Test Specification

purpose

Ensure that the company's products meet customer requirements, provide a basis for product inspection, and ensure product quality.

Scope of application

This standard applies to all TFT module products produced by XX.

Testing Equipment

Electric measuring machine, test fixture, magnifying glass, fluorescent lamp, vernier caliper

Sampling plan and check environmental conditions

The manufacturing unit (or process QC) performs full inspection for appearance inspection and electrical performance test, and for size measurement or special inspection, the first piece of each model is sampled and tested 5pcs.

The quality unit measures 5pcs for the first sample of each model, and adopts the GB/—2012 normal inspection one-time sampling plan for the appearance inspection, and the general inspection level is II.

Unqualified level Allowable level(AQL) Qualified quality standard assessment
Main deficiency   If the size is defective, 0 receive 1 return
Submissive  
total

The examiner needs to wear an electrostatic ring and eight finger cots on both hands.If it is an LCD without a polarizer attached, all fingers should wear finger cots.

The examiner can visually check or compare with the film comparison table.

Please refer to the sample for the electrical test using test fixture and display screen.

The distance between the inspector’s eyes and the product is 30~40 cm. The inspection viewing angle is ±15 degrees on the front surface of the vertical display panel and ±45 degrees on the front surface of the horizontal display panel (see the figure below)

tft img1

Environment lighting: 800~1200LUX for visual inspection

Environment temperature: 25±5 ℃

Humidity: 25~75% RH

Check item

(1) Definition of point defects caused by internal panels.

a) Bright spots: bright, constant-sized dots appear on the LCD under the black pattern.

b) Dark dots: In the pure red, green, and blue pictures, dark dots with the same size appear on the LCD.

c) 2 points adjacent = 1 pair = 2 points.

tft img2

Show check

item description Acceptable quantity MAJ MIN
Highlights random N≤3  
Two adjacent points N≤0
Two adjacent points N≤0
distance Minimum distance between two bright spots 5mm
dark spot random N≤4  
Two adjacent points N≤0
Two adjacent points N≤0
Total number of dark spots and bright spots N≤6  
distance Minimum distance between two bright spots (dark spots) 5mm  
Small highlights D≤can be ignored,<D≤, N≤4,spacing≧5mmD(Point diameter) √ 
Show fault V/H line/line crossover line etc. Not allowed  
Chromatic aberration, uneven; ripple; hot spot Pass 5% filter under 50% dark light Invisible, can be judged by limit sample if necessary    

*Note: Defects on the black matrix (outside the active area) are not considered defects

Visual inspection

item description Acceptable quantity MAJ MIN
Point defect (display and appearance) Black spots, white spots, bright spotstft img4 D≤ignorable, <D≤, N≤4, spacing ≥5mm (Figure 2)  
Bad linearity (display and appearance) Black line, white line, bright line tft img5 W≤ignorable, <W≤,L≤, N≤4,  
Polarizer defect Dents, bubbles D≤ignorable, <D≤, N≤4,  
Scratch W≤ignorable,<W≤,L≤, N≤4  
Panel crack  tft img6 Not allowed
Damaged TFT non-lead side  tft img7 The distance between the minimum break point area, d1≧, cannot be ignored; d1<, N≦0d 1: the minimum distance between the break point area and the dot area
Damaged TFT pin side  tft img8 The alignment mark is damaged, the damaged angle>90  
W≦,L is ignored, but the pin cannot be damaged
W≦, (D depth)≦1/2 (1 layer glass thickness)
Damaged TFT lead side corner  tft img9 The swastika cannot be damaged. W≦,L≦5mm  
TFT / CF edge burr  tft img10 d2≦d 2: The distance between the burr and the edge of the TFT  
other Poor sealing glue Height: no more than length: no more than 80mm, the sealing glue must completely cover the crystal filling mouth and the penetration depth is greater than  
LCD dimensions The size refers to the design specification, the tolerance is ± mm, if it exceeds the tolerance range, it is unqualified  
The liquid crystal is not completely poured into the box Not allowed  
Gas enters the box during crystal filling Not allowed  
Smudge Stain that cannot be wiped off is not allowed to have liquid crystal on the surface or in the glass gap  
Module appearance Newton ring

tft img11

There are Newton rings and interference lines on the touch screen, rejected  
 tft img12 The pattern font is clear, the font line becomes thicker or thinner than the normal line width ≤1/3 (and ≤+/), no hyphenation. accept  
Drums on the touch screen Acceptable without affecting writing  
There are fish-eye bubbles on the surface of the touch screen FILM According to the inspection standard of the touch screen  
Poor assembly Module assembly does not match the assembly instructions Reject  
Poor assembly The assembly does not meet the process requirements (fixed double-sided tape or shading tape is not attached, etc.) Reject  
The connection between the components is not strong (the glass is separated from the backlight, etc.) Reject  
Defects when attaching transfer paper Insufficient adhesion to tear off the protective film Reject  
Attach position Does not meet the specifications, rejected  
Attaching angle Attached to the edge of the LCD edge angle is greater than ±15 degrees, rejected  
Poor coding   Does not meet the document requirements  
Other items PCBA, HSC, FPC, backlight, etc. Refer to "LCM Finished Product Inspection Specification" ~ conduct inspection    

Remarks:

1. Ignore any defects on the protective film of the polarizer, such as scratches, bubbles and particles on the protective film.

2. The angle of all damage must be greater than 90 degrees as shown on the right.

3. If the customer has specified requirements according to customer requirements.

tft img3