page_title: Surface-barrier transistor
section_title: Commercial manufacturing license agreements
hierarchical_section_title: Surface-barrier transistor / Commercial manufacturing license agreements
caption_attribution_description: English: This is a Sprague high-frequency surface-barrier (SB100) transistor that was licensed by Philco in late 1955, to manufacture and sell. This transistor is from my personal collection.
context_page_description: The surface-barrier transistor is a type of transistor developed by Philco in 1953 as an improvement to the alloy-junction transistor and the earlier point-contact transistor. Like the modern Schottky transistor, it offered much higher speed than earlier transistors and used metal–semiconductor junctions, but unlike the schottky transistor, both junctions were metal–semiconductor junctions.
context_section_description: Starting in 1955, Philco had decided to sell commercial manufacturing license agreements with other large electronic semiconductor companies, which allowed them the right to produce and sell its high-frequency surface-barrier transistors. Sprague Electric Company was one of the first companies to purchase a license agreement from Philco in late 1955 and started to manufacture the surface-barrier transistors under its Sprague name, in early 1956. Another company to purchase a license agreement from Philco in early 1957, was Semiconductors Limited, a division of the British-based Plessey Company. In 1959, General Transistor Corporation had also purchased a license agreement from Philco, to manufacture its complete line of high-speed transistors.
caption: Sprague surface-barrier (SB100) transistor licensed by Philco Corporation
exif: {"Image Orientation": "Horizontal (normal)", "Image XResolution": "339", "Image YResolution": "339", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Adobe Photoshop Elements 2.0", "Image DateTime": "2013:05:22 19:50:58", "Image ExifOffset": "164", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "302", "Thumbnail JPEGInterchangeFormatLength": "3082", "EXIF ColorSpace": "Uncalibrated", "EXIF ExifImageWidth": "232", "EXIF ExifImageLength": "410"}