Classifications

• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W95/00—Packaging processes not covered by the other groups of this subclass
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W74/00—Encapsulations, e.g. protective coatings
  • H10W74/01—Manufacture or treatment
  • H10W74/012—Manufacture or treatment of encapsulations on active surfaces of flip-chip devices, e.g. forming underfills
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W74/00—Encapsulations, e.g. protective coatings
  • H10W74/10—Encapsulations, e.g. protective coatings characterised by their shape or disposition
  • H10W74/15—Encapsulations, e.g. protective coatings characterised by their shape or disposition on active surfaces of flip-chip devices, e.g. underfills
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W70/00—Package substrates; Interposers; Redistribution layers [RDL]
  • H10W70/60—Insulating or insulated package substrates; Interposers; Redistribution layers
  • H10W70/67—Insulating or insulated package substrates; Interposers; Redistribution layers characterised by their insulating layers or insulating parts
  • H10W70/68—Shapes or dispositions thereof
  • H10W70/681—Shapes or dispositions thereof comprising holes not having chips therein, e.g. for outgassing, underfilling or bond wire passage
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W72/00—Interconnections or connectors in packages
  • H10W72/851—Dispositions of multiple connectors or interconnections
  • H10W72/853—On the same surface
  • H10W72/856—Bump connectors and die-attach connectors
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W90/00—Package configurations
  • H10W90/701—Package configurations characterised by the relative positions of pads or connectors relative to package parts
  • H10W90/721—Package configurations characterised by the relative positions of pads or connectors relative to package parts of bump connectors
  • H10W90/724—Package configurations characterised by the relative positions of pads or connectors relative to package parts of bump connectors between a chip and a stacked insulating package substrate, interposer or RDL
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W90/00—Package configurations
  • H10W90/701—Package configurations characterised by the relative positions of pads or connectors relative to package parts
  • H10W90/731—Package configurations characterised by the relative positions of pads or connectors relative to package parts of die-attach connectors
  • H10W90/734—Package configurations characterised by the relative positions of pads or connectors relative to package parts of die-attach connectors between a chip and a stacked insulating package substrate, interposer or RDL
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49002—Electrical device making
  • Y10T29/49117—Conductor or circuit manufacturing
  • Y10T29/49124—On flat or curved insulated base, e.g., printed circuit, etc.
  • Y10T29/4913—Assembling to base an electrical component, e.g., capacitor, etc.
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49002—Electrical device making
  • Y10T29/49117—Conductor or circuit manufacturing
  • Y10T29/49124—On flat or curved insulated base, e.g., printed circuit, etc.
  • Y10T29/4913—Assembling to base an electrical component, e.g., capacitor, etc.
  • Y10T29/49146—Assembling to base an electrical component, e.g., capacitor, etc. with encapsulating, e.g., potting, etc.
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49002—Electrical device making
  • Y10T29/49117—Conductor or circuit manufacturing
  • Y10T29/49124—On flat or curved insulated base, e.g., printed circuit, etc.
  • Y10T29/49155—Manufacturing circuit on or in base
  • Y10T29/49163—Manufacturing circuit on or in base with sintering of base
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49002—Electrical device making
  • Y10T29/49117—Conductor or circuit manufacturing
  • Y10T29/49124—On flat or curved insulated base, e.g., printed circuit, etc.
  • Y10T29/49155—Manufacturing circuit on or in base
  • Y10T29/49165—Manufacturing circuit on or in base by forming conductive walled aperture in base

Definitions

• This invention relates in general to an integrated circuit package, and more particularly, to an integrated circuit package having a substrate vent hole.
• Integrated circuits are typically assembled into a package that is soldered to a printed circuit board.
• Figure 1 illustrates a type of integrated circuit package that is commonly referred to as flip chip of C4 package.
• the integrated circuit 1 contains a number of solder bumps 2 that are soldered to a top surface of a substrate 3.
• the package may include an underfill material 4 that is located between the integrated circuit 1 and the substrate 3.
• the underfill material 4 is typically an epoxy which strengthens the solder joint reliability and the thermo- mechanical moisture stability of the IC package.
• the package may have hundreds of solder bumps 2 arranged in a two- dimensional array across the bottom of the integrated circuit 1.
• the epoxy 4 is typically applied to the solder bump interface by dispensing a single line of uncured epoxy material along one side of the integrated circuit. The epoxy then flows between the solder bumps. The epoxy then flows between the solder bumps. The epoxy must be dispensed in a manner that covers all of the solder bumps 2. It is desirable to dispense the epoxy 4 at only one side of the integrated circuit to insure that air voids are not formed in the underfill. Air voids weaken the structural integrity of the integrated circuit /substrate interface. Such air voids are typically formed from trapped air or from gasses released during the underfill cure process.
• Moisture released during the underfill process may also be absorbed by the substrate, resulting in delamination and other reliability-related failures during the surface mount process. Moreover, the bumps may extrude into the voids during thermal loading, particularly for packages with a relatively high bump density.
• the present invention involves a method of providing an integrated circuit package having a substrate with a vent opening.
• the integrated circuit package includes a substrate having an opening and an integrated circuit mounted to the substrate.
• An underfill material is dispensed between the substrate and the integrated circuit.
• Figure 1 is a side view of an integrated circuit package of the prior art.
• Figure 2A is a top view of an embodiment of an integrated circuit package of the present invention.
• Figure 2B is a bottom view of the integrated circuit package as shown in Figure 2A.
• Figure 3 is an enlarged side view of one embodiment of the integrated circuit package of Figures 2 A and 2B.
• Figures 4A-D are schematics showing a process for assembling the integrated circuit package of Figures 2A and 2B.
• Figures 2A and 2B are respectively, a top and bottom view of an integrated circuit package of the present invention.
• Figure 3 is an enlarged side view of one embodiment of the integrated circuit package of Figures 2A and 2B.
• the package 10 may include a substrate 12 which has a first surface 14 and a second opposite surface 16.
• An integrated circuit 18 may be attached to the first surface 14 of the substrate 12 by a plurality of solder bumps 20.
• the solder bumps 20 may be arranged in a two-dimensional array across the integrated circuit 18 and to the substrate 12 with a process commonly referred to as controlled collapse chip connection (C4).
• C4 controlled collapse chip connection
• the solder bumps 20 may carry electrical current between the integrated circuit 18 and the substrate 12.
• the substrate 12 may include an organic dielectric material.
• the package 10 may include a plurality of solder balls 22 that are attached to the second surface 16 of the substrate 12. The solder balls 22 can be reflowed to attach the package 10 to a printed circuit board (not shown).
• the substrate 12 may contain routing traces, power/ground planes, vias, etc., which electrically connect the solder bumps 20 on the first surface 14 to the solder balls 22 on the second surface 16.
• the substrate 12 also includes a substrate vent opening 15 that is provided through the substrate at a predetermined location. In one embodiment, the substrate vent opening 15 is located at a low stress area of the substrate. In another embodiment, the substrate vent opening 15 is located at the center of the substrate 12. In a further embodiment, the substrate vent opening 15 is sized to provide efficient out- gassing of moisture, while preserving the stability and integrity of the substrate 12. In one embodiment, the substrate opening is selected from a range from 20- 62 mm in diameter, although in alternate embodiments, the size of the substrate vent opening 15 may be determined according to need and other design specifications.
• the package 10 may include an underfill material 24 that is located between the integrated circuit 18 and the substrate 12.
• the underfill material 24 may form a circumferential fillet that surrounds and seals the edges of the IC 18.
• the uniform sealing function of the underfill material 24 may inhibit moisture migration, and cracking of the IC 18.
• the seal process may also reduce delamination.
• the underfill material 24 also reduces stresses on the solder bumps 20.
• the underfill material 24 is an epoxy.
• the integrated circuit 18 may be encapsulated by an encapsulant (not shown).
• the encapsulant may be an injection molded material.
• the package 10 may incorporate a thermal element (not shown) such as a heat slug or a heat sink to remove heat generated by the integrated circuit 18.
• Figures 4A-D illustrates a process for assembling the package 10.
• the process is a single pass four-sided dispensing process.
• the use of a vent hole 15 in implementing the IC package 10 facilitates the use of a single pass four-sided dispensing process.
• a substrate vent opening 15 is first drilled or lazed into the substrate 12 at a predetermined location during the substrate manufacturing process.
• the substrate 12 may then be baked in an oven 28 to remove moisture from the substrate material, as shown in Figure 4A.
• the substrate 12 is preferably baked at a temperature greater than the process temperatures of the underfill process steps to insure that moisture is not released from the substrate 12 in the subsequent steps.
• the substrate 12 may be baked at 163 degrees Centigrade (C).
• the integrated circuit 18 may then be mounted onto the substrate 12, as shown in Figure 4B.
• the integrated circuit 18 is typically mounted by reflowing the solder bumps 20.
• the underfill material 24 may be dispensed onto the substrate 12 along all four sides 26a-d of the IC 18 at a dispensing station 30, as shown in Figures 4C and 4D.
• Figure 4C illustrates the flow of a typical underfill material 24 when the underfill material 24 is dispensed along all four sides 26a-d of the IC 18.
• Figure 4D illustrates a top view of the underfilled IC package 10 having a substrate vent hole 15.
• the underfill material 24 may be dispersed in a manner which creates a fillet that encloses and seals the IC 18.
• One advantage of using the four-sided dispense pattern is that it is able to form a uniform fillet at all four sides of the IC 18. A non-uniform fillet can result to cracking of the IC 18.
• the use of a four sided dispense process typically results in a fillet that provides a tight seal, so that delamination between the IC 18 and the underfill material 24 and /or between the underfill material 24 and the substrate 12 does not occur. This in turn results in strong adhesion between the IC 18 and the underfill material 24 and /or between the underfill material 24 and the substrate 12.
• the process control for forming this uniform fillet is simple and the process yield is high.
• the underfill material 24 may be dispensed at a temperature of approximately 80°-120°C.
• the use of a single pass dispense pattern reduces the underfill material interaction effects of multiple passes. During multiple passes, the underfill material is subjected to heating and gelling before subsequent passes.
• the use of a single pass dispense process results in a more robust process, reduced processing time and eliminates the need for tight material gelling control.
• the underfill material 24 may be cured into a hardened state.
• the underfill material 24 may be cured at a temperature of approximately 150° C. After the underfill material 24 is cured, solder balls 22 can then be attached to the substrate 12, typically with a reflow process, to complete the package 10.
• the implementation of the present invention reduces void formation by allowing out-gassing of trapped air from the center of the substrate 12 when the underfill material 24 is dispensed at four sides of the IC 18.
• the vent hole 15 allows the underfill material 24 to flow under capillary effect before and during the curing process.
• the time control of the underfill material 24 is not as critical as compared to existing processes in which multiple passes are required. This provides the opportunity for eliminating infra red (IR) and /or convective heating, which are typically required in processes utilizing multiple passes, so as to enhance the underfill material 24 flow for subsequent dispense passes.
• IR infra red
• a substrate vent hole 15 also shortens the flow travel distance to half, since a four sided dispense process may be used, as described above. This in turn reduces the time needed for providing a full underfill and thus provides the opportunity for eliminating a flow enhancement heating process, such as the IR and BTU heating processes, after underfill dispensing.
• the use of a vent hole 15 reduces the characterization work needed for underfill process development, which in turn reduces the intense handling and timing interaction associated with the equipment and process. As a result, operational costs are reduced, while manufacturing yields are increased.

Landscapes

• Wire Bonding (AREA)
• Structures Or Materials For Encapsulating Or Coating Semiconductor Devices Or Solid State Devices (AREA)
• Encapsulation Of And Coatings For Semiconductor Or Solid State Devices (AREA)

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Citations (3)

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• 1999
  • 1999-06-11 US US09/330,373 patent/US6490166B1/en not_active Ceased
• 2000
  • 2000-06-05 KR KR10-2001-7015293A patent/KR100456443B1/ko not_active Expired - Fee Related
  • 2000-06-05 IL IL14686500A patent/IL146865A0/xx active IP Right Grant
  • 2000-06-05 HK HK02103549.8A patent/HK1042013B/en not_active IP Right Cessation
  • 2000-06-05 EP EP00943433A patent/EP1186212B1/en not_active Expired - Lifetime
  • 2000-06-05 AU AU57907/00A patent/AU5790700A/en not_active Abandoned
  • 2000-06-05 WO PCT/US2000/040107 patent/WO2000078103A1/en not_active Ceased
  • 2000-06-05 DE DE60026028T patent/DE60026028T2/de not_active Expired - Lifetime
  • 2000-06-05 JP JP2001502624A patent/JP2003501841A/ja active Pending
• 2001
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• 2004
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