TO-5
{{Short description|Standardized metal semiconductor package}}
File:TO-5 Heatsinks.jpgs for TO-5 packages.]]
In electronics, TO-5 (Transistor Outline 5) is a designation for a standardized metal semiconductor package used for transistors and some integrated circuits. The TO element stands for "transistor outline" and refers to a series of technical drawings produced by JEDEC. The first commercial silicon transistors, the 2N696 and 2N697 from Fairchild Semiconductor, came in a TO-5 package.{{cite web |url=http://semiconductormuseum.com/PhotoGallery/PhotoGallery_2N697.htm |title=Fairchild 2N697 |publisher=Transistor Museum |access-date=2021-07-16}}
Construction and orientation
The tab is located 45° from pin 1, which is typically the emitter. The typical TO-5 package has a base diameter of {{convert|8.9|mm|abbr=on}}, a cap diameter of {{convert|8.1|mm|abbr=on}}, a cap height of {{convert|6.3|mm|abbr=on}}. The pins are isolated from the package by individual glass-metal seals, or by a single resin potting. Sometimes one pin is connected directly to the metal case.
Variants
Several variants of the original TO-5 package have the same cap dimensions but differ in the number and length of the leads (wires). Somewhat incorrectly, TO-5 and TO-39 are often used in manufacturer's literature as synonyms for any package with the cap dimensions of TO-5, regardless of the number of leads, or even for any package with the diameter of TO-5, regardless of the cap height and the number of leads.{{cite web |url=https://www.ti.com/lit/an/snoa033/snoa033.pdf |title=Metal Can Packages |publisher=National Semiconductor / Texas Instruments |date=August 1999 |pages=7–14 |access-date=2021-06-21}} Compared to TO-5, for the other variants (except TO-33 and TO-42) the minimum length of the leads was shortened from {{convert|38.1|mm|abbr=on}} to {{convert|12.7|mm|abbr=on}} which is sufficient for through-hole technology and leads to a cost reduction, whereas the longer leads were needed for point-to-point construction. Lead lengths of {{convert|25.4|mm|abbr=on}} and {{convert|19.05|mm|abbr=on}} are quite common but were not standardized separately by JEDEC. There are variants with between 2 and 12 leads. The leads are arranged in a circle with a diameter of {{convert|5.08|mm|abbr=on}} (except TO-96, TO-97, TO-100, TO-101). Before the introduction of dual in-line packages in 1965, integrated circuits were packaged mostly in metal can packages such as the TO-5 variants with more than 3 leads.{{cite web |url=https://www.computerhistory.org/siliconengine/package-is-the-first-to-accommodate-system-design-considerations/ |title=1965: Package is the first to accommodate system design considerations |publisher=Computer History Museum |access-date=2021-06-21}}
={{anchor|TO-39|TO-9|TO-16|TO-42}}TO-39 / TO-9 / TO-16 / TO-42=
The TO-39, TO-9, and TO-16 packages have 3 leads and differ in the shortened leads mentioned above from TO-5.{{cite web |url=http://www.jedec.org/sites/default/files/docs/archive/to/to-039.pdf |title=TO-39 |publisher=JEDEC |archive-url=https://web.archive.org/web/20160410012520/http://www.jedec.org/sites/default/files/docs/archive/to/to-039.pdf |archive-date=2016-04-10 |access-date=2021-06-21}} Additionally, the TO-9 and TO-16 packages do not have a tab.{{cite web |url=http://www.jedec.org/sites/default/files/docs/archive/to/to-009.pdf |title=TO-9 |publisher=JEDEC |archive-url=https://web.archive.org/web/20160410012409/http://www.jedec.org/sites/default/files/docs/archive/to/to-009.pdf |archive-date=2016-04-10 |access-date=2021-06-21}} The TO-42 package is almost identical to the TO-5 package (including the long leads) but has four stand-offs at the bottom of the base that keep the base about 0.5 mm above the circuit board."...does not meet the minimum criteria ...for registration." {{cite web |url=http://www.jedec.org/sites/default/files/docs/archive/to/to-042.pdf |title=TO-42 |publisher=JEDEC |archive-url=https://web.archive.org/web/20160405133801/http://www.jedec.org/sites/default/files/docs/archive/to/to-042.pdf |archive-date=2016-04-05 |access-date=2021-06-21}} Possibly the TO-16 and TO-42 designations were not actually used.
={{anchor|TO-12|TO-33}}TO-12 / TO-33=
File:Perkin Elmer VTL2C1 cm.jpg VTL2C1 in a TO-33 package]]
The TO-12 and TO-33 packages have 4 leads.{{cite web |url=http://www.jedec.org/sites/default/files/docs/archive/to/to-012.pdf |title=TO-12 |publisher=JEDEC |archive-url=https://web.archive.org/web/20160405133738/http://www.jedec.org/sites/default/files/docs/archive/to/to-012.pdf |archive-date=2016-04-05 |access-date=2021-06-21}} TO-33 has {{convert|38.1|mm|abbr=on}} leads{{cite web |url=http://www.jedec.org/sites/default/files/docs/archive/to/to-033.pdf |title=TO-33 |publisher=JEDEC |archive-url=https://web.archive.org/web/20160404193725/http://www.jedec.org/sites/default/files/docs/archive/to/to-033.pdf |archive-date=2016-04-04 |access-date=2021-06-21}} like TO-5 while TO-12 has {{convert|12.7|mm|abbr=on}} leads. For transistors, the fourth wire is typically connected to the metal case as a means of electromagnetic shielding for radio frequency applications.
=TO-75=
The TO-75 package has 6 leads (at most one of those may be omitted).{{cite web |url=http://www.jedec.org/sites/default/files/docs/archive/to/to-075.pdf |title=TO-75 |publisher=JEDEC |archive-url=https://web.archive.org/web/20160405141946/http://www.jedec.org/sites/default/files/docs/archive/to/to-075.pdf |archive-date=2016-04-05 |access-date=2021-06-21}} The minimum angle between two adjacent leads is 60°.
={{anchor|TO-76|TO-77}}TO-76 / TO-77=
File:Tesla MAA723.jpg MAA723) in a TO-76 package.]]
The TO-76 and TO-77 packages have 8 leads (up to three of those may be omitted).{{cite web |url=http://www.jedec.org/sites/default/files/docs/archive/to/to-076.pdf |title=TO-76 |publisher=JEDEC |archive-url=https://web.archive.org/web/20160404203006/http://www.jedec.org/sites/default/files/docs/archive/to/to-076.pdf |archive-date=2016-04-04 |access-date=2021-06-21}} The minimum angle between two adjacent leads is 45°. The TO-77 package differs from the TO-76 package only in that the bottom of a TO-77 package can sit directly on a circuit board whereas the TO-76 package requires a distance of up to {{convert|1.02|mm|abbr=on}} between circuit board and package.{{cite web |url=http://www.jedec.org/sites/default/files/docs/archive/to/to-077.pdf |title=TO-77 |publisher=JEDEC |archive-url=https://web.archive.org/web/20160405014716/http://www.jedec.org/sites/default/files/docs/archive/to/to-077.pdf |archive-date=2016-04-05 |access-date=2021-06-21}}
={{anchor|TO-78|TO-79|TO-80|TO-99}}TO-78 / TO-79 / TO-80 / TO-99=
File:Tesla MAC198.jpg MAC198) in a reduced-height TO-99 package.]]
The TO-78,{{cite web |url=http://www.jedec.org/sites/default/files/docs/archive/to/to-078.pdf |title=TO-78 |publisher=JEDEC |archive-url=https://web.archive.org/web/20160405073854/http://www.jedec.org/sites/default/files/docs/archive/to/to-078.pdf |archive-date=2016-04-05 |access-date=2021-06-21}} TO-79,{{cite web |url=http://www.jedec.org/sites/default/files/docs/archive/to/to-079.pdf |title=TO-79 |publisher=JEDEC |archive-url=https://web.archive.org/web/20160410045840/http://www.jedec.org/sites/default/files/docs/archive/to/to-079.pdf |archive-date=2016-04-10 |access-date=2021-06-21}} TO-80,{{cite web |url=http://www.jedec.org/sites/default/files/docs/archive/to/to-080.pdf |title=TO-80 |publisher=JEDEC |archive-url=https://web.archive.org/web/20160405021054/http://www.jedec.org/sites/default/files/docs/archive/to/to-080.pdf |archive-date=2016-04-05 |access-date=2021-06-21}} and TO-99{{cite web |url=http://www.jedec.org/sites/default/files/docs/archive/to/to-099.pdf |title=TO-99 |publisher=JEDEC |archive-url=https://web.archive.org/web/20160410011937/http://www.jedec.org/sites/default/files/docs/archive/to/to-099.pdf |archive-date=2016-04-10 |access-date=2021-06-21}} packages have 8 leads (up to three of those may be omitted). The minimum angle between two adjacent leads is 45°. These packages differ from other variants in the height of the cap. Instead of {{convert|6.3|mm|abbr=on}} the cap height is only {{convert|4.45|mm|abbr=on}} for TO-78 / TO-99, {{convert|3.81|mm|abbr=on}} for TO-79, and {{convert|2.41|mm|abbr=on}} for TO-80. The TO-78 package differs from the TO-99 package only in that the bottom of a TO-78 package can sit directly on a circuit board whereas the TO-99 package requires a distance of up to {{convert|1.02|mm|abbr=on}} between circuit board and package.
=TO-74=
The TO-74 package has 10 leads (at most one of those may be omitted).{{cite web |url=http://www.jedec.org/sites/default/files/docs/archive/to/to-074.pdf |title=TO-74 |publisher=JEDEC |archive-url=https://web.archive.org/web/20160410042045/http://www.jedec.org/sites/default/files/docs/archive/to/to-074.pdf |archive-date=2016-04-10 |access-date=2021-06-21}} The minimum angle between two adjacent leads is 36°.
={{anchor|TO-96|TO-97|TO-100}}TO-96 / TO-97 / TO-100=
The TO-96,{{cite web |url=http://www.jedec.org/sites/default/files/docs/archive/to/to-096.pdf |title=TO-96 |publisher=JEDEC |archive-url=https://web.archive.org/web/20160410131547/http://www.jedec.org/sites/default/files/docs/archive/to/to-096.pdf |archive-date=2016-04-10 |access-date=2021-06-21}} TO-97,{{cite web |url=http://www.jedec.org/sites/default/files/docs/archive/to/to-097.pdf |title=TO-97 |publisher=JEDEC |archive-url=https://web.archive.org/web/20160405150355/http://www.jedec.org/sites/default/files/docs/archive/to/to-097.pdf |archive-date=2016-04-05 |access-date=2021-06-21}} and TO-100{{cite web |url=http://www.jedec.org/sites/default/files/docs/archive/to/to-100.pdf |title=TO-100 |publisher=JEDEC |archive-url=https://web.archive.org/web/20160410045719/http://www.jedec.org/sites/default/files/docs/archive/to/to-100.pdf |archive-date=2016-04-10 |access-date=2021-06-21}} packages have 10 leads (at most one of those may be omitted). The minimum angle between two adjacent leads is 36°. For these packages the diameter of the circle of leads is increased from {{convert|5.08|mm|abbr=on}} to {{convert|5.84|mm|abbr=on}}. This allows a slightly increased chip area in a cap of unchanged diameter. TO-96 has the standard cap height of {{convert|6.3|mm|abbr=on}}, while TO-100 and TO-97 have reduced cap heights of {{convert|4.45|mm|abbr=on}} (like TO-78) and {{convert|3.81|mm|abbr=on}} (like TO-79), respectively.
=TO-73=
The TO-73 package has 12 leads (at most one of those may be omitted).{{cite web |url=http://www.jedec.org/sites/default/files/docs/archive/to/to-073.pdf |title=TO-73 |publisher=JEDEC |archive-url=https://web.archive.org/web/20160410011735/http://www.jedec.org/sites/default/files/docs/archive/to/to-073.pdf |archive-date=2016-04-10 |access-date=2021-06-21}} The minimum angle between two adjacent leads is 30°.
=TO-101=
The TO-101 package has 12 leads (at most one of those may be omitted).{{cite web |url=http://www.jedec.org/sites/default/files/docs/archive/to/to-101.pdf |title=TO-101 |publisher=JEDEC |archive-url=https://web.archive.org/web/20160410010900/http://www.jedec.org/sites/default/files/docs/archive/to/to-101.pdf |archive-date=2016-04-10 |access-date=2021-06-21}} The minimum angle between two adjacent leads is 30°. For this package the diameter of the circle of leads is increased from {{convert|5.08|mm|abbr=on}} to {{convert|5.84|mm|abbr=on}}. This allows a slightly increased chip area in a cap of unchanged diameter. TO-101 has a reduced cap height of {{convert|4.45|mm|abbr=on}} (like TO-78).
=TO-205=
File:NatSemi LH0070.jpg LH0070) in a TO-205-AF package]]
TO-205 is intended to replace previous definitions of packages with leads arranged in a circle with a diameter of {{convert|5.08|mm|abbr=on}}.{{cite book |url=https://www.jedec.org/sites/default/files/TOIND_DT.pdf |title=JEDEC Publication No. 95 |chapter=Index by Device Type of Registered Transistor Outlines (TO) |publisher=JEDEC |date=October 2010 |accessdate=2021-07-13}}{{cite book |url=https://www.jedec.org/system/files/docs/To-205e.pdf |url-access=registration |title=JEDEC Publication No. 95 |chapter=Header Family 0.200 Pin Circle |publisher=JEDEC |pages=178–181 |date=November 1982 |accessdate=2021-07-13}} The different outlines are now defined as variants of TO-205: TO-5 is renamed to TO-205-AA, TO-12 to TO-205-AB, TO-33 to TO-205-AC, TO-39 to TO-205-AD. A new package with 3 leads and a cap height of {{convert|4.32|mm|abbr=on}} (similar to TO-78 / TO-99) is added as TO-205-AF.
National Standards
{{notelist}}
References
{{Reflist|refs=
{{cite web |title=JEDEC TO-5 package specification |url=https://www.jedec.org/sites/default/files/docs/archive/to/to-005.pdf |website=JEDEC |archiveurl=https://web.archive.org/web/20170618142922/https://www.jedec.org/sites/default/files/docs/archive/to/to-005.pdf |archivedate=June 18, 2017}}
}}
External links
- [http://eesemi.com/to5.htm TO-5 package] from EESemi.com
{{Semiconductor packages}}