US20010053563A1 - Method for manufacturing a chip scale package having slits formed on a substrate - Google Patents
Method for manufacturing a chip scale package having slits formed on a substrateDownload PDFInfo
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- US20010053563A1 US20010053563A1US09/840,725US84072501AUS2001053563A1US 20010053563 A1US20010053563 A1US 20010053563A1US 84072501 AUS84072501 AUS 84072501AUS 2001053563 A1US2001053563 A1US 2001053563A1
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L23/00—Details of semiconductor or other solid state devices
- H01L23/28—Encapsulations, e.g. encapsulating layers, coatings, e.g. for protection
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L23/00—Details of semiconductor or other solid state devices
- H01L23/28—Encapsulations, e.g. encapsulating layers, coatings, e.g. for protection
- H01L23/31—Encapsulations, e.g. encapsulating layers, coatings, e.g. for protection characterised by the arrangement or shape
- H01L23/3107—Encapsulations, e.g. encapsulating layers, coatings, e.g. for protection characterised by the arrangement or shape the device being completely enclosed
- H01L23/3121—Encapsulations, e.g. encapsulating layers, coatings, e.g. for protection characterised by the arrangement or shape the device being completely enclosed a substrate forming part of the encapsulation
- 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
- H01L2224/26—Layer connectors, e.g. plate connectors, solder or adhesive layers; Manufacturing methods related thereto
- H01L2224/31—Structure, shape, material or disposition of the layer connectors after the connecting process
- H01L2224/32—Structure, shape, material or disposition of the layer connectors after the connecting process of an individual layer connector
- H01L2224/321—Disposition
- H01L2224/32151—Disposition the layer connector 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
- H01L2224/32221—Disposition the layer connector 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
- H01L2224/32225—Disposition the layer connector 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
- 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
- H01L2224/44—Structure, shape, material or disposition of the wire connectors prior to the connecting process
- H01L2224/45—Structure, shape, material or disposition of the wire connectors prior to the connecting process of an individual wire connector
- H01L2224/45001—Core members of the connector
- H01L2224/45099—Material
- H01L2224/451—Material with a principal constituent of the material being a metal or a metalloid, e.g. boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po), and alloys thereof
- 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
- H01L2224/4824—Connecting between the body and an opposite side of the item with respect to the body
- 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
- H01L2224/73—Means for bonding being of different types provided for in two or more of groups H01L2224/10, H01L2224/18, H01L2224/26, H01L2224/34, H01L2224/42, H01L2224/50, H01L2224/63, H01L2224/71
- H01L2224/732—Location after the connecting process
- H01L2224/73201—Location after the connecting process on the same surface
- H01L2224/73215—Layer and wire connectors
- 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
- H01L24/44—Structure, shape, material or disposition of the wire connectors prior to the connecting process
- H01L24/45—Structure, shape, material or disposition of the wire connectors prior to the connecting process of an individual wire connector
- 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
- H01L2924/01079—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
- H01L2924/06—Polymers
- H01L2924/078—Adhesive characteristics other than chemical
- H01L2924/07802—Adhesive characteristics other than chemical not being an ohmic electrical conductor
- 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
- H01L2924/15—Details of package parts other than the semiconductor or other solid state devices to be connected
- H01L2924/151—Die mounting substrate
- H01L2924/153—Connection portion
- H01L2924/1531—Connection portion the connection portion being formed only on the surface of the substrate opposite to the die mounting surface
- H01L2924/15311—Connection portion the connection portion being formed only on the surface of the substrate opposite to the die mounting surface being a ball array, e.g. BGA
Definitions
- This inventionrelates to a semiconductor packaging technology, and in particular to a method for manufacturing chip scale packages.
- a ball grid array (BGA) packageprovides a relatively high surface-mount density and improved electrical performance as compared to conventional plastic packages having a metal lead frame.
- the BGA packageis different from a conventional plastic package in that the electrical connection between the semiconductor chip and the main board is provided by a substrate including multiple layers with circuit patterns instead of the lead frame of the plastic packages.
- the semiconductor chipis attached and electrically connected to a substrate having vias that interconnect electrically conductive traces on the top of the substrate where the chip is attached to terminals on the bottom of the substrate opposite the chip.
- the terminals on the bottom of the substratecan be provided in an array pattern so that the area occupied by the BGA package on a main board is smaller than that of the conventional plastic package with peripheral terminals.
- the substrate used in the BGA packagemay still be larger than the semiconductor chip because an area without conductive traces may be required when attaching the chip to the substrate.
- a further reduction in the size of the BGA packagemay thus be limited.
- the further size reduction of semiconductor chip packageshave been provided by a chip scale package (CSP, also referred to as ‘chip size package’).
- CSPchip scale package
- micro-BGAis a representative chip scale package developed by Tessera.
- the micro-BGAemploys a tape-wiring substrate such as a thin flexible circuit board.
- One of the characteristics of the micro-BGAis that beam leads are bonded to bond pads of the semiconductor chip through a window formed in the tape-wiring substrate all at the same time.
- the wire-bonding-type CSPapplies a wire-bonding technology to ensure reliability of the CSP by replacing beam lead bonding of the micro-BGA with the wire bonding.
- the wire-bonding-type BGAcan be manufactured through the same process, except for wire bonding and plasma cleaning steps.
- FIG. 1shows a cross-sectional view of conventional wire-bonding-type chip scale package.
- a substrate 40is attached by a non-conductive adhesive 30 .
- a wiring pattern 50which may be of copper.
- a photosensitive resin layer 60is deposited and patterned. The photosensitive resin layer 60 is used to prevent the neighboring patterns from being short-circuited and burnt during test processes such as a THB (thermal humidity bias) test.
- Each solder ball 70is bonded to a corresponding solder ball land 55 , which is formed by patterning the wiring pattern 50 and the photosensitive resin layer 60 .
- Bonding wires 80electrically connect the semiconductor chip 10 and the wiring pattern 50 . Thereafter, the bonding wire areas of the semiconductor 10 are encapsulated with an encapsulant 90 .
- the loop height of the bonding wire 80is higher than that of the photosensitive resin layer 60 . Therefore, the encapsulant 90 rises above the top surface of the photosensitive resin layer 60 . This results in an overflow of the encapsulant 90 into the solder ball land 55 , although not shown in FIG. 1. If this happens, before the solder balls 70 are attached to the solder ball lands 55 , the overflowed encapsulant 90 can be stuck to the attached solder balls 70 . This weakens the bonding between the solder balls 70 and the solder ball lands 55 . At worst, this may result in physical detachment of the solder balls 70 from the solder ball lands 55 . Also, an electrical resistance in the solder joint can be increased and testing of the CSP can fail when test pins are repeatedly closed and opened to pick and release the solder balls 70 contaminated with the overflowed encapsulant 90 .
- a method for manufacturing a chip scale package (CSP) including a semiconductor chip and conductive bumpsis disclosed.
- a flexible substrateis provided with a conductive pattern formed thereon.
- the substratehas a top surface and a bottom surface.
- a first photosensitive resin patternis formed over the top surface of the substrate.
- the first photosensitive resin patternis cured.
- a second photosensitive resin patternis formed over the cured first photosensitive resin pattern.
- the second photosensitive resin patternincludes a slit comprising a bottom of the first photosensitive resin pattern and side walls of the second photosensitive resin pattern.
- FIG. 1is a cross-sectional view of a conventional wire-bonding-type chip scale package.
- FIGS. 2 a through 2 hare cross-sectional views of a chip scale package according to this invention and illustrate the flow of the invented manufacturing process thereof.
- FIG. 3is a partial cross-sectional view of a chip scale package according to this invention.
- FIG. 4is a plan top view of a chip scale package according to this invention.
- FIGS. 2 a through 2 hare cross-sectional views for illustrating the manufacturing process of a chip scale package according to the present invention.
- a substrate 145 of the present inventionpreferably comprises a polyimide tape 150 on which conductive wiring patterns 140 are formed.
- the substrate 145may be flexible and provides a base structure to which a semiconductor chip is attached. Any other suitable material other than polyimide can be used for the substrate 145 within the sprit and scope of the present invention.
- the conductive wiring patterns 140can be formed of metal, typically copper.
- a first photosensitive resin layer 160 ais deposited, as shown in FIG. 2 b .
- the first photosensitive resin layer 160 ahas a thickness of at least approximately 3 ⁇ m, e.g. approximately 10 ⁇ m.
- the photosensitive resin layer 160 amay be a PSR4000 series available from Tao Ink in Japan, or any other suitable resin.
- the substrate 145is exposed by using a mask 175 a in which a bonding finger region 142 a and solder ball land regions 144 a and 146 a are defined.
- the bonding finger region 142 adefines where bonding wires are bonded, while the solder ball land regions 144 a and 146 a define where solder balls are bonded.
- the first photosensitive resin pattern 160 bis obtained by developing and etching the exposed first photosensitive resin layer 160 a , as shown in FIG. 2 d . This first photosensitive resin pattern 160 b is cured at high temperature, for example at 150 degrees Celsius.
- a second photosensitive resin 160 cis further deposited on the cured first photosensitive resin pattern 160 b .
- the second photosensitive resin 160 chas a thickness of at least approximately 7 ⁇ m, e.g. approximately 20 ⁇ m.
- the second photosensitive resin 160 cis exposed by using a mask 175 b in which a bonding finger region 142 b , solder ball land regions 144 b and 146 b and a slit region 177 are formed.
- the second photosensitive resin layer 160 cis then developed and etched to form a second photosensitive resin pattern 160 d as shown in FIG. 2 g .
- a slit 165is formed.
- the slit 165comprises a bottom made of the first photosensitive resin pattern 160 b and side walls made of the second photosensitive resin pattern 160 d .
- the slit 165has a recess having a predetermined depth from the top surface of the second photosensitive resin pattern 160 d .
- the predetermined depth of the recesscorresponds to the thickness of the second photosensitive resin pattern 160 d , for example, approximately 20 ⁇ m.
- a portion of the first photosensitive resin pattern 160 b which remains in the slit region 165was cured in the step of FIG. 2 d , and therefore has not been removed during etching of the second photosensitive resin layer 160 c.
- a conductive layer 160 e of e.g., nickel/gold compound metal layeris deposited onto the bonding finger region 167 and the solder ball land regions 155 and 157 as a solder ball land or an under bump metallurgy layer or the like for electrical interconnection and/or mechanical support.
- the substrate 145 for a chip scale packagehas slits on its top surface, which can prevent overflow of an encapsulating material. Moreover, except for the bonding finger region 167 , there is no exposed wiring pattern 140 on the top surface of the substrate. Therefore, the burnt problem of neighboring patterns does not occur during the THB test.
- the THB testis a form of reliability test performed in a high temperature environment, e.g. of 85 Celsius degrees and humidity of e.g., 85% while the semiconductor chip is biased to be in an operational state. If moisture penetrates into the copper patterns 140 during the THB test, the copper may corrode and/or melt to flow out, resulting in short circuits to neighboring copper patterns, thereby burning a portion of the copper patterns 140 black.
- the burning of the copper patternsdoes not occur, because the slits are formed on the substrate 145 such that the copper pattern is covered with the photosensitive resin layer which comprises the bottom surface of the slit.
- FIG. 3is a partial cross-sectional view of a chip scale package according to one embodiment the present invention
- FIG. 4is a top plan view of a chip scale package according to one embodiment of the present invention.
- a substrate 150is attached to an active surface (i.e., on which circuit elements are formed) of a semiconductor chip 110 using a non-conductive adhesive 130 .
- the non-conductive adhesive 130is preferably formed of an elastic material.
- the first and second photosensitive resin patterns 160 b , 160 dare formed overlying the conductive wiring patterns 140 .
- solder balls 170are bonded to corresponding solder ball lands 155 .
- the solder balls 170electrically connect the semiconductor chip 110 with various external devices (not shown).
- the solder balls 170are connected to bond pads 112 of the semiconductor chip 110 via the copper wiring patterns 140 and one or more bonding wires such as wire 180 .
- the semiconductor chip 110 and the conductive wiring patterns 140are electrically connected by bonding metal wires 180 to both a bonding finger region 167 and the bond pads 112 .
- the semiconductor chip 110is encapsulated with an encapsulant 120 , e.g. an epoxy molding compound, and a region where the wires 180 are bonded also is covered with an encapsulant 190 .
- the overflow of the encapsulant 190can be prevented using a slit 165 comprising the bottom made of the first photosensitive resin pattern 160 b and the side walls made of the second photosensitive resin pattern 160 d.
- the height of the loop of the bonding wire 180 in the bonding finger region 167is approximately 60 to 80 ⁇ m.
- the combined thickness of the photosensitive resin patterns 160 b , 160 dis approximately 30 ⁇ m as described with reference to FIG. 2, the height of the encapsulant 190 for covering the bonding wire 180 is inevitably greater than the height of the top surface of the second photosensitive resin pattern 160 d . This can result in the overflow of the encapsulant 190 onto the second photosensitive resin 160 .
- a printing techniquemay be used for depositing the encapsulant 190 .
- the printing techniquehas some drawbacks in that it requires expensive equipment and labors.
- the overflow problem of the encapsulant or mold resincan be solved without using an expensive printing technique.
- the flow of the encapsulantapproximately stops at the slit 165 and does not fill the slit 165 , because of the surface tension of the encapsulant 190 . Therefore, the bottom surface of the slit 165 is exposed without being covered with the encapsulant 190 . Because the bottom surface of the slit 165 is exposed, curing of the first photosensitive resin pattern 160 d illustrated in the step of FIG. 2 d is important.
- the slit 165 of the present inventionsplits divides the photosensitive resin patterns 160 b , 160 d in a direction parallel to the direction along which bond pads 112 are arranged.
- an overflow of the encapsulant into the solder ball land region 155can be prevented.
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- Computer Hardware Design (AREA)
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Abstract
Description
- 1. Technical Field of the Invention[0001]
- This invention relates to a semiconductor packaging technology, and in particular to a method for manufacturing chip scale packages.[0002]
- 2. Description of Related Art[0003]
- It has long been desired to produce semiconductor chips that are lighter, smaller, and having higher speed, multi-function and improved reliability at low costs. Various packaging technologies have been developed to address these needs. For example, a ball grid array (BGA) package provides a relatively high surface-mount density and improved electrical performance as compared to conventional plastic packages having a metal lead frame.[0004]
- The BGA package is different from a conventional plastic package in that the electrical connection between the semiconductor chip and the main board is provided by a substrate including multiple layers with circuit patterns instead of the lead frame of the plastic packages. In the BGA package, the semiconductor chip is attached and electrically connected to a substrate having vias that interconnect electrically conductive traces on the top of the substrate where the chip is attached to terminals on the bottom of the substrate opposite the chip. The terminals on the bottom of the substrate can be provided in an array pattern so that the area occupied by the BGA package on a main board is smaller than that of the conventional plastic package with peripheral terminals.[0005]
- The substrate used in the BGA package, however, may still be larger than the semiconductor chip because an area without conductive traces may be required when attaching the chip to the substrate. A further reduction in the size of the BGA package may thus be limited. In response, the further size reduction of semiconductor chip packages have been provided by a chip scale package (CSP, also referred to as ‘chip size package’).[0006]
- In recent years, various CSP models have been introduced by several semiconductor manufacturers in the USA Japan and Korea, and the development for the new form of the CSP is under way. Among them, the micro-BGA (μBGA) is a representative chip scale package developed by Tessera. The micro-BGA employs a tape-wiring substrate such as a thin flexible circuit board. One of the characteristics of the micro-BGA is that beam leads are bonded to bond pads of the semiconductor chip through a window formed in the tape-wiring substrate all at the same time.[0007]
- However, as the semiconductor chip scales further down, it has become more difficult for the micro-BGA to accommodate fine pitch and arrangement of the bond pads in two rows. In response to these problems, a wire-bonding-type CSP has been introduced. The wire-bonding-type CSP applies a wire-bonding technology to ensure reliability of the CSP by replacing beam lead bonding of the micro-BGA with the wire bonding. The wire-bonding-type BGA can be manufactured through the same process, except for wire bonding and plasma cleaning steps.[0008]
- FIG. 1 shows a cross-sectional view of conventional wire-bonding-type chip scale package.[0009]
- To an active surface of a[0010]
semiconductor chip 10, asubstrate 40 is attached by anon-conductive adhesive 30. On the surface of thesubstrate 40 is formed awiring pattern 50, which may be of copper. Aphotosensitive resin layer 60 is deposited and patterned. Thephotosensitive resin layer 60 is used to prevent the neighboring patterns from being short-circuited and burnt during test processes such as a THB (thermal humidity bias) test. Eachsolder ball 70 is bonded to a correspondingsolder ball land 55, which is formed by patterning thewiring pattern 50 and thephotosensitive resin layer 60.Bonding wires 80 electrically connect thesemiconductor chip 10 and thewiring pattern 50. Thereafter, the bonding wire areas of thesemiconductor 10 are encapsulated with an encapsulant90. - However, in the conventional wire-bonding-[0011]
type CSP 100, the loop height of thebonding wire 80 is higher than that of thephotosensitive resin layer 60. Therefore, theencapsulant 90 rises above the top surface of thephotosensitive resin layer 60. This results in an overflow of theencapsulant 90 into thesolder ball land 55, although not shown in FIG. 1. If this happens, before thesolder balls 70 are attached to thesolder ball lands 55, the overflowed encapsulant90 can be stuck to the attachedsolder balls 70. This weakens the bonding between thesolder balls 70 and thesolder ball lands 55. At worst, this may result in physical detachment of thesolder balls 70 from thesolder ball lands 55. Also, an electrical resistance in the solder joint can be increased and testing of the CSP can fail when test pins are repeatedly closed and opened to pick and release thesolder balls 70 contaminated with theoverflowed encapsulant 90. - Accordingly, it is an object of this invention to provide a method for manufacturing a chip scale package having a structure capable of preventing an overflow of an encapsulant.[0012]
- It is another object of this invention to provide a method for manufacturing a chip scale package, which can overcome the problem of burning of neighboring patterns.[0013]
- According to one aspect of this invention, a method for manufacturing a chip scale package (CSP) including a semiconductor chip and conductive bumps is disclosed. In one embodiment of the present invention, a flexible substrate is provided with a conductive pattern formed thereon. The substrate has a top surface and a bottom surface. Then, a first photosensitive resin pattern is formed over the top surface of the substrate. Next, the first photosensitive resin pattern is cured. Subsequently, a second photosensitive resin pattern is formed over the cured first photosensitive resin pattern. The second photosensitive resin pattern includes a slit comprising a bottom of the first photosensitive resin pattern and side walls of the second photosensitive resin pattern.[0014]
- These and other features, and advantages, will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings. It is important to point out that the illustrations may not necessarily be drawn to scale, and that there may be other embodiment of this invention, which is not specifically illustrated.[0015]
- FIG. 1 is a cross-sectional view of a conventional wire-bonding-type chip scale package.[0016]
- FIGS. 2[0017]athrough2hare cross-sectional views of a chip scale package according to this invention and illustrate the flow of the invented manufacturing process thereof.
- FIG. 3 is a partial cross-sectional view of a chip scale package according to this invention.[0018]
- FIG. 4 is a plan top view of a chip scale package according to this invention.[0019]
- FIGS. 2[0020]athrough2hare cross-sectional views for illustrating the manufacturing process of a chip scale package according to the present invention.
- As shown in FIG. 2[0021]a, a substrate145 of the present invention preferably comprises a
polyimide tape 150 on whichconductive wiring patterns 140 are formed. The substrate145 may be flexible and provides a base structure to which a semiconductor chip is attached. Any other suitable material other than polyimide can be used for the substrate145 within the sprit and scope of the present invention. Theconductive wiring patterns 140 can be formed of metal, typically copper. Over a portion of the top of the substrate145, a firstphotosensitive resin layer 160ais deposited, as shown in FIG. 2b. The firstphotosensitive resin layer 160ahas a thickness of at least approximately 3 μm, e.g. approximately 10 μm. Thephotosensitive resin layer 160amay be a PSR4000 series available from Tao Ink in Japan, or any other suitable resin. - In FIG. 2[0022]c, the substrate145 is exposed by using a
mask 175ain which abonding finger region 142aand solderball land regions 144aand146aare defined. Thebonding finger region 142adefines where bonding wires are bonded, while the solderball land regions 144aand146adefine where solder balls are bonded. The firstphotosensitive resin pattern 160bis obtained by developing and etching the exposed firstphotosensitive resin layer 160a, as shown in FIG. 2d. This firstphotosensitive resin pattern 160bis cured at high temperature, for example at 150 degrees Celsius. - Now referring to FIG. 2[0023]e, a second
photosensitive resin 160cis further deposited on the cured firstphotosensitive resin pattern 160b. The secondphotosensitive resin 160chas a thickness of at least approximately 7 μm, e.g. approximately 20 μm. - In FIG. 2[0024]f, the second
photosensitive resin 160cis exposed by using a mask175bin which a bonding finger region142b, solderball land regions slit region 177 are formed. - The second[0025]
photosensitive resin layer 160cis then developed and etched to form a secondphotosensitive resin pattern 160das shown in FIG. 2g. In this pattern formation step, aslit 165 is formed. Theslit 165 comprises a bottom made of the firstphotosensitive resin pattern 160band side walls made of the secondphotosensitive resin pattern 160d. Further, theslit 165 has a recess having a predetermined depth from the top surface of the secondphotosensitive resin pattern 160d. The predetermined depth of the recess corresponds to the thickness of the secondphotosensitive resin pattern 160d, for example, approximately 20 μm. A portion of the firstphotosensitive resin pattern 160bwhich remains in theslit region 165 was cured in the step of FIG. 2d, and therefore has not been removed during etching of the secondphotosensitive resin layer 160c. - Finally, as shown in FIG. 2[0026]h, a
conductive layer 160eof e.g., nickel/gold compound metal layer is deposited onto thebonding finger region 167 and the solderball land regions - According to the present invention, then the substrate[0027]145 for a chip scale package has slits on its top surface, which can prevent overflow of an encapsulating material. Moreover, except for the
bonding finger region 167, there is no exposedwiring pattern 140 on the top surface of the substrate. Therefore, the burnt problem of neighboring patterns does not occur during the THB test. The THB test is a form of reliability test performed in a high temperature environment, e.g. of 85 Celsius degrees and humidity of e.g., 85% while the semiconductor chip is biased to be in an operational state. If moisture penetrates into thecopper patterns 140 during the THB test, the copper may corrode and/or melt to flow out, resulting in short circuits to neighboring copper patterns, thereby burning a portion of thecopper patterns 140 black. - However, with the present invention, the burning of the copper patterns does not occur, because the slits are formed on the substrate[0028]145 such that the copper pattern is covered with the photosensitive resin layer which comprises the bottom surface of the slit.
- FIG. 3 is a partial cross-sectional view of a chip scale package according to one embodiment the present invention, and FIG. 4 is a top plan view of a chip scale package according to one embodiment of the present invention.[0029]
- Referring to FIG. 3, a[0030]
substrate 150 is attached to an active surface (i.e., on which circuit elements are formed) of asemiconductor chip 110 using anon-conductive adhesive 130. Thenon-conductive adhesive 130 is preferably formed of an elastic material. - The first and second[0031]
photosensitive resin patterns conductive wiring patterns 140. Also,solder balls 170 are bonded to corresponding solder ball lands155. Thesolder balls 170 electrically connect thesemiconductor chip 110 with various external devices (not shown). Thesolder balls 170 are connected to bondpads 112 of thesemiconductor chip 110 via thecopper wiring patterns 140 and one or more bonding wires such aswire 180. Thesemiconductor chip 110 and theconductive wiring patterns 140 are electrically connected by bondingmetal wires 180 to both abonding finger region 167 and thebond pads 112. Thesemiconductor chip 110 is encapsulated with anencapsulant 120, e.g. an epoxy molding compound, and a region where thewires 180 are bonded also is covered with anencapsulant 190. - As shown in FIG. 3, the overflow of the[0032]
encapsulant 190 can be prevented using aslit 165 comprising the bottom made of the firstphotosensitive resin pattern 160band the side walls made of the secondphotosensitive resin pattern 160d. - Generally, the height of the loop of the[0033]
bonding wire 180 in thebonding finger region 167 is approximately 60 to 80 μm. However, because the combined thickness of thephotosensitive resin patterns encapsulant 190 for covering thebonding wire 180 is inevitably greater than the height of the top surface of the secondphotosensitive resin pattern 160d. This can result in the overflow of theencapsulant 190 onto the secondphotosensitive resin 160. - Therefore, a solution to such an overflow problem has been needed. A printing technique may be used for depositing the[0034]
encapsulant 190. However, the printing technique has some drawbacks in that it requires expensive equipment and labors. - In accordance with the present inventive structure having a slit between the[0035]
bond finger region 167 and thesolder ball land 155, the overflow problem of the encapsulant or mold resin can be solved without using an expensive printing technique. The flow of the encapsulant approximately stops at theslit 165 and does not fill theslit 165, because of the surface tension of theencapsulant 190. Therefore, the bottom surface of theslit 165 is exposed without being covered with theencapsulant 190. Because the bottom surface of theslit 165 is exposed, curing of the firstphotosensitive resin pattern 160dillustrated in the step of FIG. 2dis important. - As shown in FIG. 4, the[0036]
slit 165 of the present invention splits divides thephotosensitive resin patterns bond pads 112 are arranged. Thus, an overflow of the encapsulant into the solderball land region 155 can be prevented. - In the drawings and specification, there have been disclosed typical preferred embodiments of this invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of this invention being set forth in the following claims.[0037]
Claims (20)
1. A method for manufacturing a chip scale package (CSP) including a semiconductor chip and conductive bumps, comprising:
providing a flexible substrate with a conductive pattern formed thereon, the substrate having a top surface and a bottom surface;
forming a first photosensitive resin pattern over the top surface of the substrate;
curing the first photosensitive resin pattern; and
forming a second photosensitive resin pattern over the cured first photosensitive resin pattern, the second photosensitive resin pattern including a slit comprising a bottom of the first photosensitive resin pattern and side walls of the second photosensitive resin pattern; the first and second photosensitive resin patterns having an opening therein to expose the conductive pattern for electrical interconnection.
2. The method as claimed in
claim 1
3. A method as claimed in
claim 2
attaching the semiconductor chip onto the bottom surface of the substrate, so that an active surface of the semiconductor chip is partially exposed from the substrate;
electrically interconnecting the semiconductor chip and the conductive pattern; and
encapsulating a portion of the exposed active surface of the semiconductor chip.
4. The method as claimed in
claim 3
5. The method as claimed in
claim 3
6. The method as claimed in
claim 1
7. The method as claimed in
claim 1
8. The method as claimed in
claim 1
9. The method as claimed in
claim 1
forming a first photosensitive resin layer,
exposing, developing and etching the deposited first photoresist resin layer.
10. A method as claimed in
claim 3
11. A method as claimed in
claim 3
13. The method as claimed in
claim 1
14. The method as claimed in
claim 3
15. A method for manufacturing a chip scale package (CSP) including a semiconductor chip and conductive bumps, comprising:
providing a flexible substrate with a conductive pattern formed thereon, the substrate having a top surface and a bottom surface;
forming a photosensitive resin pattern over the top surface of the substrate, the photosensitive resin pattern including an encapsulant-overflow-resistant gap comprising a bottom and side walls of the photosensitive resin pattern; the photosensitive resin pattern having an opening therein to expose the conductive pattern for electrical interconnection.
16. The method as claimed in
claim 15
17. A method as claimed in
claim 15
attaching the semiconductor chip onto the bottom surface of the substrate, so that an active surface of the semiconductor chip is partially exposed from the substrate;
electrically interconnecting the semiconductor chip and the conductive pattern; and
encapsulating a portion of the exposed active surface of the semiconductor chip.
18. The method as claimed in
claim 17
19. The method as claimed in
claim 17
20. The method as claimed in
claim 19
21. The method as claimed in
claim 15
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR00-33815 | 2000-06-20 | ||
| KR1020000033815AKR20020000012A (en) | 2000-06-20 | 2000-06-20 | Method for manufacturing chip scale package having slits |
| KR2000-33815 | 2000-06-20 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| US20010053563A1true US20010053563A1 (en) | 2001-12-20 |
| US6432746B2 US6432746B2 (en) | 2002-08-13 |
Family
ID=19672689
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US09/840,725Expired - Fee RelatedUS6432746B2 (en) | 2000-06-20 | 2001-04-23 | Method for manufacturing a chip scale package having slits formed on a substrate |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US6432746B2 (en) |
| KR (1) | KR20020000012A (en) |
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| US20030164541A1 (en)* | 2002-03-04 | 2003-09-04 | Lee Teck Kheng | Method and apparatus for dielectric filling of flip chip on interposer assembly |
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| US20050029550A1 (en)* | 2002-03-04 | 2005-02-10 | Lee Teck Kheng | Semiconductor die packages with recessed interconnecting structures |
| SG111935A1 (en)* | 2002-03-04 | 2005-06-29 | Micron Technology Inc | Interposer configured to reduce the profiles of semiconductor device assemblies and packages including the same and methods |
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| US7320933B2 (en) | 2002-08-20 | 2008-01-22 | Micron Technology, Inc. | Double bumping of flexible substrate for first and second level interconnects |
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| KR101614856B1 (en)* | 2009-10-12 | 2016-04-22 | 삼성전자주식회사 | Wiring substrate for a semiconductor chip, semiconductor package having the wiring substrate and method of manufacturing the semiconductor package |
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Also Published As
| Publication number | Publication date |
|---|---|
| KR20020000012A (en) | 2002-01-04 |
| US6432746B2 (en) | 2002-08-13 |
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