, Wrong polarity,
defective components, and current leakages in the circuit
- Most of the parameters can be checked without applying power to the
PCB under test
Limitations of PCB Grid Testing:
- Fixtures used in bed of nails testing are expensive since they are
mechanical and require a different wiring assembly for a different
PCB board
- Fixtures are mechanical so any change in the number of pins or
their position require extra cost
- This test doesn’t test continuity through connectors so there are
the chances that the connectors’ faults may remain unnoticed.
- Faults related to solder joints, excess solder, solder quality, and
solder void also remain unidentified
This type of testing is called In-Circuit Testing. Another test
process used for In-Circuit testing is Flying Probe Testing.
