An LCC package, or leadless chip carrier, is a surface-mount IC package that connects to the board through metallized pads and edge castellations instead of protruding leads. Most are ceramic and hermetic, which is why they still dominate aerospace, defense, and space hardware. This guide covers the specifications, the JEDEC drawings, how the LCC compares to PLCC, CLCC, and QFN, and the solder-joint reliability math that decides where you can actually use one.

Key takeaways

• An LCC (leadless chip carrier) terminates in edge pads and castellations, not leads; the ceramic, hermetic version (CLCC or LCCC) is the one you meet in high-reliability designs.
• Standard pitch is 1.27 mm (50 mil) or 1.016 mm (40 mil), with pad counts from 8 to 100, registered under JEDEC drawings MS-002 through MS-009.
• The constraint that matters most: alumina ceramic expands at about 6 ppm/°C and FR-4 at roughly 15–18 ppm/°C, and that mismatch fatigues the corner solder joints first.
• Castellated terminations wick solder up the package edge, so joints stay visible for optical and X-ray inspection — an advantage over the QFN.
• For most new commercial designs, QFN or BGA has replaced the LCC; specify a ceramic LCC when you need hermeticity, a wide temperature range, or radiation tolerance.

What is an LCC (leadless chip carrier) package?

A leadless chip carrier (LCC) is a square or rectangular surface-mount package that houses an IC and terminates in flat metal pads and castellated grooves around its bottom edge rather than in leads. It solders directly to the board, is usually ceramic and hermetically sealed, and is valued for its resistance to vibration and temperature extremes.

Most LCCs carry the die on a multilayer ceramic substrate, with short internal traces running to the castellations on all four sides. Removing the leads shortens the electrical path, which helps at high frequency, and the ceramic body seals the die against moisture.

The naming trap: LCC, LCCC, CLCC, PLCC, and JLCC

The acronyms around chip carriers are genuinely inconsistent, and getting one wrong on a bill of materials orders the wrong part.

• LCC is read as leadless chip carrier by most vendors, but a few (including the Texas Instruments package finder) use the “L” for leaded. Always confirm against the mechanical drawing.
• CLCC and LCCC both mean ceramic leadless chip carrier — the same package under two acronyms.
• PLCC is a plastic leaded chip carrier: a molded plastic body with J-shaped leads folded under all four sides at 1.27 mm pitch. It is a lower-cost evolution of the ceramic leadless carrier, not the same package.
• JLCC is the ceramic, J-leaded cousin of the PLCC.

One more point, because search engines file the two together: an LCC is not an HSOP. An HSOP (heat-sink small outline package) is a two-sided SOP with gull-wing leads and a copper heat slug for power dissipation. It shares nothing structural with a leadless chip carrier.

LCC package specifications at a glance

The table below covers the parameters an engineer checks first. Pad counts and pitch follow the ceramic leadless family documented by materials suppliers such as Evergreen Semiconductor; the JEDEC registrations come from Publication 95, the microelectronic-standards (MS) index.

Parameter	Typical value or range
Termination	Edge pads plus castellated grooves; no leads
Pitch	1.27 mm (50 mil) or 1.016 mm (40 mil)
Pad / pin count	8 to 100
Body material	Alumina ceramic (Al₂O₃); plastic variants exist
Sealing	Hermetic, with a ceramic or metal lid
Operating temperature (mil/space grades)	−55 °C to +125 °C
JEDEC drawings	MS-002/003/004/005 (.050 in leadless, Types A–D); MS-009, MS-014 (.040 in leadless)

Pin 1 is set by a chamfered or marked corner, and pads are numbered from there per the specific drawing. Because a leadless footprint is unforgiving, that keying is the first thing to verify at placement.

LCC vs PLCC vs CLCC vs QFN: how to choose

These four packages solve overlapping problems with different trade-offs in cost, temperature range, and solder-joint behavior. Use the comparison to narrow the field, then the decision path below it.

Attribute	LCC / CLCC (ceramic leadless)	PLCC (plastic J-lead)	QFN (plastic leadless)
Termination	Edge pads + castellations	J-leads, four sides	Bottom pads, optional wettable flanks
Body material	Ceramic (hermetic)	Molded plastic	Molded plastic
Pitch	1.27 or 1.016 mm	1.27 mm	0.4–0.65 mm typical
Pad / pin count	8–100	18–84	up to ~100+
Hermetic seal	Yes	No	No
Temp range	to −55…+125 °C (mil)	commercial / industrial	commercial / industrial
Joint compliance	Low (rigid)	High (J-lead flexes)	Low
Joint inspection	Good (side fillet visible)	Good (leads visible)	Poor (under body)
Relative cost	High	Low	Low
Typical use	Aerospace, defense, space	Sockets, ROM/PLD, legacy	Modern high-density commercial

A short decision path:

• Need hermeticity, a −55/+125 °C range, or radiation tolerance? Choose a ceramic LCC or CLCC.
• Need a socketable, swappable device such as a ROM or PLD? Choose PLCC.
• New commercial design, space-constrained, no hermeticity requirement? Choose QFN or BGA.
• Large ceramic LCC on an organic board? Budget for CTE mitigation (next section) or move the function to a leaded package.

The reliability reality: CTE mismatch and solder-joint fatigue

The single biggest risk with a ceramic LCC is not the part; it is the solder joint. A leadless package has no compliant lead to absorb the differential expansion between the ceramic body and the board, so every thermal cycle loads the solder directly.

The numbers explain why. Alumina ceramic has a CTE near 6 ppm/°C, while standard FR-4 sits around 15–18 ppm/°C in-plane, a gap documented in Engelmaier’s solder-joint reliability work and in PCB-material CTE references. Across a −55 °C to +125 °C swing the two materials grow by different amounts, the joint shears, and fatigue cracks start at the corner joints, which see the largest displacement — a result established in Hall’s 1984 IEEE study of leadless ceramic chip carriers on printed boards. The larger the package, the worse it gets, because displacement scales with distance from the package center.

That is why leadless ceramic carriers historically lived on ceramic or CTE-matched boards, which are heavy and costly. When they must sit on an organic board, engineers add compliance in one of three ways.

• Solder-column mounting. Replacing the fillet with a tall column, for example high-lead Sn10Pb90, raises joint height and absorbs shear; a study of LCCC solder joints in Microelectronics Reliability found joint height to be the dominant fatigue-life factor and reported that Sn10Pb90 columns met most environmental requirements.
• Interposer or adapter boards. Mounting the LCCC to a small CTE-matched adapter, then attaching that adapter to the FR-4, is a documented approach for large pin counts; the technique appears in Raytheon-era patents covering 84-pin leadless ceramic carriers.
• CTE-matched laminates. Substrates with lower in-plane expansion than standard FR-4 shrink the mismatch directly.

Rule of thumb: the larger the leadless ceramic package and the wider the temperature swing, the sooner you need one of these measures. Small parts, roughly 20 pads or fewer, on an industrial board often survive without special handling; large ones under mil-spec cycling do not.

Assembly, footprint, and inspection notes

Castellations are the LCC’s assembly advantage. During reflow, paste wicks from the board pad up into the plated groove and forms a fillet on the side of the package. Because that fillet is exposed, you can inspect it optically or by X-ray, unlike a QFN whose terminations hide under the body. Coarse-pitch parts can even be hand-reworked, since an iron can reach the side fillet.

Footprint points worth getting right:

• Match the land pattern to the exact pad count and drawing; a 20-pad carrier will not sit on a 16-pad footprint.
• Give solder-paste coverage that fills the castellation, not just the flat land, so the side fillet forms.
• If the part has a central thermal pad, it is for heat, not signal; tie it to a copper pour with thermal vias.

Moisture and handling differ by body type. Plastic leaded and leadless parts carry a J-STD-020 Moisture Sensitivity Level (MSL) and need bake and float-time control, while hermetic ceramic LCCs are immune to moisture ingress — one more reason they persist in high-reliability builds.

Where LCC packages are still used (with real part numbers)

New commercial silicon rarely ships in an LCC; QFN, BGA, and wafer-level packages won on size and cost. The LCC survives where hermeticity and wide temperature range are non-negotiable: avionics, defense, space, some precision sensors, and crystal oscillators.

Examples on current or recent datasheets:

• Texas Instruments UC1825-SP and UC1825B-SP PWM controllers are offered in an LCCC option under standard microcircuit drawing 5962-87681, rated −55 °C to +125 °C and QMLV / radiation-hardness-assured (TI space-products guide, SLYT532).
• The TI LM185-2.5QML-SP voltage reference lists CDIP and LCCC packages under 5962-87594 in the same guide.
• Analog Devices’ legacy LTC “LS” package is a 20-pin leadless chip carrier, square, 0.350 in (8.89 mm) on a side, hermetic, per the ADI package drawing.

Lifecycle reality: many LCC and CLCC parts are marked obsolete or last-time-buy. The LT1222 in its ceramic package, for instance, is shown obsolete on its Analog Devices datasheet. Before you design one in, confirm active status and a second source, and order against the QML or SMD number rather than the commercial base part.

Frequently asked questions

Is an LCC package the same as a QFN?

No. Both are leadless, but a QFN is a small plastic molded package with bottom-only pads and fine pitch of 0.4–0.65 mm, while a classic LCC is usually a hermetic ceramic package with edge castellations and 1.27 mm or 1.016 mm pitch. Some vendors informally call small leadless parts “LCC,” which adds to the confusion.

Does the “L” in LCC mean leadless or leaded?

Usually leadless, but not always. Most manufacturers use LCC for leadless chip carrier and PLCC for the plastic leaded version, yet a few package finders label leaded parts “LCC.” Confirm against the mechanical drawing before ordering.

Can you hand-solder an LCC package?

Coarse-pitch leadless carriers with castellated edges can be hand-soldered, because the plated groove lets solder wick to the side where an iron reaches. Fine-pitch or bottom-terminated parts need reflow with a stencil. Add flux at pin 1 and align to the footprint before the joint solidifies.

What is the difference between LCC and PLCC?

An LCC (leadless chip carrier) has no leads; it terminates in edge pads and castellations and is usually ceramic and hermetic. A PLCC (plastic leaded chip carrier) has J-shaped leads on all four sides, a molded plastic body, and a lower cost. The J-leads flex, which improves solder-joint reliability under thermal cycling.

Why are LCC packages used in aerospace and military electronics?

The ceramic body is hermetic, so it protects the die from moisture; the package is rated across −55 °C to +125 °C; and versions exist that are radiation-hardness-assured under MIL-PRF-38535 (QMLV). Resistance to vibration and shock, from having no fragile leads, is a further reason they appear in avionics.

Are LCC packages RoHS compliant?

Plastic leadless and leaded chip carriers are widely available in RoHS-compliant, lead-free finishes. Hermetic ceramic parts for military and space often ship under exemptions with tin-lead or gold finishes, because lead-free solder reliability is not always qualified for those missions. Check the specific part’s material declaration.

What to do next

Reach for a ceramic LCC or CLCC when the mission demands hermeticity, a −55 °C to +125 °C range, or radiation tolerance, and budget from the start for the solder-joint mitigation the CTE mismatch forces — solder columns, an adapter board, or a CTE-matched laminate, sized to the package. If none of those constraints apply, a QFN or BGA will be smaller, cheaper, and easier to source. And whatever the datasheet’s base part number says, order against the QML or SMD number and a verified second source, because most leadless ceramic parts are late in their lifecycle.