{"id":3468,"date":"2026-10-22T08:00:00","date_gmt":"2026-10-22T08:00:00","guid":{"rendered":"https:\/\/swesd.com\/?p=3468"},"modified":"2026-10-21T15:27:01","modified_gmt":"2026-10-21T15:27:01","slug":"jedec-tray-surface-resistance-testing","status":"publish","type":"post","link":"https:\/\/swesd.com\/pt\/blog\/jedec-tray-surface-resistance-testing\/","title":{"rendered":"Testes de Resist\u00eancia \u00e0 Superf\u00edcie da Bandeja JEDEC: Geometria, Contato e Relat\u00f3rios"},"content":{"rendered":"

JEDEC tray surface resistance testing should begin by defining the property, measurement locations and contact geometry that the result must represent. A matrix tray contains pockets, ribs, openings and handling features, so a method intended for a sufficiently large planar specimen may not fit every accessible location. Choose the applicable current method with the ESD owner or laboratory, record the exact tray and conditioning state, and report the actual arrangement. A resistance value alone does not establish low charging, shielding or compatibility with a particular automated handling system.<\/p>\n

State the decision before choosing an electrode<\/h2>\n

Identify whether the work concerns product qualification, comparison of material candidates, an incoming check or investigation of a changed result. These decisions may require different sampling and evidence. Record the tray product, revision, material designation and relevant use boundary. Do not begin with whichever meter happens to be available and then invent an acceptance rule around its reading.<\/p>\n

Define which surfaces matter to the approved application. A pocket contact area, handling rim and underside can present different geometry. Record why each proposed measurement location is included and what conclusion it can support. A result from an easy external surface should not be described as a direct measurement of every internal pocket or as proof that all parts of a finished tray behave identically.<\/p>\n

Distinguish resistance from resistivity and other properties<\/h2>\n

The surface resistance versus resistivity guide<\/a> explains why electrode arrangement and reporting terminology matter. Keep the measured property and units explicit. Do not convert a finished-tray resistance value into a material resistivity by an unsupported geometry factor or compare unlike measurements simply because both numbers include powers of ten.<\/p>\n

Keep volume properties, charging behavior and discharge shielding separate. A material description such as conductive is not a substitute for the required report, and a successful resistance check cannot independently qualify an open tray as a shielding enclosure. The acceptance record should identify the protective function and exact evidence used for it rather than attach a general pass label to the entire packaging system.<\/p>\n

Select a method that fits the actual geometry<\/h2>\n

The EOS\/ESD Association laboratory-method listing<\/a> distinguishes surface resistance measurements of planar materials, volume resistance and two-point resistance measurements. Those distinctions are important when reviewing a matrix tray with limited flat areas. The responsible laboratory should determine applicability and the current complete procedure for the chosen specimen and decision.<\/p>\n

The ANSI\/ESD STM11.13 overview<\/a> identifies a two-point resistance measurement method. It does not mean that any pair of pointed probes placed anywhere on a tray produces a compliant result. Obtain and follow the complete applicable method, including its apparatus, preparation and reporting requirements. This guide supplies no substitute electrode force, spacing, voltage or numerical acceptance limit.<\/p>\n

\"Black
Black SWESD matrix tray and separate unconnected specimen probes. Illustration based on the SWESD product reference; application suitability must be verified.<\/figcaption><\/figure>\n

Record contact locations and supporting geometry<\/h2>\n

Use a controlled drawing, photograph or location map to identify the measurement areas without obscuring the product identity. Show the relevant rib, pocket or rim and the orientation used. Record how the tray is supported and whether that support can influence the measurement. Avoid a setup that inadvertently changes contact or creates an unintended electrical path while appearing convenient to the operator.<\/p>\n

Where the required contact cannot be established on a finished feature, discuss the evidence gap with the laboratory and product owner. A separately molded coupon may help characterize a material, but it is not automatically the same evidence as a measurement on the finished tray. Identify the specimen type and the scope of the conclusion instead of silently replacing the difficult geometry with an easier sample.<\/p>\n

\n\n\n\n\n\n\n\n\n\n
Report element<\/th>\nRecord explicitly<\/th>\nAvoid inferring<\/th>\n<\/tr>\n<\/thead>\n
Property<\/td>\nResistance, location and units<\/td>\nOne result establishes all ESD functions<\/td>\n<\/tr>\n
Geometry<\/td>\nContact area, location and support<\/td>\nAny probe pair follows a standard<\/td>\n<\/tr>\n
Specimen<\/td>\nFinished tray or identified material coupon<\/td>\nCoupon results automatically describe every pocket<\/td>\n<\/tr>\n
Conditioning<\/td>\nPreparation, environment and timing<\/td>\nUnlike states can be ranked directly<\/td>\n<\/tr>\n
Decision<\/td>\nMethod scope, criteria and limitations<\/td>\nA stable display proves an appropriate setup<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

Control the specimen and conditioning state<\/h2>\n

Record the exact tray, lot, revision, material and preparation. Follow the selected method for conditioning and handling. Do not wipe, wash or treat a specimen informally to obtain a more stable reading. If the purpose is to compare as-received and cleaned conditions, identify them as separate preparation states under the agreed plan and retain both sets of observations.<\/p>\n

Record the relevant environmental conditions and timing required by the procedure. Results obtained under different conditioning arrangements should not be ranked as though the only difference were supplier quality. When an application needs evidence after use, cleaning or a storage exposure, state that requirement explicitly. A new-tray report does not automatically represent every later condition of a reusable carrier.<\/p>\n

Verify the measuring system within its intended use<\/h2>\n

Use the apparatus and accessories required by the chosen method, with the appropriate maintenance, checks and calibration evidence. Inspect contact surfaces and connections according to the instructions. Do not infer that a stable display proves a correct setup. The range and capability must suit the measurement, while the laboratory or ESD owner determines how the result will be interpreted against the application criteria.<\/p>\n

NIST’s metrological traceability guidance<\/a> connects a measurement result to a documented calibration chain with contributing uncertainty. A calibration label alone does not establish that the tray geometry, contact or preparation was appropriate. Keep the instrument evidence and the complete test arrangement together, and avoid implying that NIST endorses the tray, supplier or application because a traceability statement appears in a report.<\/p>\n

\"Black
Black SWESD matrix trays separated for a traceable measurement study. Illustration based on the SWESD product reference; application suitability must be verified.<\/figcaption><\/figure>\n

Use repeat observations to investigate variation<\/h2>\n

Select locations and specimens according to the approved plan, rather than retesting only the most favorable point. Record the original observations and any authorized repeats. If results differ, investigate contact, specimen condition, location, apparatus and preparation before declaring a material failure. A repeat that produces a preferred value does not erase the first result or explain why it changed.<\/p>\n

The IC tray incoming inspection guide<\/a> provides a broader lot-review context. This article focuses on electrical measurement geometry, not an overall receiving sample size. The quality owner should define how the selected specimens relate to the delivery and what acceptance decision the results support. Avoid converting a small exploratory set into a claim about every future tray.<\/p>\n

Keep electrical and mechanical approvals complementary<\/h2>\n

A resistance result does not establish pocket clearance, component support or reliable pickup. The tray pickup troubleshooting guide<\/a> addresses those machine and handling questions separately. Maintain the accepted package and machine-interface evidence alongside the electrical report rather than assuming that an electrically suitable material is automatically compatible with a particular component or recipe.<\/p>\n

If an electrode or specimen preparation could damage a critical feature, agree a suitable sampling and disposition plan before testing. Do not return an altered engineering specimen to production as an unmarked accepted tray. Record its identity and state clearly. The testing program should support the real application without creating a new uncontrolled handling or traceability problem.<\/p>\n

Write a report that another laboratory can understand<\/h2>\n

Include product and specimen identity, method and edition, preparation, conditioning, apparatus, contact arrangement, location map, raw observations, result and acceptance basis. State deviations and limitations. If the work is an engineering comparison rather than a fully conforming standard test, label it accurately. The report should show what was measured without relying on an operator’s recollection of where the probes were placed.<\/p>\n

Do not fill missing information with a generic material certificate. Ask the supplier or laboratory to clarify the connection between the report and the exact offered item. A result for a base material, another tray revision or a different conditioning state may be useful background, but its role must be explained before it is used to accept the production configuration.<\/p>\n

Carry the method into the purchasing specification<\/h2>\n

For a SWESD IC tray enquiry<\/a>, provide the relevant package and tray identity, intended use, requested electrical evidence and the proposed measurement boundary. Ask which offered material and construction the supplier can document. The product image identifies visible geometry but cannot establish a resistance value, test method or automatic compliance with a customer’s requirement.<\/p>\n

Define the approved method and report expectations, incoming verification and change-notification rules. Review material, processing, coating, cleaning or design changes before extending the original acceptance. Keeping the method and geometry attached to the product makes later comparisons more useful and prevents an unexplained meter reading from becoming the only evidence supporting a repeated purchase.<\/p>\n

Educational background<\/h2>\n

The EOS\/ESD Association video below introduces electrostatic control. It does not demonstrate a tray-specific resistance method or establish acceptance limits. Use the applicable complete method and approved application criteria for the actual measurement decision.<\/p>\n