US4884237A
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US
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Stacked double density memory module using industry standard memory chips
Assignee: International Business Machines Corp
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Filing: 1989-03-17
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Granted: 1989-11-28
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Expires: 2009-03-17
Abstract
Abstract A stacked double density memory module may be formed from two industry standard memory chips, by jumpering the unused and chip enable pins on one chip and then stacking the jumpered chip on the other chip with the pins on the jumpered (top) chip contacting the corresponding pins on the other (bottom) chip except for the chip select pins. In a preferred embodiment for use with 64K or one megabit DRAMs, the top chip is jumpered with a U-shaped strap which runs from the unused pin to the chip enable pin. The chip enable pin is bent toward the chip body to retain the strap in place. The technique may also be employed for stacking other industry standard memory or array chips.
Inventors
- 👤 Wolfgang R. Mueller
- 👤 II Gwynne W. Spencer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 03:19
CPC Classifications
G; G11; G11C; G11C11/00; G11C11/21; G11C5/00; H; H10; H10W; H10W72/00; H10W90/00; H10W70/00; H10W70/40
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
106 words
A method of forming a stacked double density memory module from first and second industry standard memory chips, each of which includes a plurality of address, power supply and data pins, a chip select pin and an unused pin, in the same pin positions on said first and second chips, comprising the steps of: placing a conductive strap on said first chip extending from the chip select pin to the unused pin thereon; and mounting said first chip on top of said second chip with the pins on said first chip directly contacting the corresponding pins on said second chip, except for the chip select pins.
Claim 2
Independent Claim
106 words
A method of forming a stacked double density memory module from first and second industry standard memory chips, each of which includes a plurality of address, power supply and data pins, a chip select pin and an unused pin, in the same pin positions on said first and second chips, comprising the steps of: placing a conductive strap on said first chip extending from the chip select pin to the unused pin thereon; and mounting said first chip on top of said second chip with the pins on said first chip directly contacting the corresponding pins on said second chip, except for the chip select pins.
Claim 3
Dependent Claim
19 words
The method of claim 1 wherein said first and second industry standard memory chips are read only memory chips.
Claim 4
Dependent Claim
20 words
The method of claim 1 wherein said first and second industry standard memory chips are programmable read only memory chips.
Claim 5
Dependent Claim
21 words
The method of claim 1 wherein said first and second industry standard memory chips are erasable programmable read only memory chips.
Claim 6
Dependent Claim
19 words
The method of claim 1 wherein said first and second industry standard memory chips are programmable logic array chips.
Claim 7
Dependent Claim
54 words
The method of claim 1 wherein said first and second industry standard memory chips do not have the same number of pins, the plurality of address, power supply, data, chip select and unused pins being at the same pin positions on said first and second chips to the extent that the pin positions overlap.
Claim 8
Dependent Claim
19 words
The method of claim 1 further comprising the step of placing the second chip on a second level package.
Claim 9
Dependent Claim
50 words
The method of claim 1 wherein said placing step comprises the step of: placing a conductive strap having a hole at both ends thereof, along the bottom surface of said top chip, with the chip select pin extending through one hole and the unused pin extending through the other hole.
Claim 10
Dependent Claim
48 words
The method of claim 8 wherein said mounting step comprises the steps of: bending the chip select pin on said top chip toward the bottom of said chip so that it retains said conductive strap in place; and mounting said first chip on top of said second chip.
Claim 11
Independent Claim
12 words
The method of claims 8 wherein said conductive strap is a wire.
Claim 12
Dependent Claim
17 words
The method of claim 1 wherein said first and second industry standard memory chips are 64K RAMs.
Claim 13
Dependent Claim
18 words
The method of claim 1 wherein said first and second industry standard memory chips are one megabit RAMs.
Claim 14
Independent Claim
26 words
The method of claims 11 or 12 wherein said chip select pin is the row address pin and wherein the unused pin is the no-connect pin.
Claim 15
Independent Claim
170 words
A method of forming a stacked double density memory module from first and second identical industry standard memory chips, each of which includes a plurality of address, power supply and data pins, a chip select pin and an unused pin, comprising the steps of: placing a metal U-shaped strap, having holes at both ends thereof, along the bottom surface of said first chip, with the chip select pin extending through one hole and the unused pin extending through the other hole; bending the chip select pin in said first chip toward the bottom surface of said first chip to retain said metal U-shaped strap in place; mounting the first chip on top of said second chip, with each pin on said first chip contacting the corresponding pin on said second chip except for the chip select pins; and, soldering the contacting pins on said first and second chips to one another and soldering the metal U-shaped strap to the chip select pin and the unused pin on said first chip.
Claim 16
Independent Claim
170 words
A method of forming a stacked double density memory module from first and second identical industry standard memory chips, each of which includes a plurality of address, power supply and data pins, a chip select pin and an unused pin, comprising the steps of: placing a metal U-shaped strap, having holes at both ends thereof, along the bottom surface of said first chip, with the chip select pin extending through one hole and the unused pin extending through the other hole; bending the chip select pin in said first chip toward the bottom surface of said first chip to retain said metal U-shaped strap in place; mounting the first chip on top of said second chip, with each pin on said first chip contacting the corresponding pin on said second chip except for the chip select pins; and, soldering the contacting pins on said first and second chips to one another and soldering the metal U-shaped strap to the chip select pin and the unused pin on said first chip.
Claim 17
Dependent Claim
38 words
The method of claim 14 wherein said first and second identical industry standard memory chips are 64K RAM chips, with the unused pin being a no-connect pin and the chip select pin being a row address select pin.
Claim 18
Dependent Claim
19 words
The method of claim 14 further comprising the step of mounting the second chip on a second level package.
Claim 19
Dependent Claim
85 words
A double density memory module comprising: first and second industry standard memory chips, each of which includes a plurality of address, power supply and data pins, a chip select pin and an unused pin, in the same pin positions on said first and second chips, with the pins on said first chip directly connected to the corresponding pins on said second chip, except for said chip select pins; and a conductive strap connecting said chip select pin and said unused pin on said first chip.
Claim 20
Dependent Claim
85 words
A double density memory module comprising: first and second industry standard memory chips, each of which includes a plurality of address, power supply and data pins, a chip select pin and an unused pin, in the same pin positions on said first and second chips, with the pins on said first chip directly connected to the corresponding pins on said second chip, except for said chip select pins; and a conductive strap connecting said chip select pin and said unused pin on said first chip.
Claim 21
Dependent Claim
44 words
The double density memory module of claim 17 wherein the chip select pin in said first chip is bent toward the first chip, so that the chip select pin on said first chip does not contact the chip select pin on said second chip.
Claim 22
Dependent Claim
43 words
The double density memory module of claim 17 wherein the end of the chip select pin on said first chip is removed so that the chip select pin on said first chip does not contact the chip select pin on said second chip.
Claim 23
Dependent Claim
20 words
The double density memory module of claim 17 wherein the pins on said first and second chip are soldered together.
Claim 24
Dependent Claim
20 words
The double density memory module of claim 17 wherein said first and second industry standard memory chips are 64K RAMs.
Claim 25
Dependent Claim
21 words
The double density memory module of claim 17 wherein said first and second industry standard memory chips are one megabit RAMs.
Claim 26
Dependent Claim
22 words
The double density memory module of claim 17 wherein said first and second industry standard memory chips are read only memory chips.
Claim 27
Dependent Claim
23 words
The double density memory module of claim 17 wherein said first and second industry standard memory chips are programmable read only memory chips.
Claim 28
Dependent Claim
24 words
The double density memory module of claim 17 wherein said first and second industry standard memory chips are erasable programmable read only memory chips.
Claim 29
Dependent Claim
22 words
The double density memory module of claim 17 wherein said first and second industry standard memory chips are programmable logic array chips.
Claim 30
Dependent Claim
57 words
The double density memory module of claim 17 wherein said first and second industry standard memory chips do not have the same number of pins; the plurality of address, power supply, data, chip select and unused pins being in the same pin positions on said first and second chips to the extent that the pin positions overlap.
Claim 31
Dependent Claim
42 words
The double density memory module of claim 13 wherein said strap has a hole at each end thereof, with the chip select pin extending through the hole at one end and the unused pin extending through the hole at the other end.
Claim 32
Dependent Claim
14 words
The double density memory module of claim 28 wherein said strap is generally U-shaped.
Claim 33
Dependent Claim
139 words
A double density memory module comprising: first and second identical industry standard memory chips, each of which includes a plurality of address, power supply and data pins, a chip select pin and an unused pin, said first chip being mounted on top of said second chip so that each pin on said first chip is in electrical contact with the corresponding pin on said second chip, except for said chip select pins; and, a metal U-shaped strap, having a hole at both ends thereof, mounted along the bottom of said first chip, with the unused pin extending through one hole in said strap and the chip select pin extending through the other hole in said strap, the chip select pin on said first chip being bent towards the bottom of said first chip to retain said strap in place.
Claim 34
Dependent Claim
139 words
A double density memory module comprising: first and second identical industry standard memory chips, each of which includes a plurality of address, power supply and data pins, a chip select pin and an unused pin, said first chip being mounted on top of said second chip so that each pin on said first chip is in electrical contact with the corresponding pin on said second chip, except for said chip select pins; and, a metal U-shaped strap, having a hole at both ends thereof, mounted along the bottom of said first chip, with the unused pin extending through one hole in said strap and the chip select pin extending through the other hole in said strap, the chip select pin on said first chip being bent towards the bottom of said first chip to retain said strap in place.
Claim 35
Dependent Claim
37 words
The double density memory module of claim 30 wherein said first and second chips are 64K RAM chips, with the unused pin being a no-connect pin and the chip select pin being a row address select pin.
Claim 36
Dependent Claim
38 words
The double density memory module of claim 30 wherein said first and second chips are one megabit RAM chips, with the unused pin being a no-connect pin and the chip select pin being a row address select pin.
Claim 37
Dependent Claim
19 words
The double density memory module of claim 30 wherein said second chip is mounted on a printed circuit board.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-11-27 | 1993-05-29 | 1993-11-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-11-27 | 1997-05-29 | 1997-11-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-11-27 | 2001-05-29 | 2001-11-28 | $7700.00 | Window Closed / Lapsed |