PAY Optical V2 001 Manufacturing

[vogeldylan]

• [x] 0.47 uF 0603 caps missing
• [x] check photodiode reflow temperature
• [x] check LED reflow temperature

[brunofalmeida]

• [x] possibly 1 mOhm 1210 resistor missing

[vogeldylan]

@brunofalmeida we found the 1 mOhm it in the 0603 resistors pile.

[brunofalmeida]

• [x] Used wrong footprint on PCB design for AD8605 op amp (PCB has SOP-65P200X125-5N, ordered/can only order SOT23-5). Need to respec using a different op amp model with a footprint matching the PCB.
• [x] Need 0.47 uF 0603 caps (at least 2 for front of board)

[brunofalmeida]

Notes:

• Chose not to attach oscillating crystals (Y1) - will use wave generated by 32M1
• Chose not to attach optional gain resistors (R9)
• Left R27 open

[brunofalmeida]

Chose AD8613 SC70 to replace AD8605

Other replacements considered:

• matching package, pin layout, and 1 pA bias current
• many are SC70 packages, which seems compatible with SOP-5 https://www.mouser.ca/datasheet/2/348/bd5291g-e-475488.pdf http://www.ti.com/lit/ds/symlink/lpv521.pdf http://www.ti.com/lit/ds/symlink/opa2348.pdf http://www.analog.com/media/en/technical-documentation/data-sheets/AD8613_8617_8619.pdf http://www.analog.com/media/en/technical-documentation/data-sheets/AD8691_8692_8694.pdf http://www.analog.com/media/en/technical-documentation/data-sheets/AD8500.pdf http://www.onsemi.com/pub/Collateral/NCS2006-D.PDF http://www.onsemi.com/pub/Collateral/NCS2008-D.PDF http://www.onsemi.com/pub/Collateral/NCS2009-D.PDF http://ww1.microchip.com/downloads/en/DeviceDoc/20005791B.pdf http://ww1.microchip.com/downloads/en/DeviceDoc/21733j.pdf http://ww1.microchip.com/downloads/en/DeviceDoc/21881e.pdf http://ww1.microchip.com/downloads/en/DeviceDoc/20002324C.pdf http://ww1.microchip.com/downloads/en/DeviceDoc/20002321C.pdf

[vogeldylan]

Issue was discovered whereby the footprint for the 470nm LEDs included a via in the center which allowed the LEDs to poke through the board. However, the pad radius surrounding the hole was too wide, and would short to either pad of the LED as it was soldered. As a result, both pins of the LED would be shorted together.

A fix was prototyped and confirmed working whereby the legs of the LED can be bent down at a slight angle to raise the part above the metal ring.

• [x] Desolder the soldered 470nm LEDs
• [x] Bend all of the LED legs
• [x] Solder the modified LEDs onto pay-optical

[vogeldylan]

Soldered the bottom side of PAY-Optical (non-reflowed side) with Cindy

• [x] Missing MCP6546 comparator for CH5 selection
• [x] Missing 330 0402s
• [x] Missing 10K 0402s

[vogeldylan]

Inspection report with Jaden:

Bottom side

• [x] R14 is missing (0 Ohm) (upper left, center left)
• [x] R27 is missing (center right, bottom left, in the UTAT logo) (supposed to be left open)
• [x] U15 is missing
• [x] 330 near A2-1 is twisted, connection looks bad on top
• [x] 330 near A2-3 is not very well connected
• [x] R19 questionable wetting on the right side (center left)
• [x] R17 doesn't look connected on the right (center-top left)
• [x] R15 (top left) is questionable
• [x] C25 is a little crooked (center left)
• [x] C25 is a little crooked (lower-centre left)
• [x] 330 near A1-4 doesn't look connected
• [x] 2 330s near A1-7 could use better wetting
• [x] R1 resistor array looks like it has poor connection (looks ok to Dylan)
• [x] R2 resistor array to check for shorts and continuity
• [x] above D3 centre bottom R20 is shorted to the bottom via
• [x] near A5-1 there's a 330 missing
• [x] R18 & R15 (bottom right) are not there
• [x] near A5-2 four resistors are missing
• [x] U1 pin 5,6 (might be in design) also 10,11 also 21, 22 are shorted
• [x] U1 top connections are big bulky balls, questionable (27, 28 & 30 are the biggest offenders)
• [x] Capacitor below C14, looks like it needs better connection on the right
• [x] 330 to the right of A4-1 has poor wetting on the left
• [x] R6 (center right) poor wetting on the left
• [x] R18 (center right) poor wetting on the left
• [x] U12 (top right) shorts on 1,2 also 4,5 also 7,8 also 11-14
• [x] U12 (bottom right) shorts on 2,3 also 7,8 also 11,12 also 13-16
• [x] U12 (furthers right) shorts on 1/2, 4-6, 7/8 and 11/12
• [x] C44 (beside bottom right U12) wetting on the left is bad

[vogeldylan]

• [ ] Update PAY-Optical schematic with smaller footprints for the multiplexers.
• Manufacture with covered vias

[brunofalmeida]

Top side inspection notes (my initial inspection):

• [x] U4 in bottom left quadrant, top row, 2nd from left - slightly crooked
• [x] C17 and R10 in centre block, top row, right side - shorted together
• [x] U1 (in middle) - pins 3/4, 6/7, 9/10 shorted
• [x] Resistor in top left near connector - shorted to via (probably intentional)
• [x] C1 and C45 (left centre) - might be shorted
• [x] U6 (top left, left side) - pins 4/5, 7/8 shorted
• [x] U7 (top left) - pins 1/2 shorted
• [x] U12 (top left, right side) - pins 5/6, 7/8 shorted, pin 16 shorted to resistor above
• [x] U6 (bottom left, left side) - pins 7/8 shorted?
• [x] R10 (top right block, bottom row, right side) - not soldered to one pad, crooked
• [x] U6 (top right block, left side) - pins 10/11/12 shorted, pins 4/5 shorted, pin 8 shorted to resistor above?
• [x] U12 (top right block, right side) - pins 12/13 shorted
• [x] U6 (bottom right block, left side) - pins 3/4, 14/15 shorted
• [x] U12 (bottom right block, right side) - pins 9/10/11 shorted, pin 16 shorted to resistor above?
• [x] C20 (bottom right block, bottom row, 2nd from left) - crooked, too close to C21

Repeated blocks:

• [x] U4 - pins 2/3 shorted
• [x] C17, R10 - crooked
• [x] U12 - pins 7/8 shorted

[brunofalmeida]

• R14 missing is not a defect, it's by design

[vogeldylan]

"Resistor in top left near connector - shorted to via (probably intentional)" Can't find on board

• [x] U12 Top right Pin 12 needs repair (lifted from board)

[vogeldylan]

Did a re-inspection of both sides, didn't find any of the issues you mentioned @brunofalmeida and didn't find any further ones.

[brunofalmeida]

@vogeldylan I'm done inspecting, didn't see any problems. I think this is done besides your notes for the next PAY-Optical iteration.

[brunofalmeida]

This PCB still needs to be tested through PAY-SSM, but this manufacturing issue is done. We can reopen it if problems arise.