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What is an Isola PCB?

An Isola PCB is a circuit board manufactured using a specified Isola laminate and prepreg construction. Isola identifies the base-material supplier; it does not identify one universal dielectric, one copper thickness or one manufacturing capability. A useful purchase specification names the material system, the copper-clad cores, the bonding layers and the finished-board requirements together.

For an engineer, the first question is which limitation needs attention: thermal exposure, electrical loss, dimensional control, an existing approved drawing or a specialty polyimide requirement. For a buyer, the same decision becomes an identifiable material, an available construction and an agreed evidence package. Start with that problem rather than selecting the largest Tg value or the smallest Df shown in a summary table.

The covers several material families. This page organizes named systems into practical engineering routes. A short, modest-speed industrial board and a long high-speed backplane may require very different constructions even when both use glass-reinforced epoxy. A material choice becomes useful when its consequences are visible in the stackup and quotation.

Choose the material page that answers your next question

These are task routes, not a ranked list of interchangeable materials. Choosing FR408HR because of a channel problem does not remove thermal and manufacturing checks. Choosing 370HR for an established construction does not remove signal-integrity analysis. Where the intended product crosses several routes, keep one controlled stackup and record the evidence required by each discipline.

For a specified low-loss multilayer, the I-Tera MT40 fabrication guide connects core and pressed-bondline dimensions with the RFQ. If the drawing names TerraGreen, first resolve the complete variant using the TerraGreen material identity and comparison guide.

For RF structures where electrical length is critical, review Astra MT77 phase sensitivity and fabrication requirements. The IS680 AG construction guide separately addresses AG identity and wavelength sensitivity. These routes are engineering reviews, not a list of approved substitutes.

Read the number and its measurement context together

A property table should identify the named grade, document revision, units and test conditions. Tg, decomposition temperature and time-to-delamination describe different observations. A higher Tg does not automatically give a higher continuous-use temperature, better insulation design or a guaranteed number of reflow passes. Refer to the High Tg material guide when the thermal terms themselves need clarification.

Electrical data needs similar care. The Dk used to compare material samples is not automatically the Dk used by the field solver for the actual construction. Glass style, resin content, frequency and test method can change the reported value. Df is also frequency- and method-dependent. Comparing a 500 MHz headline for one material against a 2 GHz value for another can produce a misleading ranking.

Keep a short data passport with the design: grade, core or prepreg identification, glass style, resin fraction, pressed thickness, foil type, frequency and source. Ask the fabricator which input will be used for impedance modeling and which test coupon will verify the build. That record is more useful than writing only 鈥淚sola, low loss鈥� in a fabrication note.

Compare two stated dielectric constructions

This optional tool compares a uniform route in two homogeneous dielectric assumptions at one frequency. Enter your own Dk and Df, length and data reference. The result separates estimated dielectric attenuation from propagation delay. It does not select a material for you or infer total channel performance from a brand name.

The comparison uses the low-loss TEM approximation: dielectric attenuation in dB per metre is approximately 8.686 脳 蟺 脳 frequency / c 脳 鈭欴k 脳 Df. Delay is length 脳 鈭欴k / c. The example uses two explicitly stated 2 GHz data pairs; it is a learning example rather than a released construction. Conductor loss, roughness, transitions and radiation are outside this calculation. See for the low-loss dielectric term.

Two useful sensitivity checks are to double route length and then change only Df. In the simplified model, doubling length doubles both delay and dielectric attenuation. Reducing Df reduces the dielectric loss term but does not shorten propagation delay. Changing Dk affects delay and also the simplified attenuation term. These relationships help explain why 鈥渇aster material鈥� is an incomplete purchasing description.

For a microstrip, fields occupy both the substrate and its surroundings. A bulk dielectric value cannot simply be inserted into this homogeneous model to approve that route. Use an appropriate field solver for the actual geometry and retain the conditions with the result. explains the distinction between stripline propagation and the effective dielectric environment of a microstrip.

Translate the material choice into a stackup

A core is already cured copper-clad laminate. Prepreg is the bonding material that flows and cures during lamination. The final gap depends on the selected material and pressing conditions, not just the glass-style name printed on a list. Copper patterns also affect the resin needed to fill the structure. Specify the intended pressed construction, not a collection of unqualified nominal sheet thicknesses.

For a multilayer board, identify every copper layer and every dielectric interval. Mark signal/reference relationships, controlled-impedance structures and any special copper requirements. The multilayer PCB guide provides the layer-planning context; the Isola grade then becomes part of that physical design. Do not approve a material change while leaving the previous stackup assumptions unexamined.

Ask whether core dimensions include copper, which foil profile is available and how finished board thickness is referenced. A drawing can appear numerically balanced yet count copper twice. A construction can also be symmetric in nominal thickness while its copper coverage is unbalanced. Use fabrication review to reconcile those details before treating the stackup as a purchasing specification.

What should be reviewed before manufacture?

Group questions by the evidence they need. Material identity is checked through purchasing and traceability records. Layer and hole geometry is addressed by the released drawings and appropriate inspection. Electrical connectivity and impedance require their agreed test methods. Application reliability requires a qualification plan tied to the actual product and exposure. One of these records cannot substitute for all the others.

If an existing board is being transferred, submit its last approved stackup, material callout, revision and relevant previous reports. Identify which features must remain unchanged and where engineering may propose alternatives. If this is a new design, label unresolved inputs rather than inventing exact values merely to complete a form. Both cases can proceed to an engineering discussion without first completing the online calculator.

The RF PCB service overview addresses broader RF manufacturing choices. That route is useful when the actual loss, frequency or geometry requires a material outside this selection. There is no reason to force an RF or microwave requirement into a general epoxy construction solely because a familiar brand is already approved elsewhere in the product.

What affects Isola PCB cost?

The quoted cost reflects a specific build: material availability in the required core and prepreg, purchased sheet utilization, copper profile, layer count, sequential processing, hole structures, finish, test scope and quantity. Material brand alone cannot generate a credible price. A low unit price may exclude tooling, qualification coupons, lot documentation or the losses associated with an unusual material purchase.

The budget brief starts without prices. Enter the technical scope first; leave costs blank if a supplier has not provided a suitable basis. If you already have allowances, identify their date and included scope, then enter the per-board, setup and batch-verification amounts in one currency. The calculation adds those amounts without applying a hidden ordinary-FR-4 multiplier or claiming to quote current Isola prices.

For two proposals, compare the same released material, finished thickness, copper, tolerances, evidence and quantity. If a supplier suggests a different grade, treat it as a separate technical option until approved. The PCB quote comparison worksheet helps distinguish an arithmetic price difference from a difference in what will actually be delivered.

Isola material questions