Celestica Corporation

A multinational electronics manufacturing services (EMS) company.

Manufacturer, Standards Setting / Certification, Training Provider

Celestica’s global manufacturing network comprises more than 40 locations in 11 countries in the Americas, Europe and Asia, supplying a wide variety of leading OEMs (original equipment manufacturers). In addition to manufacturing, the company's global services include design and engineering, systems assembly, fulfillment and after-market services.

Celestica Corporation Postings

7 technical articles »

Whisker Formation Induced by Component and Assembly Ionic Contamination


This paper describes the results of an intensive whisker formation study on Pb-free assemblies with different levels of cleanliness. Thirteen types of as-received surface-mount and pin-through-hole components were cleaned and intentionally contaminated with solutions containing chloride, sulfate, bromide, and nitrate. Then the parts were assembled on double-sided boards that were also cleaned or intentionally contaminated with three fluxes having different halide contents. The assemblies were subjected to high-temperature/high-humidity testing (85_C/85% RH). Periodic examination found that contamination triggered whisker formation on both exposed tin and solder fillets. Whisker occurrence and parameters depending on the type and level of contamination are discussed. Cross-sections were used to assess the metallurgical aspects of whisker formation and the microstructural changes occurring during corrosion....


Oct 11, 2022 | John McMahon and Brian Gray

The increased temperatures associated with Pb-free processes have produced significant challenges for PWB laminates. Newly developed laminates have different curing processes, are commonly filled with ceramic particles or micro-clays and can have higher Tg values. These changes which are aimed at improving the materials resistance to thermal excursions and maintaining electrical integrity through primary attach and rework operations have also had the effect of producing harder resin systems with lower fracture toughness....

The Great SAC Debate: Comparing The Reliability Of SAC305 And SAC405 Solders In A Variety Of Applications

Sep 08, 2021 | Heather McCormick, Polina Snugovsky, Craig Hamilton, Zohreh Bagheri, and Simin Bagheri

Although the electronics industry has largely settled on the use of SAC alloys for the assembly of the majority of lead free products, debate continues to exist over which SAC alloy – SAC305 (Sn3.0Ag0.5Cu) or SAC405 (Sn3.8Ag0.8Cu) – to use. The North American industry generally favours SAC405, while the Asian industry favours SAC305. SAC305 has the significant benefit of being less expensive than SAC405 owing to its lower silver content. However, there are lingering questions about whether the reliability of SAC305 is comparable to that of SAC405. Recent studies have concluded that no significant difference exists, but many potential applications were not studied. This paper compares the results of reliability testing of SAC305 and SAC405 in three different cases on a test vehicle representative of a mid-complexity server-type product which included a range of component types from CBGAs to discrete resistors....

Deposition of Solder Paste into High Density Cavity Assemblies

Feb 28, 2018 | Fernando Coma, Jeffrey Kennedy, Thilo Sack

Circuit functional density requirements continue to drive innovative approaches to high performance packaging. Some new approaches include; aggressive space reduction, embedded solutions, and those that offer some form of risk reduction and rework potential are now options that are being explored by customers. Requirements for assembly of these types of packages necessitate the deposition of solder paste and assembly of components into cavities of the substrates to gain z-axis density as well as area functional density. Advances in the fabrication of PWB’s with cavities using newly developed laser micro-fabrication processes along with increased circuit pitch density of 50 micron lines and spaces permit new applications for high performance electronic substrates.

First published at SMTA Pan Pacific Symposium...

Implementing Robust Bead Probe Test Processes into Standard Pb-Free Assembly

Aug 20, 2015 | John McMahon P.Eng, Tom Blaszczyk, Peter Barber

Increasing system integration and component densities continue to significantly reduce the opportunity to access nets using standard test points. Over time the size of test points has been drastically reduced (as small as 0.5 mm in diameter) but current product design parameters have created space and access limitations that remove even the option for these test points. Many high speed signal lines have now been restricted to inner layers only. Where surface traces are still available for access, bead probe technology is an option that reduces test point space requirements as well as their effects on high speed nets and distributes mechanical loading away from BGA footprints enabling test access and reducing the risk of mechanical defects associated with the concentration of ICT spring forces under BGA devices.

Building on Celestica's previous work characterizing contact resistance associated with Pr-free compatible surface finishes and process chemistry; this paper will describe experimentation to define a robust process window for the implementation of bead probe and similar bump technology that is compatible with standard Pb-free assembly processes. Test Vehicle assembly process, test methods and "Design of Experiments" will be described. Bead Probe formation and deformation under use will also be presented along with selected results....

Solving the ENIG Black Pad Problem: An ITRI Report on Round 2

Jan 17, 2013 | F.D.Bruce Houghton

A problem exists with electroless nickel / immersion gold (ENIG) surface finish on some pads, on some boards, that causes the solder joint to separate from the nickel surface, causing an open. The solder has wet and dissolved the gold. A weak tin to nickel intermetallic bond initially occurs, but the intermetallic bond cracks and separates when put under stress. Since the electroless nickel / immersion gold finish performs satisfactory in most applications, there had to be some area within the current chemistry process window that was satisfactory. The problem has been described as a 'BGA Black Pad Problem' or by HP as an 'Interfacial Fracture of BGA Packages…'[1]. A 24 variable experiment using three different chemistries was conducted during the ITRI (Interconnect Technology Research Institute) ENIG Project, Round 1, to investigate what process parameters of the chemical matrix were potentially satisfactory to use and which process parameters of the chemical matrix need to be avoided. The ITRI ENIG Project has completed Round 1 of testing and is now in the process of Round 2 TV (Test Vehicle) build....

The Application of Spherical Bend Testing to Predict Safe Working Manufacturing Process Strains

Jan 09, 2013 | John McMahon P.Eng, Brian Gray P.Eng,

The increased temperatures associated with lead free processes have produced significant challenges for PWB laminates. Newly developed laminates have different curing processes, are commonly filled with ceramic particles or micro-clays and can have higher Tg values. These changes designed to reduce Z-axis expansion and improve the materials resistance to thermal excursions through primary attach and rework operations have also produced harder resin systems with reduced fracture toughness....

6 news releases »

Celestica Recognized as Canadian Manufacturer of the Year

Jul 13, 2011 | Celestica has been awarded Canadian Manufacturer of the Year by Canadian Manufacturers and Exporters (CME).

Celestica Recognized for Outstanding Contribution to the Electronics Industry

Apr 22, 2011 | Celestica has been named by IPC as the 2011 recipient of the Stan Plzak Corporate Recognition Award.

Celestica Introduces an ITANIUM� 2-Based Reference Design for Workstations

Jun 30, 2003 | The Reference Design Will Enable Broader Adoption of Itanium 2-Based Workstations

Celestica will Close Oklahoma City Factory

Feb 28, 2003 | Celestica will shutter its Oklahoma City PCB operation by November and do away with 450 jobs.

NEC and Celestica announce significantly expanded

Jan 08, 2002 | strategic outsourcing relationship

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