US3793474A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lead configurations for plastic encapsulated semiconductor devices
Assignee: Motorola Solutions Inc
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Filing: 1971-12-09
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Granted: 1974-02-19
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Expires: 1991-12-09
Abstract
Abstract The disclosed lead configurations protect fragile bonds associated with connecting wires extending between the ends of leads and bonding pads on a semiconductor chip, which are all included in an encapulsated body, from the harmful stresses caused by thermally and mechanically generated forces. The encapsulated portions of each lead includes a transverse segment which is generally perpendicular to the axis of expansion and an integral longitudinal segment which lies generally along the axis. These two segments form a shoulder which is located near the chip to reduce movement of the lead end away from its pad in response to thermal expansion. Moreover, each lead also includes a further segment having a smaller cross-sectional area than an associated protruding portion. This further segment and the shoulder forming segments absorb externally applied forces to protect the fragile bonds.
Inventors
- 👤 T Dunn
- 👤 G Kirk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:16
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/40; H10W70/421; H10W72/00; H10W72/50; H10W72/541; H10W72/5449; H10W74/00; H10W90/00; H10W90/701; H10W90/751; H10W90/756; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49121
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
409 words
A metal frame member having a thermal expansion and contraction factor adapted for use in the manufacture of a plastic encapsulated semiconductor device wherein the plastic encapsulation has a thermal expansion and contraction factor different from that of the metal frame member, said frame member including a plurality of leads with each such lead having an end portion and a mounting portion for a semiconductor unit to be mounted thereon, each of such leads being adapted to be electrically connected by a fragile bonded connection at a lead end portion with such a semiconductor unit at corresponding contact pads on the semiconductor unit, each said lead having an improved configuration for attenuating the transmission of mechanical forces due to thermal contraction and expansion of the lead and due to thermal contraction and expansion of the plastic encapsulation so as to protect the fragile bonded connection between the lead and semiconductor unit at the contact pads against separation from one another, said improved configuration of said leads including at least two portions in each lead, each said portion being laterally displaced in the lead from the bonded connection at the end portion of such lead with the one of said portions lying in a longitudinal direction relative to the application of the mechanical force due to thermal contraction and expansion and a second portion extending from said first portion in a direction at right angles to said longitudinal direction, with said two portions together providing a first locking shoulder adapted to act to anchor the lead at such shoulder in plastic when it is ultimately embedded in the plastic encapsulation of a semiconductor device, and at least one of the leads in said plurality of leads having a configuration providing at least two pairs of portions with one pair spaced an incremental distance apart from the other pair over the length of said one lead, with each such pair of portions having one portion thereof at right angles relative to the other portion and providing a first pair locking shoulder thereby and a second pair of portions at right angles to one another providing a second pair locking shoulder thereby said first pair and second pair of locking shoulders on said one lead adapted to anchor that lead in plastic when embedded in plastic encapsulation, said anchoring acting to minimize relative movement between said encapsulation and a lead and thereby protect a fragile connection from separation at a semiconductor unit.
Claim 2
Dependent Claim
409 words
A metal frame member having a thermal expansion and contraction factor adapted for use in the manufacture of a plastic encapsulated semiconductor device wherein the plastic encapsulation has a thermal expansion and contraction factor different from that of the metal frame member, said frame member including a plurality of leads with each such lead having an end portion and a mounting portion for a semiconductor unit to be mounted thereon, each of such leads being adapted to be electrically connected by a fragile bonded connection at a lead end portion with such a semiconductor unit at corresponding contact pads on the semiconductor unit, each said lead having an improved configuration for attenuating the transmission of mechanical forces due to thermal contraction and expansion of the lead and due to thermal contraction and expansion of the plastic encapsulation so as to protect the fragile bonded connection between the lead and semiconductor unit at the contact pads against separation from one another, said improved configuration of said leads including at least two portions in each lead, each said portion being laterally displaced in the lead from the bonded connection at the end portion of such lead with the one of said portions lying in a longitudinal direction relative to the application of the mechanical force due to thermal contraction and expansion and a second portion extending from said first portion in a direction at right angles to said longitudinal direction, with said two portions together providing a first locking shoulder adapted to act to anchor the lead at such shoulder in plastic when it is ultimately embedded in the plastic encapsulation of a semiconductor device, and at least one of the leads in said plurality of leads having a configuration providing at least two pairs of portions with one pair spaced an incremental distance apart from the other pair over the length of said one lead, with each such pair of portions having one portion thereof at right angles relative to the other portion and providing a first pair locking shoulder thereby and a second pair of portions at right angles to one another providing a second pair locking shoulder thereby said first pair and second pair of locking shoulders on said one lead adapted to anchor that lead in plastic when embedded in plastic encapsulation, said anchoring acting to minimize relative movement between said encapsulation and a lead and thereby protect a fragile connection from separation at a semiconductor unit.
Claim 3
Dependent Claim
119 words
A metal frame member as defined in claim 1 wherein said improved configuration of a lead has at least two functions, one of which is the function of attenuating the movement of the parts of the metal frame member due to thermal expansion and contraction and accomplishing said one function by the said anchor interlock between a shoulder of the lead and plastic encapsulation for a semiconductor device, and a second function is that by which forces applied to a lead external of said plastic housing are relieved, said lead having a reduced cross section in the dimension thereof at a position adapted to be within the plastic encapsulation for a semiconductor device to accomplish the said second function.
Claim 4
Dependent Claim
134 words
A metal frame member as defined in claim 1 wherein the semiconductor device for which it is to be used utilizes fine wires for effecting the fragile bonded connections between contact pads on the semiconductor unit and corresponding leads, and said metal frame member is one of a plurality of corresponding frame members in a one-piece metal strip, said metal strip having a first portion and a second portion, each defining a respective outside Longitudinal edge of the strip, a semiconductor unit mounting means connected between said first and second portions and positioned centrally between such portions for receiving a semiconductor unit thereon, with said improved configuration of the leads of each frame member adapted to minimize the possibility of disrupting the fragile bonded connections in a semiconductor device assembled with each frame member.
Claim 5
Dependent Claim
108 words
A metal frame member as defined in claim 1 wherein one other of said leads has at least three pairs of portions spaced apart an incremental distance from one another longitudinally on the lead away from the end of said lead adapted to have a bonded connection thereon extending to a semiconductor unit in an ultimate device, each pair of lead portions being at right angles to one another and providing a locking shoulder at each pair, with the lead configuration provided by said pairs of portions acting to minimize relative movement between said lead and a plastic body encapsulation for a device utilizing said metal frame member.
Claim 6
Dependent Claim
56 words
A metal frame member as defined in claim 1 wherein each lead in said frame member includes an end portion at the end thereof which would be within the plastic body encapsulation having a reduced cross-section for accommodating forces applied to the lead outside a device to minimize any harmful effect of said externally applied forces.
Claim 7
Dependent Claim
409 words
In a semiconductor device with a plastic body encapsulation therefor having a semiconductor unit with contact pads thereon housed in said plastic body, a plurality of metal leads each having a portion embedded in said plastic body and another portion outside said body, electrical connectors embedded in said plastic body and each of which has a connection at one end to a contact pad on the semiconductor unit and has said connection at the other end to an end portion of a metal lead, with said connections comprising generally fragile connections, said plastic body having one coefficient of thermal expansion and contraction and the material for the metal leads having a different coefficient of thermal expansion and contraction, and means in said metal leads acting upon an increase in the temperature of said device for attenuating the relative movement between such plastic body and a metal lead due to said different coefficients and minimizing the possibility of the separation of an electrical connector at a said connection, said means including an improved configuration for the portion of at least one metal lead embedded in the plastic body comprising two lead portions with one lead portion at right angles to the second lead portion and together providing a first locking shoulder, and said means including an improved configuration for the portion of at least a second metal lead of said plurality of metal leads embedded in the plastic body, said second metal lead comprising a plurality of pairs of lead portions with said pairs spaced apart from one another incrementally over the length of said second metal lead, with one said lead portion of each pair of lead portions in said second metal lead being at right angles to the other lead portion of a pair and providing a locking shoulder, with the locking shoulders provided by the plurality of pairs of lead portions in the second metal lead embedded in the plastic body, and with the locking shoulders of said one metal lead and of said second metal lead respectively cooperating with the plastic body to anchor said one and said second metal leads therein in a manner to minimize relative movement between the plastic body encapsulation and said respective metal leads to protect the fragile connections corresponding to said one and said second metal leads from separation upon an increase in the temperature of the device and the thermal expansion of the plastic body due to such increase.
Claim 8
Dependent Claim
409 words
In a semiconductor device with a plastic body encapsulation therefor having a semiconductor unit with contact pads thereon housed in said plastic body, a plurality of metal leads each having a portion embedded in said plastic body and another portion outside said body, electrical connectors embedded in said plastic body and each of which has a connection at one end to a contact pad on the semiconductor unit and has said connection at the other end to an end portion of a metal lead, with said connections comprising generally fragile connections, said plastic body having one coefficient of thermal expansion and contraction and the material for the metal leads having a different coefficient of thermal expansion and contraction, and means in said metal leads acting upon an increase in the temperature of said device for attenuating the relative movement between such plastic body and a metal lead due to said different coefficients and minimizing the possibility of the separation of an electrical connector at a said connection, said means including an improved configuration for the portion of at least one metal lead embedded in the plastic body comprising two lead portions with one lead portion at right angles to the second lead portion and together providing a first locking shoulder, and said means including an improved configuration for the portion of at least a second metal lead of said plurality of metal leads embedded in the plastic body, said second metal lead comprising a plurality of pairs of lead portions with said pairs spaced apart from one another incrementally over the length of said second metal lead, with one said lead portion of each pair of lead portions in said second metal lead being at right angles to the other lead portion of a pair and providing a locking shoulder, with the locking shoulders provided by the plurality of pairs of lead portions in the second metal lead embedded in the plastic body, and with the locking shoulders of said one metal lead and of said second metal lead respectively cooperating with the plastic body to anchor said one and said second metal leads therein in a manner to minimize relative movement between the plastic body encapsulation and said respective metal leads to protect the fragile connections corresponding to said one and said second metal leads from separation upon an increase in the temperature of the device and the thermal expansion of the plastic body due to such increase.
Claim 9
Dependent Claim
98 words
A semiconductor device as defined in claim 6 wherein said one metal lead and said second metal lead each have an enlarged portion outwardly from the most outwardly positioned locking shoulder of each, and said enlarged portion of each said metal lead having therein a pair of oppositely positioned slots which reduce the cross-section of each said metal lead at said slots for the purpose of minimizing the effect of mechanical forces applied to the external portion of each said metal lead with respect to the generally fragile connections at the internal end of each said metal lead.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-18 | 1977-08-20 | 1978-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-18 | 1981-08-20 | 1982-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-18 | 1985-08-20 | 1986-02-19 | $7700.00 | Window Closed / Lapsed |