1 :30pm-2:00pm(lnvited) ThTi

Optoelectronics Module Msnufacturiiig arid fts l'rosf)ects/narr,iers For Asseriibly Automation

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Newport Cosporution, Fibesopics and Photonics Divisiow, I'hotoriics l'uckuging trnd Advtmce Automation Sy,ytems I791 Deere Averrue, Irvint:, Cd!jhrnia 92606

7id: (949)253- 1625; bay: (949)253-1240; e-trttril: .sjung@nc wpost.coni

Introduction arid Uackgruond:

With ever-iricieasirig demaiids for high-spcccl signal transmission bandwidth and device c;ip;icity to handle various coinmunicaiiot~ data links, optoelccironics modtiles and its assembly automation strategy play a critical tole in fiberoptics communication and its tcchnology. In term of the capability ancl capacity, some of these optoelectronics modules, ranging from high-spced transiiiittcrs :ind inotlulators to optical arnpliiiers arid high-speccl receiveus, require an unprecedented manufacitiring l'aiiip-up. '&refore, antoination inailtifacttiring technology is playing iiii iiicrcnsingly viid role in the quality and cconolny of optoelectronics nrotlnle manufacturing.

On the othei' Iianci, wllilc automation systcnis for. nianui'acturing stich clevices itre now commercially avaikibk, the lack of opioekxironics nIodulc designs tiolnpatihlc for osscmbly antornation has IIec(Jli1c a

inanntiicturing impose acltlitioniil challenges for addressing p - > ! I l d - [ J ~ ~ ~ assembly dcvice/iibei-hantlliiiig issues that ili'c critical i t1 overall automated clevicc iiiantitiicttrriiig strategy.

b ari : ier to it reliable high-voltrrnc device mantifaciui.itig. Such device designs not coritlucivc to automation

Practical Example with Typicid 980nim Purnii-l ,I) Mutliile:

b'or the purpose of illustration an asseriibly prnccss h i , a 9XOnm l l t i i i ip-t , i~) uiotlulc -- one of the most tlcmanding opioclcctroi~ics tlcvices in ihe markct ~ ~ was sclccictl. Typical solxisseiriblics a n c l cotnponents for this inoclulc design ai'c shown i n Pigtire 1 . Uuc to thc 980-1 ,l)'s rclativcly lligl! fzlr-ticltl aspect ratio, the i'ibcr is typically wedge-slraped to form i i cylindrical Icns (witli about a 4.0 io 5 . 5 p radius along the cylindrical-axis), so lliui ilie emitted light caii bc directly coupled to into the ilbcr tip io maximize the coupling efticiency. This niodole design is specifically designed f i x laser welding its the attachment method. This iinphcs that the sub-asscinbks and coiii~~oiients, as well ;IS the cot rcsponding processes, Iiaive bccn tlcsigiicd for laser welding; Ircncc, the weld-clip, weltl-plate (on ihc i )SA), and thc fererrtilc secul.irig the wedge-shaped fiber are fabricated li.om Ncl: Y A(; lascr-welding compatible materials (see Figure 2).

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Cliallenges with tlic Optics and Assembly Process:

such package design, cspccially the optical train, presents several challenges, particuhrly in thc arcas 0.f dcvice and fiber handling, fiber alignment arid attachnicnt, and post-assembly dcvice Iiandling. ‘Ihe alignment scnsitivity is typically on tlie orcler of f O . 1 5 p i and +3.Opm across the vertical (y-axis) and horizontal (x-axis), respectively, which represents about 5% (0.25 dU) throughput loss f ~ a n the maximum coupling alignment point. Ai optimal alignincnt, tlic typical distance betwecn the 1 ,D chip- facet to the iibcr tip is oii the order of 5 to 8pm. Hence, one ciin only imagine the challenges involvc in loading and positioning all critical and extremely tiny precision components with respect to each other.

Vor cxainplc, all the assembly components are typically riiariually loaded i t1 to inside of tlic modiile, asscmbled/pigtailed (process is autoinated), and tlieii unloaded, one tlcvicc at a time. l’ypically, thc total assembly cycle-tiine 0 1 a well-developed proccss can range from 15 to 30 minutes using such couvcntional method, depending on the extent of the in-situ device validation required. However, the alignnient and attachment processes by tliernsclves can be as fast as just 2 to 3 minutes. Hence, the time consumed performing prts handling and other peripheral processes on the assembly machine can occupy most o i thc prccious machine time, limiting througliput and constrain the cost-per-pait pararnetcr.

Eurthennorc, and more impoi tautly, multiple handling steps during the iibcr-pigtailing process (from device subassembly, to fibci pigiailing, to seam-scaliiig, temperatiire cycling, and finally post-assembly module qualification), can induce breakage, static damage, 01 othcr handling-related yield problems throughout the dcvice inaiiufacturing cycle. While such manufacturing practice is widely used in the industry today, it has also been speculated to be a contributing Factor in “packagirig induced failure,” otherwise known as the PIE’ factor.

Optoelectronics Module 1)esign Conducive For Assembly Autonraiion:

l‘ypically, a machine is the physical manifestation of the process. Hence, optoelectronics module desigiied with the view of automation manufacturing is the key to lowering thc barriers to a siiccessiiil assembly automation that will reduce, if not eliminate, some of the clialleiiges as stated above. Therefore, many constraints on assembly cycle time are crcated by the package designs themselves, and few existing optoelectronics packages have been truly designed with assembly autoination in mind. Everything inattcrs in designiug optoelectronics niodulc for autoinated assembly. For the above example, many of the process related designs that have an impact on the assembly automation - - e.g., opto-mechanical tolcrances, aligu, attach, arid parts handling - can be coiisidercd in to the optoelectronics module design and asscmbly automatioil strategy in such way that the dcvice design is conducive to automation. It would require technology development effort i n the areas of micro-optics, material science, high- precision automation mechanisms, and aclveiice process automation.

Conclusion:

In our cfforts to address some of these issues, we have developed a combination approach to the solution by examining the system, tooling, and process for sonic well-known device types, such as thc 98Onin Pump-LD module, pigtailed or coniicctorized coaxial devices, ant1 various planar passive waveguide splitters. While them is still considerable room for refining and iinproviiig our current antomation technology, it should also be emphasizes tliat tlicrc is a symbiotic relationship that exists between the package dcsign, thc asscnibly process, and the rnachine’s capability and capacity to execute the intended design of‘ each. That is to say, most autoination equipment is simply the physical manifestation of the package design and asseinhly process. Without this holistic approach to solving the assembly cost problem, we are rnilikcly to successtiilly meet the ever-increasing market demands for higher quantities, lower cost, and improved quality.

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