National Semiconductor Corporation

Other

Eastman-kodak Company

Shaw Wei Lee

Hem P Takiar

Ashok S Prabhu

Nghia Thuc Tu

Sadanand R Patil

Ranjan J Mathew

Alexander H Owens

Anthony E Panczak

Santhiran S/o Nadarajah

Lim Peng Soon

Glenn Narvaez

Thanh Lequang

Hee Jhin Kim

Anindya Poddar

Jaime A Bayan

Visvamohan Yegnashankaran

Jagdish G Belani

Lee Han Meng @ Eugene Lee

Yee Kim Lee

Fred Drummond

Wayne W Lee

William Jeffery Schaefer

Ein Sun Ng

Ram Veeraraghavan

Chue Siak Liu

Poh Ling Lee

Various semiconductor package arrangements and methods that improve the reliability of wire bonding a die to ground or other outside contacts are described. In one aspect, selected ground pads on the die are wire bonded to a bonding region located on the tie bar portion of the lead frame. The tie bar is connected to an exposed die attach pad that is downset from the bonding region of the tie bar. In some embodiments, the bonding region and the leads are at substantially the same elevation above the die and die attach pad. The die, bonding wires, and at least a portion of the lead frame can be encapsulated with a plastic encapsulant material while leaving a contact surface of the die attach pad exposed to facilitate electrically coupling the die attach pad to an external device.

Leadframe packages having enhanced ground-bond reliability

Techniques for forming micro-array style packages are disclosed. A matrix of isolated contact posts are placed on an adhesive carrier. Dice are then mounted (directly or indirectly) on the carrier and each die is electrically connected to a plurality of associated contacts. The dice and portions of the contacts are then encapsulated in a manner that leaves at least bottom portions of the contacts exposed to facilitate electrical connection to external devices. The encapsulant serves to hold the contacts in place after the carrier has been removed.

Universal lead frame for micro-array packages

A semiconductor device of the invention includes an integrated circuit formed on a semiconductor substrate having first and second surfaces and a notch region along the edges. The first surface includes electrical contact pads electrically connected with the integrated circuit. The first surface of the semiconductor substrate includes a top protective layer that has a surface portion extending beyond the edges of the semiconductor substrate. The second surface of the semiconductor substrate includes a bottom protective layer with electrical connectors. The surface portion of the top protective layer includes electrical contact pads that are electrically interconnected with electrical contact pad extensions. The electrical contact pad extensions are interconnected with electrical connectors via a backside electrical connector that overlaps the electrical contact pad extensions forming a lap connection. Methods for constructing such devices and connections are also disclosed.

Electrical die contact structure and fabrication method

A method and apparatus for making reliable miniature semiconductor packages having a reduced height and footprint is provided. The package includes a semiconductor chip having an active surface and a non-active surface and one or more contacts positioned adjacent the semiconductor chip. Electrical connections are formed between the contacts and the semiconductor chip. An adhesive tape provided adjacent the non-active surface of the semiconductor chip and the one or more contacts positioned adjacent the semiconductor chip. An adhesive material provided between the non-active surface of the chip and the adhesive tape.

Apparatus and method for miniature semiconductor packages

An method and apparatus for fabricating a die having imaging circuitry and fabricating a lid having a transparent region and support regions having a predetermined height. The lid is fabricated by applying a photo-sensitive adhesive layer with a thickness substantially equal to the predetermined height to a transparent plate and patterning the photo-sensitive adhesive layer to form the transparent region and the support regions. Once fabrication of the lid is complete, it is mounted directly onto the die so that the transparent region generally covers the imaging circuitry. The resulting apparatus includes a lid mounted directly onto the die with the transparent region generally positioned above the imaging circuitry. A gap, having a height dimension substantially equal to the predetermined height of the support regions of the lid, is spaced between the transparent region of the lid and the imaging circuitry on the die.

Apparatus and method for packaging image sensing semiconductor chips

A solder pad configuration for use in an IC package is described. Various embodiments of the invention describe IC packages, lead-frames, or substrate panels configured with generally noncircular solder pads at their bottom surfaces. The noncircular shapes allow for greater surface area than circular solder pads having diameters equal to a major dimension of the noncircular shapes, while maintaining the same metal-to-metal clearance between the pads and adjacent leads. This increased surface area provides for stronger and more reliable solder joints.

Solder pad configuration for use in a micro-array integrated circuit package

A method and apparatus for the dicing of semiconductor wafers using pressure to mechanically separate the individual die from the wafer without the use of a wafer saw. The method includes forming trenches along the scribe lines on a semiconductor wafer and then applying a mechanical pressure to the semiconductor wafer. The mechanical pressure causes a 'clean break' of the wafer along the scribe lines, thereby singulating individual die on the wafer. The apparatus comprises a pad for supporting a semiconductor wafer and a positioning member to position the semiconductor wafer on the pad. A pressure mechanism is provided to apply a mechanical pressure to the wafer so as to singulate the individual die on the wafer.

Apparatus and method for dicing semiconductor wafers

An apparatus and method for wafer level packaging of optical imaging die using conventional semiconductor packaging techniques. The method comprises forming spacing structures over imaging circuitry on a plurality of dice on a semiconductor wafer, attaching a transparent template on the spacing structures on the plurality dice on the semiconductor wafer, singulating the plurality of dice on the semiconductor wafer, and packaging the plurality of dice after being singulated from the wafer. The apparatus comprises a semiconductor wafer including a plurality of dice, each of the dice including imaging circuitry and bond pads. A translucent template is positioned over the semiconductor wafer. The translucent plate includes die cover regions configured to cover the imaging circuitry of the dice and recess regions to exposed the bond pads of the dice respectively. The resulting chip, after further packaging steps, includes the substrate, the semiconductor die having imaging circuitry and bond pads, the semiconductor die mounted onto the substrate and the transparent template positioned over the semiconductor die. The transparent template includes the a die cover region configured to be positioned over the imaging circuitry of the semiconductor die and recess regions to expose the bond pads of the semiconductor die.

Apparatus and method for wafer level packaging of optical imaging semiconductor devices

A variety of leadless packaging arrangements and methods of packaging integrated circuits in leadless packages are disclosed. The described lead frames are generally arranged such that each device area has a plurality of contacts but no die attach pad. With this arrangement, the back surface of the die is exposed and coplanar with the exposed bottom surface of the contacts. A casing material (typically plastic) holds the contacts and die in place. In one aspect of the invention, the back surface of the die is metallized. The metallization forms a good attachment surface for the package and serves as a good thermal path to transfer heat away from the die. In another aspect, at least some of the contacts have a top surface, a shelf, and a bottom surface. The die is wire bonded (or otherwise electrically connected) to the shelf portions of the contacts. The described package is quite versatile. In some embodiments, the top surfaces of the contacts are also left exposed which provides a very low profile device that is particularly well suited for stacking. A stack of LLP devices can thus readily be provided or other devices can be stacked on top of the described devices. In some embodiments, a heat sink may be attached directly to the metallized bottom surface of the die or package. This tends to provide a good thermal path from the die. In another aspect of the invention, a lead frame panel suitable for use in packaging these semiconductor devices is described.

Leadless package

Techniques for improving the manufacture and structure of leadframe chip scale packages and land grid array packages are described. One aspect of the invention pertains to a method for patterning a conductive substrate, which is utilized to form a packaged semiconductor device, wherein a metallic barrier layer and a second metallic layer are utilized as an etching resist. A method, according to another aspect of the invention pertains to covering a metallic barrier layer and second metallic layer with a etch resistant cap such that the etch resistant cap is used as a etching resist. In another aspect of the present invention, a method for treating a conductive leadframe with a CZ treatment is disclosed. In yet another aspect of the present invention, techniques relating to locking grooves within the studs of a studded leadframe are disclosed.

Chip scale and land grid array semiconductor packages

A number of techniques and substrate arrangements are described that working individually and in common have been found to significantly improve the environmental resistance of the resulting package. In one aspect, conductive pads (referred to herein as landing pads) on the top surface of a substrate are slightly undercut. This permits molding material applied during later packaging to flow into the undercut regions to help improve adhesion between the substrate and the molding material. In another aspect, metallic die attach pads formed on the substrate are patterned to provide better adhesion between the substrate and a solder mask that covers the die attach pads. More specifically, the metallic die attach pads are patterned to have a number of opening defined therein that leave corresponding portions of the substrate exposed. In substrates where a solder mask is applied over the die attach pad, the openings permit the solder mask to adhere directly to the substrate panel in the openings thereby strengthening the attachment of the solder mask to the substrate. In still another aspect, elongated slots are provided in the solder mask such that the slots expose one or more rows of adjacent landing pads instead of simply the landing pads themselves. With this arrangement, some substrate material between adjacent landing pads is exposed which tends to improve the adhesion of molding material to the substrate.

Substrate for use in semiconductor packaging

A method of forming an integrated circuit package includes providing a flip chip integrating circuit die having a first plurality of contacts for electrically connecting the die to other elements. A second plurality of contacts for electrically connecting the integrated circuit package to external elements is also provided. A substrate for supporting the flip chip die and the second plurality of contacts is initially prepared. The substrate includes a connecting arrangement for electrically connecting the first plurality of contacts on the die to the second plurality of contacts. The method includes the step positioning the flip chip integrated circuit die and the second plurality of contacts on the substrate. With the flip chip die and the second plurality of contacts in position, both the first plurality of contacts on the flip chip die and the second plurality of contacts are simultaneously attached to the substrate thereby electrically connecting the die and the second plurality of contacts to the substrate. In one embodiment, a metal cap is attached to the integrated circuit package to cover and protect the die. In this embodiment, the metal cap may be used to provide a direct thermal path from the die to the external element to which the integrated circuit package is to the connected. An additional heat sink may also be attached to the package.

Manufacturing methods and construction for integrated circuit packages

An assembly process provides a chip scale package (CSP) which characteristically includes (i) a perforated substrate in which vias can be embedded, (ii) a solder mask on which the integrated circuit die can be attached, and (iii) efficient use of the surface area for electrically routing signals from the integrated circuit die to the external terminals attached to the perforated substrate. The resulting package is highly compact and therefore has a foot print minimally larger than the surface area of the integrated circuit chip. Consequently, the costs of substrate and capsulation materials are minimized. The assembly process allows very high volume production because a large number of integrated circuits can be made on a single unit of the substrate, and singulation is performed in the assembly process at a stage much later than the corresponding stage in a conventional process.

Growing community of inventors

Cupertino, CA, United States of America

Shaw Wei Lee