Inspection standard and inspection method of LCM products
1 LCM product inspection standards:
(1) test conditions:
The environmental conditions (room temperature) to 20~25 DEG C, (at room temperature) 65% + 5%RH (humidity).
The test tool for 20W fluorescent lamp lighting, away from the table above 50cm (product), visual distance of more than 30cm under the conditions of visual inspection.
(2) inspection standards:
Inspection mainly by batch sampling inspection, sampling standard based on GB2828-93.

2 commonly used terms in LCM test:
(1), black spots
Dark spots and dark spots of the linear power, does not have a big change of liquid crystal driving voltage change.
The power line dot was dark, a large change in liquid crystal drive voltage changes.
(2).
Light spots of power, does not have a big change of liquid crystal driving voltage change.
Light spots of power, a large change in liquid crystal drive voltage changes.
(3) the white line
Linear spot light display of power, does not have a big change of liquid crystal driving voltage change.
According to the linear spot light power, and the change of liquid crystal driving voltage change.
(4) blue
Display a deep color spots and power, a large change in liquid crystal driving change.
(5) vertical (vertical) defect
Power, the longitudinal (usually a short axis) line is not bright, simple.
(6) the line defect
Power, the transverse (usually long) line is not bright, simple.
(7) cross the line defect
When power, horizontal and vertical lines intersection is not bright.

3 the scope of inspection:
(1) the general visual inspection:
All the dimensions of LCM (the device).
Polarizer LCM LCD screen appearance, color uniformity. Polaroid appearance including: scratch, indentation, bubble and dirt.
The flux, solder joints weld, weld, solder, bridging, overflow (material).
The appearance of LCM shell, electroplating paint is uniform, whether there are scratches, paint.
The uniformity of the components between the leads, whether there are scratches.
Solder mask the PCB board is off (the size limit), copper foil or scratch line.
The screw fastening, fastening the shell toe degree.
(2) an electrifying display check:
Comparison of the input voltage, frequency, current consumption, LCD degree and speed of response.
The power (according to the standard input voltage range, the angle of view) display graphics or the defect and dislocation pattern.

4 LCM sampling test:
But for a variety of environmental sampling test in LCM before leaving the factory, including:
The high power, high temperature (40 DEG, 60 DEG C) placing test.
The low power, low temperature (0 DEG C or -20) placing test.
The high temperature and high humidity, power set.
The vibration test.
The temperature test and control in a certain period of time.

5 testing methods of LCM products:
Several cases of LCM examination and test of products. The number of classification according to inspection exemption, inspection, sampling inspection. According to the test mode classification of self and mutual inspection, special inspection. Physical and chemical inspection, sensory test according to test method.
(1) sensory test:
Sensory test LCM, that is used for visual inspection of LCM shell, without scratches, off screen surface plating; LCD if there is a scratch, there is no bubble. The PCB board member, whether the defect (including lead screw); visual items also include: solder flux, solder mask is off, the color LCD screen.
(2) physical and chemical inspection:
LCM physical and chemical testing is the use of machinery, electronics or chemical measuring method, determination of the physical and chemical properties of LCM. Such as:
The use of vernier caliper, the magnifying glass to detect LCD screen polarizer scratch length, the number and size of the bubble. These defects in the judgment standard is in a certain number and size limit.
The magnifying glass can be PCB in LCM solder joint inspection on: whether there is leakage welding, weld, solder, solder overflow, whether the bridge etc..
The microscope examination: PCB graphics board (Du Jinceng), the line to line, and whether there are defects of short circuit and open circuit.
The installation according to standard file with the detection of self-made test shows that testing for LCM electrical performance. Such as:
Check the power detection and display, LCD screen, in the standard input voltage range, the angle of view, display graphics, color depth is consistent with the test standard, display area are black, white, white. In the electricity in the display process, the rated input voltage, current consumption should be according to the "LCD" standard specification, using a multimeter to detect frequency; and should be used to detect whether the oscilloscope with LCD "specification".