Through the related training for the final inspection staff, let each end staff master the acceptance criteria of appearance inspection, improve the skill of checking board, and improve more effectively. production efficiency and quality assurance.
Scope: all final quality inspection staff
Process: Pass FQA- Spot check -Pass -Packaging
1m =1000mm 1mm=1000um
1inch =1000mil 1mil=1000u’
Conversion of public and British system
1inch=25.4mm 1mil =0.0254mm
1mm =0.0394inch =39.4mil
1) Surface finishing
2）Common explanations on flowcharts
DRL PTH D/F W/F C/M HAL PROU E/T PAD Ring
C/S S/S MAX MIN VIA
PTH NPTH Breakout
Slot Film Date cold L/W Space LOGO SMD
Four operation procedure
1 plate warpage check:
In order to check the bending degree of circuit board in the manufacturing process, FQC needs to conduct 100% bending inspection on all E-T qualified boards.
3. Definition of plate curve
The flatness of the plate has been deformed, and one of the corners fails to fall on the plane formed by the other three corners. Plate bending includes plate bending and plate warping.
4. Operation method
1) Place the plate on the platform, tap the four corners and the middle part, check whether the plate moves in the vertical direction relative to the platform reference plane, and check whether the plate has cylindrical or spherical deformation relative to the platform reference plane.
2) If there is no such situation, the plate shall be free of bending deformation and temporarily placed in the designated area for visual inspection by FQC.
3) In case of the above situation, the plate has been bent and deformed. It is necessary to measure whether the deformation degree is within the tolerance range allowed by the customer.
3) Measurement and calculation
1) Choose the right diameter needle gauge
Calculate the diameter D of the needle gauge according to the plate curve value X1 required by mi (1.5% for single panel, 0.7% for double-sided panel and 1.0% for multi-layer panel if MI is not required).
D = x1 × L (L is the diagonal length of the board, l = √ side length 2 + side length 2)
2) Place the curved plate on the measuring platform, with the concave side facing down, gently press and hold three of the plate angles to make it contact with the platform, and insert the selected needle gauge into the gap between the plate and the platform to measure the bending.
3) On the contrary, with the concave facing up, gently press and hold the three plate angles to make them contact with the platform, and insert the selected needle gauge into the gap between the plate and the platform to measure the plate curvature.
4) If the needle gauge can be inserted into the gap between the plate and the platform, the plate is qualified and can be placed in the designated area for visual inspection. On the contrary, the plate is unqualified, which shall be placed in the unqualified area, and shall be inspected and judged according to the above methods after being sent to the repair group for pressing plate bending treatment.
2 appearance inspection
（1） First board inspection
1) Find out the MI corresponding to the board to be inspected, and check whether the version number on the first page and the features marked in the "board features" column are consistent with the board. (to distinguish lead-free tin spray from lead-free tin spray, use white paper to wipe the tin surface for 2-3 times. If the paper is black, lead tin spray is available.)
2) Check the process sequence on page 3 of MI. First, check whether there are any special requirements for sheet metal, copper thickness and sheet metal supplier. (Jiantao board has KB watermark, composite board has u watermark, if there is no watermark, it can represent any board.)
3) Check forming a: whether there is Gong copper sink slot and Gong hole sinking process. This process is sometimes placed before forming B, i.e. E / T.
4) Check the dry film column for cycle requirements.
5) Check the green bar: single side or double side, cycle, green color, green thickness, via hole requirements. (via hole plug hole is light proof; sealing hole is green. Via hole diameter less than 0.4mm is acceptable regardless of MI requirements.)
6) Check screen B: whether there is carbon oil, C / s surface or S / s surface and carbon oil gap.
7) Check screen a: whether there is white character, single side or double side, white character color, C / s side or S / s side, cycle requirements.
8) Check molding B: beer or Gong, golden finger bevel requirements, V pit requirements, whether there is a counterbore. (find the forming peripheral drawing and check the number of v-pit knives carefully; the oblique edge of the golden finger shall be measured with ten times mirror.)
9) View the E / T column: e / TS tag, color, location.
10) Check screen C: whether there is adhesive tape, blue glue position, thickness and model. (at present, there are two types of blue glue: 2955 and 2954. 2954 dark blue; 2955 light blue, green blue glue.)
1) Check the final inspection column: wire thickness, wire gap, tin ring, connection position and plate thickness. (when measuring the thickness of the board, the place with copper on both sides shall prevail. If there is gold finger, the place with gold finger shall prevail.)
2) ) view package column: number of scrap units and scrap marks allowed. (there are different requirements for different plates of scrap marks, do not simply understand it as "х")
3) ) check the special items and the last page of MI: whether there are special requirements for appearance and whether the repair plate is separately packed.
Note: the above items must be carefully checked with the actual board and MI, and batch inspection can be carried out only after the records are made. In case of any nonconformity or doubt, immediately
Inform the team leader or supervisor to handle。
（2） Batch inspection
1) Remove the paper sheet, align the boards in the same direction, check the E-T conformity mark first, and carefully check each board during the inspection. If there is any fuzzy mark or no mark, immediately inform the team leader to return it for test and retest. No one is allowed to mark the test conformity mark on the board at will!
2) After checking the E-T qualification mark, if the board has white words, V-CUT, beveled edge, etc., 20-30 boards shall be taken first to tilt in order, and check one by one to see if there is any missing white words, V-CUT, beveled edge or V-CUT, beveled edge is bad.
3) If there are npth holes, gongs slots, beer pits, etc., you should pick up about 10 pieces (depending on the thickness of the plate) to check whether there is npth
Kong Youtong, missed Gong / beer, Gong / beer not worn, etc.
4) All the above problems can only be checked for appearance problems after they are checked to be OK. Hold the edge of the board with both hands. Carefully check the two sides of the board from top to bottom or from left to right according to personal habits. (pay special attention to the place where the hand is pinched). If there is any problem, stick a red label on the top of the light table,
And separate the paper. After 100 pieces of qualified boards have been inspected, it is necessary to recheck whether there is a mixed red label, and then open a waiting list to be sent to QA waiting area.
5) After random inspection of pass by QA, the package shall be sent by specially assigned person. If rej is needed, it shall be re inspected, and the problems of rej by QA shall be mainly inspected. Fill in the rework form after the re inspection is qualified and send it to QA for spot check.
All Board inspectors must strictly follow the above board inspection procedures: e.g. E-T conformity mark → white words (V-CUT, beveled edge) → npth hole (Gong / beer tank)
→ appearance, do not omit any link to prevent serious functional problems from leaking out. (appearance and function problems: V-CUT, beveled edge, Gong / beer, hole big / small, plug hole, hole copper peeling, S / m in hole, etc.).
5、 How to use measuring tools
1. Use of the platform
2) Keep the platform flat
3) Wipe the surface of the platform with a rag
4) Place the plate to be tested on the platform stably
5) The platform must be adjusted regularly (sent by me to the special department for adjustment)
2. Use of micrometer caliper:
1) Rotate the main rod of the micrometer caliper to make full contact between the two measuring heads, and press the reset key to return to zero;
2) Turn the top screw to loosen the probe (depending on the size of the measured object);
3) Rotate the screw to make the bayonet and the tested object contact well, and at least make three sounds to stop; 4) repeat the 1-4 use method to retest once. 5) Read out the reading (pay attention to the unit, there is a metric English conversion key on the caliper)
3. Usage of vernier caliper:
1) Push the caliper roller, and press the reset key to return to zero after good contact;
2) Align the vernier caliper with the measured object;
3) Push the roller so that the bayonet contacts the tested object well;
4) Read the reading (pay attention to the unit, press the unit conversion key to change the required unit)
5) Repeat 1-4 for one time.
4. How to use tenfold mirror and centuple mirror
1) Put the ten times mirror and the hundred times mirror on the top of the object to be measured, so that the measured point falls under the object;
2) Adjust the focus knob until you can see the object clearly;
3) Adjust the eyepiece to make the object clearer;
4) Rotate the scale to make it level with the measured object;
5) Read out the grid number and calculate the value (3.3937mil/0.1mm for ten times mirror and 0.3937mil/0.01mm for one hundred times mirror). VI. operation requirements
1) Anyone must wear socks before taking the board. It is strictly prohibited to touch the board with bare hands to prevent oxidation caused by hand perspiration;
1) Handle with care. All boards larger than 5 / / × 5 / / must be separated by paper to prevent scratching;
2) The height of the laminated plate shall not exceed 25cm. When carrying the plate, it is not allowed to carry too much at one time, so as to prevent the angle of the plate from being damaged and the plate from being scratched by falling or falling.
7、 Quality control
（1） Quality control of plate bending post
Improper operation during the inspection of plate bent is easy to cause quality hidden dangers such as scratch, broken plate, missing plate bent, oxidation, collision and so on.
1. wipe flowers
Causes: during the process of plate bending inspection, the plate is dragged too hard or bent at the edge of the platform, the platform is not clean, the plates are placed disorderly, the laminated plates are not neat or the laminated plates are too high.
1) Clean the table with cloth before bending the inspection plate;
2) When checking the bending of the board, handle it with care. For the board with large independent line height on the pad surface, it should be more gentle. It is strictly prohibited to pull the board and bend the board at the platform edge;
3) The qualified boards shall be stacked in order and shall not exceed the high warning line, and the defective boards shall be sent out in time;
4) One platform can only check one type of board at a time.
2. broken plate
Cause: the V-CUT or stamp hole connected multi unit delivery plate plate plate bending, plate holding method is not right or the laminated plate is too high, too many plates are moved, etc. Prevention:
11) Such boards shall be held by both hands and shall not hold the board edge or fragile edge;
12) If there is a plate plate that slightly exceeds the requirements of plate bending, one hand shall be used to press V pit or stamp hole, the other hand shall be used to press gently, and the serious one shall be sent to the repair team for treatment;
13) The laminated plates shall be neat and shall not exceed the height warning line. If the blue rubber plate is used, the height shall be reduced properly;
14) The qualified board and problem Board shall be sent out in time. The Board shall not be moved too much, and the two hands shall be firm.
3. Curved plate of leakage plate
Reason: put the problem board into the qualified board by mistake, or judge by experience that a certain model or batch of boards have no board bending but have not been inspected. Prevention:
1) All plates shall be inspected 100% of the plate bending, and the plates not inspected shall not be regarded as qualified plates based on personal experience;
2) The identification shall be clear, and the problem board in the unqualified area shall be sent out in time;
Cause: the bare touch board or platform is not clean and dry. Prevention:
d) Take board must wear socks, socks damaged immediately replace;
e) Clean the platform with cloth at any time and keep the platform clean and dry.
5. crash plate
Reason: incorrect operation gesture, too much force or falling board. Prevention:
a) Handle with care, operate with both hands, and hold the board firmly;
B) when moving the board