MIL-STD-130N requires that vast numbers of DoD parts or components be marked with a permanent, "life of the part" Data Matrix code. This requirement has Defense Contractors and Maintenance Depots scrambling to determine the materials and methods that will work for them, given their specific needs. End use applications and the environment in which parts operate differ wildly, of course, but what should remain the same is the thought process by which UID parts marking decisions are made. The balance of this article will describe a process that has been shown to work.

First, What Material Should I Use For UID Labels?

As was mentioned above, the environment in which parts operate ranges from benign to the most extreme. If your end use application may be characterized as benign, congratulations! You are one of the lucky few and any of several material choices should be suitable.

Given the business of DoD, however, it is far more likely that the component you are responsible for marking operates in conditions that may be described as harsh, if not hostile! It is for this reason that material selection should be the first consideration in the decision making process. Questions to consider, include:

• Under what conditions must your part and hence your label or mark survive?
• Will the part or component be subjected to weathering and UV?
• Will it be subjected to extreme temperature cycles?
• Will it come in contact with chemicals, fuel, oil, hydraulic fluid or other fluids?
• Will it be subjected to salt spray?
• Does it operate under desert conditions?
• Over what period of time and in what combinations of these conditions must your part and label survive?

The answers to these questions will lead you down the path of material selection, be it Paper or Plastic, Steel or Anodized Aluminum.

Next, What Print Method Should I Use?

After having decided upon Material, the method used to construct a mark or label is the next consideration. That is, how is the mark to be created? Depending on the material, there are various methods:

• Surface print methods, such as ink jet, thermal transfer or laser bonding, are additive in nature and involve the deposition of inks, toner or thermal resin.
  
• Altered surface print methods, such as chemical etching or laser cutting, are considered to be subtractive in that material is being removed.
  
• Integrated print methods, such as photo anodized, are neither additive nor subtractive but are, instead, transformative as a result of the process.
  

It is important to note that the decision regarding which print method to use is not stand-alone in the sense that the same types of questions asked in the Material section above come into play here. Material comes first, but it is the proper combination of material and print method that will allow you to produce UID Data Matrix labels that satisfy the requirements of MIL-STD-130N and survive the rigors of the field environment in which parts operate.

Lastly, Should I Make or Buy My UID Labels?

Often times it makes sense to buy pre-printed labels from a qualified source. Other times it's better to make your own UID labels on-site, when and where they are needed. Things to consider when making this decision include production requirements (current and future demand), lead-time sensitivity and facility requirements.

Summary:

Defense Contractors and Military Maintenance Depots are required to comply with MIL-STD-130N. Vast numbers of DoD parts must be marked with permanent UID Data Matrix bar codes. The environment in which many parts operate is harsh. Depending on the end use application, thought must be given to ensure that the best and most suitable materials and marking methods are selected. This article describes a thought process for UID parts marking that has proven successful.