Let's say (hypothetically) I want to start building electronics projects intended for use in military and naval applications. Naturally, the PCBs and their respective components must be absurdly durable and reliable, being able to withstand extreme temperature, pressure, shock, and corrosive environments.

A good place to start is using low profile ICs and components, in addition to abiding by the IPC class 3 standards. What are some other measures I can take to make sure these circuits are fool proof? What about the board mounted cable connectors? The Molex ones I have are quite tall and seem like they could break a solder joint if stressed too hard.

All input is greatly appreciated!
Justin

 

There are military rated/approved components and design requirements.
They are all defined in MIL-STD and MIL-SPEC documents.
I suggest you get familiar with them.
Commercial components may not be allowed, depending upon the customer.
Which specs to use depends upon the specific military/naval customer requirements.

 

There are military rated/approved components and design requirements.
They are all defined in MIL-STD and MIL-SPEC documents.
I suggest you get familiar with them.
Commercial components may not be allowed, depending upon the customer.
Which specs to use depends upon the specific military/naval customer requirements.

Thank you for the lead. Unfortunately for me, these military specification documents are always bloated and never concise. Extracting the meat and potatoes (specifications for PCB design and electronic components) from these resources is like finding a needle in a haystack.

 

Thank you for the lead. Unfortunately for me, these military specification documents are always bloated and never concise. Extracting the meat and potatoes (specifications for PCB design and electronic components) from these resources is like finding a needle in a haystack.

Welcome to the world of military design.

 

Thank you for the lead. Unfortunately for me, these military specification documents are always bloated and never concise. Extracting the meat and potatoes (specifications for PCB design and electronic components) from these resources is like finding a needle in a haystack.

Exactly, the only way to make electronics projects (something actually expected to be fielded and not just an R&D project) intended for use in military and naval application is to work (or have worked with a company) certified for that sort of work. It's expensive, time consuming and labor intensive to setup and maintain.

Example:
https://roemerind.com/isocertified/

Military and Government Compliance:
Roemer Industries manufactures custom graphic identification products to military and government specifications. These compliances are specific to certain materials and markings that are federally mandated.

Our compliances include:

Fed-Std-595	Standard Colors and Gloss for Government Procurement
Fed-Std-123	Military Marking for Shipment Identification
Mil-Std-130	Marking for US Military and UID Compliance
Mil-Std-129	Military Marking for Shipment and Storage
Mil-Std-171	Finishing of Metal Surfaces
Mil-Std-13231	Military Marking of Electronic Items
Mil-A-8625	Anodic Coating for Aluminum
Mil-M-43719	Self-Adhesive Markers and Decals
Mil-P-514	Nameplates and Identification for Military Property
Mil-P-6906	Nameplates and Identification for US Military Aircraft
Mil-Dtl-15024	Identification of Equipment, Foil and Nameplates
Mil-P-19834	Plate Identification, Metal Foil, Adhesive Backed
GG-P-455	Photosensitive Anodized Aluminum Foils
QQ-A-250	General Sheet and Plate
QQ-S-766	Steel, Stainless and Heat Resisting Alloys, Plates and Sheet
A-A-59485	Aerospace Markings and Decals
A-A-50271	Nameplates and Identification for Military Equipment
NSA-2H	Nameplates and Markings
SSP 50007	Aerospace Inventory Label Specification

 

Really, the summary of the performance standards is rather clear and easy to understand. The details have already been described.
So the summary is: The item must not fail at any time under any conditions, and must at all times perform as specified..
AND the full documentation must prove this.

One company that I worked at did actually produce an order of replacement parts fora military system, and I was the fortunate one who got to do the testing prior to my employer delivering for the military approval testing. That was an interesting experience but it turned out very well. All of the items passed both our tests and then their tests.. Lots of paperwork. So it seems that the paperwork is what adds so much to the price.

 

Thank you for the lead. Unfortunately for me, these military specification documents are always bloated and never concise. Extracting the meat and potatoes (specifications for PCB design and electronic components) from these resources is like finding a needle in a haystack.

Yes and they are what they are. Years ago there were more mil spec standards but today many just reference AMS standards. Either way if you manufacture for military it will meet military standards including military testing specifications. Many of us played this game. Even your packaging must comply to mil-spec.

Now you know why a $10.00 claw hammer cost $100.00.

Ron

 

When I worked within that world as a supply chain inspector I would receive a part that had to meet a particular standard. Within that standard were sub-standards; no, not sub-standard standards but rather additional information pertaining to the part in question. Within those sub-standards were additional references to yet other standards. I'll use a playing card as an example as I don't know if I speak about actual products could get me into trouble. So I received this playing card. It had to be made of particular materials. Within the standard for those materials was yet another standard that had to be referenced. Within THAT standard was yet another. And another. And yes, still one more. In the end I was able to accept the part because it met the final standard that applied. But to get there I had to chase down a gauntlet of paperwork.

Another requirement - - - I had to pass a background check and obtain a security clearance. If I had ANY issues in my background I could kiss that job goodbye. So it's not just "I want to make products for the military" it's a whole lot more. AND as a production facility you need to set up ISO standards. ISO-9001, 2 or 3, and others, which I've been out of that game over two decades, things like QS-900X and still more. If you're going to pursue this you REALLY REALLY REALLY need to be dedicated to learning ALL the in's and out's of the business. Then you need insurance. I have no idea what that might entail. You could be building Mission Critical or Life Critical products. If something fails - it's coming back on YOU!

Sure you want to do this?

Today I'm a custom cabinets and wood furniture shop. I have very little business. Right now I'm making new closet doors and repairing drawers for a client. Built a "Loft Ladder" that has to be able to support the weight of a human plus whatever they may be carrying up the ladder. I'm starting today some window framing work with white oak. There's some drywall repairs and I need to contract with an electrician to move a light switch five inches. Yes, I could do it on my own but because I'm a business and need to protect my client - it must be done by a licensed electrician. Or by someone who's a friend or family member who can handle moving a box a few inches. There ARE things you need to consider when you're a business. Not to mention licensing and insurance as well as probably paying an accountant to do your taxes. This last tax season I paid $450 to an accountant. Mostly because my documentation was impeccable. Something you learn when you work in the field of quality control. Documentation is critical.

So yes, you're going to have to not only search through a haystack of documents you're also going to have to know and understand all of them. And comply with all the associated requirements.

I wish you the best in your endeavor. And I haven't EVEN begun to address ESD and environmental controls necessary for your business dreams.

 

Even your packaging must comply to mil-spec.

Awe geez, yes. Packaging is yet another issue.

Now you know why a $10.00 claw hammer cost $100.00.

Or a nylon foot on a stool for a C-17 cost the government $18,000.oo U.S.

 

In the commercial world, the customer does the final testing, with any infant failures normally repaired under warranty.
The military world doesn't tolerate that, so the parts are hermetically packaged (usually no plastic), initially screened for reliability, and then the final testing to insure reliability during operation under environmental extremes for some specified period of test operation, is done by the manufacturer.

Easy to see why the cost of military electronics is a factor of ten or more higher than commercial.
For the extreme required reliability of electronics that go into space, the factor is much higher than that.

 

Really, the summary of the performance standards is rather clear and easy to understand. The details have already been described.
So the summary is: The item must not fail at any time under any conditions, and must at all times perform as specified..
AND the full documentation must prove this.

One company that I worked at did actually produce an order of replacement parts fora military system, and I was the fortunate one who got to do the testing prior to my employer delivering for the military approval testing. That was an interesting experience but it turned out very well. All of the items passed both our tests and then their tests.. Lots of paperwork. So it seems that the paperwork is what adds so much to the price.

Today, the requirements for automotive parts is almost as bad with the latest cybersecurity Road Vehicle requirements.
https://www.iso.org/obp/ui/en/#iso:std:iso-sae:21434:ed-1:v1:en

https://www.iso.org/obp/ui/en/#iso:std:iso:26262:-1:ed-2:v1:en
ISO 26262-1:2018(en) Road vehicles — Functional safety


When people wonder how China can sell some cars so low, one of the reasons is they ignore most of the ISO requirements for the cheap EV's they sell mainly internally.
https://www.tuv.com/greater-china/en/電動汽車出口驗證.html

 

Thank you all for the input. I am not trying to start a business out of this I am just conducting research for one part of a possible project. Someone else is handling all that other stuff.

I should've been more clear in my opening message. I am curious what others have done specifically to make PCBs and electronic systems more reliable and rugged.

 

I also worked in a small but well established transformer manufacturing company. We mostly supplied to commercial customers, but had a segregated area for military products. The amount of paperwork that had to be filled and archived was astounding. Amongst the requirements was full traceability of materials, almost all the way to the mines where the iron and copper had come from.

 

I should've been more clear in my opening message. I am curious what others have done specifically to make PCBs and electronic systems more reliable and rugged.

Component De-rating, and testing, testing, testing, performing a thorough analysis on any failures or performance deviations you encounter. Make a solid DFMEA.

It also goes without saying that you should purchase components from reputable distributors and if subcontracting the assembly, audit it’s quality systems and make sure that they have a strong engineering team that can provide solid corrective actions when required.

 

Exactly,

A few to add to the list, from old memory (no warranties, etc.)

MIL-STD-461 - EMI (think FCC on steroids)
MIL-STD-704 - Aircraft power sources, and power requirements for things in aircraft
MIL-STD-810 - This has many environmental limits such as temperature, shock, and vib.
MIL-STD 1275 - Ground power
MIL-STD-1399 - Shipboard power
MIL-DTL-38999 - Those big, fat circular connectors
MIL-HDBK-217 - Reliability guides

And my fav - MIL-STD-901 - This has the Navy shock and vib specs, including the "Little Hammer" and "Big Hammer" tests. Hint: It involves a raft and depth charges.

ak

 

A few to add to the list, from old memory (no warranties, etc.)

MIL-STD-461 - EMI (think FCC on steroids)
MIL-STD-704 - Aircraft power sources, and power requirements for things in aircraft
MIL-STD-810 - This has many environmental limits such as temperature, shock, and vib.
MIL-STD 1275 - Ground power
MIL-STD-1399 - Shipboard power
MIL-DTL-38999 - Those big, fat circular connectors
MIL-HDBK-217 - Reliability guides

And my fav - MIL-STD-901 - This has the Navy shock and vib specs, including the "Little Hammer" and "Big Hammer" tests. Hint: It involves a raft and depth charges.

ak

Been there and done that. The computer system for a company I worked for had equipment on the FFG-7 (and other classes of chips) shock tests. It was not pretty.

 

Funny story. It was maybe 20 years ago. We were having in house several engineers from KAPL (Knowles Atomic Power Laboratories) to do some testing on an old design removed from an old reactor system. I was tasked with designing a RPI (Rod Position Indicator) at the last possible minute. I got my design finished at home on a Sunday. This was to be an in house only box, not for any use other than their testing. Since it was a Sunday afternoon I labeled the box Bear Products. Bear was one of our dogs. I included a manual for operation and everything. Everything worked fine, KAPL was happy and my world was a happy place.

Unknown to me when they departed they took a copy of my manual. Six months later my department head gets a call from the program office. Seems KAPL wanted to buy four of the units I designed but could not find "Bear Products". Now my department head had to explain things.

OK they still wanted four units. What I designed was about $1,000 in parts. When all was said and done the new units, assembled to Mil-Spec including Mil-Spec packing for shipping cost $4,500 per unit. They were fine with the cost and found Bear Products to be humorous. Anyway, we see where adding Mil-Spec increased the cost.

Something else I noticed, a comment of making something fool proof. My department head would frequently tell me Ron, make it fool proof. My response was always Mike, I can't make it fool proof because fools are very ingenious people.

The most important Mil-Spec I stressed to manufacturing was always comply to MIL-T-FD41.

Ron

 

My department head would frequently tell me Ron, make it fool proof. My response was always Mike, I can't make it fool proof because fools are very ingenious people.

Here is the original:

A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.
- Douglas Adams, "Mostly Harmless"

ak

 

Considering the quality of the majority of current consumer electronics and it becomes obvious why mil-specs are so demanding. The relative stress levels are quite different. I clarified that in one job interview when they asked about how I handled stress, specifically.
I replied that I tried to avoid it. Then they asked what I considered "high stress". I responded: "Coming under heavy automatic weapons fire." They assured me that was not part of the job, and hired me. And they were correct.
The point being that in many tactical situations there is no room for equipment failure to perform perfectly. Lives and more depend on it.

 

Here is the original:

A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.
- Douglas Adams, "Mostly Harmless"

ak

I always wondered where that came from. Thanks for sharing that.

Ron