HT12E CAD Model and Footprint Alignment

Thought for 9 mins 6 sec
Thought for 6 sec
Created 2 tasks.
1/2 Read the package drawing and generate and place the CAD model.

Read the package drawing and generate and place the CAD model.

Verify the model asset, root placement, and footprint alignment.

Thought for 11 sec
Awaiting 1 task
"HT12E-20SOP 3D Model" completed.

flux

Created the datasheet-based

3D Model

Design view of Package Model Design
and linked it through the Asset rule of SOP package v1, directly under root and outside the footprint folder. Verified physical scale, all 20 lead landings, pin-1 orientation, and seating height; the footprint and symbol remain unchanged. The model card offers STEP download.
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Pins

Symbol

Layout

3D View

Package Model Design
Deliverable and scope
Completed: one parametric black molded SOP-20 body with 20 separately tin-colored gull-wing leads, rounded bends, end notch and pin-1 dimple. Initial build passed; zero geometry repairs. No pads, footprint geometry, or symbol were altered by this model task.

3D Model

Design view of Package Model Design
Exact asset name: sop20-package.build123d. The model card offers source, STEP and mesh downloads.
Dimensional authority
The current project's Datasheet URL was read, and its original Holtek HT12A/HT12E Rev. 1.10, January 24 2003, page 11 mechanical drawing was downloaded and visually inspected, not merely inferred from the footprint. It identifies 20-pin SOP (300 mil). Dimensions below originate from that table; mm conversion uses exactly 0.0254 mm/mil.

Table

FeatureDatasheet (mil)Model selection (mm)
A, overall lead span394–41910.3251 (midpoint)
B, molded body width290–3007.493 (midpoint)
C′, molded body length490–51012.700 (midpoint)
D, molded body thickness92–1042.4892 (midpoint)
E, pitch50 nominal1.270
F, body standoff4 minimum0.150 selected, above 0.1016 minimum
C, lead width14–200.4318 (midpoint)
H, lead thickness4–120.2032 (midpoint)
G, foot length32–380.889 profile target; 0.847535 measured flat after blending
The above ranges are verified table values. D's graphical endpoints were inspected directly as body thickness, with F below the body; total modeled seated height is therefore 2.6392 mm. The automated drawing-description query alone could not resolve these endpoints, so it was not used as sole authority.
Body draft insets (0.15 bottom / 0.20 top), 0.065 bend radius, 1.30 lead exit height, and marker dimensions are visualization selections, not claimed manufacturer-controlled dimensions. Lead feet are horizontal. The outline depicts an orientation notch; an additional corner dimple is a visual pin-1 aid. Pin assignment identifies pin 1 as NC at the upper left.
Placement and orientation
  • Model node: SOP package v1, UID 85e740e2-6284-4abe-a742-665a8458a104.
  • Parent: ROOT, directly outside the footprint, per explicit user override. This intentionally departs from normal footprint-parenting; moving the footprint later will require moving this independent model too.
  • Existing footprint UID: 718eaf5b-692a-b9a1-c88a-4f647fdd9516; position and rotation both zero, so root-relative model position (0,0,0) mm, rotation (0,0,0) degrees align the model.
  • Read-back: active=true, scale=(1,1,1), Z-up=true, physicalMaterials=true, showEdges unset/computed false; Asset resolves to the durable source and pipeline GLB.
  • Source axes: width X, length Y, height +Z; lead seating plane Z=0.
  • Authoritative computed Y-up pad positions: X=±4.600 mm; Y=±0.635, ±1.905, ±3.175, ±4.445, ±5.715 mm. Pads are 1.900 × 0.600 mm.
  • Pin 1 NC UID a834f732-64ad-a605-1e6a-db8bea340b21: (-4.600,+5.715) mm. Model pin-1 lead has Y=+5.715 on the negative-X side; dimple (-2.9465,+5.4500) mm has matching (-X,+Y) signs. End notch is at +Y. This agrees with the upper-left silk extension; source SVG/KiCad Y-down values were not used as model coordinates.
Verification evidence
Native compilation/report: upload succeeded before any computer model processing; 21 solids, 298 faces, volume 230.517 mm³. Overall dimensions 10.3251 × 12.700 × 2.6392 mm; body 7.493 × 12.700 × 2.4892 mm.
Scene read-back: confirmed model is a ROOT child, exact asset reference resolves, zero transform, scale 1, enabled, physical materials true. All 20 original pad nodes remain.
Downloaded pipeline STEP inspection: imported the actual asset-pipeline STEP, not a separately compiled source. All 21 solids are valid; all 20 lead minimum Z values are exactly 0. Bounds are X=±5.16255, Y≈±6.3500001, Z=0…2.6392001 mm. One representative flat foot measured X=4.315015…5.16255 mm, length 0.847535 mm, width 0.4318 mm, area 0.365966 mm²; identical mirrored/repeated geometry supplies the other feet. Its straight length lies within the sourced 0.8128…0.9652 mm G range.
Computed pad matching: each lead's Y center equals its pad's Y center. Foot X range is inside the corresponding positive pad X=3.650…5.550 mm (mirrored on negative side); transverse lead-to-pad margin is (0.600−0.4318)/2=0.0841 mm per side. Toe margin is 5.550−5.16255=0.38745 mm. Feet seat at the pad datum without a Z offset.
Actual rendered inspection: native project ISO, top and front 1024px images were returned and visually inspected. They show the body upright and centered over the pad field, all 20 leads landing on pads, correct pin-1 end/quadrant, and feet seated rather than floating or sunk. This is actual project-render evidence, distinct from the computed geometry checks; interactive browser visibility was not separately tested.
Findings and limitations
  • Info: the geometry report flags each lead's 0.1899 mm³ volume (<1 mm³) and 0.4318 mm width (<0.8 mm). These are expected IC lead dimensions, not defects; this is a package representation, not a printable object.
  • Info: rounded lead bends/body draft/marker detail are a nominal visual reconstruction, not vendor production tooling CAD or a worst-case mechanical envelope.
  • Info: normal footprint-tracking is intentionally absent because ROOT parenting was requested.
  • Native board DRC hooks returned NOT CHECKED for this part project; no clean DRC/ERC claim is made. Pad geometry and symbol edits are outside this task and were left untouched.
  • No blocking model-geometry, placement, or render issues remain. Publishing the part and overall project completion are outside this assigned batch.

  • Deliverable and scope

  • Dimensional authority

  • Placement and orientation

  • Verification evidence

  • Findings and limitations