How Silcotech Industry Helped a Telecom Equipment Manufacturer Fix Inconsistent Thermal Performance Across a High-Volume Assembly Line

How Silcotech Industry Helped a Telecom Equipment Manufacturer Fix Inconsistent Thermal Performance Across a High-Volume Assembly Line

A telecom equipment manufacturer building outdoor network enclosures had a problem that only showed up in the field, never in the lab: a small but persistent percentage of units were running hotter than expected, and nobody could pin down why. Every unit used the same components, the same enclosure, the same thermal design. The only thing that varied, it turned out, was how consistently a gap-filling thermal material was making contact between the heat-generating components and the heat sink across thousands of units a month.

The Challenge

The manufacturer's existing solution relied on a thermal grease applied by hand at the point of assembly. On paper, grease should have filled the gap between each component and its heat sink evenly. In practice, gap heights varied slightly from unit to unit due to normal tolerance stack-up, and grease application depended on the technician doing the work — too little in some spots, too much squeezed out in others.

• Field failures traced to localized overheating showed no clear pattern tied to component batch or supplier
• Root cause investigation pointed to inconsistent grease coverage across the varying gap heights created by tolerance stack-up
• Manual grease application was slowing down the assembly line and creating a cleanup and rework burden
• The manufacturer needed a fix that worked across a range of gap heights without requiring tighter mechanical tolerances on the enclosure
• Any new material had to maintain the same electrical insulation and flame retardancy properties the design already depended on for outdoor, unattended installations

This wasn't a one-time engineering fix the manufacturer could solve and move past — it was a recurring quality and reliability risk built into a process running thousands of units a month, with field failures that were expensive to diagnose and worse to explain to their own customers.

The Solution

Silcotech's engineering team started by looking at the problem as a process consistency issue, not just a material selection issue. Thermal grease could theoretically work, but it was fighting against a variable — gap height — that wasn't going away.

1. Reviewed the actual gap height range across the manufacturer's tolerance stack-up — rather than recommend a single-thickness solution, Silcotech's team looked at the real distribution of gap heights the assembly process was producing.
2. Recommended a switch to a thermally conductive silicone pad — a compressible, cuttable gap-filling material designed specifically for applications where the gap between a heat source and a heat sink needs to be bridged consistently, regardless of small variations in gap height.
3. Matched pad thickness and compressibility to the tolerance range — Silcotech worked through pad options that could compress to accommodate the tightest gaps in the distribution while still maintaining full contact at the widest gaps, rather than a one-size compromise.
4. Confirmed electrical insulation and flame retardancy requirements were maintained — since the application involved outdoor, unattended equipment, Silcotech verified the pad's insulation and flame-retardant properties met the same standards the manufacturer's existing grease-based solution was certified against.

5. Supported a line trial with pre-cut pads — because the pad material can be cut to size, Silcotech worked with the manufacturer to have pads pre-cut to the exact dimensions needed for the application, removing the variability of manual grease application entirely.

    

Technical Support & Collaboration

The manufacturer's process engineering team had been treating this as a materials science problem, bringing in different grease formulations and getting marginal improvement each time. What changed the trajectory was a conversation with Silcotech's applications engineers that started with a question the manufacturer hadn't been asked before: what does your actual gap height distribution look like across the line, not just in the nominal design?

From there, the collaboration moved fast. Silcotech didn't just ship a product recommendation — they worked directly with the manufacturer's process engineers to size pre-cut pads to the application, cutting out a step where miscommunication or measurement error could creep back in. When early trial units needed a slightly different pad thickness after the first round of testing, that turnaround happened through a direct engineering conversation, not a formal change-order process that would have added weeks to the trial.

The Outcome

Switching to pre-cut thermally conductive silicone pads eliminated the variability that manual grease application had introduced. Thermal performance across trial units became consistent regardless of where each unit fell in the gap height distribution, and the manufacturer's field failure rate tied to localized overheating dropped substantially in the units built with the new process.

The change also solved a problem the manufacturer hadn't originally called Silcotech about: assembly line speed. Removing manual grease application and the associated cleanup step shortened the time needed per unit and eliminated a source of rework that had been quietly eating into throughput.

Why It Worked

• Starting with the real process variation, not the ideal design spec — Understanding the actual gap height distribution led to a solution that worked across the full range, not just the nominal case.
• A material properties match, not just a thermal conductivity number — Confirming electrical insulation and flame retardancy held up meant the fix didn't create a new compliance question to solve.
• Direct engineering collaboration on cut-to-size logistics — Working through pre-cut pad sizing together removed a manual step that had been the actual source of the original problem.
• Fast iteration without formal change-order delays — Adjusting pad thickness after early trial results happened through a direct conversation, not a slow approval chain.

Thermal issues that show up inconsistently across a high-volume line are often process problems wearing a materials science disguise. The fix here wasn't a fundamentally different thermal conductivity number — it was a material format built for the way real assembly lines actually produce variation, matched by a vendor willing to ask about the process before recommending a product.

Dealing with inconsistent thermal performance across a high-volume assembly process? Contact our team at info@silcotechindustry.com to talk through your specific application.

Frequently Asked Questions

What's the difference between a thermally conductive silicone pad and a thermal grease or paste? A thermally conductive pad is a solid, compressible material cut to a defined shape and thickness, designed to bridge a gap between a heat source and a heat sink with consistent contact. Thermal grease is a semi-liquid applied by hand or dispenser, which can perform well when applied precisely but is more sensitive to application technique and gap variation across a production run.

Can a silicone pad really handle variation in gap height across different units? Within a defined compression range, yes. Pads are selected based on their compressibility and thickness relative to the actual gap height distribution in the application, so a properly matched pad maintains contact across the tightest and widest gaps in that range without requiring the gap itself to be tightly controlled.

Does switching from grease to a pad affect electrical insulation or flame retardancy? Not inherently, but it shouldn't be assumed. Pad formulations vary in their electrical insulation and flame-retardant properties just as grease formulations do, so any switch should be validated against the same certification requirements the original material was meeting, particularly for outdoor or unattended equipment.

Is pad thickness a fixed choice, or can it be customized to an application? Thermally conductive silicone pads can typically be cut to specific dimensions and are available in multiple thickness options, which allows a vendor to match the pad to a specific gap height range rather than forcing an application into a generic, off-the-shelf size.

Does using pre-cut pads actually improve assembly line speed? It can, particularly when the process it replaces involves manual dispensing and cleanup, both of which take time and introduce variability. Removing that manual step often shortens per-unit assembly time in addition to improving thermal consistency, though the actual gain depends on the specific process being replaced.

How should a buyer evaluate whether a gap-filling pad is the right fix versus a design change? If the underlying issue is variation in a gap that's a normal result of tolerance stack-up, a properly matched gap pad is usually more practical than tightening mechanical tolerances across an entire enclosure design. If the gap itself is too large or too inconsistent for any pad in a reasonable compression range to bridge reliably, that's a signal the mechanical design needs attention first.