Investing in Thai PCB plants: BOI incentives and what the money buys

Since 2023, printed circuit board (PCB) makers, mostly from China, Taiwan, Hong Kong and Japan, have filed more than 200 applications for Thai investment promotion. The Board of Investment (BOI) puts PCB and PCB-material applications for 2023 to 2025 at 222 projects worth 320,078 million baht, and ranks Thailand as the largest PCB producer in ASEAN and fifth in the world.^[1]

Key points

• BOI totals measure investment applications; the BOI tracks realised spending separately.^[2]
• HDI and large-scale flexible or multilayer projects qualify for an eight-year corporate income tax exemption capped at the project's investment; other PCB projects (group B) receive no tax holiday.^[3]
• The largest reported project is the Zhen Ding Technology (ZDT) joint venture in Prachin Buri, with more than 65,000 million baht approved.^[4]
• New Thai plants are in ramp-up, with listed parents reporting customer qualification and start-up costs.^[5][6]

BOI incentives for PCB activities

BOI incentives are set per activity. By mid-2024 the BOI had widened the PCB list to cover the whole chain, from fabrication and assembly to raw materials, components and services.^[7] The 2026 BOI guide sets the PCB activities as follows.^[3]

The group sets the corporate income tax (CIT) exemption: eight years for A2, five for A3, three for A4 and none for B. For A2 to A4 the exempt amount is capped at 100 percent of the project's investment. Every group, including B, gets import-duty exemptions on machinery and some raw materials, and non-tax rights such as land ownership and work permits for foreign experts.^[3] A3 and A4 projects in BOI-promoted industrial estates or zones get one extra year; A2 projects do not. Spending on R&D, advanced training or local suppliers can add years, up to 13 in total for groups A1+, A1 and A2.^[3]

Aoshikang reports that its Thai subsidiary's BOI certificate exempts profits for up to eight years, with the total exemption limited to the project's actual investment, excluding land and working capital.^[6]

Two developments reduce the value of a tax holiday for the largest investors. The OECD global minimum tax has applied since 1 January 2025: groups with consolidated revenue above 750 million euros pay at least 15 percent, so profit exempted under a BOI holiday can still attract a top-up tax. The BOI expected about 1,500 companies in Thailand to be affected and was preparing, as of August 2025, refundable tax credits (QRTC) linked to R&D, skills and similar spending.^[8] The BOI puts ZDT's revenue at more than 180,000 million baht a year, well above the threshold.^[4] In September 2026 the BOI announced that it would phase out tax breaks for low-margin operations and measure success by realised investment rather than application volume.^[9]

The evidence suggests incentives rarely determine location. An OECD review of Southeast Asia cites surveys in which more than 80 percent of investors in Thailand and Viet Nam would have invested without incentives, and notes that tax holidays favour the most profitable firms.^[10] A study of more than 40 countries found that longer tax holidays attracted foreign direct investment in Latin America and the Caribbean, but that no tax incentive raised total private fixed investment.^[11] On MPBxChange's reading, and consistent with the OECD's view that incentives matter most between shortlisted locations, the BOI package for PCB plants is more likely to lower project cost at the final choice of site than to drive the decision to invest in Thailand.^[10]

BOI investment figures: definitions and totals

Investment amounts for a single project are reported at five stages:

1. Announced: a company's stated plan, often covering many years.
2. Applied: the investment stated in a BOI application. All PCB totals below are at this stage.
3. Approved: projects accepted by the BOI board or its subcommittee.
4. Certified: approved projects that have received a promotion certificate. Of the first 25 fast-tracked projects, all approved, 19 had certificates by September 2026.^[9]
5. Invested: spending on buildings and machinery, which the BOI now tracks quarterly.^[2]

The BOI has published PCB application totals for overlapping periods and varying scopes.

Applications averaged 15,750 million baht a year in 2021 and 2022, then exceeded 100,860 million baht in 2023 alone.^[12] Over 2023 to 2025 they averaged about 106,700 million baht a year, nearly seven times the earlier level (MPBxChange calculation: 320,078 / 3), although the earlier years cover PCB and PCBA and the later period PCB and PCB materials, so the ratio is indicative only.^[1] Because periods and scopes differ, the cumulative totals do not yield annual figures by subtraction. The 222 projects for 2023 to 2025 cover PCB and PCB materials,^[1] while the 224 projects to mid-2026 cover PCBs and electronic components;^[17] with different scopes, the two counts do not show how many applications were filed in 2026. The BOI has not published a PCB-only figure for 2026.

The BOI expressed the same 331,000 million baht as USD 9.85 billion on 3 August 2026 and as more than USD 10.1 billion on 26 August 2026, the latter at the Bank of Thailand average selling rate of about 32.8 baht per dollar.^[17][18] At that rate the 320,078 million baht for 2023 to 2025 equals about USD 9.8 billion (MPBxChange calculation). Other amounts are shown in the source currency.

Realised spending lags applications. The BOI reports realised investment of more than 127,000 million baht in the second quarter of 2026 across AI-linked industries, a group that includes PCBs alongside optical transceivers, hard disk drives and digital infrastructure, with no separate PCB figure.^[2] At project level, Suntak Technology puts the first phase of its Prachin Buri plant at about RMB 1 billion; by 30 June 2026 it had spent 8.45 percent of its RMB 800 million Thai construction budget, and it expects the first phase to be built in the first quarter of 2027.^[19]

The largest reported projects

The ZDT project illustrates how amounts grow between announcement and approval. In January 2024 the partners described a first phase of about 10,000 million baht and more than 50,000 million baht by 2030.^[22] Two years later the BOI had approved four projects worth more than 65,000 million baht, with about 5,600 Thai jobs in total across the four, the first project producing since September 2025.^[4]

Compeq invests in Thailand through two companies, and the BOI amounts belong to separate projects rather than to one phase. When Compeq (Thailand) opened its plant in December 2024, the BOI gave an investment of 10,417 million baht on 112 rai, for multilayer boards of up to 34 layers, more than 90 percent exported, with about 600 jobs rising to more than 1,500.^[14] In May 2026 the BOI described Compeq Technology (Thailand) as a flexible-board project with a first phase of 13,000 million baht and an approved second phase of 9,170 million baht.^[1] Compeq's own site lists its Thai plant with 1,400 employees.^[23]

The May 2026 second phases of Compeq, Multi-Fineline and Gold Circuit add 22,200 million baht to about 35,000 million baht of first phases, and more than 5,000 jobs to the 7,000 already hired.^[1]

Capacity, jobs, technology and output

Capacity

Few projects publish capacity alongside cost. As reported by the trade site ic-pcb.com, Advanced Interconnection Technology plans about 360,000 square metres a year, or about 30,000 square metres a month, for about 3,889 million baht.^[21] This implies roughly 10,800 baht of investment per square metre of annual capacity (MPBxChange calculation: 3,889 million / 360,000); the ratio varies with product mix and is indicative only.

Jobs

The BOI attaches planned jobs to approvals: about 5,600 at ZDT across four projects and more than 12,000 across Compeq, Multi-Fineline and Gold Circuit after both phases.^[4][1] In 2024 the Thai Printed Circuit Association (THPCA) projected that about 50 more BOI-backed plants could lift Thailand's share of world circuit-board output from 4 percent to 10 percent and create 50,000 to 80,000 jobs.^[12]

Technology

The incentive structure favours more complex boards,^[3] and the largest approvals fall in that tier: ZDT's projects cover multilayer, flexible, substrate-like and HDI boards; Compeq (Thailand) makes multilayer boards of up to 34 layers and Compeq Technology (Thailand) flexible boards; Gold Circuit makes multilayer and HDI boards.^[4][14][1]

Output and trade

According to a BOI forum release, David Bergman of the Global Electronics Association put Thailand's PCB output at more than USD 5 billion in 2025.^[24] Official statistics track volume: the Office of Industrial Economics (OIE) includes printed wiring boards (PWB) as one item in its electronics production index. In December 2025 PWB output was 4.9 percent lower than a year earlier, while board assembly (PCBA) was 16.2 percent higher.^[33] Thai customs reported USD 1.58 billion of bare-board exports and USD 3.54 billion of imports in 2025, leaving Thailand a net importer of bare boards.^[34]

Plants

The MPBxChange register holds 39 researched PCB plants in Thailand: 33 reported operating or ramping, and 6 under construction or announced. Of the 39 that publish a founding year, 28 were registered in Thailand from 2022 onwards.

The BOI says most PCB plants are in Prachin Buri, Phra Nakhon Si Ayutthaya and Samut Prakan.^[15]

The supporting chain: laminate, glass fabric, foil and chemicals

Upstream materials qualify too: CCL, flexible CCL and prepreg projects can reach group A2.^[3] The BOI reported these materials projects in 2026.^[25][26]

In MPBxChange's review, BOI releases from 2024 to 2026 name no copper-foil or PCB-chemicals project. First Quality Circuit, a Chinese-owned fab in Rayong, told a trade journal in 2025 that core materials and high-end chemicals came mainly from China, and that its start-up costs ran 10 to 15 percent above levels in China.^[27] In MPBxChange's assessment, locally made copper foil and plating chemicals are the most evident gap in the Thai chain and the clearest opening for the next round of investment.

Risks and indicators to monitor

Demand beyond AI

Nearly 60 Chinese and Taiwanese PCB makers set up factories in under three years, and Thai press in 2025 noted that demand outside AI is more variable.^[28] Listed parents describe new Thai capacity as ramping up, with customer qualification and product introduction under way, the usual first stage of a new site.^[20][5][6] Thai utilisation rates are not published.

Execution and permits

Imported materials, logistics and new teams raise start-up costs.^[27] Thailand FastPass, which covers eight agencies including Customs, the Department of Industrial Works and the power utilities, aims to cut approval times by 20 to 50 percent.^[24] PCB plating produces metal-bearing wastewater, which places treatment capacity and the factory licence on the critical path; the Rayong fab cited above can treat 1,500 tonnes of wastewater a day.^[27] MPBxChange found no public record of a Thai PCB project halted on environmental grounds, although public evidence on this point is limited.

Labour

An executive at a PCB materials maker in Thailand told Nikkei Asia that pay for experienced production line managers had doubled in two to three years, to 80,000 to 100,000 baht a month from about 40,000 baht.^[29] ZDT's joint venture has signed curriculum agreements with five Thai universities to build its own talent pipeline.^[4]

Tariffs and origin

A US executive order of 31 July 2025 set Thailand's reciprocal tariff at 19 percent, with 40 percent for goods that US Customs finds were transshipped to evade duties.^[30] In February 2026 the US Supreme Court held that the emergency-powers law behind those reciprocal tariffs does not authorise tariffs.^[31] A temporary 10 percent surcharge under Section 122 applied from 24 February to 24 July 2026.^[35] From 24 July 2026 goods from Thailand carry a 12.5 percent tariff under Section 301, with exemptions listed in the notice's annexes that do not include printed circuits under heading 8534; the same action set 10 percent for Malaysia, India, Indonesia and Mexico.^[32] For boards made in Thailand from imported laminate and chemicals, origin documentation matters as much as the rate. Rates set by executive order can change at short notice; the applicable rate is the one in force on the date of entry.

Outlook

The approvals point to more Thai HDI and high-layer capacity in 2026 and 2027 and a wider choice of plants, with qualification of new plants adding lead time to sourcing plans. In MPBxChange's assessment, copper foil and plating chemicals remain open to materials investment. The 320,078 million baht of applications^[1] records intent; certificates issued, realised spending and utilisation are the more informative measures, and the BOI and listed parents have begun to report them.

Data and method

Sources comprise BOI press releases from 2024 to 2026 on the BOI's One Start One Stop site, the BOI Investment Promotion Guide 2026, half-year reports and investor relations records of Shenzhen-listed parents, company websites, US executive orders, a proclamation, a USTR notice and a Supreme Court opinion, monthly reports of Thailand's Office of Industrial Economics, Thailand's customs returns to UN Comtrade, Thai and trade press, and two research studies on tax incentives. Plant counts are from the MPBxChange register of PCB plants in Thailand and update with the register. Amounts are in each source's currency; conversions and ratios marked as MPBxChange calculations are derived from the cited figures. Research date: 24 September 2026.