INTEGRATED CIRCUIT PACKAGE

Abstract: An integrated circuit package with a lead frame that incorporates crossunder (12, 13) members for power distribution. It uses a paddle member (11) for chip support and back plane contact, with crossunders extending alongside the paddle. Insulating means (17) is interposed between the chip and the lead frame with an opening to allow contact between the chip (21) to the paddle.

Description: INTEGRATED CIRCUIT PACKAGE Background of the Invention Integrated circuit chips have grown in size and packing density to meet user demand for more functions and storage capacity at lower cost. With this development, advantages in distributing electrical power to the chip become important. A common approach is to incorporate a power distribution network into the chip itself. However, the power busses tend to be large and the chip size must be increased, or functional space sacrificed, to accommodate them. This is generally undesirable. An alternative to increasing the chip size to accommodate the power distribution network is to distribute the power off chip and introduce power between more than two chip terminals. However, each new chip terminal consumes a package terminal pin and it is desirable to avoid multiple pins for power as well as to avoid separate power distribution means on the mounting board. Thus, a need exists for distributing electrical power to a chip in a manner which neither requires an increase in chip size nor the use of extra terminal pins. Statement of the Invention Power is distributed off chip without using additional pins by incorporating the power distribution network in a specially designed lead frame. The lead frame employs an elongated paddle member that extends the length of the chip but is narrower than the width of the chip. On one (or both) sides of the paddle are crossunders for power connections to various sites.on the chip. An insulating interlayer is provided to electrically insulate the chip backside from the crossunders. That layer does not completely cover the paddle allowing contact regions or contact members to extend from said paddle into contact with the backside of the chip. Brief Description of the Drawings FIG. 1 is a perspective view of a lead frame designed in accordance with one aspect of the invention; FIG. 2 is a perspective view, partly cut away, of the lead frame encapsulated in a plastic package; FIG. 3 is a view similar to FIG. 2 showing a chip installed in the package. Detailed Description A lead frame designed in accordance with the invention is shown in FIG. 1. The lead frame is standard except for the interior portion, often referred to as the paddle portion. The elongated section 11 extends the length of the chip that will later be attached to the lead frame, and serves both as the chip support and the contact to the back of the chip. Alongside the paddle member are crossunder members 12 and 13 which also extend the length of the chip, plus an additional length sufficient to provide wire bonding sites as will later be shown. The remainder of the lead frame is conventional with a plurality of bonding sites 14 shown arranged around the periphery of the central paddle and crossunder region. It will be understood by those skilled in the art that the frame shown is typically part of an endless tape with repeating lead frame units onto which chips are attached in assembly line fashion. Affixed to, or integral with, the central paddle member 11 are contact pins 16. The lead frame of FIG. 1 is shown in FIG. 2 installed in a conventional plastic packaging material but with the chip removed to show the lead frame detail. Covering the crossunder members 12 and 13 is an insulating film 17 made for example, from mylar or the like. Openings in the film 17 are provided for the protruding pins 16. When the chip is installed over the central portion of the lead frame the back of the chip will be insulated from the crossunder members 12 and 13, but will electrically contact the paddle member 11 via pins 16. to accommodate a backplane wire contact. Alternatively, paddle 11 may communicate electrically with an external lead. The means for establishing electrical contact between the back of the chip and the paddle member 11 may assume a variety of forms. The pin arrangement of FIG. 1 is but one choice. The contact means may be, for example, simply an opening in the insulating film to allow the chip to be soldered or conductively bonded directly to the member 11. The completed package is shown in FIG. 3 with a portion cut away, as in FIG. 2, to show the manner in which the chip 21 is installed in the package. Here wire bonds 20 are shown extending from the various bonding sites on the lead frame to bonding sites 14 (FIG. 1) on the chip 21. Bonds to crossunder 12 are shown at 25 and 26, and bonds to crossunder 13 are shown at 27 and 28. To distribute power to various sites on the chip 21, power is applied, via two package terminal pins, between the two cross-unders 12 and 13, and thence to the chip sites via the wire bonds 25-27. Additional sites on the chip can be similarly connected to the cross-unders (power busses) 12 and 13. Thus, while but two terminal pins are allocated to applying power to the chip, any number of sites on the chip 21 can receive power.

Claims: Claims 1. An integrated circuit device comprising a lead frame including a plurality of metal bonding sites formed in an integral web-like configuration and a plurality of electrical conductor members extending outwardly from said plurality of bonding sites, a central chip support region in the interior of the web-like bonding site configuration, CHARACTERIZED BY a chip support paddle (11), a conductive crossunder member (12) extending alongside the chip support paddle, a semiconductor chip (21 ) electrically contacting said chip support paddle and overlying said crossunder member, said crossunder member extending beyond an edge of the chip, and a conductive wire bond (25) extending from said chip to said crossunder member. 2. The device of claim 1 including wire bonds connecting a plurality of sites on the chip with said crossunder member. 3. The device of claim 2 having at two crossunder members (11, 12). 4. The device of claim 1 in which the semiconductor chip contacts the chip support paddle by means of pins (16) extending from said paddle into contact with said chip. 5. The device of claim 1 including insulating means (17) between the chip and the crossunder members. 6. The device of claim 5 in which the insulating means is a film of dielectric material with openings in the film through which the chip contacts the said paddle. 7. The device of claim 5 in which the chip contacts the paddle via pins integral with the paddle, said ins extendin throu h said o enin s.

Inventors: MOYER HAROLD WILLIAM, MOYER, HAROLD, WILLIAM
Applicants: AMERICAN TELEPHONE & TELEGRAPH, AMERICAN TELEPHONE & TELEGRAPH COMPANY
Application year: 1985
Main classification: H01L23
IPC codes: H01L21, H01L23