JPH1154651A - Composite package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composite package excellent in heat dissipation by making a trench on the surface of a board made of a high thermal conductivity material facing a resin board thereby decreasing thermal resistance. SOLUTION: The composite package comprises a ceramic substrate 11 composed of either one of alumina, aluminum nitride, silicon nitride, silicon carbide or diamond having a recess for mounting a semiconductor chip 1. The ceramic substrate 11 is bonded to a resin board 10 through an adhesive. A trench 92 is made on the surface of the ceramic substrate 11 in the vicinity of the interface between the resin board 10 and the ceramic substrate 11. According to the structure, warping of the package can be suppressed even if the ceramic substrate 11 is made thin and the heat dissipation of the package can be enhanced while decreasing the thickness thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-terminal, narrow-pitch semiconductor element package having good heat radiation characteristics, and more particularly to a semiconductor element composite package in which a high thermal conductive material substrate and a resin substrate are bonded and joined.

[0002]

2. Description of the Related Art Various types of packages, such as ceramics, resins, and metals, on which semiconductor chips such as LSIs are mounted, have been increased in density due to high integration, high speed, large power consumption, and large chips of LSIs. High-speed response and high heat dissipation are required. In addition, the applications of these semiconductor chips are wide ranging from industrial applications such as workstations, personal computers, and computers to electronic devices such as portable devices, printers, copiers, cameras, televisions, and videos. The performance itself has also improved.

As described above, a high-performance, high-density LSI
The package on which the chip is mounted must be able to be connected to the LSI chip with multiple terminals and a narrow pitch, have a high wiring density, have good heat dissipation, can handle high-speed signals, and have many input / output terminals of the package. -It is required that the pitch can be reduced. further,
There is a need for a technique for manufacturing a high-performance package that satisfies these conditions at a low cost with a simple process under high reliability.

[0004] In order to enhance the function of a semiconductor element, three pillars, ie, multi-bit, large capacity, and high speed are the pillars. Among them, the demand for high speed has had a great influence on the package. This is because the number of input / output terminals (the number of pins) to the semiconductor element is increased and data is processed in parallel to increase the speed. For this reason, multi-terminals (multi-pins) has become one proposition in packages. In addition, the miniaturization of portable devices and the miniaturization of packages for high-density mounting are also required. This demand is particularly great in the field of multimedia, amusement and communication equipment, which will greatly increase in the future. Various packages have been developed to meet these two needs of multi-pin and miniaturization. In order for the connection technology with the semiconductor chip to function effectively, the package side must also have a narrow-pitch, multi-terminal inner lead part, and the connection between the mounting board, such as a printed circuit board, and the package must also have a multi-terminal, narrow pitch. It is necessary to do. Further, as described above, the package needs to handle high-speed signals due to the increase in the speed of the LSI, so that it is necessary to consider the electrical characteristics.

[0005] In order to satisfy the above demand for a package having multiple terminals and a narrow pitch, a package structure is a conventional pin insertion type or a surface mount type such as a QFP (Quad Flood Package). From BGA
(Ball Grid Array) package. This is because, in the case of a surface mount package, in order to reduce the number of terminals and the pitch, it is becoming possible to limit the accuracy of the terminals, the inductance caused by the leads, the strength of the leads themselves, and the accuracy at the time of mounting. Another reason is that the surface mount type package has a disadvantage that the outer dimensions must be increased with the increase in the number of terminals.

The BGA can reduce the inductance compared to the conventional package, and can adapt the multilayer wiring structure of the package body at high speed, and is used for consumer products such as large computers, personal computers, and portable devices. Is spreading. BGA is a protruding connector (solder ball) made of solder as the input / output terminal of the package
It is possible to improve the reflection delay of a high-speed signal and the like due to the inductance caused by the pins and leads as described above. Further, in addition to shortening of the connection distance by the solder ball, narrow pitch and multiple terminals can be easily achieved by forming the solder ball.
Promising as an SI package. Furthermore, the narrow pitch and multiple terminals due to the formation of the solder balls reduce the package size itself, improve the mounting density on printed circuit boards, etc., improve the electrical characteristics by reducing the parasitic capacitance, inductance, and resistance of wiring, and improve the package. Improvement of high frequency characteristics and the like can be expected by downsizing.

On the other hand, when viewed from the heat dissipation surface of the package, L
As the integration density and the speed of the SI increase, the power consumption increases, and the amount of heat generated tends to increase year by year. Moreover, in the computer, while the size of the main body has been reduced, the number of boards has been increasing, and the gap between the boards has been gradually narrowed. For this reason, the package itself is required to be thin and have a structure excellent in heat dissipation and a material having high thermal conductivity. Metals such as copper, aluminum, alloys containing copper or aluminum, and high thermal conductive materials,
There are ceramics such as aluminum nitride, silicon nitride, alumina, and glass ceramics, and these are properly used depending on specifications such as heat generation and high-frequency characteristics.

In a package using ceramics, which is a material having high thermal conductivity, the difference in thermal expansion coefficient between the package and the printed circuit board when mounted on the printed circuit board is large. (Reliability) (mounting reliability). This difference in the coefficient of thermal expansion may be caused by heat history in the reflow soldering process when mounting the BGA package on a printed circuit board, or by a change in environmental temperature during normal use. Due to the large difference in the coefficient of thermal expansion between the high thermal conductive material and the printed circuit board, thermal stress concentrates on the solder ball part with low mechanical strength, causing cracks in the solder ball and further breaking the solder ball. As a result, there is a problem that the reliability of the connection part is reduced.

In view of the problem caused by the difference in the coefficient of thermal expansion, a composite package in which a resin substrate is bonded to a high thermal conductive material substrate by thermocompression or the like has recently been receiving attention. This is because the resin substrate has a thermal expansion coefficient close to that of the printed circuit board, so that concentration of thermal stress on the solder bump portion can be expected to be reduced. Further, the resin substrate has an advantage that it can be easily miniaturized by lithography and is inexpensive. Therefore, a structure utilizing both the advantages of these resin substrates and the high heat dissipation characteristics of the high thermal conductive material substrate is expected.

[0010]

In the above-described composite package, when the thickness of the resin substrate is increased, the resin substrate portion functions as a heat resistance layer in structure, so that it is difficult to ensure high heat dissipation. The use of a radiation fin or the like is necessary, resulting in an increase in cost and an increase in the package thickness.

In order to avoid this, the thickness of the resin substrate is set to 15
The present inventors have found that when the thickness is reduced to 0 μm or less, particularly 100 μm or less, the thermal resistance rise is not so large. FIG. 10 is a diagram showing the relationship between the thickness of the resin substrate in the composite package and the thermal resistance obtained experimentally by the present inventors. FIG.
The circles indicate data of a composite package of a normal chip mounting type targeting a power consumption of 4 W, and the triangles indicate data of a composite package of a flip chip mounting type targeting a power consumption of 3 W. Each is a package having an outer dimension of 31 mm □ for a 300-pin semiconductor element, but the thickness t of the ceramic substrate of the normal chip is 0.8.
mm, and the thickness t of the flip-chip mounting type ceramic substrate is 0.6 mm. FIG. 10 shows that when the thickness of the resin substrate is 100 μm or less, a low thermal resistance is exhibited. In particular, in the flip-chip mounting type, when the thickness of the resin substrate is 100 μm or less, the thermal resistance rapidly decreases. FIG. 10 shows a ceramic substrate having a thermal conductivity of 1
This is a case where aluminum nitride (AIN) of 80 W / (m · K) is used. The resin substrate has a structure in which a liquid crystal polymer is a main component and copper foils are bonded to both sides thereof. The data is for a case where the resin substrate and the ceramic substrate are bonded with an acrylic adhesive. Wiring layers and through-holes are not provided on the ceramic substrate of the normal chip mounting type.
μm through holes are provided and tungsten (W)
Is embedded in the conductor layer.

Further, the present inventors set the thickness of the resin substrate to 15
It has been found that reducing the thickness to 0 μm or less, preferably 100 μm or less, reduces the warpage of the package. As described above, the package is required to be thinner as the number of boards increases, but as shown in FIG. 11, when the thickness t of the ceramic substrate becomes 0.6 mm or less, the warpage of the package becomes remarkable. ing. From the point of mounting reliability, the warp must be about 65 μm or less.
The thickness of the resin substrate is 150 μm or less, preferably 100 μm.
When it is less than m, a remarkable effect was observed in reducing the warpage.

[0013] The resin substrate having a thickness of 150 µm or less and the high thermal conductive material are generally bonded with an adhesive. However, it has become clear that the adhesive strength between the resin substrate and the high thermal conductive material substrate deteriorates as the thickness of the resin substrate decreases. For example, there is a case where the air layer remains between the adhesive and the high thermal conductive material substrate, and the resin substrate is thin, so that it appears as swelling of the resin substrate. In particular, this swelling becomes remarkable in a high temperature environment after joining. Further, in the composite package, it has become clear that the electrical connection gradually becomes poor and the thermal resistance increases in a thermal cycle in which the temperature is repeatedly increased and decreased. Further, it has become clear that the mechanical bonding strength is also deteriorated due to the heat cycle, and the mounting reliability is insufficient.

Further, when ceramics is selected as a material having a high thermal conductivity, it is necessary to apply a constant pressure during thermocompression bonding. However, the problem that the ceramics is cracked by this bonding pressure has become clear.

In general, a package is mounted by electrically connecting to a resin mounting board or printed board using solder balls or the like. Different coefficient of thermal expansion. For this reason, when a thermal cycle test is performed, cracks are formed in the solder balls and the conductive resin, and connection failure is likely to occur. In a composite package in which a resin substrate and a ceramic substrate are bonded together, the solder balls are connected between the resin substrate and the resinous board or printed circuit board. , The thickness of the resin substrate is 150μ
When the thickness is less than m, the resin substrate is restrained by the ceramic substrate and does not move. Therefore, a new problem that connection reliability is more likely to be reduced than in the case of pure resins has also been clarified.

As described above, various new technical difficulties and problems have become apparent in reducing the thickness of the resin substrate to 150 μm or less, particularly 100 μm or less.

In view of the above problems, an object of the present invention is to provide a composite package having a small heat resistance and good heat radiation characteristics.

Another object of the present invention is to provide a composite package in which the warpage is kept below an allowable value even when the thickness of the high thermal conductive material substrate is reduced.

Still another object of the present invention is to provide a high reliability of a joint between a resin substrate and a high thermal conductive material substrate, and to operate stably without increasing thermal resistance even under repeated severe thermal cycles. To provide a composite package.

Another object of the present invention is to reduce the thickness of the resin substrate to 15
An object of the present invention is to provide a composite package in which the adhesive strength is not reduced even when the thickness is reduced to 0 μm or less, particularly 100 μm or less.

Still another object of the present invention is to provide a composite package which does not swell even when the thickness of the resin substrate is reduced to 150 μm or less, particularly 100 μm or less.

Still another object of the present invention is to provide a composite package which can obtain good adhesive strength even when the pressure during bonding is reduced.

Still another object of the present invention is to provide a composite package which can ensure good connection reliability with a mounting board.

[0024]

In order to achieve the above object, a first feature of the present invention is a semiconductor element package formed by bonding a high thermal conductive material substrate and a resin substrate, and comprises a high thermal conductive package. The composite package has a groove on the surface of the material substrate facing the resin substrate.

The high heat conductive material substrate is made of copper, aluminum,
Alloy containing copper, metal substrate made of any of alloys containing aluminum, or alumina, aluminum nitride,
Any ceramic substrate made of any one of silicon nitride, silicon carbide, and diamond may be used. Further, a composite substrate composed of two or more of these may be used.

Conventionally, a pressure of ²⁰ to 40 kgf / cm ² has been applied at a predetermined temperature in joining a high thermal conductive material substrate and a resin substrate. Generally, it is a combination of a metal substrate and a resin substrate that are easily deformed under high pressure, so that entrainment of the air layer is unlikely to occur, but if the pressure is not applied uniformly, the air layer remains. . We have:
It has been discovered that if a groove is formed on the surface of the high thermal conductive material substrate, the entrapment of the air layer can be prevented. The grooves on the surface of the high thermal conductive material substrate may be formed by a general method such as a method of pressing the high thermal conductive material substrate with a press having linear projections, a method of forming the substrate by etching, and the like.

According to a first feature of the present invention, 10 kgf /
Even when contact is made at a pressure of not more than cm ^2, no air layer is involved. Therefore, good adhesion between the ceramic substrate, which is a brittle material, and the resin substrate can be realized without damaging the ceramic substrate. By providing a groove on the surface of the high thermal conductive substrate, the thickness of the resin substrate can be reduced to 150 μm or less,
Even if the thickness is less than 00 μm, no swelling of the resin substrate occurs. Also, swelling does not occur even in a high temperature environment after bonding.

A second feature of the present invention is a semiconductor element package formed by bonding a high thermal conductive material substrate and a resin substrate, wherein a center line average of the surface of the high thermal conductive material substrate facing the resin substrate is provided. The composite package has a roughness Ra ≧ 0.05 μm.

The high thermal conductive material substrate is made of copper, aluminum,
Alloy containing copper, metal substrate made of any of alloys containing aluminum, or alumina, aluminum nitride,
Any ceramic substrate made of any one of silicon nitride, silicon carbide, and diamond may be used. Further, a composite substrate composed of two or more of these may be used.

Conventionally, in bonding a high thermal conductive material substrate having a glossy surface and a resin substrate, a predetermined temperature of 20-40 kgf / c
m ² pressure was applied. However, when joining the surface of a highly heat conductive material substrate having a glossy surface, the joining strength is reduced. The inventors have found that if the surface roughness of the high thermal conductive material substrate is center line average roughness Ra ≧ 0.05 μm, good strength can be obtained. For example, in the case of connection between a ceramic substrate and a resin substrate, 40 gf / cm
Applying about ² pressures will cause cracking. Therefore, the pressure is desirably 10 kgf / cm ² or less. However, when pressed at a low pressure, the adhesive strength tends to decrease accordingly. As a result of intensive studies, the present inventors have invented that the bonding strength can be ensured even at low pressure by roughening the surface roughness of the ceramic as shown in the second feature of the present invention.

A third feature of the present invention is a semiconductor device package formed by bonding a high thermal conductive material substrate and a resin substrate, wherein the high thermal conductive material substrate has a land portion having a groove, This is a composite package in which a land having a groove and a land of a resin substrate are electrically connected to each other via a bump. The shape of the groove is V
It may be a U-shape or a two-step groove. Further, the high thermal conductive material substrate is a metal substrate made of copper, aluminum, an alloy containing copper, an alloy containing aluminum, or a ceramic substrate made of any of alumina, aluminum nitride, silicon nitride, silicon carbide, and diamond. Either may be used. And two of these
A composite substrate in which at least one kind is selected may be used.

The bumps have a particle size of, for example, 0.5 to 5 μm.
An epoxy conductive paste containing about 80% (weight percent) of a silver filler of about m, Au epoxy, or Ag polyimide may be patterned and dried.
As for the mechanical connection between the high thermal conductive material substrate and the resin substrate, an adhesive sheet may be laid between the high thermal conductive material substrate and the resin substrate and bonded by applying heat and pressure. At this time, the protruding bumps formed on the high thermal conductive material substrate side or the resin substrate side break through the adhesive sheet, or pass through holes previously opened in the adhesive sheet,
The structure is such that the high heat conductive material substrate and the resin substrate are electrically connected.

Land (surface wiring) on the ceramic substrate side
May be used in which nickel and gold are plated on tungsten. The land on the resin substrate side is
A copper wiring plated with nickel and gold may be used. As described above, the electrical connection between the high thermal conductive material substrate and the resin substrate uses a bump made of silver or the like, so that the gold formed on the surface of the land on the resin substrate and the high thermal conductive material substrate Is a mechanical connection that does not form a reaction layer, and it is clear that there is a problem in connection reliability. The present inventors have conducted intensive research on this, and as a result, a groove such as a V-groove is formed in advance on the land portion on the high thermal conductive material substrate side, and a bump is formed thereon, and the resin substrate is connected to the high thermal conductive material. It was confirmed that the connection reliability of the protruding bump portion can be improved by bonding the material substrate.

In general, the bonding between the resin substrate and the substrate made of a high thermal conductive material such as ceramics is performed in consideration of the heat resistance of the resin.
Crimping is performed at around 200 ° C. Epoxy conductive paste containing silver filler that requires electrical connection, at the above temperature,
No reaction occurs with the gold plating layer on the surface of the land formed on the resin substrate and the high thermal conductive material substrate. Therefore, the electrical connection is due to the deformation of the silver filler by pressure bonding and to the epoxy curing.

In the composite package, there is a concern that the reliability may be reduced due to the difference in the coefficient of thermal expansion between the resin substrate and the high thermal conductive material substrate such as ceramics. For example, the coefficient of thermal expansion of a resin differs from that of a ceramic by about 10 times or more.
From this, the bonded product not only reduces the bonding strength due to the heat history, but also affects the projection bump portion made of the silver epoxy conductive paste which is the electrical connection portion, and the connection strength is reduced. As a result, an increase in connection resistance occurs.
In this case, the bonding temperature of the adhesive used is 200 ° C. or less, and the adhesion with the resin substrate or the resin film is better than the adhesion with the high thermal conductive material substrate, and the increase in the connection resistance of the projecting bumps is as follows. Occurs at the connection with the protruding bump on the high thermal conductive material substrate side. According to a third aspect of the present invention,
The contact area of the projection bumps at the connection portion is large, an anchor effect can be expected, and the connection reliability is improved. As described above, by forming a predetermined groove portion having a large contact area on the land portion of the high thermal conductive material substrate on the side to be bonded to the resin substrate, connection reliability is improved.

A fourth feature of the present invention is a semiconductor element package formed by bonding a high thermal conductive material substrate and a resin substrate, and directly above or directly below a connection pad serving as an electrical connection portion with a mounting board. An adhesive is formed unevenly so as to have a void portion, and a high heat transfer material substrate and a resin substrate are bonded to each other. That is, mounting is performed by providing a region without an adhesive layer directly above or directly below a connection pad serving as an electrical connection portion when electrically connecting the composite package to the mounting board using a metal ball or a columnar metal. Reliability is improved. here,
If the mounting board is arranged at the top of the composite package, a gap is placed directly below the connection pad, and if the mounting board is arranged at the bottom of the composite package, the gap is placed just above the connection pad. Become. However, it will be apparent from an understanding of the spirit of the fourth feature of the present invention that it is only relatively meaningful which one is called “upper” and which is called “lower”. Therefore, “directly above or directly below” means the position of the adhesive layer closest to the connection pad.

If the adhesive layer for bonding the high thermal conductive substrate and the resin substrate of the composite package is uniformly and sufficiently directly above or directly below the connection pad portion, the resin substrate is restrained by the adhesive and the high thermal conductive material substrate. It behaves like a high thermal conductive material substrate. However, if the adhesive layer is eliminated and only this portion is made substantially hollow, the resin substrate can be deformed following the deformation of the mounting hood. In particular, when the thickness of the resin substrate is 150 μm or less, the deformation is likely to occur, which is advantageous for improving the mounting reliability. It is desirable that the resin used for the present resin substrate has a strong strength itself, such as a liquid crystal polymer, a BT resin, or a resin containing a fibrous sheet. On the other hand, the high thermal conductive material substrate is a metal substrate made of any of copper, aluminum, an alloy containing copper, an alloy containing aluminum, or a ceramic substrate made of any of alumina, aluminum nitride, silicon nitride, silicon carbide, and diamond. Either may be used. Further, the high thermal conductive material substrate may be configured as a composite substrate combining two or more of these.

[0038]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
It is a schematic diagram of a section of a compound package concerning an embodiment. As shown in FIG. 1, a composite package according to a first embodiment of the present invention includes a metal substrate 9 having a concave portion for mounting the semiconductor chip 1, and a resin substrate 10 bonded to the metal substrate 9 with an adhesive. It is composed of Metal substrate 9
A groove 91 is provided on the surface of the metal substrate 9 located near the interface between the metal substrate 9 and the resin substrate 10.

The composite package shown in FIG. 1 is a 300-pin semiconductor device package. The resin substrate 10 is composed of a liquid crystal polymer as a main component and copper bonded to both sides thereof. The thickness of the insulating layer of the resin substrate is 0.05 mm.
Other materials used for the resin substrate 10 include BT
Those using a resin or those using a glass epoxy resin may be used. Further, copper was used as the material of the metal substrate 9. The thickness of the metal substrate 9 is 0.6 mm
And the external dimensions are 35 mm □. In addition, as the material of the metal substrate 9, besides copper, aluminum, copper, an alloy containing aluminum, or the like can be used.

In the composite package according to the first embodiment of the present invention shown in FIG.
A μm groove 91 is formed. The groove width is 50 μm to 0.1 μm.
The typical pitch is about 5 mm, and the pitch of the grooves is 0.1 mm to 5 mm. The finer the pitch of the grooves, the better. Although a U-shaped groove is shown in FIG. 1, other cross-sectional shapes such as a V-shaped groove may be used. It is preferable to form the groove with a flat pattern reaching the end of the package rather than a flat pattern closed inside because the air entrapment is small. Use an acrylic adhesive for the adhesive,
The joining was performed at a joining pressure of 20 kgf / cm ² . The adhesive is preferably filled so as to completely fill the groove.

As a comparative example, a metal substrate having no surface groove was manufactured. The appearance of the prepared sample when heated at 260 ° C. was measured and compared with the present invention. Table 1 shows the results.

[0043]

[Table 1] (Second Embodiment) FIG. 2 is a schematic sectional view of a composite package according to a second embodiment of the present invention. As shown in FIG. 2, a composite package according to a second embodiment of the present invention includes a ceramic substrate 11 having a concave portion for mounting the semiconductor chip 1, and a resin substrate 10 bonded to the ceramic substrate 11 with an adhesive. It is composed of A groove 92 is provided on the surface of the ceramic substrate 11 located near the interface between the ceramic substrate 11 and the resin substrate 10.

The composite package shown in FIG. 2 is a 300-pin semiconductor device package. The resin substrate 10 is composed of a liquid crystal polymer as a main component and copper bonded to both sides thereof. The thickness of the insulating layer of the resin substrate is 0.05 mm.
Other materials used for the resin substrate 10 include BT
Those using a resin or those using a glass epoxy resin may be used.

Further, aluminum nitride ceramics was used as the material of the ceramic substrate 11 constituting the heat radiation part. The thermal conductivity of nitrided ceramics is 180 W / (m ·
K). The thickness of the ceramic substrate 11 is 0.6 mm
And the external dimensions are 35 mm □. Ceramic substrate 11
Although there is no wiring layer on the surface or inside, it is possible to form a metallized layer or a through hole on the surface of the ceramic substrate 11. In addition, any of alumina, silicon nitride, silicon carbide, boron nitride, and diamond may be used as the supporting substrate.

In the second embodiment of the present invention, the surface roughness of aluminum nitride is determined by calculating the center line average roughness Ra =
A groove of approximately 3 μm depth of 0.05 μm with a laser
It was prepared at 0 μm. The groove width is typically about 50 μm to 0.5 mm, and the pitch of the grooves is typically 0.1 mm to 5 mm. The finer the pitch of the grooves, the better. In FIG. 1, U
Although a V-shaped groove is shown, it goes without saying that other cross-sectional shapes such as a V-shape may be used. It is preferable to form the groove with a flat pattern reaching the end of the package rather than a flat pattern closed inside because the air entrapment is small. An acrylic adhesive was used as the adhesive, and bonding was performed at a bonding pressure of 10 kgf / cm ² . The adhesive is preferably filled so as to completely fill the groove.

[0047]

[Table 2] Table 2 shows, as a comparative example, a ceramic substrate having no groove on the surface thereof, and a sample prepared at 260 ° C.
The results are shown in FIG.

(Third Embodiment) FIG. 3 shows a third embodiment of the present invention.
It is a schematic diagram of a section of a compound package concerning an embodiment. As shown in FIG. 3, a composite package according to a third embodiment of the present invention includes a metal substrate 9 having a concave portion for mounting the semiconductor chip 1, and a resin substrate 10 bonded to the metal substrate 9 with an adhesive. It is composed of Metal substrate 9
The surface of the metal substrate 9 located near the interface between the metal substrate 9 and the resin substrate 10 is a rough surface having a center line average roughness Ra ≧ 0.05 μm or more.

The composite package shown in FIG. 3 is a 300-pin package for a semiconductor device. The resin substrate 10 is composed of a liquid crystal polymer as a main component and copper bonded to both sides thereof. The thickness of the insulating layer of the resin substrate is 0.05 mm.
Other materials used for the resin substrate 10 include BT
Those using a resin or those using a glass epoxy resin may be used. Aluminum was used as the material of the metal substrate 9. The thickness of the metal substrate 9 is 0.06 mm, and the external dimensions are 35 mm □. In addition, besides aluminum, the material of the metal substrate 9 is
Copper, an alloy containing copper or aluminum, or the like can be used.

In the third embodiment of the present invention, the surface roughness of aluminum as a substrate having a high thermal conductivity is Ra = 0.
05, 0.1 μm was prepared. An acrylic adhesive was used as the adhesive, and bonding was performed at a bonding pressure of 40 kgf / cm ² .

FIG. 4 shows the difference in bonding strength between the composite package according to the embodiment of the present invention and the comparative example. Comparative example is R
a = 0.01 μm, but the bonding strength is as small as 300 gf. It can be seen that according to the third embodiment of the present invention, a good bonding strength of 1.7 kg or more can be obtained.

(Fourth Embodiment) FIG. 5 shows a fourth embodiment of the present invention.
It is a schematic diagram of a section of a compound package concerning an embodiment. As shown in FIG. 5, a composite package according to a fourth embodiment of the present invention includes a ceramic substrate 11 having a concave portion for mounting the semiconductor chip 1, and a resin substrate 10 bonded to the ceramic substrate 11 with an adhesive. It is composed of The surface of the ceramic substrate 11 located near the interface between the ceramic substrate 11 and the resin substrate 10 is a rough surface having a center line average roughness Ra ≧ 0.05 μm or more.

The composite package shown in FIG. 5 is a 300-pin semiconductor device package. The resin substrate 10 is composed of a liquid crystal polymer as a main component and copper bonded to both sides thereof. The thickness of the insulating layer of the resin substrate is 0.05 mm.
Other materials used for the resin substrate 10 include BT
Those using a resin or those using a glass epoxy resin may be used. Aluminum nitride ceramics was used as the material of the ceramic substrate 11 constituting the heat radiating portion. The thermal conductivity of aluminum nitride is 180 W / (m · K). The thickness of the ceramic substrate 11 is 0.6 mm, and the outer dimensions are 35 mm □. Although no wiring layer is provided on the surface or inside of the ceramic substrate 11, it is possible to form a metallized layer or a through hole on the surface of the ceramic substrate 11. In addition, any of alumina, silicon nitride, silicon carbide, boron nitride, and diamond may be used as the supporting substrate.

In the fourth embodiment of the present invention, the surface roughness of aluminum nitride is Ra = 0.05, 0.1,
One having a thickness of 0.3 μm was produced. An acrylic adhesive was used as the adhesive, and bonding was performed at a bonding pressure of 4 kgf / cm ² .

FIG. 6 shows a surface roughness Ra = 0.0 as a comparative example.
9 shows the bonding strength between a 1 μm composite package and a composite package according to a fourth embodiment of the present invention. Ra = 0.01
In the case of μm, the bonding strength is as weak as 400 gf, but Ra = 0.0
1.3kgf at 5,0.1,0.3μm,
It can be seen that a strong bonding strength of 1.6 kgf and 1.7 kgf can be obtained even at a low bonding pressure. Ra = 0.1
μm and Ra = 0.3 μm are almost similar values.
When a ≧ 0.1 μm or more, there is a tendency for saturation. Therefore, the center line average roughness Ra of 0.05 μm or more and 0.3 μm or less is sufficient, but this does not prevent Ra from being about 0.6 to 1.0.

(Fifth Embodiment) FIG. 7A schematically shows a cross-sectional structure of a composite package according to a fifth embodiment of the present invention, and FIG. It is an enlarged view of the A section. As shown in FIG. 7, the composite package according to the fifth embodiment of the present invention is a package for a semiconductor device formed by bonding a high thermal conductive material substrate 11 and a resin substrate 10 to each other. Reference numeral 11 denotes a land portion 12a having a V-groove shape, and the land portion 12a of the high thermal conductive material substrate 11 and the land portion 34 of the resin substrate 10 are electrically connected to each other via the bumps 55. .

More specifically, the high thermal conductive material substrate shown in FIG. 7 is a ceramic substrate 11 using aluminum nitride.
A through-hole is provided in the ceramic substrate 11, and a through-hole metal 12 is embedded in the through-hole. The land portion 12a is formed integrally with the through-hole metal 12, and has a V-groove shape as shown in FIG. 7B. The resin substrate 10 has a liquid crystal polymer 23 as a main material, a surface wiring 35 formed of a copper foil on the upper portion of the liquid crystal polymer, and a land 34 formed of a copper foil on the lower portion.
Are formed. That is, the resin substrate 10 has a structure in which a liquid crystal polymer is sandwiched between two copper foils. The surface wiring 35 and the land 34 are electrically connected by the silver bump 22. The bumps 55 for electrically connecting the lands 34 and the lands 12a are silver bumps obtained by patterning an Ag epoxy paste and drying.

As shown in FIG. 7B, the land portion 12a has a V-groove shape and comes into contact with the projection bump 55 with a large contact area, so that the projection bump 55 and the land portion 12a make good ohmic contact. The contact between the projection bump 55 and the land 34 is originally good. Therefore, good electrical contact between the resin substrate 10 and the ceramic substrate 11 is obtained, and the reliability is high.

The composite package according to the fifth embodiment of the present invention can be manufactured by the following steps.

(A) A through-hole is prepared in the aluminum nitride green sheet 19, and a through-hole metal 12 (after firing, 1.0 mm) is formed in the through-hole.
Here, two green sheets 19 having a thickness of 0.55 mm were used. Then, as a laminated jig, the resin substrate 1
Using a material having a protrusion such that a buoy groove is formed in a portion corresponding to the land portion 12a on the side to be bonded to 0, laminating and pressing, and firing in a reducing atmosphere. Next, the land portion 12a is plated with Ni / Au to obtain a ceramic substrate 11 as shown in FIG.

(B) Next, as shown in FIG.
A portion corresponding to a semiconductor input / output pad and a portion corresponding to a land of a package body are formed on a copper foil 21 having a thickness of μm.
A silver bump 22 of 00 μm is formed. Thereafter, a liquid crystal polymer 23 having a thickness of 50 μm is applied so that the tip of the silver bump 22 can easily break through, and another copper foil 21 is further applied thereon. That is, as shown in FIG. 8C, two copper foils 21 are stacked on both sides of the liquid crystal polymer 23,
The resin substrate 10 is formed by applying the temperature and the pressure and stacking.

(C) Thereafter, the central portion of the copper foil 21 is punched out by a press for mounting a semiconductor chip, and the resin substrate 10
Open a window at Then, the remaining copper foil 21 is etched to form a surface wiring 3 on the surface as shown in FIG.
5 is formed. Similarly, a land 34 is formed on the back surface at a portion corresponding to the land of the package. Thereafter, a solder resist 24 is formed on the surface layer of the resin substrate 10 and the back layer that adheres to the ceramics by screen printing. Next, the surface wiring 35 and the land 34 are plated with nickel and gold to complete the resin substrate 10.

(D) Next, as shown in FIG. 8E, a silver epoxy paste is screen-printed on the lands 12a of the ceramic substrate 11 which are to be electrically connected to the lands 34 of the resin substrate 10. A silver bump 55 is formed selectively on the buoy groove of the land part 12a by forming it selectively by a technique and drying.

(E) Next, the land 12a of the ceramic substrate 11 and the land 34 of the resin substrate 10 are mechanically fitted to each other using an adhesive film 13 having relatively good adhesion to ceramics. Apply a predetermined temperature and a predetermined pressure (10 kgf / cm ² ) using
By electrically and mechanically connecting, the composite package according to the fifth embodiment of the present invention shown in FIG. 7 is completed.

Using the composite package according to the fifth embodiment of the present invention, in a cooling / heating cycle test at a high temperature side of 120 ° C. and a low temperature side of −45 ° C., no change in electric resistance was observed even after repeating 700 cycles or more. . As a comparison, a reliability test similar to that described above was performed using a ceramic substrate having no buoy groove formed on the land on the ceramic substrate side. As a result, the electric resistance increased in 450 cycles.

In the fifth embodiment of the present invention, the package structure has a cavity-up structure, but it is needless to say that the present invention can be similarly applied to a cavity-down structure. Although the case where the ceramic is aluminum nitride has been described, other ceramic materials such as alumina, silicon nitride, and low-temperature fired glass ceramic can be used. For resin substrates, liquid crystal polymer, polyimide, glass epoxy, F
A film made of a resin such as R4 or a substrate may be used.

For the bumps 55 for electrically connecting the resin substrate and the ceramic substrate, Au epoxy or Ag polyimide can be used in addition to the Ag epoxy paste. In this case also, the connection reliability does not change. And good bonding strength was obtained. As the adhesive, a sheet-like or paste-like adhesive made of a thermosetting resin, an epoxy resin paste and a sheet, a polyimide resin paste and a sheet, and the like can be practically used.

(Sixth Embodiment) FIG. 9A is a schematic cross section showing a state in which a composite package according to a sixth embodiment of the present invention is joined to a mounting board 5 with solder balls 3. FIG. 9B is an enlarged view of a portion B in FIG. 9A. The composite package according to the sixth embodiment of the present invention is a 300-pin semiconductor device package shown in FIG.
As shown in FIG. 1, a resin substrate 10 having a thickness of 100 μm or less and a ceramic substrate 11 which is a high thermal conductive material substrate are bonded with an adhesive 13. And solder ball 3
The adhesive 13 immediately above the connection pad (solder ball connection pad) 39 for arranging is formed partially with the gap 15 interposed therebetween. Adhesive 1 directly above input / output pads 35 and other surface wiring parts other than solder ball connection pads 39
It is not necessary to form a void in 3.

The resin substrate 10 shown in FIG. 9 is composed of a liquid crystal polymer as a main component and copper bonded to both sides thereof. The thickness of the liquid crystal polymer is 0.05 mm. In addition, as the resin substrate 10, one using BT resin, one using glass epoxy resin, or the like may be used.

As the heat conductive material substrate 11, an aluminum nitride ceramic was used. The thermal conductivity of aluminum nitride was 180 W / (m · K). The thickness of the ceramic substrate 11 is 0.6 mm, and the outer dimensions are 35 m.
m □. Although no wiring layer is provided on the surface or inside of the ceramic substrate 11, it is possible to form a metallized layer or a through hole on the surface of the ceramic substrate 11. In addition, as a material of the ceramics substrate 11, any of alumina, silicon nitride, silicon carbide, boron nitride, and diamond, or a composite ceramics of two or more of these may be used in addition to the above-described aluminum nitride. . In the sixth embodiment of the present invention, an acrylic adhesive is used as the adhesive 13 and the bonding is performed at a bonding pressure of 4 kgf / cm ² . The bonding area of the adhesive is such that a gap 15 mm is formed in the area of 0.6 mmφ immediately above the area of 0.9 mmφ in the solder ball connection pad portion 39.
Is formed and joined so that the adhesive 13 does not get on.
In order to form the gap 15 of the adhesive 13, a holed hole is prepared in advance in the adhesive sheet, and the resin substrate 10 and the ceramic substrate 11 are bonded using the adhesive sheet using the hole. Good.

[0071]

[Table 3] Table 3 shows the number of cycles until the electrical resistance increases when a temperature cycle test of ΔT = 165 ° C. is performed on the sample prepared according to the sixth embodiment of the present invention. Table 3 shows, as a comparative example, a case where there is no gap, that is, the bonding area of the adhesive is 0.9% of the solder ball connection pad.
The results of a temperature cycle test on a sample manufactured so as to adhere to the entire surface of mmφ are also shown. It is shown that the provision of the gap increases the number of temperature cycles by about two times, indicating that the device has high mounting reliability.

In the above description, the case of bonding to the mounting board with solder balls has been described. However, it is needless to say that the mounting to the mounting board may be performed with a metal board other than solder or a columnar metal.

[0073]

According to the present invention, the thickness of the resin substrate is set to 150.
Since the thickness can be set to μm or less, particularly 100 μm or less, the heat radiation characteristic of the composite package is improved.

According to the present invention, the warpage of the package can be suppressed even if the ceramic substrate is thinned, and the package can be made thinner and the heat radiation characteristics can be improved.

Further, according to the present invention, there can be provided a composite package which does not increase in electrical resistance and thermal resistance even under repeated severe thermal cycles and has high reliability and high power consumption.

Further, according to the present invention, even if the thickness of the expansion substrate is reduced, the adhesion strength does not decrease or swelling does not occur. Therefore, a composite package having high reliability and good heat dissipation can be provided.

Further, according to the present invention, good adhesive strength can be obtained even when the pressure during bonding is reduced. Therefore, even in the case of brittle materials such as ceramics, cracks do not occur in the joining step, and the production yield is improved, and therefore, the productivity is improved.

Further, according to the present invention, the distortion due to the difference in the coefficient of thermal expansion between the mounting board and the high thermal conductive material substrate is reduced, and the mounting reliability is improved.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a structure of a composite package for a semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a schematic sectional view showing the structure of a composite package for a semiconductor device according to a second embodiment of the present invention.

FIG. 3 is a schematic sectional view showing a structure of a composite package for a semiconductor device according to a third embodiment of the present invention.

FIG. 4 is a diagram showing a relationship between bonding strength of a composite package for a semiconductor device and a center line average roughness Ra of a metal substrate surface according to a third embodiment of the present invention.

FIG. 5 is a schematic sectional view showing a structure of a composite package for a semiconductor device according to a fourth embodiment of the present invention.

FIG. 6 is a diagram showing a relationship between bonding strength of a composite package for a semiconductor device and a center line average roughness Ra of a ceramic substrate surface according to a fourth embodiment of the present invention.

FIG. 7 is a schematic sectional view showing a structure of a composite package for a semiconductor device according to a fifth embodiment of the present invention.

FIG. 8 is a process diagram illustrating a method for manufacturing a composite package for a semiconductor device according to a fifth embodiment of the present invention.

FIG. 9 is a schematic sectional view showing a state in which a composite package for a semiconductor device according to a sixth embodiment of the present invention is joined to a mounting board with solder balls.

FIG. 10 is a diagram showing the relationship between the thickness of a resin substrate and the thermal resistance of a composite package for a semiconductor element.

FIG. 11 is a diagram showing the relationship between the thickness of a resin substrate and the warpage of a composite package for a semiconductor element.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 semiconductor chip 3 solder ball 5 mounting board 9 metal substrate 10 resin substrate 11 ceramic substrate 12 through-hole metal 12 a, 34 land 13 adhesive 15 void 19 aluminum nitride (green sheet) 21 copper foil 22 silver bump 23 liquid crystal polymer 24 Solder / resist 35 Surface wiring (input / output pad) 39 Solder ball connection pad 41,44 Plating layer 55 Protrusion bump 91,92 Groove

Claims (4)

[Claims] 1. A semiconductor element package comprising a high thermal conductive material substrate and a resin substrate bonded to each other, wherein a groove is provided on a surface of the high thermal conductive material substrate facing the resin substrate. And composite package. 2. A semiconductor element package comprising a high thermal conductive material substrate and a resin substrate bonded to each other, wherein a center line average roughness Ra ≧ 0 of a surface of the high thermal conductive material substrate facing the resin substrate. A composite package having a thickness of 0.05 μm. 3. A package for a semiconductor device, comprising a high thermal conductive material substrate and a resin substrate bonded to each other, wherein the high thermal conductive material substrate has a land portion having a groove, and is provided with a protrusion bump. A composite package, wherein the land having the groove and the land of the resin substrate are electrically connected to each other. 4. A semiconductor element package formed by bonding a high thermal conductive material substrate and a resin substrate, wherein the semiconductor element package has a void portion directly above or immediately below a connection pad serving as an electrical connection portion with a mounting board. Wherein the adhesive is formed non-uniformly, and the high thermal conductive material substrate and the resin substrate are bonded to each other.