Saved unreviewed touch-panel draft · earlier batch

Saved report · Original source proposals/2026-10-09-continuation/research-bfs/section03/01-touch-panel.md · original SHA256 db8a5473c42754adf4841473f13c3fcf14cee6c2be8f28bb0c1644ea253d940f · immutable published snapshot proposals/research-artifact-archive/b4c09b119655/db8a5473c42754adf4841473f13c3fcf14cee6c2be8f28bb0c1644ea253d940f.md · SHA256 db8a5473c42754adf4841473f13c3fcf14cee6c2be8f28bb0c1644ea253d940f

Bounded research/review evidence. This artifact does not certify physical manufacturing closure or later changed routes.

Touch panel

Part · evidence research draft · closure open. This level1 assembly translates finger contacts into electrical position signals for the handset. It is section03 item1/5, following the first five completed root reports. Order was chosen from revision90; exact current records are in base-snapshot.json. Scenario coordinated-discovery-v1, selected discovery-touch-panel-v1. No discovery ownership or live route changes are made here.

Required capability

One accepted incorporated touch assembly plus trial/coupon/loss stock, quantities unknown. Active area, simultaneous contacts, spatial error, latency, scan rate, cover/bond thickness, electrode resistance/transmission, controller noise/range, host interface, power, temperature and wet/glove/charger-noise behavior are not yet specified. Compatible flagship-equivalent use is inherited. Freeze the physical stack and controller interface before adopting any sensor layout. Capacitive measurement, position decoding and tuning are black-box software functions, not software-making dependencies.

All selected immediate requirements

All eight selected obligations are preserved. touch-production already exposes holder/lamination stage, deposition, lithography, etching, masks, presses/dispensers, vacuum, test coupons, impedance measurement, power/control/cable, cleanroom, cleaning and chemical protection/effluent. They are transitive declared requirements, not missing factories. Their construction stock does not automatically supply production's electrode feed, masks, clean wipes/rinse, adhesive charge, liners and rejected assemblies. Allocate clean work surfaces, protected carriers/storage, handling, test contacts and waste capture to the actual operation.

touch-electrodes consumes transparent conductor and patterning tools but does not name its supporting substrate. The parent also lists a completed electrode item and display-substrate. Resolve whether electrodes mean a layer patterned onto this sheet, a transferable film, or a completed sensor sheet. Preserve crossing insulation/bridges if the chosen X/Y layout needs them; do not invent a mandatory extra dielectric for every architecture. Existing backplane-dielectric-stock, substrate/conductor and flex identities are reuse candidates requiring chemistry/optical/process matching, not interchangeable by name.

Bounded making method

Choose one capacitive arrangement and a compatible controller. Establish layer ownership across cover glass, sensor substrate and display: a separate laminated sensor and an integrated sensor-on-cover/display have different inventories. Prepare the actual sheet, clean it, deposit/pattern the chosen conductors with coherent routing and isolation, and verify resistance/continuity and optical defects. Transfer or laminate only layers that physically exist in the chosen method. Connect the sensor and controller through the qualified flex/contact interfaces; retain hardware protection and supply decoupling within the actual controller board/module consumer.

Microchip AN2934 describes self/mutual capacitance, cover effects, shielding and surface layouts with routing/crossovers. It supports the need to match geometry, dielectric stack and acquisition electronics. Its button/slider/surface examples are not evidence of a flagship phone's multi-touch accuracy or a transferable production pitch. Microchip sensor design guide [T1]

Select one bond chemistry. Place clean layers against the appropriate carrier/lamination controls, establish the bond line, remove trapped defects by a supported process, and preserve cleanliness during curing or pressure bonding. 3M documents an ITO-compatible free-film adhesive for glass-to-sensor bonding that requires no UV cure. This is a concrete alternative to a liquid curing adhesive, not the project's selected chemistry or a natural supply. Do not combine its no-cure method with mandatory UV steps from another adhesive. 3M adhesive example [T2]

Acceptance, reuse and alternatives

Check finished stack geometry, bond voids/haze/transmission, conductor integrity, insulation, controller timing/noise and touch response over the actual mounted display/enclosure/power condition. touch-electrode-simulator supports controller characterization as an unqualified existing frontier; it does not alone simulate real fingers, cover mechanics, moisture or complete handset interference. Physical stimulus/position fixtures, reference contacts, environmental samples and host readout need range/uncertainty and quantity allocation. Do not accept the controller solely using its own decoded coordinates.

Current touch-controller construction includes physical chip packaging, simulator/references, programmer/loading contacts/cable, earlier workshop host, power and environment. These obligations already exist transitively. Programs needed for production/test must be available earlier on those physical hosts; final handset software may be installed after import. A schematic/interface definition is not available controller stock.

A coarser self-capacitance control can test earlier acquisition but cannot silently satisfy unfrozen multi-touch phone demands. Separate sensor glass versus sensor-on-cover, alternative transparent conductors and liquid versus film bonding remain coherent candidate routes requiring distinct compatibility evidence. Reuse existing layer/tool identities when their states and capabilities match; no new identity is requested in this report.

Exact discovery feedback

• Declared-inventory fact: parent/electrode records leave the supporting workpiece state and consumption allocation unclear; fix a state ledger before moving edges.
• Method-supported obligation: a chosen crossing X/Y layout needs its actual routing/isolation; the lamination operation needs real installed carriers, bond stock and test contacts. Existing tool construction does not allocate job quantities.
• Unresolved decision/suitability: shielding, glove/wet performance, integrated stack, controller range and physical position test thresholds remain target-dependent. These are not confirmed universally absent parts.

Next: freeze stack/layout/controller demand, assign operational stock and independent full-panel acceptance, and review earlier capability availability. No complete inventory, endpoint or accepted physical touch panel is claimed.