Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L23/00—Details of semiconductor or other solid state devices
  • H01L23/52—Arrangements for conducting electric current within the device in operation from one component to another, i.e. interconnections, e.g. wires, lead frames
  • H01L23/538—Arrangements for conducting electric current within the device in operation from one component to another, i.e. interconnections, e.g. wires, lead frames the interconnection structure between a plurality of semiconductor chips being formed on, or in, insulating substrates
  • H01L23/5383—Multilayer substrates
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L23/00—Details of semiconductor or other solid state devices
  • H01L23/48—Arrangements for conducting electric current to or from the solid state body in operation, e.g. leads, terminal arrangements ; Selection of materials therefor
  • H01L23/488—Arrangements for conducting electric current to or from the solid state body in operation, e.g. leads, terminal arrangements ; Selection of materials therefor consisting of soldered or bonded constructions
  • H01L23/495—Lead-frames or other flat leads
  • H01L23/49541—Geometry of the lead-frame
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
  • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
  • H01L2224/42—Wire connectors; Manufacturing methods related thereto
  • H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
  • H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
  • H01L2224/481—Disposition
  • H01L2224/48151—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
  • H01L2224/48221—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
  • H01L2224/48225—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation
  • H01L2224/48227—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation connecting the wire to a bond pad of the item
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
  • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
  • H01L2224/42—Wire connectors; Manufacturing methods related thereto
  • H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
  • H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
  • H01L2224/484—Connecting portions
  • H01L2224/4847—Connecting portions the connecting portion on the bonding area of the semiconductor or solid-state body being a wedge bond
  • H01L2224/48472—Connecting portions the connecting portion on the bonding area of the semiconductor or solid-state body being a wedge bond the other connecting portion not on the bonding area also being a wedge bond, i.e. wedge-to-wedge
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L24/00—Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
  • H01L24/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
  • H01L24/42—Wire connectors; Manufacturing methods related thereto
  • H01L24/47—Structure, shape, material or disposition of the wire connectors after the connecting process
  • H01L24/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
  • H01L2924/0001—Technical content checked by a classifier
  • H01L2924/00014—Technical content checked by a classifier the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
  • H01L2924/01—Chemical elements
  • H01L2924/01014—Silicon [Si]
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
  • H01L2924/01—Chemical elements
  • H01L2924/01057—Lanthanum [La]
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
  • H01L2924/01—Chemical elements
  • H01L2924/01078—Platinum [Pt]
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
  • H01L2924/01—Chemical elements
  • H01L2924/01079—Gold [Au]
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
  • H01L2924/10—Details of semiconductor or other solid state devices to be connected
  • H01L2924/102—Material of the semiconductor or solid state bodies
  • H01L2924/1025—Semiconducting materials
  • H01L2924/10251—Elemental semiconductors, i.e. Group IV
  • H01L2924/10253—Silicon [Si]
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
  • H01L2924/10—Details of semiconductor or other solid state devices to be connected
  • H01L2924/11—Device type
  • H01L2924/12—Passive devices, e.g. 2 terminal devices
  • H01L2924/1203—Rectifying Diode
  • H01L2924/12033—Gunn diode
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
  • H01L2924/10—Details of semiconductor or other solid state devices to be connected
  • H01L2924/11—Device type
  • H01L2924/14—Integrated circuits
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
  • H01L2924/19—Details of hybrid assemblies other than the semiconductor or other solid state devices to be connected
  • H01L2924/191—Disposition
  • H01L2924/19101—Disposition of discrete passive components
  • H01L2924/19107—Disposition of discrete passive components off-chip wires

Definitions

• This invention relates to a Wafer Scale Package System and Header and Method of Manufacture Thereof.
• a driving force between wafer force integration is that when interconnecting substrates are packaged as wafer scale devices the circuit density of the integrated circuits is increased and the distance between logic and between logic and memory become closer increasing reliability and speed.
• mechanical connection between wafers and circuit boards has to be improved in order to take advantage of increasing reliability and speed.
• the wafer scale devices must be connected to the outside world.
• Figures 1 and 1A are respectively a view and section of the preferred embodiment of our wafer scale package system.
• Figure 2 shows an alternate embodiment of Figure 1.
• Figure 3 shows the package system of Figure 1 before it is mounted on the support board.
• Figure 4 shows a wafer package of Figure 3 in partial section taken along line 3-3 of Figure 3.
• Figure 5 shows a section of the header.
• Figure 6 shows a corner portion of the header, while Figure 6A shows a ma sk f or F igure 6 .
• Figure 7 shows the same corner as Figure 6 in a view of the other side of the header in an intermediate step of manufacture.
• Figure 8 shows a finished view of the corner view of Figure 7.
• Figure 9 shows a top view of a wafer which may be used in the wafer scale package system.
• Figure 10 is a microscopic view of the connection edge of the wafer of Figure 9.
• Figure 11 shows a microscopic view like Figure 10, showing a header edge showing alternate bonding.
• Figure 12 is a view like Figure 11 showing primary bonding.
• Figure 13 shows a corner of the header and wafer.
• Figure 14 shows a closer view of the top portion of Figure 13.
• Figure 15 shows a partial side section sketch of the wafer system package of Figure 1.
• Figure 16 shows a partial side section sketch of the wafer system package of Figure 2.
• Figure 17 shows a mechanical schematic of Figures 15 and 16.
• Figure 18 shows a mechanical schematic of Figures 15 and 16 at a higher temperature than Figure 17.
• Figure 19 is a schematic cross-section of a preferred wafer device which is part of the wafer system.
• the wafer 10 is shown in Figure 1.
• the same wafer is shown in Figure in 31 also numbered 10 showing the header 20 before it is mounted on the board carrier 30.
• the wafer itself is generally described with reference to Figure 9 and features of the wafer shown in Figure 9 are shown in Figures 3, 4, 10 and 11-14.
• the wafer is also shown in Figure 2 which discloses our alternative packaging embodiment which is preferred in some situations instead of a preferred embodiment of Figure 1.
• Figure 1A shows a cross section of the preferred embodiment taken along line 1A showing how two wafers are mounted on board 30.
• each wafer has a cell areas 3 on which are mounted or deposited integrated circuits 6 similar to those shown as chips 11. These chips 11 are understood to be either directly formed on the wafer or placed on the wafer and interconnected to the wafer by means of downbonding wires 12. When hybrid circuits are incorporated on a wafer with an interconnection substrate one bonds the wafer to a cell area 3 at bonding points on the interconnection wafer. Interconnecting various circuits as integrated circuits 11 on the wafer are orthogonal lines 8 and 7 representing vertical and horizontal lines acting as padlines or netlines generally referred to as net or network lines, which are formed on the wafer 10. These lines may be programmat ically interconnected at point 9.
• cell areas 6 may be formed on the wafer itself, with- or without the illustrated hybrid circuit configuration, which can be for example monolithic memory which is interconnected to another cell area 3 or 13 via the interconnection lines 7 and 8. These cell areas can also support independent hybrid integrated circuits 11 and interconnected thereto via bond wires 12.
• a header 20 which in turn is connected to a printed circuit board 30 in the form of a wafer scale package system.
• the wafer, header and board package system is shown in Figures 1, 2 and 3 with details shown in additional figures.
• the wafer is mounted backside out on the printed circuit board and connected to the header such that the integrated circuits 6 and 11 are disposed toward the printed circuit board.
• these devices are disposed on the printed circuit board 30 facing outwardly.
• the header 20 is a substantially identical device.
• the cross section of the header 20 is represented generally in Figure 5. It is a flexible circuit intended to facilitate the connections from the wafer scale device to the next higher level of package and/or first wiring on the board 30 as described further herein. It provides at least 800 signal lines including 32 signal ground connections for a net of 768 signal lines as well as additional connections for power ground and power (single voltage).
• the header is fabricated from a thin insulator 21. Preferably manufactured from Kapton or alternatively Mylar and approximately 25 microns, that's 25 urn (1 mil) thickness. This insulator 21 is coated on the top with an adhesive such as Pyralux or its equivalent as adhesive 22 which is approximately also 25 microns (1 mil) thick.
• an adhesive 23 Pyralux or its equivalent, is applied to the bottom of the insulator 21.
• a top conductor 24 is applied to the adhesive 22. This is preferably of copper, approximately 60 microns (2.4 mil) thick. Also preferably made of "one ounce copper”.
• a like bottom conductor 25 is similarly affixed with adhesive 25 to the insulator 21.
• the top surface is flash plated with a top surface plating 26.
• This top surface plating is gold, at least 1.2 micron (50 micro inches) thick, over nickel which is also at least 1.2 micron (50 micro inches) thick.
• bottom surface 27 is similarly Flash plated a bottom surface plating 27 of gold over nickel each approximately 1.2 micron (50 micro inches) thick.
• header 20 While details of the header 20 will be described in greater detail, an understanding of the manufacturing method coupled with the particular features which are important for the header 20 will be first described.
• the top (top means the surface viewing the reader in Figure 1, and hidden from the reader in Figure 2) metal layer, which is preferably in this orientation, predominately a ground plane. is a part of the Figure 1 preferred embodiment which is mounted on the printed circuit board so as to face the reader.
• the bottom layer which is the metal layer carrying signals from the inside or wafer to the outside world is not shown in Figure 1.
• the top layer is shown facing the inside or printed circuit board side of the assembly while the top layer or ground plane is hidden from view.
• preferred embodiment in Figure 1 and the alternate preferred embodiment in Figure 2 show essentially the same header 20.
• the orientation of the header in the different preferred embodiments has significance which will be described below.
• Figure 2B also contains structure used in the manufacturing process of plating and drilling. These process parts are discarded when the header is trimmed to size.
• the signal ground plane is shown in view in Figure 2.
• the first step of the manufacturing process of the header is to prepare a large sheet of material, from which say twenty headers will be fabricated.
• This sheet is a lamina composed of the flexible insulator 21 and the copper layers 24 and 25 including the adhesive layers 22 and 23.
• the ground layer or top layers 24 and the signal ground layers 25 are replicated to produce the multi-header mask used by the manufacturer.
• the insulator layer has holes drilled therethrough. Some of the structures in the signal ground masks are formed with openings 45 as seen in Figure 2B in the metal layers so as to show the location of the holes to be drilled through the insulating layer 22.
• the multi-header single ground mask is used to set up an automatic drilling machine using the openings which will be described.
• the manufacturer may add alignment marks outside the active header area for his own use so that in the manufacturing process alignment holes may be drilled in the sheet in areas which be later discarded.
• an electroless plating process is used to deposit copper in the holes and at least .5 mil of copper is plated on both the sheet and in the holes.
• a photo resist is added to both sides, and exposed using two multi-header masks. Since the openings in. the signal ground layer 25 for drill positions are smaller than the holes drilled in the material, the resist will fill the holes and protect the edges from etching. Both sides of the sheet are then etched in one step, leaving a number of header patterns all of which are temporarily connected together in a single circuit (for additional plating). The resist is then removed.
• Additional copper is plated on the circuit, in part to compensate for undercutting the resist etching, and in part to increase the thickness of the metal lines and the amount of copper in the plated through holes.
• the next step in the plating operation adds the layer of nickel to the circuits. A flash of gold is then added immediately, to preserve the nickel surface. Since gold is so expensive, the ground side 24 is masked to prevent further plating. Additional gold is then plated, to provide a good surface for wire bonding. Then the plating mask for the signal ground side 24 is then removed. Then individual headers are cut from the initial sheet, using either a steel rule die or hard tooling. The initial alignment holes which will be described are also used in this punching operation.
• Figure 6 shows the signal ground layer of the header before it is trimmed. When it is trimmed it follows the drawing shown in Figures 1, 2, 3, and 6.
• Figure 6A also shows a mask of the signal ground layer of the header 20 before it is trimmed which shows in more detail but in negative form the linear side of header 20.
• the header has a group of signal and ground lines which are adapted to be connected to the wafer itself and which run to the outside world.
• Each side of the header has 200 signal lines including 8 signal ground connections.
• the signal lines run directly from inside of the header in parallel and at some point on a V-shaped spreadline 39.
• the direct connect inside signal lines 36 turn at an angle of approximately 120 degrees and continue toward an outside connecting area 37.
• the angular lines 38 then turn at the same angle and connect to bonding pads in the area 37.
• the width of the bonding pads in the area 37 differ. Lines which act as signal ground lines 42 are wider at the outside bonding point, so as to permit a via hole 55 through to the ground plane (the top surface shown in Figure 5) as shown in Figure 3 and 8.
• the other bonding pads 41 which in Figure 6 are approximately twice the width of the signal lines shown as 38 and 36.
• the header is fabricated preferably as a generally rectangular or square shaped final device having alignment holes 33, not through plated, punched in each of the four corners. Each of the four corners has a pattern formed thereon which is substantially identical at each corner.
• the alignment holes 33 that are not through plated are punched out as shown in Figures 3 , 1 and 2. These alignment holes are used to position the header itself in position for soldering onto the printed circuit board 30.
• At each corner are also four through plated holes 51 which are used for power hook-up, and four corner cut-outs 47, to be considered corner apertures. The purpose of them will be described in greater detail hereinafter.
• the corner alignment holes 33 are used for alignment, mounting and for ground hook-up.
• the plated through holes 51 are used for power hook-up to the bottom area 34 and the four corner flexure apertures or cut-outs 47 are utilized for obtaining linear movement of the sides of the header after attachment to board 30 as well as, also importantly, to enable grasping of the header, by a holding fixture during subsequent manufacture.
• the four V-shaped corner cut-outs 47 have a wider section aperture nearer to the center square donut-hole area of the header and are narrower across the edge adjacent the corners. This permits the edge of the wafer 10 to be gripped directly by a fixture in a subsequent manufacturing operation.
• the wafer can be seen in Figure 2 from the bottom side and the wafer can be seen in Figure 1 from the top side.
• the round plated through holes 51 and the four corner cut-outs need not be but can be plated through.
• the header contains 138 small via holes which are used exclusively for electrical connections between the top and bottom metal layers.
• the drill diameter of these holes is approximately 0.5 micrometers or 0.018 inches before plating.
• the holes are plated through and it doesn't matter whether or not the holes are closed by the plating process. Locations of these via holes are marked by holes drill size in the mask to be used for the patterning of the metal layer.
• each side of the header along the outer edge has 8 via holes 55 in Figures 6 and 8 through the signal ground lead 42 on the bottom of the header which connects through to the top ground plane of the header.
• the ground plane is the metal conductor which is shown in detail in Figure 8.
• Figure 7 is a detail formed prior to the use of the blanking die, being representative of an intermediary step in the manufacturing process prior to Figure 8.
• Figure 8 there is shown one corner of the wafer in greater detail which shows a number of via holes.
• each side two of the 8 via holes 55 along the outside edge of the header which connects the center signal ground line of a group of 25 lines to the ground plane which is the top of the header in Figure 1.
• the center lines or signal ground lines do not have a common ground connection at the inner edges of the header. Instead of a ground connection area 49 at the inner edge of the header is each provided with a total of 8 via holes 57 is provided for each of the sides of the four fields with 200 lines each.
• inner corner via holes 57 which connect the power ground bonding area of the back of the header which has the main pattern to the ground plane top of the header seen in Figure 8.
• inner ground via holes 56 which connect to the ground.
• Adjacent the V-shaped corner cut-out on the top side is a round solder splash area separated from the ground plating by a circular area of insulator. The purpose of this is to prevent solder splash from the voltage hole 51 utilized for power hook-up so that it does not connect to ground.
• Figure 2 is a view which shows the lid of the package removed.
• the underlying printed circuit wafer package support and interconnect board is shown as bearing an encapsulated wafer 10 of the hybrid type. This encapsulated wafer bears chips 11 which are downbonded to the wafer 10.
• the printed circuit board 30 is not shown in full detail in Figure 12.
• the header 20 is physically attached to the wafer 10 and adhesively attached to the header is a package side wall 101 to which a lid 105 is attached by a lid adhesive 103. Chips 11 are adhered to the wafer 10 adhesively.
• the bonding points on each chip are connected to a bonding point on the wafer 10 via bond wire 104 and another lead from the wafer 10 is connected to a signal lead 102 by another bond wire.
• the entire device is potted by a polymer encapsulant 106 and the lid adhesively attached.
• the wafer is shown with its face up.
• the wafer has the ground plane of the header up and the patterned signal ground side down, for connection of the lines on the header to the outside world. These may be connected either directly to another port, signal line, or another wafer by a bus structure. This may be inserted into a slot bus fixture to form a main frame. Which of the slot connectors 120 are connect to which bonding pads on the header is a matter of specific adaption to a purpose required of the device.
• Each wafer has a connection rim of a wafer 10 as shown in Figure 9.
• the rim structure area 74 is shown in part in an enlarged size view Figure 10 and also shown in details in Figures 11 and 14.
• Figure 10 is shown a design portion of the rim ' 74 of Figure 9 in which 61 is a primary bonding pad and 62 is a secondary bonding pad which is used for an alternate bonding site in the event there is something wrong with the intended netline 7 or 8 attachment at the primary pad 61 and it is needed to have an external signal at that particular point on the header.
• Probe or bonding points 65 and 66 are additional probe points to check the continuity of the netline 7 or 8 segments, so that one can get on one end, for example at a primary pad 61, and test whether that point can be connected on one other side of the wafer at a probe point 65 on that other side of the wafer. By probing the two points we can verify that the line segment 7 or 8 extending from pad 61 on one side to a test pad 65 on the other is in fact connected with no openings.
• Figures 11 and 14 show bonding at various points at the edge of the wafer to the header.
• Figure 13 a corner which has a ground bonding area 49 to the ground plane and a voltage bond site 34 both of which use a plurality of voltage and ground bond wires 130 and 131.
• Figure 12 shows the number of signal bond wires going from the primary pads directly over to the cross-bonding position 36 on the header.
• Figure 11 also shows an alternate bond wire 134 connecting from a secondary pad 67 to the corresponding position 36 on the header. This is the connection that is used in the event that there is a problem with the netline 7 associated with the primary bonding pad site. We can go to an alternate one to pick up an adjacent redundant netline 137.
• the Figure 14 shows how multiple connections need to be made from the ground point (like the voltage connect point) on the rim 74 from the power point 99 on the rim 44 to the voltage portion 34 on the header. Similarly, the multiple bonds would be made from a similar ground point connection on the rim to the ground point 49 on the patterned surface of the wafer which is connected then to the ground top of the header by way of the via holes 57 as shown in the sketch Figure 13 and Figures 8 and 6.
• Figure 15 is a schematic representation of the mounting of a wafer on a printed circuit board in accordance with Figure 1 while Figure 16 is a similar schematic showing the mounting of the wafer device on a printed circuit board in accordance with Figure 2.
• Figure 18 is a schematic mechanical view of the wafers of Figures 14 and 15 at the time the wafer is mounted on the printed circuit board or at the period of high-temperature operation.
• Figure 17 is a view of the printed circuit board of Figures 14 and 15 when the wafer is in operation in a cooler environment.
• the header 20 is mounted on the printed circuit board 30 with the wafer 10 in place.
• the header and wafer are at the time of mounting in the form as shown in Figure 3.
• the header is bonded to the printed circuit board at, a high temperature so that the header is elongated between printed circuit board bonding point 161 and wafer bonding point 162.
• the header leads are made to contact corresponding leads 20 of the printed circuit board.
• the lines from the wafer 10 exit through the header 20 to the leads 120 on the printed circuit board. There they are connected to the outside world. Mechanically, there may be some thermal difference in the coefficient of expansion between the wafer 10 and the printed circuit board 30.
• the use of the flexible header allows the connection to compensate for changes in temperature.
• Figure 19 is a single drawing illustrating the preferred wafer embodiment of our invention as disclosed in U.S. Serial No. 532391.
• Figure 19 The details of Figure 19 can be understood by those skilled in the art who know that a wafer is usually a very thin cylinder of silicon on which die are deposited. Figure 19 represents a cross section of that silicon wafer and of the other items we use and which we shall describe.
• Connections between the metal layers or between the metal layers and the substrate can be made through via holes in the insulation layer between metals or between layers respectively.
• the real estate of the wafer is divided into special areas called cells and signal hookup areas and power hookup areas are provided.
• the cells were intended to host integrated circuit chips in a hybrid system of chips and metal layers with the interconnections providing signal connections between the chips on the surface.
• this embodiment utilizes a different substrate.
• the preferred substrate has been replaced by a silicon wafer 201 (corresponding to 10) with active die incorporated on it, which die are isolated one from the other, and which each have die contact sites 202 normally used for probing during testing and for bonding during packaging.
• a thin adhesive layer of polyimide resin insulation layer 204 To the wafer 201, and on the upper die carrying surface, has been layered a thin adhesive layer of polyimide resin insulation layer 204.
• This resin during the process of manufacturing the monolithic wafer, is cured and then etched to provide holes through the surface of the wafer to the die contact sites 202 so that these are covered temporarily.
• the resin performs the principal task of smoothing the surface of the wafer, which is important to subsequent processing and improves step coverage.
• a thin film interconnection system 203 of which the prior interconnection system which has bee incorporated by reference as a preferred example, deposited on the insulation layer 204.
• the interconnection system 203 has incorporated therein its own contact sites. On the upper surface are bond contact sites 205, situated at sites suitable for wire bonding. There are probe contact sites 206 suitable for probing with a test probe 215, and there are coupling contact sites 207 suitable for coupling of the interconnection system to the underlying die at die contact site 202. While in general any contact site may be coupled to any contact site, there is a special direct connection 208 between the probe contact sites 206 and the coupling contact sites 207 for the purpose of making direct' test access to the buried contact site of 207 and coupled die contact site 202.
• wafers with isolated die formed thereon are common techniques in the intermediate process of making circuits.
• the wafer of the preferred embodiment is made like these wafers.
• the interconnection system which has been described, is programmable in the manner taught by the aforementioned prior application so that interconnection can be made for signal purposes throughout any or all of the dies on the wafer, which previously had been isolated.
• the underlying die can be a plurality of 64K or 256KRAM die, and these can be unified into a mass memory.
• These die can be unified into a full system, which can include instruction processor chips, I/O interfaces, and many other chips which are required to make a full system.
• the die can be replaced, if not in working order or unwanted, by a substitute die.
• the additional chips used to make a full system or the substitute die can be placed over the die on the wafer by adhesively bonding the downbond hybrid chips 207 carrying the desired circuits where they are placed on the surface on the interconnection system 203.
• a wire bond 211 is made to selected bonding sites, as from a site on the chip 209 to an upper bond contact site 205.
• an upper bond contact site 205 can be used to bond an external wire bond 212 to a printed circuit board 210 but preferably to a header 20.
• Stitch bonds 213 may be made between upper bonding sites 205 of the wafer. All of the interconnections of the system make the wafer into a true monolithic wafer, and when additional or substitute chips are downbonded to the surface of the wafer we consider this a hybrid monolithic wafer system.
• This wafer system is preferably packaged in the system employing the previously described header.

Landscapes

• Physics & Mathematics (AREA)
• Condensed Matter Physics & Semiconductors (AREA)
• General Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Computer Hardware Design (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Power Engineering (AREA)
• Semiconductor Integrated Circuits (AREA)
• Combinations Of Printed Boards (AREA)

Applications Claiming Priority (2)

Related Child Applications (1)

Publications (2)

Family

ID=24327329

Family Applications (1)

Country Status (3)

Families Citing this family (3)

Citations (2)

Family Cites Families (9)

• 1985
  • 1985-02-21 JP JP60500990A patent/JPS61501295A/ja active Granted
  • 1985-02-21 EP EP19850901256 patent/EP0174950A4/de not_active Withdrawn
  • 1985-02-21 WO PCT/US1985/000280 patent/WO1985003804A1/en not_active Application Discontinuation

Patent Citations (2)

Non-Patent Citations (2)

Also Published As

Similar Documents

Legal Events