Precision submounts and hermetic packaging for optical and RF systems.
Single-crystal SiC submounts at 350–400 W/m·K — one of the only qualified sources accessible to US engineers. Plus polycrystalline ALN, TO headers, and hermetic packages from ISO9001-certified manufacturers with 2–4 week lead times.
Get pricing in 24 hours
Key outcomes
350 W/m·K
Single-crystal SiC — the highest thermal conductivity available in a ceramic submount.
Without polycrystalline grain boundaries, phonon transport is unimpeded. FerraLink is one of the only sources of qualified single-crystal SiC submounts accessible to US engineering teams.
Learn more →170 W/m·K
Polycrystalline ALN — best CTE match for InP and GaAs laser diodes.
Grain boundaries limit conductivity to 170–210 W/m·K — still 6–8× better than alumina. The right choice when CTE matching and cost matter more than absolute thermal performance.
Learn more →≤1×10⁻³ Pa·cm³/s
Hermetic packages tested to the tightest leak rate standards.
Every hermetic package meets ≤1.0×10⁻³ Pa·cm³/s leak rate, ≥500V AC dielectric withstanding, and ≥10,000 MΩ insulation resistance — qualified for −65°C to +150°C operating environments.
Learn more →2–4 weeks
Typical first-sample turnaround — so your program stays on schedule.
From design review to first article in weeks, not months. Responsive engineering support means you iterate quickly from prototype to production without sacrificing quality.
Learn more →Product
FerraLink provides single-crystal SiC and polycrystalline ALN submounts, TO headers, hermetic packages, and optical transceivers — sourced from ISO9001-certified manufacturers and engineered to meet your thermal, mechanical, and connectivity requirements from prototype to production.
Single-crystal SiC, polycrystalline ALN
TO headers, packages, HTCC
Transceivers, optical windows
Single-crystal SiC — smooth crystalline facets, 2000×
SiC Submounts
Only US sourceSingle-crystal silicon carbide delivers 350–400 W/m·K — the highest thermal conductivity of any practical ceramic substrate. Without polycrystalline grain boundaries, phonon transport is unimpeded. FerraLink is one of the only sources of qualified SiC submounts accessible to US engineering teams.
- Single-crystal SiC — 350–400 W/m·K, no grain-boundary phonon scattering
- CTE: 3.7–4.3 ppm/°C — excellent match for GaN and Si power devices
- Ideal for multi-watt laser bars, pulsed lidar emitters, GaN RF, EV power modules
- Metallization: Ti/Pt/Au, Ti/Ni/Au, Au/Sn 80/20 (3–5 µm)
- Custom sizes and thickness available; standard sizes in stock
Standard part numbers
Polycrystalline ALN — grain boundaries visible, 2000×
ALN Submounts
Polycrystalline aluminum nitride combines 170–210 W/m·K thermal conductivity with a CTE that closely matches InP and GaAs laser diodes. Grain boundaries visible in SEM — still 6–8× better than alumina. Edge gap down to 5 µm for precision edge-mount assembly.
- Polycrystalline ALN — 170–210 W/m·K, best CTE match for InP/GaAs
- CTE: 4.3–4.6 ppm/°C — ideal for InP (4.5) and GaAs (5.7) devices
- Au/Sn 80/20 selective deposition eliminates solder preform handling
- Edge gap down to 5 µm for edge-emitting laser diode assembly
- Metallization: Ti/Pt/Au, Ti/Ni/Au, Au/Sn 80/20
Standard part numbers
TO Headers
Full range of transistor outline headers for optical, laser, and electronic device packaging.
- Laser diodes: TO18, TO46, TO56, TO60 (2.5G, 10G, 25G)
- Sensors: TO5, TO8, TO39
- RF & microwave: TO3, TO220-style flanged housings
- Custom pin counts, glass-to-metal seals, lensed caps
- Optical windows: sapphire, AR-coated, ball lens, flat, aspheric
Standard part numbers
Hermetic Packages
Metal-ceramic hermetic packages for high-reliability optical, sensor, and RF applications.
- Butterfly / TOSA / ROSA: 25G, 100G, coherent
- Cavity packages: lidar, RGB laser, high-power diode bars
- Mixed-circuit housings for hybrid integrated circuits
- HTCC co-fired ceramic packages (SMD, LCC, multi-pin)
- Leak rate: ≤1.0×10⁻³ Pa·cm³/s | Temp: −65°C to +150°C
Standard part numbers
Optical Transceivers
Cost-effective, reliable transceivers for data communications, industrial, and specialty connectivity.
- Datacom: SFP, SFP+, QSFP form factors
- Industrial and specialty: single-mode and multimode
- Wavelengths: 850 nm, 1310 nm, 1550 nm
- Qualified for enterprise, telecom, and harsh environments
Standard part numbers
Custom sizes and metallizations available — send design files in DXF, DWG, or Gerber to info@ferralink.com
Order evaluation samples
10-piece standard sample boxes — evaluate FerraLink quality directly in your lab before committing to production. Ships within 2–4 weeks with full material documentation.
Place your order
Order summary
← Select a sample box
We confirm and send a payment link within 1 business day.
Engineering services
FerraLink is not only a parts supplier — we help you select materials, freeze stackups, and move from sample evaluation to custom production.
DFM review
Send your drawing — feasibility, lead time, MOQ, and risk flags within 2 business days.
Start DFM review →Submount co-design
Chip + system review → submount geometry, metallization, and package stackup with part numbers.
Book walkthrough →Prototype → production
Standard samples first, then custom qualification at ~2,000 pc MOQ, then production release.
See full path →How we work
Small volume means standard samples only. Custom submounts typically require a 2,000 pc MOQ — we respond to RFQs within 2 business days.
Standard samples
- ALN box $250 · SiC box $500
- Catalog samples from $25 / $50
- Lead time 2–4 weeks
Custom production
- Custom size, pads, metallization
- DXF, Gerber, STEP accepted
- Lead time quoted after DFM
| Order type | Typical lead time |
|---|---|
| Standard sample box | 2–4 weeks |
| Catalog sample | 2–4 weeks |
| Custom geometry | Quoted per project |
| Production repeat | Quoted per PO |
Industries we serve
FerraLink components are qualified and in use across demanding applications where thermal performance, hermeticity, and precision matter.
TO18/46/56, butterfly packages, 25G/100G TOSA/ROSA, optical transceivers
Hermetic cavity packages, HTCC ceramics, high-reliability ALN submounts
High-power TO headers, SiC submounts, AuSn solder preforms, lensed caps
Hermetic SMT packages, sapphire optical windows, sensor housings
RGB laser packages, cavity packages, ALN substrates with CTE-matched metallization
DBC/AMB substrates, HTCC packages, current capacity >50 A, up to mm-wave frequencies
SiC and ALN DBC/AMB substrates for EV, traction, and industrial power modules
High-density thick-film substrates, solid metal vias, integrated resistors
Why FerraLink
Engineering teams have three options for submounts and hermetic packaging. Here is an honest comparison.
Why not buy direct from a manufacturer?
Direct relationships with overseas manufacturers require MOQs, long lead times, and managing quality across language and timezone barriers. One supplier change can stall your program for months.
FerraLink qualifies and manages supplier relationships so you get competitive pricing, multi-source optionality, and a single point of accountability — without the overhead of managing international vendors yourself.
Why not use a general distributor?
General distributors fill orders — they don't help you select substrate material, troubleshoot hermetic seal failures, or adapt a package design to your thermal requirements. You get catalog numbers, not engineering guidance.
FerraLink engineers speak the language of thermal design, hermeticity, and optical alignment. We help you select the right substrate, metallization, and package before you place an order — and stay accountable through qualification.
Why FerraLink for SiC?
SiC submounts deliver 350–400 W/m·K — the highest thermal conductivity in any practical ceramic substrate. But almost no distributor stocks them, and the handful of manufacturers that produce them are not easily accessible to US engineering teams.
FerraLink is one of the only sources of qualified SiC submounts with short lead times available to US engineers. We stock standard sizes, support custom dimensions and metallization, and can ship evaluation samples within 2–4 weeks — something no general distributor or US domestic fab can match.
Technology
FerraLink partners deliver precision ceramics and hermetic packaging using the same fabrication technologies found in defense, telecom, and aerospace supply chains.
Performance benefits
SiC — single-crystal, highest conductivity
Single-crystal silicon carbide has no grain-boundary phonon scattering — the highest thermal performance of any practical ceramic substrate. FerraLink is one of the only US-accessible sources.
ALN — polycrystalline, best CTE match
Polycrystalline ALN combines strong thermal conductivity with a CTE that closely matches InP (4.5) and GaAs (5.7) laser diodes — grain boundaries visible in SEM.
Fine-line patterning
DPC process achieves minimum line/space of 50 µm on ALN and SiC — enabling dense photonic and RF circuit layouts.
High current capacity
Thick plated copper metallization on ceramic carriers handles >50 A continuously — suitable for power modules and driver circuits.
Hermetic integrity
All hermetic packages tested to ≤1.0×10⁻³ Pa·cm³/s leak rate and ≥500 V AC dielectric withstanding voltage.
Qualified environments
Packages qualified through 1000+ thermal cycles per MIL-STD-810 — ready for defense, aerospace, and industrial deployment.
Substrate material comparison
| Property | SiC | ALN | Al₂O₃ (Alumina) |
|---|---|---|---|
| Crystal structure | Single crystal | Polycrystalline | Polycrystalline |
| Thermal conductivity | 350–400 W/m·K | 170–210 W/m·K | 26–30 W/m·K |
| CTE (ppm/°C) | 3.7–4.3 | 4.3–4.6 | 6.7–8.1 |
| Dielectric constant | ~10 | 8.8–8.9 | 9.4–10 |
| Flexural strength | 400–500 MPa | 300–400 MPa | 300–400 MPa |
| Device compatibility | GaN, Si power devices, lidar | Si, GaAs, InP — best CTE match | GaAs-based (general use) |
| Key benefit | Highest thermal conductivity available | Best CTE match for InP/GaAs lasers | Low cost, mature supply chain |
| Typical application | Power electronics, lidar, laser bars, EV | Laser diode, high-power RF, optical modules | General purpose substrates |
Material verification — SEM & EDS
The thermal performance difference between SiC and ALN starts at the microstructure level. Single-crystal SiC conducts heat with minimal phonon scattering, while polycrystalline ALN — though still far superior to alumina — loses conductivity at every grain boundary.
SiC (single crystal)
FerraLink SiC submounts use single-crystal silicon carbide. Without grain-boundary phonon scattering, thermal conductivity reaches 350–400 W/m·K — the highest of any practical ceramic substrate available to packaging engineers.
ALN (polycrystalline)
ALN submounts are polycrystalline ceramics. Phonons scatter at grain boundaries, which limits bulk thermal conductivity to 170–210 W/m·K — still 6–8× better than alumina, with excellent CTE match to InP and GaAs laser diodes.
Manufacturing processes
DPC — Direct Plated Copper
Sputter-deposit Cu on ceramic, then build up with electroplating. Delivers the highest patterning resolution (<50 µm) for fine-pitch submounts and densely interconnected photonic layouts.
AMB — Active Metal Brazing
Bond thick copper foil to ALN or SiC using active-metal braze paste under controlled atmosphere. Optimum for high-power modules where current-carrying capacity and thermal cycling life matter most.
DCB — Direct Copper Bonding
Diffusion-bond copper to Al₂O₃ or ALN using a Cu₂O eutectic process. No filler material needed — ideal for power electronics requiring outstanding thermal fatigue resistance.
HTCC — High-Temperature Co-fired Ceramic
Multilayer ceramic co-fired at >1500°C with W/Mo metallization. Used for hermetic SMD packages, TO-replacements, and multi-pin signal housings in defense and telecom.
Standard submount metallizations
| Stack | Thickness | Best for | Notes |
|---|---|---|---|
| Ti/Pt/Au | 1000Å / 1500Å / 5000Å | Universal — wire bond & die attach | Best all-round choice; Pt barrier prevents Au–Ti interdiffusion |
| Ti/Ni/Au | 1000Å / 1500Å / 10000Å min. | Solder die attach, high Au thickness | Ni diffusion barrier active above 350°C — verify reflow profile |
| Au/Sn (80/20) | 3–5 µm | Laser diode die attach preform replacement | Eliminates solder preform handling; avoids rollup at edge pads |
| Ti/TiW/Au | Custom | High-reliability hermetic applications | TiW diffusion barrier; suitable for −65°C to +150°C cycling |
Design tolerances
Three tiers available depending on your application. Contact us to confirm which tier applies to your design.
| Specification | Typical | Select | Critical |
|---|---|---|---|
| Au/Sn pad placement accuracy | ±0.0005" (±12.7 µm) | ±0.0003" (±7.6 µm) | On request |
| Minimum line / space | 50 µm | 25 µm | On request |
| Edge gap (edge-mount laser) | 10 µm | 5 µm | On request |
| Au/Sn solder thickness | 4–6 µm sputtered | 4–7 µm plated | ±2 µm tolerance |
| Substrate thickness tolerance | ±10% | ±5% | ±2% |
| Circuit dimensional tolerance | ±0.002" (50.8 µm) | ±0.001" (25.4 µm) | ±0.0005" (12.7 µm) |
| Front-to-back registration | ±0.001" (25.4 µm) | ±0.0005" (12.7 µm) | On request |
Reliability & hermeticity
Leak rate
≤1.0×10⁻³ Pa·cm³/s
all hermetic packages
Dielectric withstanding
≥500 V AC
between pin and housing
Insulation resistance
≥10,000 MΩ
100 V DC, 25°C
Operating temperature
−65°C to +150°C
qualified range
Thermal cycling
1000 cycles min.
per MIL-STD-810 profile
Marking permanence
MIL-M-13231C
lot traceability
Technical articles
Practical guides and research notes for engineers — including SEM and EDS data from FerraLink ALN and single-crystal SiC material lots.
Thermal Path Design for Pulsed LiDAR Emitters: Junction to Heat Sink
GaN RF Power Module Submount Selection: SiC vs ALN vs Cu-Mo-Cu
What Is a Laser Diode Submount? Types, Materials, and Selection Guide
ALN vs SiC Submounts: Thermal Conductivity, CTE, and Cost Comparison
Cooled vs. Uncooled TO56/TO60: When Do You Need a TEC?
AuSn Pre-deposited Submounts: Why They Improve Assembly Yield
TO18, TO46, TO56, TO60: Which Laser Diode Header for Your Application?
Hermetic Packaging for LiDAR Applications
How to Qualify a Ceramic Substrate Supplier
How to Reduce Laser Packaging Costs Without Compromising Hermeticity
Resources
Datasheets, design guides, and application notes are available on request. Tell us which product you are evaluating and we will send the relevant documents directly.
A technology leader needed hermetic seal packaging for advanced semiconductor applications with tight reliability and timeline requirements. FerraLink delivered custom packaging with unmatched reliability and precision, plus exceptional support throughout the project. The result: a qualified solution that met their performance and program goals on schedule.
Request full case study →Datasheets & application notes by product line
ALN & SiC Submounts
- Datasheet: ALN submount standard sizes and metallization optionsPDF on request
- Design guide: AuSn solder pad layout and placement tolerancesPDF on request
- Application note: CTE matching for GaAs, InP, and Si devicesPDF on request
TO Headers
- Datasheet: TO18 / TO46 / TO56 / TO60 outline dimensionsPDF on request
- Application note: optical window selection (sapphire, AR coat, ball lens)PDF on request
- Design guide: pin count and glass-to-metal seal optionsPDF on request
Hermetic Packages
- Datasheet: butterfly / TOSA / ROSA packages (25G, 100G)PDF on request
- Datasheet: HTCC ceramic SMD and multi-pin packagesPDF on request
- Test report: leak rate, dielectric withstanding, thermal cyclingPDF on request
Optical Transceivers
- Datasheet: SFP / SFP+ / QSFP form factorsPDF on request
- Application note: wavelength selection (850 nm, 1310 nm, 1550 nm)PDF on request
- Qualification summary: industrial and harsh-environment variantsPDF on request
Design guidelines
General design rules
PDFMinimum line/space, via rules, substrate thickness tolerances, and metallization stack options for ALN and SiC.
Thermal performance guide
PDFHow to select substrate material and thickness for your power density and junction temperature target.
CAD data guidelines
PDFFile formats, layer naming, and annotation requirements. Design files accepted in DXF, DWG, or Gerber.
Design for manufacturability
PDFCovers solder pad geometry, pullback rules, AuSn reflow profiles, and assembly best practices.
Company
Our story
FerraLink specializes in precision ceramic substrates and hermetic packaging for optical, RF, and high-power electronic systems. We bring together deep materials knowledge, rigorous process engineering, and a supply chain built for both performance and efficiency — so engineering teams can access the quality their programs demand without the cost and complexity that typically comes with it.
Our components are produced under ISO9001, IATF16949, and ISO14001 certified quality systems, with full lot traceability and material certification on every shipment. Specifications are owned and controlled end-to-end — from substrate design and metallization stack through final inspection — ensuring consistency from first prototype to production volume.
Competitive pricing at FerraLink is the result of deliberate design — optimized processes, efficient volume management, and a supply chain built to eliminate unnecessary cost at every stage. Customers receive the documentation and performance of a premium supplier at a price point that makes qualification straightforward and adoption easy to justify.
Team
Leadership
Founder and leadership with deep experience in materials, packaging, and manufacturing for high-reliability applications.
Engineering
Technical team specializing in substrate selection, hermetic sealing, optical packaging, and thermal design — so you work with people who speak your language.
Operations
Manufacturing and supply chain focused on quality, turnaround, and consistency from prototype to production.
Supplier certifications
Our manufacturing partners carry the following certifications — each verified as part of FerraLink's supplier qualification process.
Work with us
We're looking for people who care about precision, reliability, and partnership. If you want to work on hard problems in materials and packaging, get in touch.
FerraLink gives you precision submounts, hermetic packaging, and reliable connectivity—with materials expertise and engineering partnership—so you can ship optical and RF systems faster and with confidence.
Schedule a technical walkthrough
Ask a quick question
Have a quick question? Email us at info@ferralink.com or call +1 617-855-8058.
What happens next?
- •We'll respond within one business day.
- •Next step is typically a short call or email to understand your requirements.
- •We'll recommend options (standard samples or custom at ~2,000 pc MOQ) and provide a quote and lead time.
- •See engineering services and how we work for MOQ and DFM details.
- •No obligation—we're happy to help you scope before you commit.
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