JP2005183879A - High heat radiation type plastic package - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high heat radiation type plastic package in which cutting quality when cutting an aggregate into independent parts is excellent, and cost is inexpensive. <P>SOLUTION: In a high heat radiation type plastic package 10 which has an internal layer Cu foil layer 14 between a plurality of resin core substrate 13, and is formed by dividing an aggregate 12, in which plural parts including a dummy portion 11 adjacently stand in a row, into each rectangular independent part, a thickness of the internal layer Cu foil layer 14 is 25μm or more, and the internal layer Cu foil layer 14 at a location through which a cutting blade 16 for dividing the aggregate 12 into the each independent part is removed in such a dimension that it is 90 to 100% of an outline length of the internal layer Cu foil layer 14 including the dummy portion 11, and that a width more greater than that of the cutting blade 16 simultaneously. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a high heat dissipation plastic package for mounting a semiconductor element, and more specifically, a high heat dissipation type having a relatively thick inner layer Cu foil or Cu core substrate for efficiently dissipating heat generated from the semiconductor element. It relates to plastic packages.

  In recent years, plastic packages for mounting semiconductor elements have increased the amount of heat generated from the semiconductor elements as the performance and miniaturization of the semiconductor elements increase, the number of terminals for connecting to the outside, and the mounting of semiconductor elements BGA (Ball Grid Array) type high heat dissipation plastic packages having a high heat dissipation structure with a devised package structure are often used from the viewpoints of performance, cost reduction, impedance reduction, and the like.

  As shown in FIG. 3A, a conventional typical high heat radiation type plastic package 50 has a high heat resistance resin substrate 51 composed of one layer or multiple layers having a conductor wiring pattern (not shown) on one side or both sides. In addition, a heat radiating plate 52 made of a metal plate such as Cu having high thermal conductivity is joined through an adhesive 53 such as a prepreg. The resin substrate 51 has a cutout portion 56 for the cavity portion 55 for mounting the semiconductor element 54 in a substantially central portion in plan view. The semiconductor element 54 is mounted on the heat dissipation plate 52 which becomes the bottom surface of the cavity portion 55 and is exposed with the cutout portion 56 of the resin substrate 51 as an opening. The semiconductor element 54 and the conductor wiring pattern on the upper surface of the resin substrate 51 are connected by bonding wires 57 and are electrically connected. The semiconductor element 54, the bonding wire 57, and the like are hermetically sealed with a sealing resin 58 in order to protect them from the external environment. On the conductor wiring pattern on the upper surface of the resin substrate 51, a solder resist film that is electrically connected to the conductor wiring pattern and exposes external connection terminal pads (not shown) for joining the external connection terminals 59 from the openings. 60 is formed. The external connection terminal 59 made of a solder ball or the like is electrically connected to the semiconductor element 54 via the conductor wiring pattern and the bonding wire 57 by being bonded to the external connection terminal pad. Since the semiconductor element 54 can be mounted in direct contact with the heat sink 52 in the high heat dissipation plastic package 50, the heat generated from the semiconductor element 54 can be efficiently radiated to the outside through the heat sink 52. The high heat dissipation plastic package 50 is a cavity down type in which the semiconductor element 54 and the external connection terminal 59 are provided on the same main surface side.

  However, in the high heat dissipation type plastic package 50, the thickness of the heat dissipation plate 52 is increased or the adhesive material such as the prepreg is increased. This is an obstacle to the use of electronic devices such as personal computers. In addition, since the package form is a cavity down type, the interval when the external connection terminal 59 is joined to a board or the like is narrowed, and there is a problem in the joining reliability of the joining portion. Therefore, as shown in FIG. 3B, the high heat radiation type plastic package 50a is formed by bonding Cu foil to both surfaces of one or a plurality of resin core substrates 51a, Cu foil to the inner layer, and further forming from Cu foil. In order to efficiently dissipate heat generated from the semiconductor element 54 to the lower surface side of the resin core substrate 51a, the upper and lower conductor wiring patterns 61 and 61 are provided. Some have thermal vias 62 for connecting the patterns 61 and 61a. In this high heat radiation type plastic package 50a, necessary portions of the conductor wiring patterns 61, 61a are exposed as openings to form the solder resist film 60, or the upper and lower conductor wiring patterns 61, 61a are electrically connected. For example, by providing conductive vias 63 for the purpose, a cavity-up type is provided in which the semiconductor element 54 and the external connection terminal 59 are provided on opposite surfaces.

In order to change from an assembly in which a plurality of packages are arranged adjacent to each other to a single-piece plastic package, a semiconductor element is mounted in the state of the assembly, and then the conductor wiring is performed from the upper surface of the sealing resin with the first dicing blade. There has been proposed a method in which a pattern is cut and a resin substrate is cut with a second dicing blade (see, for example, Patent Document 1). Also, a plastic package is proposed that is formed by cutting with reference to a cutting guide mark having a width larger than the cutting cutting edge width provided in the dummy portion in order to change the package from an aggregate to a single piece. (For example, refer to Patent Document 2). Furthermore, a package using a metal core as a core substrate has also been proposed as a high heat dissipation plastic package (see, for example, Patent Document 3).
JP 2000-183218 A JP 2002-16172 A JP 7-321250 A

However, the conventional high heat dissipation plastic package as described above has the following problems.
(1) A high heat dissipation plastic package formed on both sides of a resin core substrate or a Cu foil bonded between a plurality of resin core substrates has a sufficient heat dissipation effect because the Cu foil is thin. However, there is a limit in heat dissipation depending on the semiconductor element to be mounted.
(2) High heat dissipation plastic packages with a thick Cu foil and high heat dissipation plastic packages using a metal plate with good thermal conductivity as the core material are used to change the package from a single piece to a single piece. In addition, since cutting is performed by a rotating method such as a dicing saw, in order to cut a relatively thick Cu foil or metal core with a cutting blade, the cutting resistance is high and the cutting blade wears heavily. As a result of burrs and the like on the cut surface due to a defect in the cutting edge, quality and yield are reduced. Also, frequent cutting blade replacement due to cutting blade wear increases the cutting blade cost and the time required for cutting processing, increasing the cost for cutting and increasing the cost of high heat dissipation plastic packages. It has become.
The present invention has been made in view of such circumstances, and an object of the present invention is to provide an inexpensive high heat radiation type plastic package which has good cutting quality when the aggregate is separated into individual pieces.

  The high heat radiation type plastic package according to the present invention that meets the above-mentioned object has an inner layer Cu foil layer between a plurality of resin core substrates, and each of the quadrangular shapes from an assembly in which a plurality including a dummy portion are arranged adjacent to each other. In a high heat dissipation type plastic package formed by dividing into individual pieces, the inner layer Cu foil layer has a thickness of 25 μm or more, and passes through a cutting blade for dividing the aggregate into individual pieces. The inner layer Cu foil layer is removed with a width of 90 to 100% of the outer length of the inner layer Cu foil layer including the dummy portion, and more than the cutting edge width.

  Another high heat radiation type plastic package according to the present invention that meets the above-mentioned object has a Cu core substrate coated with a resin base material, and a plurality of adjacent squares including a dummy portion are arranged from respective assemblies. In a high heat dissipation plastic package formed by dividing into individual pieces, the location where the thickness of the Cu core substrate is 80 μm or more, and a cutting blade for dividing the aggregate into individual pieces is passed through The Cu core substrate is removed with 90 to 98% of the external length of the Cu core substrate including the dummy portion, and with a width larger than the cutting edge width.

  The high heat radiation type plastic package according to claim 1, wherein the inner layer Cu foil layer has a thickness of 25 μm or more, and the inner layer Cu foil layer in a place through which a cutting cutting blade for dividing the aggregate into individual pieces is passed. , 90-100% of the outer length of the inner layer Cu foil layer including the dummy portion is removed with a width larger than the cutting edge width, so that the cutting edge contacts the thick inner layer Cu foil. Therefore, it is possible to manufacture a single-piece package from the assembly with a small amount of manufacturing, and it is possible to provide an inexpensive high heat radiation type plastic package with good quality and high yield.

  The high heat radiation type plastic package according to claim 2, wherein the Cu core substrate has a thickness of 80 μm or more, and the Cu core substrate at a location through which cutting blades for dividing the aggregate into individual pieces are passed is a dummy. 90% to 98% of the external length of the Cu core substrate including the portion, and more than the cutting cutting edge width, the cutting cutting blade comes into contact with the thick Cu core substrate. A package of individual pieces can be manufactured from the assembly with a small amount, and an inexpensive high heat radiation type plastic package with good quality and good yield can be provided.

Subsequently, the best mode for carrying out the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention.
1A to 1C are respectively a top plan view, a bottom plan view, a longitudinal sectional view, and a vertical sectional view of a high heat dissipation plastic package according to an embodiment of the present invention. C) is a top plan view, a bottom plan view, and a longitudinal sectional view, respectively, of a high heat dissipation plastic package according to another embodiment of the present invention.

  As shown in FIGS. 1A to 1C, a high heat radiation type plastic package 10 according to an embodiment of the present invention includes a dummy portion 11 and a plurality of adjacent ones in a matrix shape or a strip shape. It is formed by dividing the assembly 12 to be divided into high-radiation plastic packages 10 each having a rectangular shape in plan view. The support for forming the aggregate 12 of the high heat dissipation plastic package 10 is a plurality of resin cores using BT resin (resin containing bis-maleimide triazine as a main component) or polyimide resin as a sheet-like base material. A relatively thick inner layer Cu foil layer 14 having a thickness of 25 μm or more is provided between the resin core substrates 13. Moreover, a relatively thin Cu foil having a thickness of about 10 to 20 μm, for example, is bonded to one or both sides of the outer surface side of the uppermost resin core substrate 13 and the lowermost resin core substrate 13, A Cu plating film is further provided thereon by electroless plating and electrolytic plating, and a conductor wiring pattern 15 is formed using a photolithography method and an etching method. The inner Cu foil layer 14 between the resin core substrates 13 is provided with a cutting edge 16 such as a dicing saw for dividing the aggregate 12 into high-radiation plastic packages 10 each having a rectangular shape. It has a portion where 90 to 100% of the outer length of the inner layer Cu foil layer 14 including the dummy portion 11 is removed by a photolithography method and an etching method in a place where it passes. In addition, the width dimension a of the removed portion has a width greater than or equal to the width dimension b of the cutting edge 16.

  Further, the high heat dissipation plastic package 10 is provided with a solder resist film 17 that exposes a necessary portion of the conductor wiring pattern 15 from the opening. In the case where the conductive wiring pattern 15 is provided on the upper and lower surfaces of the high heat radiation type plastic package 10, through holes are formed in the respective resin core substrates 13 and Cu is plated on the wall surfaces of the through holes in order to establish electrical continuity between the patterns. The conductive via 18 is formed by providing a film. In addition, the high heat dissipation plastic package 10 has thermal vias 20 formed by providing through holes in each resin core substrate 13 in order to dissipate heat from the lower surface of the resin core substrate 13 where the semiconductor element 19 is mounted. Have.

  This high heat radiation type plastic package 10 is usually formed as a cavity-up type package, in which the semiconductor element 19 and the conductor wiring pattern 15 on the upper surface side are joined by the bonding wires 21 on the upper surface side, and the lower surface side on the lower surface side. An external connection terminal 22 made of, for example, solder balls or the like is joined to the conductor wiring pattern 15 so that the semiconductor element 19 and the external connection terminal 22 are electrically connected. In addition, after the semiconductor element 19 is mounted on the upper surface side of the high heat radiation type plastic package 10, a sealing resin 23 is provided so as to cover the semiconductor element 19, the bonding wire 21, and the like. 21 etc. are protected from the outside air and hermetically sealed. Then, the assembly 12 of the high heat dissipation plastic package 10 on which the semiconductor elements 19 and the like are mounted is divided at a place where a cutting edge 16 such as a dicing saw passes, so that the semiconductor elements 19 and the like are mounted. A high heat radiation type plastic package 10 made of a single body is produced. Note that a connection terminal similar to the external connection terminal 22 is joined to the thermal via 20 in order to dissipate heat generated from the semiconductor element 19 through the thermal via 20.

  If the thickness of the inner Cu foil layer 14 of the high heat dissipation plastic package 10 is less than 25 μm, the heat dissipation effect is reduced, and efficient heat dissipation cannot be ensured. Further, the length of the inner layer Cu foil layer 14 existing where the cutting edge 16 for dividing the individual piece from the assembly 12 passes is the outer length of the inner layer Cu foil layer 14 including the dummy portion 11. If it exceeds 10% or the width dimension a of the removed portion of the inner Cu foil layer 14 is smaller than the width dimension b of the cutting blade 16, the quality of the cut portion when cutting with the cutting blade 16 is deteriorated.

  Next, as shown in FIGS. 2A to 2C, a plurality of high heat radiation type plastic packages 10a according to other embodiments of the present invention include a dummy shape 11 and a matrix shape or a strip shape. Are divided into high-radiation type plastic packages 10a each having a rectangular shape in plan view from the assembly 12 arranged adjacent to each other. The support for forming the aggregate 12 of the high heat radiation type plastic package 10a is a sheet-like high heat radiation metal plate having good thermal conductivity, and is composed of a Cu core substrate 24 having a thickness of 80 μm or more. An insulating resin base 25 is provided on both surfaces of the substrate 24. A portion corresponding to each piece of the resin base material 25 of the Cu core substrate 24 is a cavity portion 26 for mounting the semiconductor element 19 in a substantially central portion of one main surface in plan view. A notch 27 is provided by being drilled. In this Cu core substrate 24, a dummy is provided at a location where a cutting edge 16 such as a dicing saw passes for dividing the aggregate 12 into high-radiation plastic packages 10 a each having a rectangular shape. 90 to 98% of the external length of the Cu core substrate 24 including the portion 11 is removed by a photolithography method and an etching method. In addition, the width dimension a of the removed portion has a width greater than or equal to the width dimension b of the cutting edge 16. Each surface of the resin base material 25 is provided with a conductor wiring pattern 15 and a solder resist film 17 that exposes a necessary portion of the conductor wiring pattern 15 from the opening. Yes. When the conductor wiring pattern 15 is provided on the upper and lower surfaces of the high heat dissipation plastic package 10a, a through hole is formed in each Cu core substrate 24 and a resin base is formed on the wall surface of the through hole in order to establish electrical continuity between the patterns. An insulating coating made of the material 25 is provided, and this insulating coating has a conductive via 18 formed by providing a Cu plating coating. In addition, the high heat dissipation plastic package 10a has a resin base material on the lower surface of each Cu core substrate 24 in order to dissipate heat generated from the semiconductor element 19 from the lower surface of the Cu core substrate 24 where the semiconductor element 19 is mounted. 25 has a thermal via 20 formed with a through hole, and a connection terminal similar to the external connection terminal 22 can be provided by being joined to the thermal via 20.

  This high heat radiation type plastic package 10a is usually formed as a cavity-up type package. A semiconductor element 19 is mounted in the cavity portion 26, and the semiconductor element 19 and the conductor wiring pattern 15 on the upper surface side are bonded by a bonding wire 21. On the lower surface side, the external connection terminals 22 made of, for example, solder balls or the like are joined to the conductor wiring pattern 15 on the lower surface side so that the semiconductor element 19 and the external connection terminals 22 are electrically connected. In addition, after the semiconductor element 19 is mounted on the upper surface side of the high heat dissipation plastic package 10a, a sealing resin 23 is provided so as to cover the semiconductor element 19, the bonding wire 21, and the like. 21 etc. are protected from the outside air and hermetically sealed. The assembly 12 of the high heat dissipation plastic package 10a on which the semiconductor elements 19 and the like are mounted is divided at a place where a cutting edge 16 such as a dicing saw passes, so that the semiconductor elements 19 and the like are mounted. A high heat radiation type plastic package 10a made of a single body is produced.

  When the thickness of the Cu core substrate 24 of the high heat dissipation plastic package 10a is less than 80 μm, the heat dissipation effect is lowered, and efficient heat dissipation cannot be ensured. Further, the length of the Cu core substrate 24 existing where the cutting blade 16 for dividing the assembly 12 into individual pieces passes is 10% of the external length of the Cu core substrate 24 including the dummy portion 11. Or the width dimension a of the removed portion of the Cu core substrate 24 is smaller than the width dimension b of the cutting blade 16, the quality of the cut portion when cutting with the cutting blade 16 is deteriorated. Further, the Cu core substrate 24 existing where the cutting blade 16 for dividing the assembly 12 into individual pieces passes is removed between the dummy portion 11 and the adjacent high heat radiation type plastic package 10a when all are removed. Since there is no connection part, it is necessary to have a minimum of about 2% in order to connect adjacent parts.

  The high heat radiation type plastic packages 10 and 10a have been described as the cavity-up type having the conductor wiring pattern 15 on both surfaces of the core substrate. However, the high heat radiation type plastic package 10 and 10a has a conductor wiring pattern only on one side. It may be a down type. In this case, it is not necessary to form the conductive via 18, and the external connection terminal 22 and the semiconductor element 19 are formed on the same side.

  As an application example of the present invention, heat from a semiconductor element having a high calorific value can be efficiently dissipated, and a thin and inexpensive package can be obtained. For example, the present invention can be applied to a mobile phone, a notebook computer, or the like.

(A)-(C) are the upper surface side top view, lower surface side top view, and longitudinal cross-sectional view of the high thermal radiation type plastic package which concerns on one embodiment of this invention, respectively. (A)-(C) are the upper surface side top view, lower surface side top view, and longitudinal cross-sectional view of the high thermal radiation type plastic package which concerns on other embodiment of this invention, respectively. (A), (B) is explanatory drawing of the conventional high thermal radiation type plastic package, respectively.

Explanation of symbols

  10, 10a: High heat radiation type plastic package, 11: Dummy part, 12: Assembly, 13: Resin core substrate, 14: Inner layer Cu foil layer, 15: Conductor wiring pattern, 16: Cutting blade, 17: Solder resist film , 18: conduction via, 19: semiconductor element, 20: thermal via, 21: bonding wire, 22: external connection terminal, 23: sealing resin, 24: Cu core substrate, 25: resin base material, 26: cavity portion, 27: Notch

Claims (2)

A high heat dissipation plastic formed by dividing an assembly of a plurality of adjacent layers including a dummy portion into a quadrangular piece having an inner layer Cu foil layer between a plurality of resin core substrates. In the package,
The inner layer Cu foil layer has a thickness of 25 μm or more, and the inner layer Cu foil layer in a place where a cutting cutting blade for dividing each of the aggregates into the individual pieces passes through the dummy portion includes the dummy portion. A high heat radiation type plastic package characterized in that it is removed with a width of 90 to 100% of the outer length of the inner layer Cu foil layer and more than the cutting edge width. A high heat radiation type plastic package having a Cu core substrate coated with a resin base material and divided into a plurality of rectangular pieces from an assembly in which a plurality of adjacent portions including a dummy portion are aligned. In
The Cu core substrate having a thickness of 80 μm or more, and the Cu core substrate where the cutting blade for dividing the aggregate into the individual pieces is passed, the Cu core including the dummy portion. A high heat radiation type plastic package characterized by being removed by 90 to 98% of the outer length of the substrate and having a width larger than the cutting edge width.

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