Electronic component date codes help identify when a device was manufactured or processed, according to the manufacturer’s marking system. They are not, by themselves, a universal expiry date. Older ICs may be suitable for a new PCBA order when their identity, source, storage condition and assembly suitability meet the approved requirements.
The difficult purchase decision usually looks like this: the specified chip is available now, but its date code is several years old. Newer stock would delay production. Should you accept the available material, ask for additional evidence or wait?
Decide at the part-and-lot level. “Old means unusable” and “unused means safe” both leave important questions unanswered.
This article focuses on packaged semiconductor devices. Do not automatically apply the same acceptance logic to batteries, electrolytic capacitors, solder paste, adhesives or other materials with different storage mechanisms and manufacturer instructions.
What Do Electronic Component Date Codes Actually Tell You?
A date code provides manufacturing-related information within a specific marking scheme. It does not describe everything that happened to the device afterward.
Confirm the manufacturer’s decoding instructions before interpreting an unfamiliar code. For example, an Analog Devices support response about ADG3257BRQZ-REEL7 explains that “2013” in the date-code format discussed means week 13 of 2020, not the year 2013. That example should not be generalized to every manufacturer or package.
Also distinguish the device date code from other dates on the shipment.
| Information | What It Helps Establish | What It Does Not Establish Alone |
|---|---|---|
| Device date code | Manufacturing-related timing under the applicable marking scheme | Storage quality or remaining service life |
| Lot or trace code | Traceability within the manufacturer’s system | A complete distribution history |
| Bag seal date | When the recorded dry-pack operation occurred | Device manufacture date or all prior handling |
| Distributor shipment date | When that seller dispatched the material | When the devices were manufactured |
| Bag opening record | A starting point for tracking exposure | Exposure that happened before the recorded opening |
A newly sealed bag can contain older devices. Likewise, an older manufacturing code does not prove the bag has been open for years.
Ask for clear photographs of the original reel, tray, bag and box labels where available. Preserve the relationship between them instead of accepting one cropped date-code photograph.
Are Electronic Component Date Codes An Expiry Date?
There is no universal rule that all packaged ICs become unusable after two or three years.
Texas Instruments’ product shelf-life guidance distinguishes its controlled internal storage from storage after customer delivery. It identifies materials, packaging, moisture sensitivity and customer handling as relevant factors.
This supports a condition-based assessment of TI products. It does not provide blanket approval for an unidentified reel from an unknown warehouse, or replace another manufacturer’s instructions.
TI’s long-term storage evaluation also examined multiple package types and finishes after extended controlled storage, including solderability and packaging-related checks. The study is useful evidence that calendar age alone is insufficient. Its results are not a certificate for the specific lot offered to you.
For a purchase decision, ask two separate questions:
- Does the manufacturer provide guidance relevant to this device and package?
- Can the supplier demonstrate that the offered material’s history and condition are consistent with acceptable use?
If your customer has an agreed date-code restriction, request approval for an exception before purchasing outside it. Technical suitability and compliance with the agreed purchasing specification are separate acceptance questions.
What Evidence Should You Request Before Accepting Older ICs?
Use electronic component date codes as one field in a receiving review, alongside the full manufacturer part number and lot information.
A proposed evidence checklist is:
| Review Area | Request From The Supplier | Reason |
|---|---|---|
| Exact identity | Full ordering code, manufacturer and package | Similar base numbers can hide different grades or variants |
| Source | Supplier identity and available purchase-chain records | Establishes where the material came from |
| Lot breakdown | Quantity by date code and lot, where identified | Prevents one sample from being treated as representative of unrelated stock |
| Packaging | Original labels and current bag, reel or tray condition | Supports inspection and handling review |
| Storage | Available storage and handling records | Helps assess unresolved environmental exposure |
| Moisture control | Applicable MSL, opening history and dry-pack records | Supports a package-specific handling decision |
| Previous processing | Disclosure of programming, reballing, lead refinishing or other work, if any | Separates unused stock from material with additional processing |
| Test evidence | Method, sample identity, quantity and results, if testing was performed | Shows what the report actually covers |
Not every legitimate small shipment comes with an uninterrupted environmental data log. Missing evidence nevertheless needs a documented disposition; it should not silently become an assumption that conditions were acceptable.
Keep the review linked to the approved BOM and the actual purchase line. Approval of one part number does not automatically approve a different suffix or an alternative package.
How Do Moisture History And Shelf Life Differ?
Shelf storage and exposure before soldering are different questions. A component can have an older date code but remain properly dry-packed. A recently manufactured component can have an unresolved exposure history.
For moisture-sensitive devices, obtain the package-specific instructions and review whether the available records support release to assembly. TI’s Component Reliability After Long Term Storage discusses storage risks and protective packaging; it should be read within its stated device and storage context.
A humidity indicator card, where supplied, is useful evidence at opening. It is not a complete historical record of every handling event.
Similarly, placing parts into a new bag does not by itself prove that earlier moisture exposure has been addressed. If drying is required, the responsible process engineer should select the procedure using applicable manufacturer guidance and handling requirements. Device packages, reels and trays may have different temperature restrictions.
The moisture sensitivity level review should therefore produce a disposition: release, controlled conditioning, further investigation or rejection. Avoid a blanket instruction to bake every older component.
Drying also does not establish authenticity, repair damaged terminals or prove electrical performance. Each unresolved concern needs its own evidence.
When Should You Ask For Solderability Or Electrical Testing?
Request additional testing to answer a defined concern, rather than buying a report simply because a date code looks old.
Solderability Checks Address The Joining Surface
If terminal condition or storage history raises a solderability concern, ask engineering or a qualified laboratory to define a suitable assessment.
Specify the package and finish, applicable method, sample selection, acceptance criteria and treatment of tested samples. Depending on the method, samples may be consumed or altered; agree whether they can return to production stock.
A passing result supports the assessed samples and lot under the defined plan. It does not automatically qualify every lot in a mixed shipment.
Also distinguish a solderability test from a general visual inspection. A photograph showing clean-looking leads does not measure wetting performance.
Electrical Testing Addresses The Parameters Actually Measured
A report stating “electrically tested” is incomplete without the conditions and scope.
Ask which functions and parameters were checked, at which voltage and temperature, using which limits. Confirm that the tested samples came from the lot offered for your order.
A basic identity read or power-on check may answer a narrow question. It does not establish full datasheet compliance, remaining operating life or authenticity.
If the part is a memory device, clarify whether testing uses destructive writes and whether the material contains data that must be preserved. Manufacturer-specified data retention and write endurance are separate concepts from the age printed on a package.
Neither an electrical pass nor a solderability pass replaces source verification. Keep that review connected to your counterfeit-component prevention process.
Can You Mix Different Date Codes In One PCBA Order?
Different electronic component date codes do not automatically require rejection or separation into different finished-product orders. However, approval should consider the relevant lot information, customer requirements and product configuration.
Check whether the offered material is the same approved ordering code and whether any applicable product-change notices, silicon revisions or documented errata affect the design. A date code alone is not a reliable substitute for that investigation.
For sensitive applications, engineering may need to establish whether the revisions can be used together. Procurement should not make that determination from package appearance.
If mixed lots are accepted, define how records will identify their use. For example, require a relationship between the material lot and the production batch, or a finer level of tracking where necessary.
Agree that level through the PCBA traceability requirements. Do not assume that receiving records automatically identify which chip lot went onto each individual board.
Electronic Component Date Codes: Compare Your Supply Options
Compare the complete route to approved production, rather than the date code or component price alone.
Consider this hypothetical purchase:
- Lot A has an older date code, documented distribution records and suitable packaging.
- Lot B has a recent date code, but the seller cannot adequately explain its source.
- Lot C is expected from an approved source later and may delay the build.
The example does not make Lot A automatically acceptable. It shows why “choose the newest” is an incomplete rule.
For each option, record the unresolved evidence, review cost, sample consumption, conditioning or testing time, and effect on the production schedule. A low-priced lot can lose its advantage if extensive investigation is needed.
Ask the sourcing team to present those conditions together with the component-sourcing proposal. Keep the purchase decision pending until the responsible quality and engineering reviewers have resolved the required acceptance questions.
If older stock is the only practical supply for a discontinued part, treat the immediate lot review and the future supply plan separately. Use an obsolescence-management review to assess redesign or alternative sourcing; accepting one lot does not solve long-term availability.
How To Write An Electronic Component Date Codes Requirement
A useful purchasing requirement explains what suppliers must disclose and what requires approval. It should reflect the end customer’s actual needs.
Avoid an ambiguous note such as “fresh stock only.” If a maximum age is required, define the permitted window and the date against which age is measured. State whether exceptions and mixed lots are allowed.
You can adapt this request:
Please identify the full manufacturer part number, available quantity, date-code and lot breakdown, source, and packaging condition before order confirmation. Disclose any known prior use or processing. Where the material falls outside our agreed date-code requirement, obtain written approval before shipment. Provide the available storage and moisture-handling records and identify any missing information.
Add project-specific acceptance conditions separately. For example, name the approved lot, quantity, required receiving checks and any pre-assembly conditioning or testing. An approval should not be reusable for later shipments with a different history.
For a Haode PCBA enquiry involving older chips, provide the BOM line, required quantity, offered labels, available supplier records and intended assembly schedule. Ask for an evidence-gap review and a proposed disposition before authorizing the material for the build.
The right question is not simply how old the chip is. It is whether this identified lot has enough evidence to meet this order’s sourcing, handling, assembly and product requirements.
