Thin Film Patterned Substrates

Table 1: Material Electrical and Mechanical Properties

Note: When metallization is requested on both top and bottom sides, the metallization will wrap around the sides as a standard unless otherwise specified.

Johanson Technology offers several different metal schemes to meet customer needs. We offer single-sided or double-sided metallization. Each side can have unique design requirements and metallization. Each metal layer typically has a specific use, whether that be adhesion, barrier or conductor layers. Selection of a metal should be based on electrical functioning demands and/or requirements.

Some designs require pads suitable for solder attachment while others require metals that could readily be wire bonded. Solderable metallization schemes are available by adding Ni or Cu barrier for thin film designs. For optimal wire bond integrity, Johanson recommends a minimum of 100µ” thickness on thin film designs, although good performance can be achieved with as low as 80µ”.

Careful selection of particular metallizations are dependent on requirements for solderability, temperature resistance, wire bonding, and electrical performance. Note: Johanson has capability to sputter and plate other metals not listed in Table 3. We will review special requests for metallizations not listed here.

Table 3: Available Plated Metals

Table 4: Available Sputtered Metals

Precise management of critical geometric features lead to excellent and dependable performances in RF, microwave, and millimeter wave designs. With accurate conductor line widths and spacing, designers can control the characteristic impedance of transmission lines, coupling between RF traces, and even manage thermal loads within RF circuits. Using high quality conductor traces with little variation allows designers to have consistent performance in RF components such as filters and couplers.

Johanson has advanced experience incorporating vias into substrate designs with demanding requirements. Vias can be offered as either filled, through-hole or plated-through. Engineers must review the existing electrical and thermal properties of their design before deciding between filled or plated-through vias. The overall process is completed by lasering through a substrate from the top to bottom layer and then sputtering or plating over the substrate via opening. Both via options are effective in routing electrical signals from one side to another.

Plated-through vias are often recommended for low-power applications or in designs that require an opening to be maintained. In contrast, filled-vias are best used in high power applications or to enhance thermal properties of the hybrid design. Filled-vias are useful in keeping heat away from the substrate, which in turn helps to prevent defects or circuit failures. Filled-vias offer the lowest RF inductance and thermal resistance. Laser machined vias have a taper equal to approximately 10% of the material thickness.

Laser machining is available to provide designers with controlled hole locations, custom shapes and sizes, and superb edge accuracy. Johanson’s team allows engineers to realize flexible designs within the ceramic substrates. Johanson’s standard laser features and tolerances can be visualized below.

We encourage all design engineers to submit their drawings or ideas for quick and easy feedback.

Before submitting your design, use the preferred practices checklist:

• Follow Johanson’s design guidelines and standard specifications
• Provide CAD data in multiple layers
• Identify “A” side and “B” side for double-patterned circuits
• Provide tolerances and annotation
• DWG, DXF, Gerbers, and STEP files are preferred

Information needed:

• Substrate: Material, surface finish, thickness, and dimensions
• Metallizations: Thickness and tolerances
• Conductor traces: Type, spacing, and tolerances
• Other: Inspection or acceptance criteria

Commitments and Certifications We are committed to making products of the highest quality, performance, and value. Our new design and manufacturing facility employs state of the art equipment and practices. All employees participate in quality awareness and SPC training classes, and our quality system is certified to ISO 9001.

RoHS Standard parts supplied by Johanson Technology, Inc. are fully compliant to the European Union Directives 2002/95/EC, 2011/65/EU, and Annex II (EU) 2015/863 of the European Parliament and of the Council of 31 March 2015 on the Restriction of the use of certain Hazardous Substances in electrical and electronics equipment (RoHS Directives).

REACH Parts (articles) supplied by Johanson Technology meet the requirements for REACH and do not contain any of the SVHC chemicals listed above the levels mandated by the ECHA.

Johanson Technology has made every effort to present data that represents the actual performance of the part.

Johanson Technology reserves the right to make design changes without notice.

Why choose Johanson Technology thin film substrates?

Johanson Technology's thin film substrates are 100% manufactured in the USA and designed for demanding RF and microwave applications. Our customers benefit from reliable domestic production, rapid prototyping, advanced thin film manufacturing capabilities, custom metallization and patterning options, superior thermal management solutions, and expert engineering support from prototype through volume production.

What are thin film substrates?

Thin film substrates are ceramic-based materials used to support and interconnect high-frequency RF and microwave circuits. They enable precise conductor patterning, high signal integrity, and compact circuit designs for advanced electronic applications.

What are thin film substrates used for?

Thin film substrates are commonly used in:

• RF and microwave circuits
• Wireless communication systems
• Power amplifiers
• Aerospace and defense electronics
• Satellite communications
• Radar systems
• Test and measurement equipment
• Custom RF modules and assemblies

Their high-performance characteristics make them ideal for high-frequency applications.

Why are thin film substrates important in RF and microwave designs?

At microwave and millimeter-wave frequencies, even small variations in conductor dimensions can impact impedance, insertion loss, filter response, and phase accuracy. Thin-film substrates enable precise control of conductor geometry, helping designers maintain consistent RF performance, minimize losses, and ensure reliable operation in critical communications, radar, and sensing applications.

Are thin-film substrates suitable for aerospace and defense applications?

Yes. Aerospace-grade thin-film substrates are designed to withstand extreme operating environments, including vibration, shock, thermal cycling, radiation exposure, and extended mission lifetimes. They are commonly used in satellites, radar systems, electronic warfare platforms, avionics, and military communications equipment where long-term reliability is essential.

How do thin film substrates improve signal integrity?

Thin film technologies allow precise conductor geometries and controlled electrical characteristics, helping maintain signal quality and reduce unwanted losses in RF and microwave circuits

What substrate materials are available?

Johanson Technology offers a variety of ceramic substrate materials to meet specific electrical, thermal, and mechanical requirements. Substrates are available in lapped, polished, or as-fired conditions, with or without metallization.

What are patterned thin film substrates?

Patterned thin film substrates are metallized ceramic substrates that have conductor traces and circuit features precisely fabricated to customer specifications using advanced patterning processes.

What metallization and patterning options are available?

Johanson Technology can create custom patterns using:

• Chemical etching
• Abrasive etching
• Plated metallization

These processes enable highly accurate RF and microwave circuit features.

What is CTE and why does it matter?

CTE (Coefficient of Thermal Expansion) measures how much a material expands and contracts with temperature changes. Matching substrate CTE to housings or heat sinks helps minimize mechanical stress during thermal cycling and improves reliability

How do thin film substrates support thermal management?

Thin-film substrates can incorporate advanced thermal features such as filled vias and high-thermal-conductivity materials like aluminum nitride. These features improve heat transfer away from active devices, reducing thermal stress and supporting reliable operation in demanding environments, including aerospace and defense systems

Can thin film substrates be customized?

Yes. Johanson Technology offers custom thin film substrate solutions tailored to customer requirements, from prototype development through high-volume production.

What are the advantages of thin film technology over traditional PCB technology?

Thin film technology can provide:

• Higher dimensional accuracy
• Improved RF performance
• Reduced circuit size
• Better thermal management
• Higher frequency capability
• Greater design flexibility for RF and microwave circuits