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Operating Segments and Enterprise-Wide Information - Revenue by Segment, Recognition Type, and Geographic Area (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 27, 2025 | Sep. 28, 2024 | Sep. 27, 2025 | Sep. 28, 2024
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | $ 202,676 | $ 207,917 | $ 569,830 | $ 574,116
Probe Cards |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 166,380 | 172,174 | 465,008 | 475,667
Systems |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 36,296 | 35,743 | 104,822 | 98,449
Taiwan |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 46,911 | 47,922 | 145,152 | 122,612
Taiwan | Probe Cards |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 35,917 | 42,105 | 123,478 | 109,476
Taiwan | Systems |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 10,994 | 5,817 | 21,674 | 13,136
United States |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 36,375 | 55,015 | 117,624 | 148,672
United States | Probe Cards |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 26,802 | 45,015 | 87,435 | 120,046
United States | Systems |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 9,573 | 10,000 | 30,189 | 28,626
China |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 11,665 | 34,513 | 34,680 | 75,213
China | Probe Cards |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 7,760 | 27,367 | 20,545 | 56,364
China | Systems |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 3,905 | 7,146 | 14,135 | 18,849
South Korea |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 70,802 | 41,728 | 171,102 | 141,552
South Korea | Probe Cards |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 68,644 | 40,870 | 166,689 | 140,233
South Korea | Systems |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 2,158 | 858 | 4,413 | 1,319
Malaysia |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 5,814 | 5,280 | 13,569 | 13,745
Malaysia | Probe Cards |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 5,633 | 4,458 | 13,297 | 11,150
Malaysia | Systems |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 181 | 822 | 272 | 2,595
Japan |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 11,385 | 8,056 | 36,370 | 24,209
Japan | Probe Cards |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 8,406 | 3,734 | 20,665 | 12,594
Japan | Systems |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 2,979 | 4,322 | 15,705 | 11,615
Europe |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 7,363 | 7,756 | 22,392 | 25,420
Europe | Probe Cards |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 2,441 | 2,149 | 9,200 | 8,927
Europe | Systems |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 4,922 | 5,607 | 13,192 | 16,493
Singapore |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 9,937 | 5,475 | 22,865 | 14,755
Singapore | Probe Cards |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 8,697 | 4,726 | 19,057 | 12,354
Singapore | Systems |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 1,240 | 749 | 3,808 | 2,401
Rest of World |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 2,424 | 2,172 | 6,076 | 7,938
Rest of World | Probe Cards |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 2,080 | 1,750 | 4,642 | 4,523
Rest of World | Systems |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 344 | 422 | 1,434 | 3,415
Products transferred at a point in time |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 198,222 | 201,260 | 555,073 | 559,306
Products transferred at a point in time | Probe Cards |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 164,573 | 166,968 | 459,846 | 464,668
Products transferred at a point in time | Systems |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 33,649 | 34,292 | 95,227 | 94,638
Products and services transferred over time |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 4,454 | 6,657 | 14,757 | 14,810
Products and services transferred over time | Probe Cards |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 1,807 | 5,206 | 5,162 | 10,999
Products and services transferred over time | Systems |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 2,647 | 1,451 | 9,595 | 3,811
Foundry & Logic |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 92,933 | 107,446 | 277,718 | 297,874
Foundry & Logic | Probe Cards |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 92,933 | 107,446 | 277,718 | 297,874
Foundry & Logic | Systems |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 0 | 0 | 0 | 0
DRAM |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 68,182 | 60,184 | 174,097 | 164,122
DRAM | Probe Cards |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 68,182 | 60,184 | 174,097 | 164,122
DRAM | Systems |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 0 | 0 | 0 | 0
Flash |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 5,265 | 4,544 | 13,193 | 13,671
Flash | Probe Cards |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 5,265 | 4,544 | 13,193 | 13,671
Flash | Systems |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 0 | 0 | 0 | 0
Systems |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 36,296 | 35,743 | 104,822 | 98,449
Systems | Probe Cards |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | 0 | 0 | 0 | 0
Systems | Systems |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenues | $ 36,296 | $ 35,743 | $ 104,822 | $ 98,449

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