Define the pair before requesting samples
A useful sample request for an EMI shielding frame and cover identifies the two parts, their drawing revisions and the conditions under which their fit will be accepted. The request should let the supplier prepare the intended combination and let the project team explain what a successful sample must demonstrate.
Start with the mating relationship. Specify whether the project needs a new frame and lid together, a replacement lid for an existing frame, or a frame that must accept an existing cover. Each situation changes the information needed and the combinations worth checking. A general request for a cover of the same length and width leaves those decisions unresolved.
The shielding frames, lids and clips guide introduces the component roles. This article focuses on turning a proposed frame-to-lid interface into a clear drawing package and sample review.
Give both parts a traceable identity
Provide the frame drawing and the lid drawing together. Put the part number, revision and drawing date in the request, then identify which revisions are intended to mate. Include an assembly view that uses those same identifiers. If a model and a dimensioned drawing differ, state which document governs and resolve the difference before approving the sample scope.
A file name such as “latest lid” becomes ambiguous when several versions circulate. Use a revision register that connects each file to its part and purpose. Mark superseded files clearly, and record whether a change affects the mating interface, the PCB attachment or another feature. This helps a reviewer distinguish a replacement cover from a newly designed assembly.
For an existing frame, provide the released drawing and a representative physical part when available. Record whether the reference part is loose, already mounted or used in service. If its revision is unknown, flag that uncertainty and agree how it will be identified. Measuring one unknown sample should not silently establish compatibility with every installed frame.
| Record | What to include | Decision it supports |
|---|---|---|
| Frame identity | Part number, revision and mounting drawing | Which frame the lid must engage |
| Lid identity | Part number, revision and applicable model | Which cover will be sampled |
| Assembly identity | Drawing listing the intended pair | Which combination can be approved |
| Existing parts | Known revisions and reference sample condition | Whether replacement compatibility is required |
| Open questions | Unconfirmed features with a named decision owner | What must be resolved before release |
Show orientation and the intended contact surfaces
Use an assembled view and an exploded view to show how the cover meets the frame. Identify the top face, board side and any features that establish orientation. Where the outline appears symmetrical, mark whether the lid can be installed in more than one orientation and which orientations are acceptable. A reviewer should be able to position both parts without interpreting an unlabelled photograph.
Mark locating features, retention features and intended electrical contact areas separately. A feature may have more than one function, but the drawing should say so. Show the relevant edges, tabs, recesses or contact regions with section views or enlarged details where the main view cannot explain the interface.
Define the installed condition. Identify the locations that indicate full seating and any surfaces that should remain clear of the other part. Agree how the inspection will distinguish a seated cover from one resting on an unintended feature. If the frame is fixed to the board, include that mounting state in the assembly description.
For component examples, review the EMI Shielding Frame and EMI Shielding Lid pages separately. Establish the mating relationship for your project through the identified drawings, parts and sample results. The product photographs alone do not establish that the illustrated components form a matched set.
Define mating dimensions at the right locations
A dimension is useful only when its measurement boundaries are clear. Specify whether a width is taken across the outside of the frame, inside the frame, across a formed lid edge or between engagement features. Show the section and height at which it is measured. Similar overall dimensions can describe different interfaces when those boundaries differ.
Choose reference surfaces or datums that connect the important features. Define the positions of locating and retention features relative to them, and explain how seating height is measured. Include corner geometry or local details when they affect engagement. Keep the dimensions needed for mating visible on both part drawings and consistent with the assembly view.
Review the permitted variation of both parts together. Ask which combinations of allowable dimensions could prevent engagement, allow unwanted movement or change seating. Agree the relevant checks with the supplier before selecting limits. This review does not provide a universal fit tolerance, insertion force or permissible gap for all shield designs.
Identify whether dimensions apply to free parts, parts held in a fixture or the mounted assembly. If different states require different checks, name each state and its method. A free-part report and a mounted trial answer different questions; the sample plan should retain both results where the project needs them.
Include material, finish and manufacturing status
Specify the material and finish for each component in the applicable drawing or purchase specification. Confirm whether mating dimensions apply before or after finishing. If the finish is still under discussion, identify it as an open decision and explain whether the first samples will represent the intended production condition.
Ask how the sample parts will be manufactured and which features will be representative of production. Record any temporary process, unfinished surface or feature awaiting tooling. The review can then approve a sample for a defined purpose, such as an initial geometry check, while keeping other requirements open.
If a material, finish or forming detail changes after sampling, review its effect on the previously approved interface. Decide which measurements or assembly checks must be repeated. Approval should refer to the configuration actually evaluated, with any restrictions stated in the record.
Choose the combinations the samples must demonstrate
State whether the requirement concerns a complete new set, replacement parts or interchangeability across a defined group of parts. A frame and lid fitted together during one trial establish a result for that recorded combination. Broader compatibility needs a sample plan covering the additional combinations that matter to the project.
| Combination | Include when | Record to retain |
|---|---|---|
| Proposed frame with proposed lid | Approving the new assembly | Both revisions and their sample identifiers |
| Existing frame with proposed lid | Supplying replacement lids for installed frames | Existing frame revision and condition |
| Proposed frame with existing lid | Reusing previously supplied covers | Existing lid revision and condition |
| Different samples within an approved revision | The project requires interchangeability | The sampling method and tested combinations |
Agree how many parts are needed for measurement, mounting, fit trials and retained reference samples. Specify quantities of frames, lids and complete sets clearly. If samples will be exchanged among frames during the trial, give each part its own identifier so the results remain traceable after the original pairs are separated.
Describe the intended opening and refitting requirement without assigning an unsupported cycle count. Define any force measurement, fixture, handling direction and acceptance limit with the project team and supplier. For removal paths and working space, use the separate inspection and service access guide.
Agree acceptance checks before the parts arrive
Replace a broad instruction such as “check that it fits” with observable checks and a record format. Decide who will perform the trial, which drawings they will use and how they will report an unresolved result. The same sample can otherwise receive different conclusions from different reviewers.
- Confirm identity. Check the received frame and lid against the requested revisions and assign sample identifiers.
- Measure the interface. Record agreed mating dimensions in the specified measurement state, using the agreed reference surfaces.
- Assemble in the defined orientation. Use the planned support and handling method. Record obstruction, incomplete engagement or an unexpected assembly step.
- Inspect seating and contact areas. Compare the assembly with the defined seated condition. Record visible deformation or damage against the agreed criteria.
- Check the required combinations. Perform replacement or interchangeability trials included in the plan, retaining each part's identity.
- Close the review. List accepted requirements, unresolved items and any drawing changes needed before another sample or production release.
Keep dimensional results, assembly results and electrical validation distinguishable. A successful fit trial does not demonstrate the required EMI or RF performance. Agree the application-specific electrical checks and whether they need to follow planned opening and refitting operations. Record outstanding validation so mechanical approval cannot be mistaken for completion of the entire project.
Send a request that can become an approval record
Combine the drawing register, mating details, sample combinations and acceptance plan into one request. Add the intended sample quantities, expected production quantities and project dates. Use the custom shielding and DFM review page to frame manufacturing questions that remain open.
Ruishuo's samples are charged. Confirm the sampling route for the agreed scope: standard samples are 3–5 days, expedited sampling is 48 hours, and tooling with sample production is 7–10 days. These are sample-stage timings; volume production and delivery are confirmed separately.
Submit the project information through the shielding project inquiry page. The form records selected drawing file names; send the actual drawing files separately to chinarswj@shieldingcover.com. Include the part revisions and the intended pair in the email so the files and request remain connected.
When the sample review finishes, record the approved frame-to-lid relationship explicitly. Retain the drawings used, sample identifiers, results and unresolved restrictions. A later change can then be assessed against a defined assembly instead of a memory that two parts once fitted together.