| Q. |
What is your minimum hole or slot size? |
| A. |
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. Click here for our Design Guide. |
| Q. |
What metal thicknesses do you manufacture out of? |
| A. |
We work with metals ranging from 0.0002” (0.005mm) to 0.062” (1.57mm) in a large variety of metals (click here to see metals). |
| Q. |
What is the largest size that you can make? |
| A. |
As a general rule, 19” (48.26 cm) by 38” (96.52cm) is the overall size. If your application stretches our guideless, please contact us with your request. |
| Q. |
What are tabs? |
| A. |
Typically, parts are laid out in to a sheet of metal (usually 12”X18” 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. To read more about tabs, click here. |
| Q. |
Isn’t the Fotofab process a burr-free process? |
| A. |
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. |
| Q. |
Can I specify where the tabs should be placed? |
| A. |
Definitely. Please indicate on your DWG or DWF 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. |
| Q. |
Can you plate my metal parts? |
| A. |
Fotofab offers a variety of secondary operations including plating. We can offer electrolytic and electroless plating, tin plating, gold, blackening, Teflon coating, anodizing and more. Click here for a more complete list, or contact us with your request. |
| Q. |
Can you etch tubes or 3-D shapes? |
| A. |
At the moment, Fotofab can only etch from 2-D surfaces (such as a metal sheet). |
| Q. |
What is a half-etch, or a bend channel? |
| A. |
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. |
| Q. |
What are the tolerances associated with etching? |
| A. |
Typically, tolerances follow a +/-10% of the metal thickness rule. The depth of etch tolerance can be a low as +/-0.0005" (0.0127mm). |
| Q. |
How long does it take to get parts made? |
| A. |
Standard lead-times are two weeks. We also offer 5-day, 3-day and same-day premium delivery. Additional lead-time may be necessary if your part needs plating, forming, heat treating, etc. We will outline premium options on your quote. |
| Q. |
Do you offer FAI? |
| A. |
Yes. Please indicate that you will need a FAI when you submit your drawing for quote. |
| Q. |
How should you form a shield with ½ etch bend lines? |
| A. |
The ½ etch bend channel should end up on the inside of the formed part. Chemical etching produces a ˝ etch in the material that is actually about 50-75% of the metal thickness. When you bend the material to hand-form your part, the full thickness sidewalls adjacent to the ½ etch meet to form a 90° bend. |
| Q. |
Do you work with mixed processes (etch and laser)? |
| A. |
Fotofab offers chemical etching and other manufacturing processes to produce your precision metal part. Where chemical etching does not offer the desired features on your part, we will consider applying other processes such as laser, wire EDM, CNC machining or other traditional methods of manufacturing. Fotofab will also offer value-added services such as plating, forming, electro-polishing and more. Fotofab wants to be your one-stop shop for precision metal parts. |
| Q. |
Why does the quote mention small burrs or tabs when parts are detached? |
| A. |
The parts are held into the sheets by small tabs, when the parts are detached from the sheet, the place were 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. |
| Q. |
Explain the ratio of hole size to metal thickness? |
| A. |
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. |
| Q. |
What is the minimum feature size? |
| A. |
The minimum bar width is generally 90% of the material thickness. |
| Q. |
Can you etch square holes? |
| A. |
There will be an inside radius making the 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 |
| Q. |
What types of packaging do we offer? |
| A. |
Parts can be shipped either still in sheets, or detached. If the parts are to be detached here are the packaging options: Bulk packing, tubes, boxed in foam layers, pick and place trays, and tape and reel |
| Q. |
What are the tradeoffs for dropout versus tabbed parts? |
| A. |
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 |
| Q. |
What types of parts can be produced? |
| A. |
Products that are commonly produced using photochemical etching include RF shields, electronic packaging lids, etc. |
| Q. |
What are the chemicals used in photo etching? |
| A. |
Various chemicals are used depending on the material that is being etched. Common etchants include ferric chloride and hydro fluoric solutions. |
| Q. |
Does photo etching alter the properties of the metal? |
| A. |
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. |
| Q. |
What are the design considerations when photo etching? |
| A. |
There are some basic minimum hole / slot sizes, minimum inside radii and other material considerations outlined in our “Design Guide to Photochemical Machining”. Click here to read more. |
| Q. |
What are some advantages of using the chemical etching process? |
| A. |
Low cost tooling, quick turn around time, and flexibility in design. Click here to read more about the process. |
