What is the difference between 96% and 99.6% alumina ceramic substrates?

96% alumina substrates are commonly used for general thick-film circuits, insulation bases and cost-sensitive electronic assemblies. 99.6% alumina substrates usually provide better surface quality, dielectric stability and chemical resistance, making them more suitable for thin-film, RF and higher-reliability circuit applications.

Can alumina ceramic substrates be used for thick-film and thin-film circuits?

Yes. Alumina substrates are widely used for thick-film circuits, resistor substrates, sensor carriers and selected thin-film applications. The required purity, surface roughness and flatness should be confirmed according to the printing, deposition or metallization process.

What surface finish should I choose for an alumina substrate?

As-fired surfaces are suitable for many insulation and general circuit supports. Ground, lapped or polished surfaces are recommended when the design requires better flatness, lower surface roughness, improved bonding consistency or thin-film deposition.

Can ADCERAX provide laser-drilled holes or laser scribing?

Yes. ADCERAX can review laser-drilled holes, slots, scribing lines and custom outlines according to the drawing. Hole diameter, pitch, substrate thickness and edge distance should be checked together before quotation.

Is alumina better than aluminum nitride for electronic substrates?

Alumina is more cost-effective and provides strong electrical insulation, mechanical strength and stable ceramic performance. Aluminum nitride is usually considered when the design needs much higher thermal conductivity. The final choice depends on heat load, voltage, circuit layout and budget.

What information is needed for a custom alumina substrate quotation?

A drawing is preferred. The RFQ should include material grade, size, thickness, tolerance, surface finish, hole layout, edge design, metallization or bonding process, operating temperature, voltage condition and order quantity.

Does the colour of the high purity alumina substrate affect its properties?

No. The typical white or off-white colour of the alumina substrate does not directly impact its electrical, thermal or mechanical properties. The colour is a natural result of the high-purity raw materials and firing process.

How does the surface roughness of a high purity alumina ceramic substrate impact its performance?

A lower surface roughness is critical for thin-film applications, as it supports better adhesion and uniformity of deposited layers. In high-frequency circuits, a smoother surface can also help reduce conductor losses.

Can this high alumina substrate be bonded to a metal heatsink?

Yes. Alumina substrates can be bonded to copper or aluminum heatsinks using thermally conductive adhesives or brazing in the case of metallized substrates. The final bonding method should be selected according to heat load, surface finish, metallization requirement and operating temperature.

High Purity Alumina Ceramic Substrates

A high purity alumina ceramic substrate is a dense Al₂O₃ ceramic plate used as an electrically insulating and thermally stable base for electronic circuits, LED packages, sensors and RF modules. Compared with polymer circuit boards, alumina provides better heat resistance, dielectric strength, dimensional stability and surface durability. The final grade, thickness, surface finish and hole layout should be selected according to the circuit type, assembly process and operating environment.

Why Engineers Choose Alumina Ceramic Substrates

Alumina ceramic substrates are selected when an electronic assembly needs reliable insulation, stable ceramic performance and controlled surface quality. Compared with polymer boards or metal carriers, dense Al₂O₃ substrates can provide better resistance to heat, voltage, dimensional drift and surface wear in demanding circuit and module designs.

Electrical Insulation

Dense Al₂O₃ provides high dielectric strength and stable volume resistivity. This helps isolate circuits, sensors and power devices from unwanted current paths, especially in assemblies where voltage stability and insulation reliability are important.

Heat Resistance

Alumina keeps mechanical and electrical stability under elevated temperatures. This makes it suitable for substrates exposed to soldering, firing, curing, bonding or repeated thermal cycling during production and service.

Surface Control

As-fired, fine-ground, lapped and polished surfaces can be selected according to the circuit process. Surface finish affects metallization, bonding, thin-film uniformity and final circuit reliability, so it should be matched to the application instead of selected only by cost.

Dimensional Stability

Alumina has a stable ceramic structure and controlled thermal expansion. This helps reduce warpage, alignment drift and assembly stress when the substrate is used in precision electronic, sensor or module structures.

Machining Flexibility

Holes, slots, scribing lines and custom outlines can be reviewed by drawing. This allows the alumina substrate to match the circuit layout, mounting position or mechanical interface more accurately before production.

Typical Properties for Alumina Ceramic Substrate Selection

Property	Typical Range / Option	Selection Note
Alumina purity	96%, 99%, 99.5%, 99.6%, 99.8%	96% is often used for general thick-film and insulation parts, while 99.6% or higher is preferred for finer surface and lower dielectric loss requirements.
Thermal conductivity	About 20–35 W/m·K, depending on grade and test condition.	Alumina provides better thermal stability than many organic boards, but AlN should be considered when very high heat spreading is required.
Dielectric strength	Grade and thickness dependent.	This parameter should be confirmed according to operating voltage, substrate thickness and edge design.
Surface finish	As-fired, fine-ground, lapped or polished.	Polished surfaces are preferred for thin-film, RF and precision bonding applications.
Thickness range	Thin sheet to thicker ceramic plate options.	Thin substrates need careful handling and packaging to avoid edge chipping or cracking.
Processing options	Laser drilling, laser scribing, cutting, grinding and polishing.	Hole diameter, pitch, edge distance and thickness must be reviewed together.

Size, Thickness and Processing Options

ADCERAX can supply alumina ceramic substrates in square, rectangular, round and drawing-based shapes. Standard sizes are suitable for prototype evaluation, circuit testing and small-batch assembly, while custom substrates can be reviewed according to circuit layout, hole position, scribing line, surface finish and thickness tolerance.

Type 1-96 Alumina Substrate Rectangular with Hole

Item NO.	L* W*Thickness (mm)	Hole Dia (mm)
TE-J-1	102.42	\
TE-J-2	102.41.5	\
TE-J-3	10150.6	4
TE-J-4	10161.5	3.5
TE-J-5	10201.6	\
TE-J-6	10166	\
TE-J-7	10102	\
TE-J-8	10142	\
TE-J-9	10.4181	3.8
TE-J-10	10.6171	3.8
TE-J-11	11111	\
TE-J-12	11171	\
TE-J-13	1171.5	\
TE-J-14	11181	4
TE-J-15	1218.50.6	3.8
TE-J-16	12180.6	3.8
TE-J-17	1218.51	\
TE-J-18	1218.50.6	\
TE-J-19	12.716.51.8	3.8
TE-J-20	13190.6	\
TE-J-21	14183	3.4
TE-J-22	14192	3.5
TE-J-23	14201	3.2/3.5
TE-J-24	14200.6	3.2
TE-J-25	14201	\
TE-J-26	14200.6	\
TE-J-27	14202	\
TE-J-28	14202	3.2
TE-J-29	1519.51	3.8
TE-J-30	1522.4	\
TE-J-31	16212.5	3.5
TE-J-32	16220.6	3.3
TE-J-33	16220.6	4
TE-J-34	16220.6	3.7
TE-J-35	16461	\
TE-J-36	17221	3.7
TE-J-37	17220.6	3.7
TE-J-38	17220.6	\
TE-J-39	17221.5	\
TE-J-40	17221	\
TE-J-41	1737.11	\
TE-J-85	22302	\
TE-J-86	22281	3.4
TE-J-87	22280.6	3.4
TE-J-88	22281	\
TE-J-89	22280.6	\
TE-J-90	22251	3.6
TE-J-91	22250.6	3.1
TE-J-92	22251	3.1
TE-J-93	22220.6	3
TE-J-94	22351	\
TE-J-95	22351.5	3.5
TE-J-96	23341	3.2
TE-J-97	24301	\
TE-J-98	2435.51	\
TE-J-99	24400.6	\
TE-J-100	24601	\
TE-J-101	24700.6	\
TE-J-102	24721	\
TE-J-103	24900.6	\
TE-J-104	24951	\
TE-J-105	241251	\
TE-J-106	241041	\
TE-J-107	25340.6	\
TE-J-108	25401	\
TE-J-109	25400.6	\
TE-J-110	251100.6	\
TE-J-111	26301	3.2
TE-J-112	26311	3.5
TE-J-113	26351	\
TE-J-114	27600.6	\
TE-J-115	27900.6	\
TE-J-116	27481	5
TE-J-117	27.54.22.5	\
TE-J-118	28401	\
TE-J-119	28420.6	\
TE-J-120	28440.6	6
TE-J-121	28641	\
TE-J-122	28721	\
TE-J-123	29331.3	\
TE-J-124	30381	3.5
TE-J-125	30401	3.5
TE-J-126	30430.6	4.5
TE-J-127	32501	\
TE-J-128	32601	\
TE-J-129	33531.3	\
TE-J-130	33731.3	\
TE-J-131	33.651.40.8	5
TE-J-132	33.651.42	5
TE-J-133	34640.6	\
TE-J-134	34390.6	\
TE-J-135	35481	5.5
TE-J-136	35681	\
TE-J-137	35451	\
TE-J-138	35850.6	\
TE-J-139	38380.6	\
TE-J-140	38500.6	\
TE-J-141	353520	\
TE-J-142	38.5411	\
TE-J-143	39910.6	\
TE-J-144	40301	3.5
TE-J-145	40561	\
TE-J-146	40430.6	\
TE-J-147	401050.635	\
TE-J-148	401400.6	\
TE-J-149	401501	\
TE-J-150	402601	\
TE-J-151	44161	\
TE-J-152	44280.6	6
TE-J-153	50501	\
TE-J-154	50503	\
TE-J-155	55182	\
TE-J-156	75182	\
TE-J-157	1001001	\
TE-J-158	1001002	\
TE-J-159	1001003	\
TE-J-160	1201602	\
TE-J-161	1201603	\
TE-J-162	1201604	\
TE-J-163	1201606	\
TE-J-164	1601601	\
TE-J-165	1601600.6	\

Type 2-96 Alumina Substrate Rectangular

Item	Length（mm）	Width（mm）	Thickness（mm）	Purity(%)
TE-J-169	10	10	0.25	96-99.8%
TE-J-170	10	10	0.5	96-99.8%
TE-J-171	10	10	0.635	96-99.8%
TE-J-172	10	10	1	96-99.8%
TE-J-173	20	20	1	96-99.8%
TE-J-174	20	20	2	96-99.8%
TE-J-175	25	25	1	96-99.8%
TE-J-176	30	30	0.635	96-99.8%
TE-J-177	30	30	1	96-99.8%
TE-J-178	30	30	2	96-99.8%
TE-J-179	35	35	1	96-99.8%
TE-J-180	40	40	1	96-99.8%
TE-J-181	40	40	5	96-99.8%
TE-J-182	50	50	0.5	96-99.8%
TE-J-183	50	50	0.635	96-99.8%
TE-J-184	50	50	1.5	96-99.8%
TE-J-185	50	50	5	96-99.8%
TE-J-191	60	60	1	96-99.8%
TE-J-192	65	74	0.2	96-99.8%
TE-J-193	65	74	0.28	96-99.8%
TE-J-194	70	70	2	96-99.8%
TE-J-195	70	70	3	96-99.8%
TE-J-196	76.2	76.2	0.75	96-99.8%
TE-J-197	80	80	3	96-99.8%
TE-J-198	80	80	5	96-99.8%
TE-J-199	80	110	5	96-99.8%
TE-J-200	84	84	0.8	96-99.8%
TE-J-201	100	100	0.5	96-99.8%
TE-J-202	100	100	0.635	96-99.8%
TE-J-203	100	100	1.2	96-99.8%
TE-J-204	100	100	1.5	96-99.8%
TE-J-205	100	100	2.2	96-99.8%
TE-J-206	100	100	2.5	96-99.8%
TE-J-207	100	100	3.5	96-99.8%
TE-J-208	100	100	0.25	96-99.8%
TE-J-209	100	100	1.055	96-99.8%
TE-J-210	100	100	0.25	96-99.8%
TE-J-211	100	100	0.35	96-99.8%
TE-J-212	100	100	0.5	96-99.8%
TE-J-213	100	100	0.6	96-99.8%
TE-J-214	100	100	0.7	96-99.8%
TE-J-215	100	100	1.5	96-99.8%
TE-J-216	100	100	2.335	96-99.8%
TE-J-217	100	100	2.5	96-99.8%
TE-J-218	100	100	3.2	96-99.8%
TE-J-219	100	100	3.5	96-99.8%
TE-J-220	100	100	4	96-99.8%
TE-J-221	100	100	5	96-99.8%
TE-J-227	109	109	1	96-99.8%
TE-J-228	110	110	5	96-99.8%
TE-J-229	114	114	1	96-99.8%
TE-J-230	114	114	0.38	96-99.8%
TE-J-231	114	114	0.5	96-99.8%
TE-J-232	114	114	0.65	96-99.8%
TE-J-233	115	115	0.12	96-99.8%
TE-J-234	115	115	0.125	96-99.8%
TE-J-235	120	120	0.25	96-99.8%
TE-J-236	120	120	0.38	96-99.8%
TE-J-237	120	120	0.5	96-99.8%
TE-J-238	120	120	0.635	96-99.8%
TE-J-239	120	120	0.8	96-99.8%
TE-J-240	120	120	0.25	96-99.8%
TE-J-241	120	120	1	96-99.8%
TE-J-242	120	120	3	96-99.8%
TE-J-243	125	125	2	96-99.8%
TE-J-244	127	127	1	96-99.8%
TE-J-245	127	127	1.5	96-99.8%
TE-J-246	138	190	0.25	96-99.8%
TE-J-247	138	190	0.38	96-99.8%
TE-J-248	138	190	0.32	96-99.8%
TE-J-249	138	190	0.5	96-99.8%
TE-J-250	138	190	0.8	96-99.8%
TE-J-251	138	190	0.65	96-99.8%
TE-J-252	138	190	1	96-99.8%
TE-J-253	138	190	0.38	96-99.8%
TE-J-254	138	190	0.5	96-99.8%
TE-J-255	138	190	0.635	96-99.8%
TE-J-256	138	190	1	96-99.8%
TE-J-257	150	150	1.8	96-99.8%
TE-J-258	150	150	1	96-99.8%
TE-J-259	150	150	1.5	96-99.8%
TE-J-260	150	150	2	96-99.8%
TE-J-261	150	150	3	96-99.8%
TE-J-262	150	150	5	96-99.8%
TE-J-263	150	150	8	96-99.8%
TE-J-264	152	152	0.635	96-99.8%
TE-J-265	160	170	2.5	96-99.8%
TE-J-266	180	180	2	96-99.8%
TE-J-267	180	180	3	96-99.8%
TE-J-268	180	180	5	96-99.8%
TE-J-269	200	200	2	96-99.8%
TE-J-270	200	200	3	96-99.8%
TE-J-271	200	200	5	96-99.8%
TE-J-272	220	220	2	96-99.8%

Type 3-96 Alumina Substrate Round

Item	Diameter(mm)	Thickness(mm)	Purity(%)
TE-AD-002	3.5	1	96-99.8%
TE-AD-003	5	1	96-99.8%
TE-AD-004	6	0.25	96-99.8%
TE-AD-005	6	0.5	96-99.8%
TE-AD-006	6	0.635	96-99.8%
TE-AD-007	6	1	96-99.8%
TE-AD-008	8	0.25	96-99.8%
TE-AD-009	8	0.5	96-99.8%
TE-AD-010	8	0.635	96-99.8%
TE-AD-011	8	1	96-99.8%
TE-AD-012	10	0.25	96-99.8%
TE-AD-013	10	0.38	96-99.8%
TE-AD-014	10	0.5	96-99.8%
TE-AD-015	10	0.635	96-99.8%
TE-AD-016	10	1	96-99.8%
TE-AD-017	12	0.25	96-99.8%
TE-AD-018	12	0.5	96-99.8%
TE-AD-019	12	0.635	96-99.8%
TE-AD-020	12	1	96-99.8%
TE-AD-021	16	0.25	96-99.8%
TE-AD-022	16	0.5	96-99.8%
TE-AD-023	16	0.635	96-99.8%
TE-AD-024	16	1	96-99.8%
TE-AD-025	18	0.5	96-99.8%
TE-AD-026	18	0.635	96-99.8%
TE-AD-027	18	1	96-99.8%
TE-AD-028	20	0.25	96-99.8%
TE-AD-029	20	0.5	96-99.8%
TE-AD-030	20	0.635	96-99.8%
TE-AD-031	20	1	96-99.8%
TE-AD-032	25	0.5	96-99.8%
TE-AD-033	25	0.65	96-99.8%
TE-AD-034	25	1	96-99.8%
TE-AD-035	30	0.5	96-99.8%
TE-AD-036	30	0.635	96-99.8%
TE-AD-037	30	1	96-99.8%
TE-AD-038	33	1	96-99.8%
TE-AD-039	35	1	96-99.8%
TE-AD-040	35	2	96-99.8%
TE-AD-041	36	4	96-99.8%
TE-AD-042	40	1	96-99.8%
TE-AD-043	40	1.5	96-99.8%
TE-AD-044	42	2	96-99.8%
TE-AD-045	50	0.5	96-99.8%
TE-AD-046	50	0.635	96-99.8%
TE-AD-047	50	1	96-99.8%
TE-AD-048	50	2	96-99.8%
TE-AD-049	55	0.5	96-99.8%
TE-AD-050	60	10	96-99.8%
TE-AD-051	65	0.5	96-99.8%
TE-AD-052	75	1	96-99.8%
TE-AD-053	82	6	96-99.8%
TE-AD-054	89	5.5	96-99.8%
TE-AD-055	100	0.5	96-99.8%
TE-AD-056	100	0.635	96-99.8%
TE-AD-057	100	1	96-99.8%
TE-AD-058	101.6	0.5	96-99.8%
TE-AD-059	101.6	1	96-99.8%
TE-AD-060	120	2	96-99.8%
TE-AD-061	125	6	96-99.8%

Type 4: Alumina ceramic substrate for thin film circuit

Specification Dimensions		Alumina Ceramic Substrate
		As-fired Wafer	Fine Ground Wafer	Polished Wafer
Outline Dimensions	Max (mm)	101.6×101.6	101.6×101.6	101.6×101.6
	Typical (mm)	50.8×50.8, 76.2×76.2, 101.6×101.6	50.8×50.8, 76.2×76.2, 101.6×101.6	50.8×50.8, 76.2×76.2, 101.6×101.6
	Tolerance (mm)	Standard Grade: ≤±0.8%, but absolute value ≥±0.1; Precision Grade: ≤±0.5%, but absolute value ≥±0.05;	Standard Grade: ≤±0.5%, but absolute value ≥±0.08; Precision Grade: ≤±0.2%, but absolute value ≥±0.05;	Standard Grade: ≤±0.5%, but absolute value ≥±0.08; Precision Grade: ≤±0.2%, but absolute value ≥±0.05;
Substrate Thickness	Thickness Range (mm)	0.15~2.5	0.15~2.5	0.15~2.5
	Typical (mm)	0.150, 0.254, 0.381, 0.508	0.150, 0.254, 0.381, 0.508	0.150, 0.254, 0.381, 0.508
	Tolerance (mm)	Standard Grade: ≤±10.0%, but absolute value ≥±0.05; Precision Grade: ≤±5.0%, but absolute value ≥±0.02;	Standard Grade: ≤±5.0%, but absolute value ≥±0.04; Precision Grade: ≤±1.0%, but absolute value ≥±0.02;	Standard Grade: ≤±5.0%, but absolute value ≥±0.04; Precision Grade: ≤±1.0%, but absolute value ≥±0.02;
Laser Drilling	Min (mm, recommended 0.8-1.5 times substrate thickness)	Φ0.08	Φ0.08	Φ0.08
	Laser Drilled Hole Front/Back Aperture Difference	≤20%	≤20%	≤20%
	Minimum Hole Pitch (mm, recommended 3 times hole diameter or more)	≥0.25	≥0.25	≥0.25
Warp	mm/mm	0.005/mm	0.003/mm	0.002/mm

Type 5: 996 Alumina Substrates size

996 Alumina Substrates
Item No.	Thickness（mm)	Length *Width（mm)
AT-AO-J1001	0.15	50.8×50.8
AT-AO-J1002	0.254
AT-AO-J1003	0.381
AT-AO-J1004	0.508
AT-AO-J1005	0.635
AT-AO-J1006	1.0
AT-AO-J1007	2.0
AT-AO-J1008	2.5
AT-AO-J1009	0.15	76.2×76.2
AT-AO-J1010	0.254
AT-AO-J1011	0.381
AT-AO-J1012	0.508
AT-AO-J1013	0.635
AT-AO-J1014	1.0
AT-AO-J1015	2.0
AT-AO-J1016	2.5
AT-AO-J1017	0.15	101.6×101.6
AT-AO-J1018	0.254
AT-AO-J1019	0.381
AT-AO-J1020	0.508
AT-AO-J1021	0.635
AT-AO-J1022	1.0
AT-AO-J1023	2.0
AT-AO-J1024	2.5
AT-AO-J1025	0.15	114.3×114.3
AT-AO-J1026	0.254
AT-AO-J1027	0.381
AT-AO-J1028	0.508
AT-AO-J1029	0.635
AT-AO-J1030	1.0
AT-AO-J1031	2.0
AT-AO-J1032	2.5

High Purity Alumina Substrates Packaging

Substrates are separated by soft, lint-free paper.
Stacked and vacuum-sealed in cleanroom-grade PE bags.

Applications for RF, LED and Sensor Assemblies

High purity alumina ceramic substrates are used when an electronic assembly needs stable insulation, moderate thermal conduction, controlled flatness and ceramic surface durability. The suitable substrate grade, thickness and surface finish should be selected according to circuit type, metallization process, operating temperature, bonding method and final module structure.

High-Frequency RF & Microwave Modules

Key Advantages

1. Low dielectric loss helps support stable signal transmission in RF and microwave circuit layouts.
2. Good dimensional stability helps maintain conductor alignment, impedance consistency and circuit repeatability.
3. Lapped or polished surfaces can support thin-film deposition, fine circuit patterns and more consistent metallization adhesion.

Problem Solved

In RF circuit carriers, unstable substrate flatness, rough surface finish or inconsistent dielectric behavior may lead to signal loss, poor impedance matching or lower production repeatability. High purity alumina substrates provide a rigid ceramic base with stable insulation and controlled surface quality, making them suitable for RF modules, microwave circuits and precision electronic carriers.

High-Power LED Packaging

Key Advantages

1. Alumina provides electrical insulation between the LED circuit and the mounting structure.
2. Ceramic heat resistance helps maintain substrate stability during soldering, bonding and long-term operation.
3. A dense ceramic surface supports reliable assembly in LED modules, light engines and power electronic insulation bases.

Problem Solved

In high-power LED packaging, polymer boards or unstable carriers may deform, age or lose insulation performance under heat. Alumina ceramic substrates help improve thermal stability, electrical isolation and dimensional control, especially in LED modules where heat, voltage and long service life must be considered together.

Advanced Sensor Technology

Key Advantages

1. Chemical stability helps protect sensor assemblies used in selected industrial, analytical and fluid-control environments.
2. Good mechanical strength supports small ceramic carriers, heater bases and sensor mounting structures.
3. Laser drilling, slot machining and custom outlines can be reviewed for compact and integrated sensor designs.

Problem Solved

Sensor assemblies often require a clean, rigid and electrically insulating base that can remain stable during heating, cleaning or exposure to controlled media. Alumina ceramic substrates can help reduce deformation, contamination risk and insulation failure compared with many organic materials, making them suitable for sensor carriers, heater substrates, detector bases and precision instrumentation modules.

High Purity Alumina Substrates Usage Instructions

High purity alumina substrates should be handled carefully to protect the ceramic surface, edges, holes and polished areas. Proper handling, cleaning and storage help reduce contamination, scratching, chipping and thermal-stress damage before assembly.

Installation & Handling

1. Handle substrates with clean gloves to avoid fingerprints, dust and surface contamination.
2. Support the substrate evenly during mounting or bonding, especially near holes, slots and thin edges.
3. Avoid hard tools, point loading and direct impact that may cause edge chips or micro-cracks.

Operation Notes

1. Confirm the operating temperature, voltage condition and assembly structure before use.
2. Control heating and cooling conditions to reduce thermal stress during firing, soldering, curing or thermal cycling.
3. Avoid exposing the substrate to chemicals or media beyond the selected alumina grade’s resistance range.

Cleaning Guidelines

1. Use a cleaning method compatible with the surface finish and downstream process.
2. Avoid abrasive brushes, hard particles or harsh cleaning methods that may scratch polished or lapped surfaces.
3. Dry the substrate completely before assembly, inspection or packaging.

Storage & Inspection

1. Store substrates in clean, dry packaging before use.
2. Keep thin sheets, polished faces and precision edges separated to avoid ceramic-to-ceramic contact.
3. Inspect visible surfaces, holes and edges before installation to identify chips, cracks or contamination early.

High Purity Alumina Ceramic Substrate FAQ

What is the difference between 96% and 99.6% alumina ceramic substrates?
96% alumina substrates are commonly used for general thick-film circuits, insulation bases and cost-sensitive electronic assemblies. 99.6% alumina substrates usually provide better surface quality, dielectric stability and chemical resistance, making them more suitable for thin-film, RF and higher-reliability circuit applications.
Can alumina ceramic substrates be used for thick-film and thin-film circuits?
Yes. Alumina substrates are widely used for thick-film circuits, resistor substrates, sensor carriers and selected thin-film applications. The required purity, surface roughness and flatness should be confirmed according to the printing, deposition or metallization process.
What surface finish should I choose for an alumina substrate?
As-fired surfaces are suitable for many insulation and general circuit supports. Ground, lapped or polished surfaces are recommended when the design requires better flatness, lower surface roughness, improved bonding consistency or thin-film deposition.
Can ADCERAX provide laser-drilled holes or laser scribing?
Yes. ADCERAX can review laser-drilled holes, slots, scribing lines and custom outlines according to the drawing. Hole diameter, pitch, substrate thickness and edge distance should be checked together before quotation.
Is alumina better than aluminum nitride for electronic substrates?
Alumina is more cost-effective and provides strong electrical insulation, mechanical strength and stable ceramic performance. Aluminum nitride is usually considered when the design needs much higher thermal conductivity. The final choice depends on heat load, voltage, circuit layout and budget.
What information is needed for a custom alumina substrate quotation?
A drawing is preferred. The RFQ should include material grade, size, thickness, tolerance, surface finish, hole layout, edge design, metallization or bonding process, operating temperature, voltage condition and order quantity.
Does the colour of the high purity alumina substrate affect its properties?
No, the typical white or off-white color of the alumina substrate does not impact its electrical, thermal, or mechanical properties. The color is a natural result of the high-purity raw materials and firing process.
How does the surface roughness (Ra) of a high purity alumina ceramic substrate impact its performance?
A lower surface roughness is critical for thin-film applications, as it ensures better adhesion and uniformity of deposited layers. In high-frequency circuits, a smoother surface reduces conductor losses.
Can this high alumina substrate be bonded to a metal heatsink?
Yes, alumina substrates can be bonded to copper or aluminum heatsinks using thermally conductive adhesives or by brazing (in the case of metallized substrates) to create high-performance cooling modules.

Catalog No.	AT-AO-J1001
Material	≥ 96% Al2O3
Thermal Conductivity	≥ 20 W/m·K (RT)
Thickness Tolerance	±0.05 mm
Dimensions/Sizes	Download PDF

High Purity Alumina Ceramic Substrates for RF, LED and Sensor Assemblies