吃瓜tv 路 ENGINEERING REFERENCE
ITEQ IT-180A PCB: Properties, Expansion & Fabrication
Review IT-180A material data, distinguish its laminate and prepreg identities, and estimate free thickness change over the published test interval.
Original engineering guidance 路 References checked September 27, 2026
IT-180A is a named construction choice, not every 鈥�180鈥� material
ITEQ IT-180A is a high-Tg laminate and prepreg family used for multilayer PCB constructions. Its practical review includes thermal expansion, assembly exposure, hole geometry and electrical requirements. Keep the A suffix. A similarly numbered ITEQ product, an older data sheet or a generic Tg180 description is not automatically an approved substitute.
The current lists a DSC Tg of 175掳C. That is a material-test result, not a continuous operating-temperature limit for your assembled board. The same page provides electrical values under defined frequency and resin-content conditions. Treat each property with its own definition rather than using the model number as a specification.
This page supports grade-specific design and procurement. Use the ITEQ manufacturing page for the overall build request and the material directory when the grade has not yet been chosen. A fabrication quote should state the actual core and bonding material, thickness convention, copper and approved documentation.
Read the property and its measurement together
| Manufacturer reference | Published value | Interpretation for the review |
|---|---|---|
| Glass transition | 175掳C, DSC | A transition measurement; not a board service-temperature approval |
| Decomposition | 345掳C at 5% mass loss | A decomposition test definition, not an allowed reflow peak |
| Z-axis expansion | 2.7%, 50鈥�260掳C, TMA | A free-expansion reference over this particular interval |
| T288 | 20 minutes, with 1 oz copper on the web table | A specific time-to-delamination result, not an assembly dwell allowance |
| Dk | 4.1 at 10 GHz, RC 50% | IPC-TM-650 2.5.5.13 reference, not an exact value for every layer |
| Df | 0.017 at 10 GHz, RC 50% | Dielectric loss reference; total channel loss includes other contributions |
These selected values come from the manufacturer鈥檚 public IT-180A table checked for this revision. Confirm the applicable controlled data sheet and purchase specification before release. The official linked data sheet identifies the copper-clad laminate as IT-180ATC and the prepreg as IT-180ABS. Keep that distinction in the bill of construction instead of labeling every dielectric row with the laminate name.
Electrical figures at another frequency or method should not be pasted into this table without their conditions. For example, a 1 GHz reference and a 10 GHz reference can legitimately differ. The ITEQ Dk/Df comparison page shows how to preserve frequency, method and resin-content grouping. A numerically convenient value is not necessarily the appropriate input for the intended transmission line.
Estimate free thickness change over the published interval
This worksheet applies the published 2.7% Z-axis expansion over 50鈥�260掳C to an entered starting dielectric thickness. It does not infer a temperature-dependent expansion curve or choose a transition temperature from DSC Tg. The endpoints are fixed because the source describes an interval result. An arbitrary operating range needs appropriate material data rather than a proportional interpolation.
IT-180A Published-Interval Expansion
The arithmetic is starting thickness multiplied by 0.027. A 1.00 mm free dielectric specimen would correspond to 0.027 mm, or 27 碌m, of thickness change in this simple calculation. For 1.60 mm of entered dielectric, the change would be 43.2 碌m. Those examples explain the dimensional scale; a finished circuit constrained by copper and other layers is a different mechanical object.
Do not convert this result into plated-through-hole fatigue life. Copper geometry, resin behavior, interfaces, moisture, temperature history and constraints affect the actual stress. The tool deliberately does not return a safe number of reflow cycles or a pass/fail reliability badge. It creates a clear question for the manufacturer: what evidence supports the proposed material and interconnect construction under the required exposure?
Specify IT-180ATC and IT-180ABS in their actual roles
A core is a cured dielectric construction with copper faces. A prepreg bondline is formed during lamination. The material family connects these products, but their dimensional states are different. Specify core dielectric thickness or clad thickness explicitly, then identify the prepreg plies and the approved pressed thickness between copper layers. Avoid counting the same core copper twice.
Consider a four-copper-layer concept containing 35 碌m copper on each layer, a 1.10 mm core dielectric and two 0.18 mm bondlines. Its nominal arithmetic is 1.60 mm before additional finish or coating conventions are considered. These are illustrative dimensions, not a published IT-180A stock construction. The chosen resin content, glass and copper coverage must support the actual pressed result.
The ITEQ stackup worksheet makes those entries visible in their physical order. The prepreg selection worksheet adds a conservative interval from supplied ply data. Neither tool selects a press recipe. Lamination parameters depend on the actual material revision, equipment and qualified process, so a generic temperature-and-pressure schedule is not provided here.
For electrical layers, state the reference plane, intended dielectric spacing and impedance requirement. A stable nominal thickness does not guarantee a stable impedance if copper shape or the appropriate dielectric model changes. The fabricator may propose width compensation or a different bondline construction; keep that proposal within the documented approval process.
Review the combination of material and interconnect geometry
Drilling and hole-wall preparation have to work with the complete construction. Board thickness, drill diameter, copper distribution and layer interfaces matter together. A laminate鈥檚 thermal data alone cannot establish the capability of a small through-hole in a thick board. Likewise, a general factory capability limit cannot prove the reliability of every material and geometry combination at that limit.
Write the required hole definitions and acceptance basis clearly. Distinguish the prepared drill from the finished plated hole. Specify special via treatments and the relevant feature population. If the project needs section evidence or particular thermal conditioning, agree the specimen, method and reporting scope in advance. Avoid assuming that an unspecified 鈥淚PC compliant鈥� description includes all tests or a specific acceptance class.
Assembly exposure is another separate input. Record the anticipated soldering profiles, repeated passes and rework scenario. A time-to-delamination property is not a permitted dwell time in the assembly oven. Qualification should consider the actual board construction and the applicable acceptance criteria, including how moisture and handling are controlled through the build sequence.
For applications with high humidity, bias or dense hole spacing, discuss the required CAF evidence with the engineering team. A material-family claim does not specify the exact coupon geometry, spacing, conditioning or acceptance threshold. These details determine what a reported test can support. Do not infer an allowed working voltage from a marketing reference to a test voltage.
Keep grade-specific costs tied to their basis
The IT-180A budget worksheet uses your own documented panel and board allowances. Identify the IT-180ATC core, IT-180ABS bonding construction, copper, finish and test scope in the source field. The calculator has no live laminate prices and no automatic surcharge based on the letters in the grade name. It organizes a cost basis that can be checked against a supplier quotation.
IT-180A Documented Lot Budget
Panel utilization can dominate a small order. The tool uses the entered positions per production panel and expected acceptance to plan a whole number of panels. Extra material, setup and minimum charges need to be included explicitly. This is expected-output arithmetic, not a statistical delivery guarantee. An exact order requires a production plan and an agreed quantity policy.
Compare quotes only after making the construction and inspection scope equivalent. A lower number may reflect a different copper weight, prepreg arrangement, panel assumption or excluded test. If the quote names an alternative laminate, request a separate engineering comparison before treating that offer as a price for the approved IT-180A construction.
IT-180A design and purchasing questions
Why does the grade name contain 180 but the table says 175掳C?
A model number is not a test specification. The current official page reports 175掳C by DSC. Preserve the method and source revision, and use the contractually agreed material requirement. Do not round a measured property to match the marketing name or silently combine values from old data sheets.
Can IT-180A be used for every high-speed channel?
Suitability depends on the electrical budget and construction. IT-180A鈥檚 published reference is not evidence that every high-speed link will pass. Review frequency, length, conductor loss, via transitions and the appropriate dielectric model. If a different family is needed, treat that change as a documented material and stackup decision.
Does the expansion worksheet predict a finished PCB?
No. It applies one published free-expansion percentage to the entered dielectric thickness over fixed endpoints. It omits constraint, copper stresses and fatigue. Its output helps explain a material property, not validate a finished interconnect.
What should accompany a quotation request?
Provide the board revision, quantities, approved material identities, core and prepreg construction, copper, thickness tolerances, hole details and electrical requirements. Add the required test records and any permitted alternatives. Mark unresolved items so the response can address them directly.
Bring the requirement and the drawing together
Send the board revision, construction, quantity and the standard or engineering question you need reviewed. Identify unresolved requirements so the response can address them.
Send requirements for reviewOptional: attach the downloaded worksheet manually. This guidance does not certify a design, approve a shipment or replace the applicable authorized standards.