Packaging Engineer- Bump Interconnect
Volantis · Volantis is a semiconductor manufacturing company that designs and manufactures AI chips optimized for high-performance computing needs.
Hybrid Remote/SF Bay Area/Austin/Boston (Remote)1-10 employeesPosted 3 months ago
Undisclosedraised 50 days agoled by Alumni Ventures, Unpopular Ventures, 7percent Ventures
This board only lists companies whose most recent round closed in the last 180 days.
<p>We’re seeking an experienced engineer to lead bump interconnect development for advanced semiconductor devices (2.5D/3D/chiplet/fan-out). </p>
<p> </p>
<p>This role spans ubump and C4 bump metallurgy, RDL design and</p>
<p>plating, chip-side and interposer capture pad design rules, OSAT engagement, reliability,</p>
<p>failure analysis, and cross-functional support through package and system productization.</p>
<p> </p>
<p><strong>Core Responsibilities</strong></p>
<ul>
<li>Own end-to-end bump interconnect development for both ubump (micro-bump) and C4</li>
</ul>
<p>processes, including bump formation, and reflow for use with mass reflow, TCB, and LAB chip</p>
<p>attach for high-performance semiconductor packages.</p>
<ul>
<li>Define and own bump metallurgy stacks for ubump (e.g., Cu pillar/SnAg) and C4 (e.g., SAC alloys)</li>
</ul>
<p>interconnects, including UBM selection and pad finish specifications for both chip-side and</p>
<p>interposer capture pads.</p>
<ul>
<li>Develop and own design rules for bump interconnects including pitch, bump diameter, standoff</li>
</ul>
<p>height, keep-outs, and land pad geometry for both the chip side and interposer or substrate</p>
<p>capture pads.</p>
<ul>
<li>Lead RDL (redistribution layer) process development including electroplating of Cu RDL traces,</li>
</ul>
<p>via fills, and pad finishes; define RDL design rules for line/space, via diameter, and layer stack-up</p>
<p>to meet electrical and reliability requirements.</p>
<ul>
<li>Collaborate with OSATs and bumping foundries to qualify ubump and C4 bumping processes,</li>
</ul>
<p>drive design rule alignment, and manage process transfers into production.</p>
<p> </p>
<ul>
<li>Evaluate and mitigate bump interconnect assembly risks including non-wet opens, voiding, head-</li>
</ul>
<p>in-pillow, intermetallic growth, and joint fatigue failures across both ubump and C4 interconnect types.</p>
<ul>
<li>Perform root cause analysis of assembly and reliability failures using cross-sectioning, SEM,</li>
</ul>
<p>CSAM, and other failure analysis techniques.</p>
<ul>
<li>Support reliability qualification including thermal cycling, drop, mechanical shock, and power cycling.</li>
</ul>
<ul>
<li>Work cross-functionally with design, reliability, thermal, and manufacturing teams to ensure</li>
</ul>
<p>robust package performance from concept through high-volume production.</p>
<p> </p>
<p><strong>Required Technical Skills</strong></p>
<ul>
<li>Strong experience in bump interconnect processes including ubump (Cu pillar, micro-bump) and</li>
</ul>
<p>C4 bumping for semiconductor devices.</p>
<p> </p>
<ul>
<li>Deep understanding of bumping metallurgy including UBM stacks, solder alloy systems (SnAg),</li>
</ul>
<p>intermetallic compound (IMC) formation and growth kinetics, and their impact on joint reliability.</p>
<ul>
<li>Experience with RDL plating processes including Cu electroplating, photoresist patterning, seed</li>
</ul>
<p>layer deposition, and associated design rules for line/space, via geometry, and pad stack.</p>
<ul>
<li>Understanding of thermo-mechanical behavior in bump interconnect assemblies including CTE</li>
</ul>
<p>mismatch, warpage, solder joint fatigue, and IMC-driven reliability risks for both ubump and C4</p>
<p>configurations.</p>
<ul>
<li>Hands-on experience with failure analysis and reliability testing (cross-sections, SEM, CSAM,</li>
</ul>
<p>thermal cycling).</p>
<ul>
<li>Ability to work with OSATs and suppliers to develop and transfer assembly processes into</li>
</ul>
<p>production.</p>
<ul>
<li>Strong problem-solving skills with ability to debug yield and reliability issues in manufacturing</li>
</ul>
<p>environments.</p>
<p> </p>
<p><strong>Preferred / Differentiating Skills</strong></p>
<ul>
<li>Experience with III-V packaging, photonics packaging, and precision chip attach.</li>
<li>Experience with advanced packaging technologies including 2.5D interposers, 3D stacking,</li>
</ul>
<p>chiplets, and CoWoS-like architectures.</p>
<ul>
<li>Familiarity with fine-pitch micro-bump and hybrid bonding approaches.</li>
<li>Experience integrating high-power or high-TDP devices with tight warpage and thermal</li>
</ul>
<p>constraints.</p>
<ul>
<li>Exposure to thermo-mechanical modeling or collaboration with simulation teams for warpage</li>
</ul>
<p>and reliability prediction.</p>
<ul>
<li>Understanding of system-level interactions (warpage, second-level interconnect reliability).</li>
<li>Deep expertise in bump metallurgy fundamentals including UBM stack design (Ti/Cu, etc.), solder</li>
</ul>
<p>alloy selection, wetting behavior, and the influence of plating chemistry and process conditions</p>
<p>on bump morphology and composition.</p>
<ul>
<li>Fundamental knowledge of intermetallic compound (IMC) formation, growth kinetics, and phase</li>
</ul>
<p>behavior in Cu/Sn, Ni/Sn, and Au/Sn systems; understanding of how IMC thickness, morphology,</p>
<p>and composition affect joint strength, electromigration resistance, and long-term reliability.</p>
<p><br><br></p>
<p><strong>Education & Experience:</strong></p>
<p>Industry experience in semiconductor packaging with strong emphasis on bump interconnect</p>
<p>processes, RDL development, and productization.</p>
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