IHP Open Assembly Design Kit documentation

Documentation source for the IHP Open Assembly Design Kit (ADK) and the open flow for 2.5D/3D heterogeneous chiplet integration built around it.

Current Status: Preview Release

Warning

The IHP Open ADK is a preview release. The interposer process has been fabricated several times at IHP, which is a statement about process maturity rather than about a complete assembly. The kit is not intended for production assembly design at this moment.

About

An Assembly Design Kit is to a package what a Process Design Kit is to a die. A PDK says whether a shape can be manufactured on a process. The ADK says whether a die may sit at a given place, at a given spacing from its neighbours, attached by a given method. The ADK sits one abstraction layer above every PDK, and the interposer and the chiplet dies remain ordinary PDKs.

This repository holds only documentation. The code it documents lives in the repositories pinned as submodules under src/:

• IHP-Open-ADK, the assembly rules and tooling
• chiplet-spec, the .chiplet interchange format
• OpenIntM4TM2, the interposer PDK
• IHP-Interconnect-IntM4TM2, the attachment method registry
• KiCad-ADK-MOD, the KiCad fork
• Chiplets-KiCad-Plugin, the export plugin and GDS generation
• gds2kicad, die GDS to KiCad conversion
• chiplet-studio, the 3D assembly viewer
• ADK-Tools, the container that pins and builds them all

Building locally

git clone --recurse-submodules https://github.com/IHP-GmbH/IHP-Open-ADK-docs.git
cd IHP-Open-ADK-docs

python3 -m venv .venv
.venv/bin/pip install -r docs/requirements.txt

# Regenerate the tables and command transcripts from the pinned sources,
# then build. The build must be warning free.
make -C docs preprocess
.venv/bin/sphinx-build -b html -W --keep-going docs docs/_build/html

Open docs/_build/html/index.html. make -C docs docs runs the whole chain and opens the result.

Generated content

Nothing normative on this site is typed by hand. docs/scripts/ reads the pinned submodules and writes the rule tables, adapter tables, version matrices and command line transcripts. The generators fail the build when the source drifts from what is documented, for example when a rule is added to a deck without a matching description. Continuous integration re-runs them and fails if the working tree is then dirty, which is what proves the published tables match the pinned revisions.

Contributing

The "Contributing to this documentation" page of the built site (docs/contrib/02_documentation.rst) carries the authoring contract, including the constraints that are factual or legal rather than stylistic. Read it before opening a pull request.

License

Copyright 2026 IHP Open ADK Authors.

Licensed under the Apache License, Version 2.0. You may obtain a copy of the License at https://www.apache.org/licenses/LICENSE-2.0.

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.