Hubbry Logo
Solid Logic TechnologySolid Logic TechnologyMain
Open search
Solid Logic Technology
Community hub
Solid Logic Technology
logo
8 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Solid Logic Technology
Solid Logic Technology
Solid Logic Technology
View on Wikipedia
from Wikipedia
Solid Logic Technology cards
A double-width SLT card. The square metal cans contain the hybrid circuits.
Three single-width SLT cards
SLT cards in situ
Many SLT cards plugged into a board
SLT cards in an IBM 129 keypunch

Solid Logic Technology (SLT) was IBM's method for hybrid packaging of electronic circuitry introduced in 1964 with the IBM System/360 series of computers. It was also used in the 1130, announced in 1965. IBM chose to design custom hybrid circuits using discrete, flip chip-mounted, glass-encapsulated transistors and diodes, with silk-screened resistors on a ceramic substrate, forming an SLT module. The circuits were either encapsulated in plastic or covered with a metal lid. Several of these SLT modules (20 in the image on the right) were then mounted on a small multi-layer printed circuit board to make an SLT card. Each SLT card had a socket on one edge that plugged into pins on the computer's backplane (the exact reverse of how most other companies' modules were mounted).

IBM considered monolithic integrated circuit technology too immature at the time.[1] SLT was a revolutionary technology for 1964, with much higher circuit densities and improved reliability over earlier packaging techniques such as the Standard Modular System. It helped propel the IBM System/360 mainframe family to overwhelming success during the 1960s. SLT research produced ball chip assembly, wafer bumping, trimmed thick-film resistors, printed discrete functions, chip capacitors and one of the first volume uses of hybrid thick-film technology.

SLT replaced the earlier Standard Modular System, although some later SMS cards held SLT modules. SLT had several updates during its life, the last being the Monolithic System Technology (MST) which replaced the single transistors of SLT with small-scale integrated circuits that held four or five transistors. MST was used in the System/370, which began to replace the System/360 in 1970.

Details

[edit]

SLT used silicon planar glass-encapsulated transistors and diodes.[2]

SLT uses dual diode chips and individual transistor chips each approximately 0.025 inches (0.64 mm) square.[3]: 15  The chips are mounted on a 0.5 inches (13 mm) square substrate with silk-screened resistors and printed connections. The whole is encapsulated to form a 0.5 inches (13 mm) square module. Up to 36 modules are mounted on each card, though a few card types had just discrete components and no modules. Cards plug into boards which are connected to form gates which form frames.[3]: 15 

SLT voltage levels, logic low to logic high, varied by circuit speed:[3]: 16 

High speed (5-10 ns) 0.9 to 3.0 V
Medium speed (30 ns) 0.0 to 3.0 V
Low speed (700 ns) 0.0 to 12.0 V
Steps in manufacturing Solid Logic Technology hybrid modules. The process starts with a blank ceramic wafer, 1⁄2 inch (13 mm) square. Circuits are laid down first, followed by resistive material. Pins are added, the circuits are soldered and the resistors trimmed to the desired value. Then individual transistors and diodes are added and the package is encapsulated.
Steps in manufacturing Solid Logic Technology hybrid modules. The process starts with a blank ceramic wafer, 1⁄2 inch (13 mm) square. Circuits are laid down first, followed by resistive material. Pins are added, the circuits are soldered and the resistors trimmed to the desired value. Then individual transistors and diodes are added and the package is encapsulated.

Later developments

[edit]

The same basic packaging technology (both device and module) was also used for the devices that replaced SLT as IBM gradually transitioned to the use of monolithic integrated circuits:

  • Solid Logic Dense (SLD) increased packaging density and circuit performance by mounting the discrete transistors and diodes on top of the substrate and the resistors on the bottom.[3]: 15  SLD voltages were the same as SLT.
  • Unit Logic Device (ULD) use flat-pack ceramic packages, much smaller than SLT's metal cans. Each package contains a ceramic wafer with up to four silicon dies on top, each die implementing one transistor or two diodes; and thick-film resistors underneath. ULDs were used in the Launch Vehicle Digital Computer and Launch Vehicle Data Adapter of the Saturn V rocket.[4][5]
  • Advanced Solid Logic Technology (ASLT) increased packaging density and circuit performance by stacking two substrates in the same package. ASLT is based on the Emitter-follower-coupled-switch used with current-steering logic.[3]: 18  ASLT voltage levels were : > +235 mV is high, < -239 mV is low.[3]: 16 

  • Monolithic System Technology (MST) increased packaging density and circuit performance by replacing discrete transistors and diodes with one to four monolithic integrated circuits (resistors now external from the package on the module). Each MST chip holds about five circuits and is the approximate equivalent of an SLT card.[3]: 18  Circuits used NPN transistors. MST was first introduced in January 1968 and provided improved cost/performance for IBM's System/370 product line of the 1970s.[6]
[edit]
  • Monolithic System Technology card with module covers removed
    Monolithic System Technology card with module covers removed
  • An uncommon half-width SLT card with no SLT modules
    An uncommon half-width SLT card with no SLT modules
  • Single-width card
    Single-width card
  • Quad-width SLT module
    Quad-width SLT module
  • Module with six transistors and three resistors, cap off
    Module with six transistors and three resistors, cap off
  • Closeup shows the raised squares of the transistors and the flat black resistors
    Closeup shows the raised squares of the transistors and the flat black resistors

See also

[edit]

References

[edit]
[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Solid Logic Technology

View on Grokipedia
from Grokipedia
Solid Logic Technology (SLT) is a hybrid packaging method developed by , introduced in 1964 as a key component of the System/360 family of mainframe computers, featuring planar transistors and diodes encapsulated in glass and mounted on small ceramic substrates along with passive components like resistors and capacitors. This technology represented IBM's innovative approach to achieving higher circuit density, reliability, and performance in third-generation computing systems, enabling the modular and scalable design of the System/360, which used SLT for logic circuits along with memory and supported both scientific and commercial applications through shared architecture and programming instructions. SLT modules, half-inch square ceramic units protected by aluminum caps, were soldered onto printed circuit boards that plugged into backplanes, facilitating compact assembly with thousands of such modules per system. The technique emphasized microminiaturization for low-cost, high-reliability circuits, delivering processing speeds ranging from approximately 0.002 MIPS in the Model 20 to over 16 MIPS in high-end models, with the System/360 Model 30 featuring 0.03 MIPS and 8 to 64 KB of main storage. By using alumina ceramic substrates—such as the 15x15 mm squares supplied in quantities of 25 million by manufacturers like in 1966—SLT ensured precise tolerances and thermal stability essential for large-scale production. SLT's design contributed to the System/360's industry-transforming impact, powering applications from business data processing to space missions, including the rocket's Launch Vehicle Digital Computer, and laid groundwork for subsequent technologies like monolithic integrated circuits in later decades. Its focus on hybrid integration marked a pivotal shift toward more efficient, durable in computing history.

History

Development and Invention

In the early 1960s, launched internal research efforts to revolutionize electronics for next-generation , motivated by the limitations of discrete components in achieving higher and reliability. Around , the company began exploring advanced techniques, including experiments with hybrid circuits that combined transistors, diodes, and resistors on small ceramic substrates to integrate multiple functions into compact modules. These initiatives were driven by the need to support ambitious projects like the System/360, which required scalable, high-performance hardware. The development of Solid Logic Technology (SLT) emerged as a proprietary solution, with conceptualization beginning in 1961 under the leadership of engineer Erich Bloch in the Components Division. Bloch, previously involved in the transistorized Stretch supercomputer, headed the SLT program starting in 1962, focusing on hybrid that encapsulated planar devices in for durability and efficiency. Although influenced by industry advancements such as Robert N. Noyce's 1959 at , pursued SLT as a hybrid approach because monolithic ICs could not yet meet production scale, cost, or speed requirements. At the Poughkeepsie laboratory, where served as chief architect for the System/360, collaborative teams integrated SLT into broader system design, though component development occurred primarily at facilities like East Fishkill. By 1963, prototypes of SLT modules underwent testing, with IBM's East Fishkill plant producing approximately half a million units that year to validate integration of discrete components into single, reliable packages. This timeline aligned with IBM's massive $5 billion investment in the System/360 project, underscoring the economic imperative for innovative packaging to enable high-volume manufacturing and competitive mainframe production. SLT's invention represented a pivotal IBM-specific advancement, culminating in a technology ready for deployment by 1964.

Introduction and Adoption

Solid Logic Technology (SLT) was officially introduced by on April 7, 1964, alongside the System/360 family of computers, marking a pivotal advancement in packaging that utilized hybrid circuits to achieve greater reliability and performance across the compatible system lineup. This technology enabled the System/360 to transition from vacuum tube-based systems to solid-state components, supporting a unified that spanned small to large-scale machines while maintaining software and peripheral compatibility. Mass production of SLT modules ramped up at IBM's East Fishkill facility in New York, beginning with approximately 12 million units in 1964 following a half-million produced there in 1963 for development. Peak volumes occurred during 1964-1965, with East Fishkill production reaching 12 million modules in 1964 and 28 million in 1965; global output was approximately 36 million in 1965, driven by the System/360 rollout. By 1966, output exceeded 90 million annually across IBM's global plants. Early scaling faced significant challenges, including defect rates as high as 25% in 1965 due to rapid manufacturing expansion, which delayed deliveries but was resolved through process improvements and new facilities. Adoption of SLT was facilitated by IBM's strategy, which encompassed in-house design, fabrication tools, and production to ensure supply chain control and rapid iteration for the System/360. Initially met with skepticism from competitors like and regarding the feasibility of the ambitious System/360 project, SLT nonetheless spurred an industry shift toward similar hybrid technologies by demonstrating scalable, high-density circuitry. The System/360 announcement event, led by IBM Chairman in , positioned SLT as the cornerstone of "third-generation" computing, bridging discrete transistors and emerging integrated circuits to enable versatile, high-performance systems.

Technical Overview

Core Components

Solid Logic Technology (SLT) modules are built on a substrate primarily composed of 96% alumina, which provides electrical insulation and effective dissipation due to its high thermal conductivity. These substrates measure approximately 0.455 by 0.455 inches and are nominally 0.060 inches thick, forming the foundational layer onto which active and passive components are mounted. The active elements in SLT consist of discrete silicon planar transistors and diodes, encapsulated in glass for protection and reliability. Transistors are NPN-type silicon devices, often mesa or diffused structures, with each chip measuring about 0.028 inches square and featuring three connections for emitter, base, and collector. Diodes are typically dual configurations on similar-sized chips, enabling logic functions such as AND and OR gates; a single module can incorporate up to four transistors alongside multiple diodes to realize complex logic circuits. Passive elements include thick-film resistors deposited via screening techniques on the ceramic substrate, using materials like ruthenium oxide for stability, with values ranging from 100 ohms to 10 kΩ and tolerances adjusted by abrasive trimming to ensure precision. Capacitors are integrated as thin-film or discrete types, or occasionally mica-based discretes for higher capacitance needs in timing circuits, supporting values from picofarads to microfarads as required by specific logic functions. Interconnections between components and the substrate utilize flip-chip bonding with controlled collapse chip connection (C4) technology, involving solder bumps—typically lead-tin alloy—on the chips that reflow to form reliable electrical and mechanical joints upon attachment to metallized pads on the alumina base. This method, pioneered in SLT, enhances reliability over traditional by minimizing mechanical stress and enabling higher density. Overall, these components achieve a density of up to 64 elements per square inch within the compact module format, balancing performance and manufacturability for high-speed logic operations.

Packaging and Assembly

Solid Logic Technology (SLT) modules featured a modular design centered on a flat-pack substrate measuring approximately 0.5 inches square, onto which discrete chips for transistors and diodes, as well as passive components, were mounted via or bonding. This hybrid approach allowed for dense integration of active and passive elements on the insulating base, with interconnections formed through deposited conductive paths. The completed assembly was protected by a hermetic metal lid, soldered in place to provide environmental sealing and mechanical stability. The fabrication process for SLT modules started with the ceramic substrate, where passive elements like resistors and capacitors were deposited using screen-printing of thick-film inks, fired to form stable conductive and layers. Thin-film conductors for precise wiring were added via , enabling multi-layer interconnects on the substrate to route signals between components. Component pins were secured using , ensuring robust, low-resistance joints without excessive heat that could damage sensitive semiconductors. Quality assurance included in-circuit burn-in testing, where modules were operated at elevated temperatures (typically 125°C) for extended periods to accelerate potential failures and screen out weak units. This rigorous process contributed to exceptional reliability, with observed field failure rates below 0.005% per across billions of cumulative module-hours in service. SLT encompassed variations tailored to performance needs, such as standard modules for general logic functions and high-speed versions that incorporated modified materials to minimize delays and support faster switching times up to 30 nanoseconds. Modules were typically 0.5 inches square, with options like quad-width for higher density.

Applications

Use in System/360

Solid Logic Technology (SLT) served as the foundational logic implementation in the family, where modules were mounted on printed-circuit cards that formed the core of the central processing units (CPUs), memory interfaces, and (I/O) channels. These hybrid modules, containing transistors, diodes, resistors, and capacitors, replaced earlier discrete component designs, enabling denser packing of logic functions on cards that could be easily inserted into backplanes for and upgrades. In the System/360 Model 30, SLT modules supported configurations with 8 to 64 KB of main storage, contributing to the system's overall for basic commercial and scientific processing. Across the family, SLT's design facilitated performance levels ranging from approximately 0.03 million (MIPS) in the entry-level Model 30 to about 1 MIPS in higher-end models like the Model 65 and Model 75, allowing the to span a wide range of computational needs while maintaining binary compatibility. SLT was instrumental in realizing key functional units in mid-range models such as the 40, 50, and 65. For instance, in the Model 40, SLT-based logic implemented arithmetic functions optimized for byte-oriented operations, with a 1-byte adder-subtractor supporting the model's 32-bit architecture, while the Model 50 employed SLT modules for control sequencing and data path management in its microprogrammed execution. In the Model 65, SLT handled a more advanced 60-bit ALU capable of efficient double-precision , alongside dedicated control units for instruction decoding and operand handling. The modular nature of SLT modules, with standardized pinouts and logic levels, was crucial for achieving upward and downward compatibility across the System/360 family, permitting scalable designs where common cards and modules could be reused or reconfigured without full hardware redesigns for different performance tiers. This approach reduced development complexity and ensured that software written for one model could execute on others, a cornerstone of the System/360's architectural philosophy.

Extensions to Other IBM Systems

Following the success of Solid Logic Technology (SLT) in the System/360 family, IBM extended its application to the System/370 lineup announced in 1970, incorporating advanced variants to support key architectural enhancements such as virtual memory. The System/370 models, including the Model 145, utilized Advanced Solid Logic Technology (ASLT), an evolution of SLT that enhanced hybrid circuit density and performance through improved packaging of transistors, diodes, and resistors on ceramic substrates. ASLT improved circuit density to support virtual memory addressing, allowing larger effective memory spaces beyond physical limits while maintaining compatibility with System/360 software. ASLT hybrid modules were also employed in channel controllers for System/370, facilitating faster data transfer rates and improved I/O handling in environments requiring high reliability. SLT found broader adoption in other IBM products beyond mainframes, including the IBM 1130 introduced in 1965, which targeted scientific and engineering users with its compact design. The 1130's CPU incorporated SLT modules for logic functions, enabling a 16-bit with core memory cycles as fast as 2.2 microseconds and up to 32K words of storage in a desk-sized . Similarly, System/360 peripherals relied on SLT for control , ensuring standardized interfaces across the . In specialized sectors, SLT supported military and government applications through IBM's Federal Systems Division, including adaptations for secure projects like those developed for the . For instance, ASLT circuits were customized for high-security environments, building on SLT's reliability in hybrid form factors. In and reservation systems, SLT powered upgrades to the SABRE airline booking network, which transitioned from earlier IBM hardware to System/360 compatibility in the late , handling millions of daily transactions via SLT-based processing units. Production of SLT and its extensions scaled massively through the 1970s, with manufacturing over 90 million modules in alone to meet demand for System/360 and derivatives, contributing to a total exceeding hundreds of millions by the mid-decade. However, extensions faced limitations as monolithic integrated circuits became more cost-effective; by the mid-1970s, rising fabrication costs for hybrid SLT modules in non-mainframe applications like minicomputers and peripherals accelerated a gradual phase-out in favor of newer technologies.

Advantages and Limitations

Key Benefits

Solid Logic Technology (SLT) offered substantial engineering advantages through enhanced component density and reliability, marking a key advancement over earlier discrete transistor-based packaging like IBM's Standard Modular System (). By integrating multiple transistors, diodes, and passive components onto compact ceramic substrates using hybrid techniques, SLT achieved 3 to 6 times the logical function density of the densest SMS modules, allowing for more efficient use of space in large-scale systems. This integration also yielded up to 100 times greater reliability compared to SMS, with significantly improved MTBF through hermetic glass encapsulation and robust interconnection methods. Economically, SLT drove significant cost efficiencies by streamlining manufacturing processes and leveraging in production. Assembly labor was reduced through automated and standardized module designs, minimizing manual wiring that plagued discrete component assembly. By 1966, high-volume fabrication had lowered the cost of individual SLT modules to around $0.40, a fraction of prior packaging expenses, enabling affordable scaling for commercial deployments. The modular nature of SLT facilitated exceptional , supporting the System/360 family's broad performance spectrum—from entry-level models to high-end configurations—without requiring fundamental technological overhauls across the lineup. This design consistency allowed configurations ranging from small-scale installations to massive multiprocessor setups, with performance varying by a factor of 25:1 or more, all built on interchangeable SLT components. These benefits collectively provided IBM with a competitive innovation edge, enabling the creation of the first fully compatible computer family and propelling the company's market dominance. By the late 1960s, System/360 powered by SLT had helped IBM secure over 65% of the global computer market share.

Technical Challenges

One of the primary technical challenges in producing Solid Logic Technology (SLT) modules was achieving consistent yields during manufacturing. Early production yields hovered around 70% due to the inherent variability in assembling hybrid components, including discrete transistors, diodes, and thin-film resistors on ceramic substrates, exacerbating defect rates in the labor-intensive assembly process. SLT modules also faced limitations in size and power efficiency compared to emerging monolithic integrated circuits (ICs). Each SLT module occupied approximately 0.25 square inches (based on a 0.5-inch square ceramic substrate), significantly larger than the 0.1 square inches typical of early monolithic ICs from competitors like Fairchild. Power draw was another drawback, with modules consuming approximately 15-70 mW per circuit, depending on the module type, leading to higher overall power requirements and thermal management issues in dense configurations. By the late , cost escalation became a critical issue for SLT. Production costs for SLT modules began to rise relative to advancing monolithic alternatives, driven by the complexity of hybrid fabrication and rising material expenses. Repair difficulties further compounded costs, as the sealed metal caps on modules made field servicing impractical, often requiring full module replacement rather than targeted fixes. In terms of competition, SLT lagged behind Fairchild's monolithic ICs in performance metrics like speed. SLT logic gates typically exhibited propagation delays of about 15-20 ns, comparable to or slightly slower than early Fairchild ICs, which achieved around 10-15 ns, limiting SLT's scalability for higher-performance applications.

Legacy

Influence on Computing

Solid Logic Technology (SLT) played a pivotal role in enabling the IBM System/360's groundbreaking , which introduced a unified family of compatible computers for the first time, spanning a wide performance range while maintaining software compatibility across models. This , facilitated by SLT's high-density hybrid packaging, allowed for scalable systems that could grow without requiring reprogramming, fundamentally shifting toward and upgradability in mainframes. The System/360's success, powered by SLT, set industry benchmarks for architectural compatibility that influenced subsequent mainframe developments, emphasizing efficient, family-wide designs over fragmented product lines. SLT's hybrid integration approach, including early flip-chip bonding techniques like controlled collapse chip connection (C4), pioneered advancements in packaging that informed later industry norms for high-density assembly. As the first widespread use of flip-chip devices in , SLT's methods contributed to the evolution of standards for reliable, compact circuitry, boosting the adoption of hybrid integrated circuits during the mid-1960s when such technologies reached peak production volumes. This innovation helped establish practices that influenced subsequent norms for semiconductor assembly and reliability. In computing history, SLT is recognized as a transitional technology bridging discrete components and monolithic integrated circuits, often highlighted in educational texts and exhibits for its role in advancing mainframe reliability and density. Artifacts such as SLT wafers and modules are preserved at the , underscoring its significance in illustrating microelectronics evolution. Economically, SLT's integration into the System/360 propelled to market dominance, with the project generating over $8.2 billion in revenue by 1971—more than doubling from 1964 levels—and funding extensive R&D initiatives, including the ambitious project in the 1970s. This financial success expanded the overall computing industry, driving double-digit growth in demand throughout the decade.

Transition to Monolithic ICs

As the progressed, initiated the shift from Solid Logic Technology (SLT) to monolithic integrated circuits (ICs) to achieve greater density and cost efficiency in . In , introduced Monolithic Systems Technology (MST), which replaced SLT's hybrid approach with single-chip ICs fabricated using advanced processes, beginning production at the company's plant. This marked the start of monolithic IC manufacturing, enabling circuits with thousands of transistors on a single die rather than discrete components bonded to ceramic substrates. A pivotal milestone came in 1970 with IBM's announcement of the System/370 Model 145, the first computer featuring 100% monolithic ICs for both logic and , signaling the decline of SLT in core processing units. Technological drivers included rapid advances in and processes during the late , which allowed for finer feature sizes and higher yields in IC production, making monolithic designs cheaper and more scalable than SLT hybrids. While SLT had served as an interim solution for high-reliability applications due to its robust packaging, its limitations in circuit density became evident as monolithic ICs offered superior performance per unit volume. The full transition to monolithic ICs for the System/370 family was completed by 1975, as subsequent models fully adopted MST and its evolutions, phasing out SLT from mainframe central processing. However, SLT-based hybrid modules persisted in peripherals and less critical subsystems into the , providing continuity in legacy systems. This evolution also influenced IBM's adoption of metal-oxide-semiconductor (MOS) ICs in 1971 at the Burlington facility, expanding monolithic technology to lower-power applications and further accelerating the obsolescence of hybrid approaches like SLT.

References

  1. https://ieeexplore.ieee.org/document/5392211/
  2. https://global.kyocera.com/inamori/about/engineer/episode-2754.html
  3. https://public.dhe.ibm.com/eserver/zseries/zos/vse/pdf3/techconf2015/orlando/zPL3222_Fifty_Years_of_zVSE_Still_going_strong.pdf
  4. https://moca.ncl.ac.uk/circuitry/360.htm
  5. https://www.computerhistory.org/revolution/mainframe-computers/7/164/654
  6. https://www.computerhistory.org/revolution/mainframe-computers/7/164
  7. https://www.computerhistory.org/revolution/mainframe-computers/7/164/579
  8. https://spectrum.ieee.org/building-the-system360-mainframe-nearly-destroyed-ibm
  9. https://ethw.org/Erich_Bloch
  10. https://www.computerhistory.org/siliconengine/hybrid-microcircuits-reach-peak-production-volumes/
  11. https://www.ibm.com/history/system-360
  12. https://ethw.org/Gene_M._Amdahl
  13. https://www.vm.ibm.com/history/360rev.pdf
  14. https://public.dhe.ibm.com/s390/zos/racf/pdf/PPLD_History_of_the_System360_2024_04_24.pdf
  15. https://www.researchgate.net/publication/297634897_Solid_logic_technology_Versatile_high-performance_microelectronics_Reprinted_from_IBM_Journal_of_Research_and_Development_vol_8_1964
  16. https://bitsavers.org/pdf/ibm/logic/SLT_Circuit_Design_Hbk.pdf
  17. http://bitsavers.informatik.uni-stuttgart.de/pdf/ibm/logic/IBM_Industrial_SLT_Modules/IBM_Industrial_SLT_Modules_700ns_Feb1968.pdf
  18. https://semiwiki.com/general/295101-examining-a-technology-sample-kit-ibm-components-from-1948-to-1986/
  19. https://www.sciencedirect.com/topics/engineering/farad
  20. https://www.researchgate.net/publication/315568668_History_of_Flip_Chip_and_Area_Array_Technology
  21. https://doi.org/10.1147/rd.82.0102
  22. https://www.hpcwire.com/aiwire/2014/04/08/ibm-system360-original-enterprise-tech/
  23. https://gunkies.org/wiki/IBM_System/360
  24. http://www.quadibloc.com/comp/pan04.htm
  25. https://www.ibm.com/history/system-370
  26. https://www.semanticscholar.org/paper/Design-of-Logic-Circuit-Technology-for-IBM-System-Fox-Nestork/484849b3db57c01dbe67a9f96b122ef8f3fe8548
  27. http://ibm1130.org/hw/cpu/
  28. https://dl.acm.org/doi/pdf/10.1145/174256.174257
  29. https://www.ibm.com/history/sabre
  30. https://dl.acm.org/doi/abs/10.1147/rd.255.0603
  31. https://www.computerhistory.org/tdih/april/7/
  32. http://bitsavers.org/pdf/ibm/logic/2-6201-H1_SLT_SLD_Module_Data_Dec1969.pdf
  33. http://www.righto.com/2021/01/examining-technology-sample-kit-ibm.html
  34. https://imapsource.org/api/v1/articles/66641-flip-chip-and-wafer-level-packaging-past-present-and-future.pdf
  35. https://www.chipsetc.com/the-ibm-slt---solid-logic-technology.html
  36. https://archive.computerhistory.org/resources/access/text/2017/02/102770626-05-01-acc.pdf
  37. https://www.sciencehistory.org/stories/magazine/patterning-the-world-the-rise-of-chemically-amplified-photoresists/
  38. https://www.vm.ibm.com/devpages/jelliott/pdfs/zhistory.pdf
  39. http://techandtrouble.blogspot.com/2014/04/happy-50th-system360-pt5-anatomy-of-slt.html
  40. https://www.eejournal.com/article/a-brief-history-of-the-mos-transistor-part-4-ibm-research-persistence-and-the-technology-no-one-wanted/
Add your contribution
Related Hubs
User Avatar
No comments yet.