Metallized ceramic is a product that generally consists of a ceramic insulator and a metal conductive coating. The coating can be applied automatically or by hand. The item is then dried and fired at high temperatures in special furnaces. When the coating is applied it offers very little conductivity but after firing the coating is quite conductive.
If the metallized ceramic component is to be brazed into a package or to another component, often nickel plating is necessary to guarantee good adhesion depending on the chosen braze material. Nickel also helps protect the molybdenum contained in many thick film metallization formulation. Electrolytic nickel per QQ-N-290 is commonly employed. Another popular choice for post-metallization plating is electroless nickel (in particular, nickel boron per AMS 2433). Nickel plating is not always necessary but it is very common and helpful.
INTA Technologies Corporation offers design assistance. Contact Jerry Walias 408-748-9955 x106 jerry@intatech.com
INTA Technologies Corporation has several reps available to visit qualified customers and prospects in many parts of North America. In Texas,Arkansas, Kansas, Louisiana, Missouri or Mexico contact:
Mr. George Dossett
2808 Bent Oaks Drive
Burleson, TX 76028
(817)447-2075
(817)447-3186 fax
gdoss@aol.com
Mr. E.C. "Woody" van der Woude
228 Peach Tree Drive
Murphy, TX 75094
(972)422-1683
(972)424-4863 fax
woody@dossettindustrialsales.com
For all other North America locations, contact 408-748-9955 x113 or sales@intatech.com
We have reps covering most of the United States and parts of Mexico. Most of our reps reside in their home regions. When you contact our main office, request a rep visit or call and we will check availability and set up a meeting if possible. The reps are mainly used to help with large orders and large customers but we aim to help all customers large and small if we can.
Yes, INTA supplies bare ceramic and metallized ceramic products. Some are available off-the-shelf but most of the products are custom made according the customer specifications and requirements.
Yes. When sending a request for quotation (RFQ) please indicate if the material will be customer supplied or INTA supplied.
Lead times depend on several factors, such as material lead times. If the customer supplies the ceramic, the lead time is often 2-3 weeks. If INTA Technologies supplies the ceramic, it will likely add three or more weeks to the lead time.
10-20 lbs. We regularly perform and analyze our own peel strengths tests. Contact INTA for further details.
Prices vary depending on the size, complexity, tolerances and surface finishes among other factors. Each project is unique and volume plays a role in many cases. To receive a quote, please provide a drawing with specs and desired quantity to Blake Kneedler 408-748-9955 x113 bkneedler@intatech.com
INTA Technologies makes very small parts including .2” or 5mm diameter. We also make thin ceramic parts, for example .030” Each project is unique, contact us for a free design review and quote.
INTA Technologies is limited in terms of maximum size. Typically, items larger than 12” in diameter and/or longer than 16” may be currently too large for INTA.
The metallization process itself is not overly complicated but it requires equipment such as gauges, microscopes, furnaces and an XRF machine. The process also requires qualified staff and well trained supervisors and inspectors.
In many cases, yes. The service is called expedite, speak to Blake Kneedler for further details. 408-748-9955 x113
The answer depends on the application. In most cases, specifying 96% min purity alumina on the drawing is adequate. Technical data is available at http://ceramics.net/materials/alumina.shtml
Yes, INTA sells bare Al-N substrates and metallized Al-N substrates.
INTA sells many types of ceramic including Al-O, Al-N, Be-O and all the ceramics listed on www.ceramics.net
As fired flatness is .006”/inch. A flatness of .001”/inch is also achievable but more costly.
The answer depends on the application. For bare ceramic, a chamfer may be preferred because during the manufacturing process chips can be encountered. If a print calls for sharp edges, a chipped edge could cause WIP to be scrapped. If, on the other hand, there is a .025 max chamfer callout and the edge is chipped .015, there is no loss. DfM (design for manufacturability) is important at INTA.
1) Sole source for metallized ceramics:
INTA Technologies Corporation
2281 Calle de Luna
Santa Clara, CA 95054
408-748-9955
408-727-3027 fax
2) Workmanship specification – indicate whether fine scratches are acceptable, indicate max allowable blister/bump/nodule diameter and height.
3) Indicate dimensions pre or post metallization
4) Indicate forming method – generally iso-pressed (contact sales@intatech.com for assistance)
5) Nickel plating? (many metallized ceramic products need nickel plating to aide in subsequent joining/brazing processes)
6) Indicate type of metallization (MoMn, Ag, etc.)
7) Indicate areas to be metallized
8) Require XRF printout to document metallization layer thickness
A typical thickness is 300-1200u” MoMn and 100-200u” Ni.
INTA’s metallized ceramic components typically are used at temperatures below 800 degrees C.
INTA Technologies readily metallizes and plates beryllium oxide (BeO). BeO is very popular for many reasons including the fact that the material is an electric insulator yet it has a very high thermal conductivity. BeO also has a very high melting point. BeO’s CTE is in the order of 7 ppm/deg C at room temperature. The density is roughly 2.9 gm/cc. BeO’s thermal conductivity is 280 W/mK. (All at RT). INTA supplies bare BeO, metallized BeO and also metallizes customer-supplied BeO and other materials.
Metallized ceramic products sent from INTA Technologies should arrive clean and ready to braze. Be sure to inform INTA at the time of your order and/or RFQ the application and type of braze and technique you plan to use. INTA uses many types of metallization formulations and customer/vendor communication is key to ensure a speedy and high quality turnaround. For assistance with your brazing project please contact Blake Kneedler, Manufacturing Engineer 408-748-9955 x113 or blake@intatech.com.
Metallized ceramic products should be stored in cool & dry places. The products should be contained in air-tight containers such as bags, trays and cases. Metallized ceramic products can chip or break if handled with force, suitable padding, popcorn or foam should be used to ensure product conformity. If you do not plan to use your metallized ceramic products for a long period of time, simply vacuum seal the remaining items or return items to the original packaging supplied by INTA and reseal. If items are left in hot or cold areas or in areas of high humidity quality can quickly become compromised.
The coefficient of thermal expansion for BeO is roughly 7 parts per million per degree Celsius (7 ppm/deg C) at room temperature. The CTE varies over a range of temperatures.
Macor is often chosen by designers due to certain material properties and a low cost factor. The CTE for Macor is roughly 9.3 ppm/deg C (@RT). Keep in mind, the maximum rated temperature for Macor is lower than most ceramics due to the high frit (glass) content. The large amount of frit allows the material to be machined with conventional tooling but it chips easily and is not readily metallized (but can be in an expensive process). The thermal conductivity of Macor is about 1.5 W/mK at room temperature making Macor very attractive as an insulator.
No need to metallize AlSiC, it is electrically conductive. INTA does not manufacture AlSiC components but a good source is CPS Technologies of Norton, MA. INTA can plate precious or non-precious metals and combinations thereof onto AlSiC substrates and/or base materials.
There is not one particular type of ceramic which metallizes better than other materials. In general, 96% min Al-O, 97-99.99% Al-O, all types of BeO and sapphire metallize very well. Materials which are difficult to metallize include Al-N, glass, quartz and fused silica.
At room temperature, the CTE of Al-N is approximately 4.5 ppm/deg C. The density at RT is approx 3.3 gm/cc. Regarding thermal conductivity, Al-N (aluminum nitride) has a very high rate of thermal conductivity compared to other ceramics. At RT, the thermal conductivity is rated at about 200 Watts per meter*Kelvin (W/mK).
Thermal conductivity of fused silica at room temperature is very low (in the range of 1.3 W/mK) in comparison to other materials. For example, silica (Si) has a thermal conductivity rating of approximately 150 W/mK and 96% minimum purity aluminum oxide (Al2O3) has a value of ~30 W/mk. Designers looking for a robust material with a high melting and softening temperature (600 deg C +) will consider fused silica if thermal isolation is critical.
The best insulating (electrical) ceramic thermal conductive material is beryllium oxide (BeO). The material is an electric insulator yet conducts heat at the alarming rate of 280 W/mK (on average at room temperature). The next best is Al-N followed by Si and Al-O. BeO is versatile, easily metallized and can be used for many applications. There are some safety issues associated with BeO but when coated and placed in a package the concerns are greatly diminished.
Coatings are generally applied in the form of liquid inks. The liquid contains metal particles and binders. The wet metallization layer ranges according to application. Typical values are roughly 300-1500u” or .0003-.0015”. After firing in a controlled atmosphere furnace, a diffusion layer is formed and the actual metal layer becomes somewhat thinner than the original ‘wet’ layer. Subsequent to a metallizing step and thermal set, additional metals such as nickel, copper, silver and/or gold are typically deposited. Nickel is by far the most common selection. Nickel thicknesses range according to application 50-300u” in general. The subsequent coatings are optional (help protect the MoMn metallization layer) but are frequently included because they help aid solder/braze wetting.
The types of coating available for most ceramics include:
MoMn
Nickel
Silver
Copper
Gold
Platinum
Palladium
Glaze – glass
Teflon
Electroless (nickel, copper)
ENIG (outsourced)
Immersion silver (outsourced)
Lead free HASL (outsourced)
Liquid photo imageable s/m (outsourced)
Immersion gold (outsourced)
Yes, gold plating of ceramic is very common and readily done. A common specification is MIL-G-45204. When specifying a gold coating on ceramic, unless noted, MoMn and nickel ‘primer’ layers [undercoats] can be expected. If specified – No MoMn (or Ag) – another process will be used which omits MoMn or Ag (thick film). If the second process is used (plating process) a ultra-thin layer of copper and/or nickel may be required by INTA.
The answer depends on the type of attachment planned. If soldering with a tin alloy, tin plating may be recommended. If the project calls for a AuGe wire-bond, a thin gold coating may be necessary. For copper brazing, copper plating is recommended. For CuAg brazing, nickel works very well. Please contact Blake Kneedler, Manufacturing Engineer (blake@intatech.com) for more detailed information relevant to your design implementation.
Popular metals used in ceramic-to-metal joints include:
Kovar (iron-nickel-cobalt)
Steel (most grades including stainless)
Copper
Indium
Tin
Silver
Molybdenum alloys
Tungsten alloys
Nickel
Difficult materials include titanium and hastalloy.
Ceramics are usually non-conductive insulators. In order to transport electrons in a specific manner or prepare the ceramic for a solder/braze attach the substrate is generally coated via a screen-printer, lathe, automatic dispenser, spin-coater, etc. After metallization and nickel plating, the ceramic is ready to be soldered into a circuit or package. Active metal brazing makes it possible to join ceramic and other materials without the metallization step. Active metal brazing is very robust, creates vacuum tight joints and has proven very effective over the years. Active metal brazing is done in a vacuum environment and there are some limitations to its application. Conventional brazing, on the other hand, requires metallization because without the metallized layer there will be no adhesion of the molten solder/braze material and there will be no practical joint formed. Here is a simple experiment – drop molten solder (AgSn works well) onto a bare ceramic piece. Note the adhesion of ceramic to metal and vice versa.
Some epoxies can be used to create conductive paths and/or to generate joints. Keep in mind most epoxies are not quite vacuum tight and can be a source of outgassing. Rather than coating non-conductors such as ceramics another process involves using stick-back metal foil. The foil can be effective for PoC and prototypes but can prove costly in production. INTA only offers the metallizing option, shying away from epoxies or glued metal foils.
The seed layer is a very thin layer of metal used to activate the surface of a non-conductive material such as Si, Al-O or BeO. In a thick film process, the seed layer is not critical. Seed layer is important for thin film applications and plating-on-conductor implementations.
No particularly but it varies according to project complexity, weight, volume and other factors. Some ceramic costs less than one cent, other pieces cost over $25k each.
Lead times vary according the product specifications. INTA has many products and sizes in stock and can ship in about 1-2 weeks but most items need to be made from scratch. Lead times can be as long as 8-10 weeks but for thin pieces with thickness < .070”, the lead time is in the range of 4-6 weeks but can be longer or shorter depending on workload and complexity.
All of INTA’s ceramic is made in the USA. Most of our ceramic comes from our sister company (STC) located in Saint Albans, Vermont. The balance of our ceramic comes from the Western United States. INTA usually buys blanks or raw material and adds value (grinding, cutting, honing, general machining) in the California facilities.
For more information please visit our sister company’s website à http://ceramics.net/methods
Ceramic Industry Magazine offers many interesting and informative articles. We recommend viewing online editions or ordering a subscription to this monthly publication. www.ceramicindustry.com
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Last revised: 03 DEC 2009
