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About Us FAQ
Frequently Asked Questions
Some frequent questions and answers about our photochemical etching process and value-added services. Can’t find your question? Feel free to contact us today and we’ll get you in touch with a Fotofab representative!
General
What is chemical etching?
Chemical etching, also known as Photo Chemical Machining or PCM, is a manufacturing process that uses acid to etch away unwanted metal leaving a precision thin metal part with exacting features. This process does not chemically alter the metal in any way, leaving the natural properties intact.
What kind of lasers do you use?
Many people think that our parts are manufactured by lasers. However, this is not the case. The Photo Chemical Machining (PCM) process uses chemicals, not lasers, to produce intricate and precision metal parts. Fotofab has been a leader in photochemical etching since 1967.
Where are your parts manufactured?
All Fotofab parts are manufactured in Chicago, IL.
Do you offer plant tours?
Yes. The Fotofab team would welcome the opportunity to show you our manufacturing facilities. Please contact us at 1-773-463-6211 to set up an appointment.
Do you have manufacturer’s reps in my area?
Fotofab has multiple manufacturing reps throughout the United States. Contact Us to locate the representative in your area.
Can I get a sample?
Yes, please take a moment to fill out the Contact Us form and we will send you some unique samples for your review.
Is Fotofab ISO/AS9100 certified?
Yes! Fotofab is ISO 9000:2015 and AS9100D certified. The AS9100 certificate includes the requirements of ISO 9001, the DOD, NASA, and FAA system assessments. See our Certifications page for the most recent version.
Is Fotofab ITAR registered?
Yes! Fotofab is ITAR registered. International Traffic in Arms Regulations (ITAR) controls the export of military and defense-related items. See our Certifications page for the most recent version.
Is Fotofab RoHS compliant?
Fotofab makes precision metal parts to the specifications of our customers, if the parts are designed as RoHS compliant, then we make them RoHS compliant. See our Certifications page for the most recent version.
Do you offer First Article Inspections (FAI)?
Yes. Please indicate that you will need an FAI when you submit your drawing for a quote.
Metals
What finishes are RoHS compliant?
Tin plating (dull or bright), black oxide, and black nickel are RoHS compliant finishes. Most other “blackening” finishes and tin-lead plating are not compliant. Feel free to call us with any concerns about RoHS.
What metals do you work with?
We etch both standard and exotic metals, non-corrosive, biocompatible, and many other types of metals. For a full list of metals we can etch, visit our Metals we Etch Page.
Do you work with non-metals?
At this time, we only etch on flat metal sheets.
Can you help me select a metal for my application?
Yes, we would be happy to help. Our engineering sales team (or estimators) is skilled at assessing materials and designs for a variety of projects. Please Contact Us for assistance.
Can I get a sample?
Yes, please let us know what you are looking for by completing our Contact Us Form.
What kind of metal should I use for my shield/encoder/etc?
Please review the Shielding Design Guide for common shielding materials and finishes. Or you may Contact Us and our team will help you determine the correct metal for your project.
I don’t need a specific material; what material is easiest/best for us to use?
Stainless Steel and Copper are readily available and easy to work with. Please make a note on your RFQ or print if you do not have a metal preference.
Where is your metal sourced from?
All metals are sourced from the United States, with the small exception of some Aluminum. If you have a specific need, please Contact Us for further assistance.
Process
What are the chemicals used in photoetching?
Various chemicals are used depending on the material that is being etched. Common etchants include ferric chloride and hydrofluoric solutions.
Does photo etching alter the properties of the metal?
No. Unlike traditional machining (such as stamping or laser cutting) there is not stress or extreme heat applied to the metal which could potentially affect the metal properties.
What are the design considerations when photo etching?
There are some basic minimum hole/slot sizes, minimum inside radii and other material considerations outlined in our “Design Guide to Photochemical Machining”.
What are some advantages of using the chemical etching process?
Low-cost tooling, quick turnaround time, and flexibility in part design.
What are the benefits of dropout versus tabbed parts?
Drop out parts will not have a burr when the part is detached from the sheet, however, it is etched less consistently, so the tolerances are greater.
What are tabs?
Typically, parts are laid out on a sheet of metal (usually 12″ X 18″ sheet) in a step and repeat fashion. Depending on the size of your part and metal thickness, a number of tabs will be placed to hold your part into the metal sheet. Removing the tabs can be easily completed by hand. For more on Tabs, visit our Tabs Page.
Is the Fotofab process a burr-free process?
Yes, technically. There are no burrs created when the part is made (such as the case with traditional metal stamping). However, Fotofab uses tabs to keep your part attached to the sheet of metal so we can keep tight tolerances during the etching process. We can choose to not use tabs and have your part drop out of the sheet, but tolerances may increase and some yield loss may occur. If you are unsure if your part is best produced as a “tabbed” or “drop out”, please contact one of our sales staff. If you are unsure if your part is best produced as a “tabbed” or “drop out”, please contact one of our sales staff.
Why does the quote mention small burrs or tabs when parts are detached?
The parts are held into the sheets by small tabs. When the parts are detached from the sheet, the place where the part was connected will leave a small burr. To etch metal parts with the best tolerances, we may opt to keep your part tabbed into the sheet.
Can I specify where the tabs should be placed?
Definitely. Please indicate on your drawing where you would like the tabs to appear (or where they cannot appear). Most parts will need 1 to 3 tabs depending on part geometry and metal thickness.
Can you etch tubes or 3D shapes?
At the moment, Fotofab can only etch from 2-D surfaces (such as a metal sheet). We cannot etch on 3D surfaces, and can only form a part after etching is complete.
Can you etch square holes?
There will be an inside radius making the corners not quite 90°, however, the sides of the square can be over-etched a little to allow for a perfect fit with a 90° degree part.
What is a half-etch, or a bend channel?
A half-etch, or a bend channel, is a partially etched area (usually 50-70% depth of the metal thickness) that can be used in hand forming. Typical applications that utilize half-etch features are RF shields.
How long does it take to get parts made?
Standard turnaround time is 10 business days. However, depending on the complexity of the order additional lead time may be necessary. For a premium, we also offer 5-day, 3-day, and same day delivery on most orders.
What types of packaging do you offer?
Parts can be shipped either still in sheets or detached. If the parts are to be detached, the packaging options include: Bulk packing, tubes, boxed in foam layers, pick and place trays, and tape and reel.
Quotes/Ordering
Who should I contact to send in my RFQ?
Here are a few ways to send in your RFQ:
Submit Online: Request a Quote
E-mail to [email protected]
Fax to (773) 463-3387
What is your minimum order quantity?
Our minimum order quantity is two sheets of material. The cost of our minimum lot run may depend on the metal type, thickness, secondaries (plating, forming, electro-polishing, etc) or packaging options.
What type of drawing files do you accept?
STEP, DXF, DWG, and X_T are the preferred formats for drawings.
Do you accept credit cards?
Yes, we accept Visa, MasterCard, AMEX, and government credit cards.
Dimensions
What is your minimum hole or slot size?
The smallest hole diameter or slot width that can be produced by the Fotofab process, as a general rule, is 1.2 times the metal thickness. The minimum practical diameter or slot width that can be machined is 90% of the metal thickness.
What is the min/max thickness that you can etch?
We work with metals ranging from 0.0002″(0.005mm) to 0.062″ (1.57mm) in a large variety of metals.
What is the largest sheet size that you can etch?
As a general rule, 24” (60.96 cm) by 36” (91.44cm) is the overall size. If your application exceeds our guidelines, please contact us with your request.
What are the tolerances associated with etching?
Typically, tolerances follow a +/- 10% of the metal thickness rule. The depth of etch tolerance can be as low as +/- 0.0005″ (0.0127mm).
Explain the ratio of hole size to metal thickness?
The smallest hole diameter that can be etched is 1.2 times the metal thickness. This is also the smallest slot width that can be etched.
What is the minimum feature size?
The minimum bar width is generally 90% of the material thickness.