HD MicroSystems

HD MicroSystems is one of the oldest and most specialized suppliers of polymer dielectrics to the semiconductor industry. It combines DuPont's Pyralin-heritage polyimide chemistry with Hitachi Chemical's resin design and photosensitive-polymer expertise in one dedicated company. Its products are liquid precursors that customers spin-coat, pattern and cure on wafers. After curing they become polyimide or PBO films that act as stress buffers, passivation layers, redistribution-layer (RDL) dielectrics, flip-chip bump insulation and temporary bonding adhesives. The portfolio covers negative-tone and positive-tone photosensitive polyimides, low-temperature-cure PBOs, non-photosensitive high-performance polyimides and temporary adhesives. These materials serve front-end passivation as well as advanced packaging for fan-in and fan-out wafer-level packaging, flip chip and 2.5D/3D heterogeneous integration. The company makes product in both Japan and the United States and supports customers from Taiwan, Korea, Japan, the US and Europe. Its main customers are leading foundries, memory makers and OSATs, including ASE, which named HDM a Best Supplier for 2025. The rapid growth of AI and high-performance-computing packaging, which needs more RDL layers, finer features and lower cure temperatures, puts HDM at one of the fastest-growing points in the semiconductor materials stack.

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What the company does. HD MicroSystems formulates, manufactures and sells liquid polyimide precursor solutions (polyamic acids and polyamic esters), photosensitive PBO precursors and related ancillaries, including thinners, adhesion promoters and developers, to semiconductor fabs and packaging houses. Customers apply the material by spin, spray or slit coating. They pattern it by photolithography (for photosensitive grades) or by etching through a resist mask (for non-photosensitive grades), then cure it thermally. The cured film is a permanent, heat-resistant, chemically resistant dielectric with high elongation and good adhesion. HDM also supplies heat-resistant temporary adhesives (HD3000 series) used to bond device wafers to carriers during thinning and back-side processing.

Company's own description. HD MicroSystems calls itself a manufacturer of liquid polyimide precursor and other highly heat-resistant coating materials. It says it has helped improve the functionality and reliability of semiconductors as a leading polyimide supplier since it was set up in 1997 as a 50/50 joint venture between DuPont (now Qnity) and Hitachi Chemical (now Resonac). It also describes itself as the premier supplier of polyimide and PBO precursor chemistries engineered specifically for microelectronic applications. Its Japanese recruiting materials describe it as a dedicated maker of heat-resistant coating materials centred on DuPont-developed liquid polyimide precursors. They add that it pursues next-generation materials by combining Resonac's resin design technology with Qnity's semiconductor lithography technology.

Business model. HDM is a pure product business. It sells formulated, specification-controlled consumables, usually by weight or volume under customer-qualified bills of materials. No subscription, licensing or service revenue mix is publicly disclosed. The company has, however, said it is prepared to out-license its flexible-substrate polyimide patents. Revenue recurs because a dielectric, once qualified into a customer's process of record, is rarely changed during a product's life. Requalification can take 12–36 months and needs reliability testing at package level. Pricing and revenue figures are not publicly disclosed.

Value-chain position. HDM sits in the specialty-materials tier. Upstream are monomer suppliers (aromatic dianhydrides, diamines and o-aminophenols), photoactive compounds, high-purity solvents and the parents' synthesis capabilities. Downstream are:

• Foundries and IDMs that apply polyimide as a final passivation or stress-buffer layer on finished wafers. This includes memory makers, where polyimide protects DRAM and NAND dies and is a building block of high-bandwidth memory (HBM) stacks.

• OSATs and foundry back-end operations that build multilayer RDL for fan-in WLP, fan-out WLP/PLP, flip-chip bumping and 2.5D/3D interposers.

• Makers of MEMS, power devices, image sensors and displays, which use polyimides as insulation, planarization or substrate layers.

Customer types. Leading-edge logic foundries, memory makers, OSATs (ASE named HDM a Best Supplier in 2018, 2023 and 2025), power and analog IDMs, MEMS foundries, and university and research labs (MEMS researchers commonly use HDM's PI2500 series and thinners).

End markets. AI accelerators and HPC (2.5D/3D, chiplets, HBM), smartphones and consumer devices (fan-in/fan-out WLP), automotive and power semiconductors (high-temperature-reliable passivation), and display and flexible electronics (polyimide substrate precursors).

Independent characterization. HDM is best seen as a focused, technology-led polymer-dielectric house with two powerful sponsors. On one side is Resonac, which describes its Semiconductor & Electronic Materials segment as the driver of about 99% of group core operating profit and markets itself as an advanced-packaging materials leader. On the other is Qnity, a USD 4.75 billion pure-play semiconductor-materials company (FY2025) with leadership in CMP, lithography materials and advanced-packaging metallization. HDM is small compared with either parent, but it holds a strategically central position: the photo-defined dielectric is the layer that defines RDL density, warpage and reliability in advanced packages. Its competitive weight comes from deep qualification at top-tier customers, a broad chemistry toolbox (negative-tone PI, positive-tone PBO, low-CTE PI, temporary adhesive) and dual-continent manufacturing. Its constraints are scale relative to diversified Japanese chemical rivals and joint-venture governance, which can slow capacity decisions.

Stated strategic themes. HDM's public communications stress four themes:

1. Advancing semiconductor packaging solutions and delivering long-term value to customers

2. Stable quality and supply, with innovative materials that support customers' future challenges

3. Combining Resonac's resin design with Qnity's lithography technology to develop next-generation materials

4. Environment-friendly product development, bonding materials and support for multiple coating methods (the four R&D themes on its website)

Initiatives in the last 24 months:

Low-shrinkage PSPI for multilayer RDL: Date: 2025–2026; Description: New photosensitive polyimide with reduced cure shrinkage for multilayer RDL stacks; Strategic intent: Address planarity and warpage in high-layer-count AI and HPC packages

HD4100GT eco-friendlier polyimide: Date: May 2025; Description: Copy-exact HD-4100 made with greener processes and raw materials; Strategic intent: Meet customer sustainability targets without requalification

Alternative coating methods: Date: Sep 2024 onward; Description: Liquid polyimide precursor applied with Yasui Seiki's Mini-Labo DX coater; Strategic intent: Support panel-level and non-spin coating, and lower material waste

Apple American Manufacturing Program: Date: Mar 2026; Description: HDM joined alongside Qnity, which Apple added to the program to supply semiconductor manufacturing materials; Strategic intent: Build US-made supply of dielectric materials for HPC and AI

Conference and technology leadership: Date: 2026; Description: Papers and exhibits at ECTC 2026 (May) and IMAPS 2026 (October); Strategic intent: Keep design-in presence with packaging engineers

Hiring at Hitachi Works: Date: 2026; Description: Recruiting process, quality-control and patterning engineers via Qnity Japan secondments; Strategic intent: Scale production engineering and customer process support

Parent strategies that shape HDM:

Qnity: long-term organic sales growth target of 6–7% a year through 2028; R&D at about 7% of sales; capex normally about 6% of sales; a multi-year transformation plan targeting a USD 100 million run-rate EBITDA benefit by 2028; and a local-for-local manufacturing model.

Resonac: concentrate investment in Semiconductor & Electronic Materials and divest non-core businesses. It leads the US-JOINT consortium in Silicon Valley (operating from 2025) and the JOINT3 consortium of nearly 30 companies (from September 2025) for next-generation packaging, including panel-level organic interposers. HDM's dielectrics are relevant to both programs.

Medium-term financial targets for HDM: not publicly disclosed.

Photosensitive polyimides — negative tone

HD-4100 series. A negative-tone, solvent-developable photosensitive polyimide precursor, developed in 2004 for copper redistribution. It became one of the first RDL dielectrics used in fan-out packaging and remains a reference product for stress buffer, flip-chip and fan-in applications. Conventional polyimides of this class cure at about 350–390 °C. That is fully compatible with front-end passivation, but it led to the low-temperature product lines below for packages built on epoxy mold compound. Target customers are foundries, bumping houses and OSATs. Pricing is not publicly disclosed.

HD4100GT (developmental, May 2025). A copy-exact version of HD-4100 made with more environmentally friendly processes and raw materials. Customers keep the same established performance in stress buffer, flip-chip and fan-in packaging but can lower the environmental footprint of their supply. Its positioning targets customer sustainability requirements without forcing requalification of electrical or mechanical performance.

HD-4000 series (1998). A high-Tg photosensitive polyimide developed for flip chip. It is the forerunner of the HD-4100 family.

HD7000 series — HD7110, HD7204 (2021 onward). Low-temperature-cure, solvent-developable, negative-tone photosensitive polyimides for multilayer RDL in fan-out and heterogeneous-integration packages, where the package's thermal budget is about 200–250 °C. HDM's published development targets include 3 µm vias in 5 µm films, 5 µm vias in 10 µm films, 2/2 µm line/space and good planarization at cure temperatures near 200 °C. In 2025–2026 HDM presented low-shrinkage photosensitive polyimide for multilayer RDL processes, which addresses topography build-up and warpage in high-layer-count AI packages.

Photosensitive PBO — positive tone

HD-8000 series (2000). An alkaline-developable, positive-tone photosensitive polyimide. It established HDM's aqueous-developable platform, which needs no organic solvent developer.

HD-8820 (HD8800 series, 2004). A high-sensitivity, positive-tone, aqueous-developable photosensitive PBO precursor. Its elongation and modulus suit buffer-coat and WLP dielectric layers.

HD-8930 / HD-8940 (HD8900 series, 2009 onward). Low-temperature-cure (about 200 °C) positive-tone photosensitive PBOs designed for fan-out WLP. Published data for HD-8940:

• Glass transition temperature: 230 °C

• Dielectric constant: 2.9

• Dissipation factor: 0.009

• Elongation: more than twice that of HD-4100 and equal to HD-8820

• Young's modulus: about 60% lower than HD-4100

HDM evaluated HD-8940 at package level in FOWLP test vehicles to confirm its reliability.

Non-photosensitive polyimides

PI2525, PI2555, PI2574 (PI2500 series). Classic polyamic-acid polyimide precursors (DuPont heritage) for applications that tolerate high cure temperatures. They are used as passivation, interlayer insulation, alpha-particle barriers, MEMS structural and insulating layers, and in research labs. They are patterned by wet or dry etching through a resist. Product bulletins give multi-step spin, soft-bake and cure guidance.

PI2545. A non-photosensitive polyimide in the same family, used as a protective coating and insulation layer.

PI2600 series. Low-stress, low-coefficient-of-thermal-expansion polyimides. Their CTE is close to silicon, which suits warpage-sensitive multilayer thin-film structures and thick dielectric stacks.

PIX-1400 / PIX-3400 series. Non-photosensitive polyimides from Hitachi Chemical's portfolio, used as buffer coats and interlayer dielectrics.

Temporary bonding

HD3000 series (2007). A highly heat-resistant temporary adhesive for bonding device wafers to carriers during thinning, TSV reveal and back-side processing, then debonding. It is relevant to 3D stacking, including memory stacks.

Flexible-substrate polyimide precursors

HDMJ holds Japanese patents JP 6288227 and JP 6206446 on polyimide precursor resin compositions for flexible device substrates. The compositions combine toughness and heat resistance, adhere strongly to glass during pixel-circuit formation and release easily from glass afterwards. The company has said it will use the patents for external collaboration, including out-licensing.

Ancillary products and services

• Thinners for viscosity adjustment and edge-bead removal

• Adhesion promoters, developers and rinses matched to each photosensitive platform

• Application engineering at the Taiwan laboratory, the Japanese development building and the US clean rooms, including process optimization, margin evaluation, coater/developer setup and reliability support

• Coating-method development, for example the 2024 work on Yasui Seiki's Mini-Labo DX coater for packaging polyimide precursors

Pricing is not publicly disclosed for any product.