Reading DIODES Labels: Date Codes, Lot Numbers, and Packaging Records

To review a DIODES date code label, identify the external part number, preserve the complete lot reference, and compare the offered packing with the purchase requirements. Record product dating, bag sealing, and shipment information separately. A readable label helps organize this review; acceptance also requires evidence connected to the material being delivered.

This guide explains the principal manufacturer fields and develops a practical purchasing workflow around them. The workflow tables are recommendations for buyers and receiving teams, rather than a DIODES acceptance standard. For ordering-code questions, begin with our DIODES part-number and ordering-suffix guide.

1. Identify the Label Fields Before Comparing Numbers

AP02006 Rev. 32 distinguishes external PN, internal House Number, traceability LOT, and packing-unit QUANTITY. On new labels, COD identifies diffusion origin and ASO assembly origin; COD does not apply to crystal products. [1]

Start a comparison record with the customer's approved part number copied exactly. Beside it, record the supplier's offered code and the field from which each photographed number was transcribed. Keep stock references in their own column. This prevents a purchasing-system reference from silently becoming the manufacturer code.

When a field is unreadable, mark it unresolved and request a clearer image. Do not fill gaps using a nearby reel's photograph or a familiar code from an earlier purchase. A useful record makes uncertainty visible to the person approving the order.

2. Read the Date Code Without Losing the Lot Number

AP02006 specifies the lot-field date code as YYWW: year and week. For example, 1926, interpreted in a 2000s context, denotes week 26 of 2019. Plant-specific lot formats are permitted, so retain the complete string. [1]

For quotation purposes, agree whether the customer requires a particular year, a permitted week range, or a maximum age at delivery. Replace an ambiguous request such as “recent date” with an explicit criterion. If a supplier writes “19+,” ask what actual codes and quantities that shorthand represents before approving a date-restricted order.

A shared year-and-week value is insufficient for a buyer to declare that two reels satisfy a single-lot requirement. Compare their full references and obtain clarification where the customer's definition of a lot requires it. Keep the agreed definition with the purchase order so the receiving team does not have to reconstruct it later.

Also avoid converting a week code into an exact production-day claim. If a customer needs the timing of a particular manufacturing operation, request evidence that explicitly identifies that event.

3. Keep Product Dates, Bag Dates, and Shipping Dates Separate

A date becomes useful when its associated event is clear. During purchasing, ask which document or label contains the date and what the issuer says it represents. The following record structure helps prevent one event from being used as evidence of another.

A later invoice or resealing entry should not replace the recorded product date code. Likewise, an earlier product code does not establish when a bag was opened. Keep both records and ask the relevant question directly. This approach is particularly useful when inventory has passed through more than one warehouse.

4. Use QR Data to Reconcile the Printed Fields

The AP02006 QR definitions map 2P to external PN, P to House Number, optional 1P to factory item, T to date-code/lot, Q and TQ to quantity, and optional 1B to a box or reel reference. [1]

Request the unedited decoded payload alongside a complete label photograph. Preserve a raw copy before importing selected fields into an ERP system. Compare field by field, including punctuation, rather than treating every part-number-like string as the same type of identifier.

If decoding fails, obtain a better image or scan. If it succeeds but differs from the visible text, document the difference and seek clarification. Neither outcome should be silently corrected by editing the raw record. A successful scan establishes that data can be read; it does not establish the physical contents or the entire supply history.

5. Review New and Older Label Layouts in Context

DIODES PCN-2770 Rev. 2, with a cover letter dated May 22, 2026, describes adding fab-site, COD, and ASO information. It lists all DIODES products as affected, allows existing standard-label stock to continue shipping until exhausted, and states that product form, fit, and function are unchanged. [2]

The purchasing implication is that layout differences deserve an explanation tied to the applicable material. A buyer should avoid making a pass-or-fail rule from a single photograph found online. Compare the actual fields, the relevant notice, and the supplier's explanation, then record the decision.

For older material, ask which historical document or clarification supports the observed format. When no adequate explanation is available, leave the issue open for the responsible quality reviewer. This is more useful than approving an unexplained difference simply because the device name appears correct.

6. Apply the MSL 3 Shelf-Life Update Within Its Scope

DIODES' shelf-life report states that MSL 3 finished goods manufactured and initially sealed after January 1, 2026 use bags stating a calculated 36-month shelf life. Earlier manufactured and sealed inventory remains in its existing bags without repacking or relabeling. The report examines material stored under controlled conditions; its results do not certify an individual supplier lot. [3]

Before applying that statement to an offer, identify the device's applicable moisture classification, the relevant packing history, and the actual caution information. Ask the assembly team to assess any opening or exposure history against the applicable handling instructions. Avoid treating a sealed-bag shelf-life statement as an allowance for time after opening.

For an opened, partial, or repacked reel, request the available original packing references and any subsequent handling records. Agree the required assessment before shipment. Do not substitute a recently printed replacement label for missing evidence about the material's earlier condition.

7. Work Through an Example Before Releasing the Order

Illustrative purchasing scenario: a buyer requests 10,000 pieces of 74AUP2G125RA3-7 and requires a single lot. The supplier proposes two reels with the same reported week code but has supplied only one label image.

The manufacturer ordering row specifies 5,000 devices per 7-inch reel for this exact ordering option. [4] Two standard full reels would therefore meet the requested quantity arithmetically, but that calculation leaves the single-lot requirement unresolved.

1. Request separate, legible label images for both offered reels.

2. Compare the external ordering codes and complete lot references.

3. Ask the supplier to confirm the actual quantity and packing condition of each reel.

4. Obtain a packing list connecting those reels to the quotation and eventual delivery.

5. Resolve any difference against the agreed single-lot requirement before order release.

If the customer accepts two lots, record that revised agreement explicitly. If a single lot remains mandatory, keep the offer pending until suitable evidence is available. This example describes a review method, not a current CST stock offer.

8. Define the Evidence Needed at Quotation and Receiving

Agree evidence requirements while the supplier can still identify and reserve the proposed material. A general request for “original labels” leaves questions about which units, which images, and which delivery records are expected.

• Identity: exact manufacturer code, complete label images, and any accepted code mapping.

• Allocation: quantity by packing unit and lot, including partial reels or split deliveries.

• Condition: disclosed packing format and available storage or handling information required by the customer.

• Documents: the requested certificate type, issuer, and references connecting it to the shipment.

• Acceptance: agreed inspection scope, responsibility for discrepancies, and required approval before release.

At receiving, compare the delivered units with the approved evidence package. Record differences before the material is mixed into general inventory. If quantities have been split since quotation, request the updated allocation and preserve its connection to the earlier records.

Keep conclusions proportionate to the evidence. A label comparison addresses recorded identity and consistency; a sample inspection addresses the inspected samples and stated scope. Neither should be expanded into an unsupported claim that every manufacturing or storage condition has been independently verified.

9. Request DIODES Supply with Clear Lot Requirements

CST Components supports electronic-component sourcing with stock and supply coordination in Hong Kong and Shenzhen. For an inquiry involving 74AUP2G125RA3-7 or another DIODES device, send the complete part number, quantity, acceptable date-code range, packing preference, and required delivery date.

State any single-lot restriction, required photographs, documents, and inspection conditions at the same time. Email ziven.wu@cstcomponents.com with your requirement. Availability, offered lot details, packing condition, supporting evidence, and dispatch timing should be confirmed for the specific quotation.

Frequently Asked Questions

Can a recent shipping date satisfy a newer date-code requirement?

Keep the two requirements separate. Request the actual product code and compare it with the customer's agreed date criterion; use shipping records for the delivery event.

Can two reels with the same week code be accepted as one lot?

Do not decide from the week value alone. Compare complete lot references and obtain the clarification needed to satisfy the customer's single-lot definition.

Can an older DIODES label be rejected solely because its layout differs?

Review the applicable manufacturer information and the offered material before deciding. The label-transition notice provides context for coexistence; an individual discrepancy still needs its own disposition.

Does a readable QR code establish authenticity?

It provides readable data for comparison. Authenticity assessment also needs the evidence and inspection scope agreed for the transaction, connected to the delivered material.