Innovations in Fiber Optics Integrated DPSK Receivers Shortterm

Innovations in Fiber Optics Integrated DPSK Receivers Short-term Solutions to Improve the Soldering of the Flex PCB and the DC Ceramic Nov. 24, 2010

Summary § Background – There was one device failure in the qualification test due to the soldering joint breakage – between the flex PCB and the DC ceramic – It was identified as a workmanship issue and the soldering quality/reliability can be improved by implementing more clear and strict in -process quality control (IPQC) § Purpose – In long run, a better design of the flex PCB can be implemented to achieve better soldering. A separate presentation will address this issue – This presentation will outline our short-term solution on improvement of the soldering and related verification test 2

Soldering Quality • The soldering of the flex PCB to the DC ceramic is a very standard soldering process. • One device was found that the soldering joint was not good and it failed in the qualification test. • This is a purely workmanship issue that can be improved and avoided by more strict IPQC 3

Process Improvement To ensure a better soldering process and soldering quality, below improvement will be implemented: • The IDRV module will be placed on a hotplate at temperature of 80 o. C. • The other soldering procedures will remain unchanged • More clear and strict IPQC will be implemented (see next slide) 4

In-Process Quality Control 1. Improve IPQC on soldering a) Operator training Start date: 11/29/2010 finish date: 11/29/2010 To define the soldering process (temp, time, and amount of solder) more quantitatively Train the operators to follow the updated procedures. b) Reference Start date: 11/29/2010 Reference soldering samples will be used by operator as a guideline bad-1 bad-2 good c) Inspection of the soldering joint under microscope will be conducted to ensure the soldering quality 5

In-Process Quality Control - continued d) High resolution Photo Start date: 11/29/2010 We will take high resolution photos of the soldering joints and send to u 2 t to review e) Update the WI Start date: 11/29/2010 finish date: 12/1/2010 Update and release the new WI. 6

Qualification Plan 2. Test Plan for current soldering a) Quantity of Samples 11 samples will be built under updated soldering process for qualification test b) Device Configuration Solder the flex pcb to DC ceramic and short circuit the other end. Use epoxy to seal the device. 7

Continuous improvement c) Mechanical shock and vibration test start date: 12/1/2010 finish date: 12/8/2010 Shock: 1000 G, 3 ms, 5 times/direction Vibration: 20 g, 60 Hz (Sinusoidal), 4 min/cycle, 4 cycle/axis d) Thermal shock and TC test start date: 12/1/2010 finish date: 2/3/2011 Thermal shock: Samples were immersed into 100 C boiled water for 2 minutes and then directly immersed into 0 C water with ice for 2 minutes. The process repeated for 5 times TC test: -40 C to 85 C, 2 C/minute; 30 minutes dwell at extremes, 500 cycles. 8

Summary 1. Improve IPQC on soldering. It will be finished by 12/1/2010 2. Test Plan for current soldering. Ø Mechanical shock and vibration tests will be finished by 12/8/2010 Ø Thermal shock will be finished by 12/6/2010 Ø 500 TC will be finished by 2/3/2010 9