JPH11220050A - Semiconductor package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor package superior in heat radiation which is used for consumer devices such as an electronic device, an electrical apparatus, a communication device, and a measurement/control device. SOLUTION: A through-hole conductor 6 embedded with a connection conductor is formed at a via hole which electrically connects a surface of a wiring board 1, where a semiconductor device 4 is mounted to a surface on which, facing the surface, metal balls 3 are arrayed. With a configuration in which the metal ball 3 is formed directly below the connection conductor, a semiconductor package is sufficiently heat-radiated, while the junction strength of the metal ball 3 is enhanced for a semiconductor package of superior reliability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor package used for electric equipment such as electronic equipment, electric equipment, communication equipment and measurement control equipment.

[0002]

2. Description of the Related Art A conventional semiconductor package is composed of a wiring board made of a resin material such as polyimide or polyester. A semiconductor device is mechanically mounted on a first surface of the wiring board. Each of the electrode pads is electrically connected to a plurality of wiring electrodes formed on the first surface of the wiring board with metal wires. On the other hand, a plurality of solder balls are arranged on the second surface of the wiring substrate so as to be planar with a predetermined dimension with respect to the second surface, and a semiconductor provided on the first surface of the wiring substrate A device is electrically connected to each of the plurality of solder balls via a plurality of via holes for electrically connecting the first surface and the second surface of the wiring substrate. Each of the plurality of solder balls is formed at a position apart from each of the via holes, and is electrically connected to a wiring conductor formed on the second surface of the wiring board.

[0003]

However, the conventional structure of a semiconductor package uses a resin substrate as a wiring substrate and electrically connects a semiconductor device to a solder ball via a via hole and a wiring conductor. ,
There has been a problem that heat conduction as the semiconductor package itself is poor, a high-power semiconductor device cannot be used, and applications are extremely limited.

An object of the present invention is to provide a semiconductor package having excellent heat dissipation.

[0005]

In order to solve the above-mentioned problems, a semiconductor package according to the present invention is provided with a wiring board provided with a concave portion having a metal foil band at a bottom portion, and a die-bonding in the concave portion of the wiring substrate. A semiconductor chip, provided on one surface of the wiring substrate, connected by a metal wire between the plurality of electrode pads of the semiconductor chip, and a number of wiring electrodes less than the number of the electrode pads, Provided on the other surface of the wiring board, the same number of ball electrodes as the wiring electrodes connected via a through-hole conductor between the wiring electrodes provided on the one surface, and each of these ball electrodes And a bonded metal ball. With this configuration, sufficient heat dissipation as a semiconductor package can be achieved.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to a wiring board provided with a concave portion having a metal foil band at the bottom,
A semiconductor chip die-bonded in a recess of the wiring board and a plurality of electrode pads of the semiconductor chip provided on one surface of the wiring board and connected by a metal wire; A smaller number of wiring electrodes than the number of
A semiconductor package including the same number of ball electrodes as the wiring electrodes connected to the wiring electrodes provided on the one surface via through-hole conductors, and metal balls bonded to each of these ball electrodes. This has the effect that sufficient heat dissipation as a package can be achieved.

According to a second aspect of the present invention, there is provided a wiring board having a hole in which an upper opening is closed with a metal foil strip, a semiconductor chip die-bonded in the hole of the wiring board, and one of the wiring boards. A wiring electrode provided on the surface and connected to the electrode pad of the semiconductor chip by a metal wire, and provided on one surface of the wiring substrate so as to be set around the wiring electrode; A semiconductor package including a ball electrode connected between the ball electrodes via a through-hole conductor, and a metal ball bonded to the ball electrode. A wiring board including a semiconductor chip is easily bonded to a circuit board. Has the effect that

According to a third aspect of the present invention, in the first aspect of the present invention, provided on the other surface of the wiring board,
A wiring electrode electrically connected to the metal foil strip, and connecting the wiring electrode to one of ball electrodes to which a metal ball provided on one surface of the wiring board is bonded via a through-hole conductor; It is a connected semiconductor package, and has an effect of quickly transmitting heat generated from a semiconductor chip to metal balls.

[0009] The invention according to claim 4 is the invention according to claims 1, 2, and
3. In the invention according to any one of the items 3, the metal foil strip provided on the wiring board is thermally bonded to a heat sink provided on the parent board when the metal foil strip is surface-mounted on the parent board via the metal ball. The semiconductor package is configured to be coupled, and has an effect that the metal ball and the through-hole conductor are easily metal-coupled to each other to increase the bonding strength.

According to a fifth aspect of the present invention, in the first or the second aspect of the present invention, the semiconductor package is a semiconductor package in which metal balls are made of solder, and has an effect of realizing a semiconductor package having good heat dissipation.

According to a sixth aspect of the present invention, in the first or second aspect of the present invention, the through-hole conductor is a semiconductor package made of a material having good heat conductivity, and an operation capable of realizing a semiconductor package having good heat dissipation. Having.

According to a seventh aspect of the present invention, in the first or second aspect, the through-hole conductor is a semiconductor package made of solder, and has an effect of realizing a semiconductor package having good heat dissipation.

According to an eighth aspect of the present invention, in the first or the second aspect of the present invention, the metal ball and the through-hole conductor are made of a solder made of the same material, and a semiconductor package having good heat dissipation can be realized. Has an action.

According to a ninth aspect of the present invention, in the first or the second aspect of the present invention, the wiring board is a semiconductor package made of ceramic, and has an effect of further improving thermal properties.

A tenth aspect of the present invention is the semiconductor package according to the first or second aspect, wherein the metal ball and the through-hole conductor are made of the same material solder, and the melting points of the solders are different from each other. It has the effect of realizing no semiconductor package.

(First Embodiment) FIG. 1 is a sectional view of a semiconductor package according to a first embodiment of the present invention. FIG.
In the figure, reference numeral 1 denotes a wiring board, whose material is ceramic (alumina sintered) or the like. Reference numeral 2 denotes a recess formed by closing the bottom of the through hole provided in the wiring board 1 with a copper foil 10 serving as a metal foil strip. A semiconductor device (bare chip) 4 is mounted in the recess 2 of the wiring board 1. , Die bonding. The wiring board 1 is composed of a multilayer wiring board, and a wiring electrode 12 is formed on one surface of the wiring board 1. Each of the electrode pads 11 of the semiconductor device 4 die-bonded in the recess 2. Are electrically connected to the respective wiring electrodes 12 by metal wires 7 formed by a wire bonding method. The wiring board 1 has a through-hole conductor 6 for electrically connecting a wiring electrode 12 formed on a surface to which a semiconductor device 4 is wire-bonded to a metal ball 3 arranged on a surface facing the surface. The metal ball 3 is provided for a ball electrode 13 provided immediately below the through-hole conductor 6. The ball electrodes 13 of the wiring board 1 are arranged so as to spread in a plane with a predetermined size. In order to connect with each other, a wiring conductor 14 having a multilayer structure is provided in the wiring board 1. Then, the wiring board 1
The through-hole conductor 6 connecting the wiring electrode 12 and the ball electrode 13 has a via hole formed by forming a conductive material on a hole wall provided in the substrate, and a heat generated from the semiconductor device 4 by a circuit board (not shown). In order to quickly conduct heat to the via hole, the connection hole is formed of a connection conductor formed in the via hole. An Ag-Pd paste is used as a conductive material for the via hole, and solder is used as the connection conductor. Reference numeral 5 denotes a high heat conductive insulating adhesive formed on the surface of the wiring substrate 1 on which the semiconductor device 4 is mounted. The wiring conductor 14 formed as a circuit pattern on the wiring board 1 on which the semiconductor device 4 is mounted and the wiring electrode 12 to which the metal line 7 is bonded are connected between the via holes. Here, an Ag-Pd-based paste is used for the wiring conductor 14 and the wiring electrode 12. Reference numeral 8 denotes a first protective resin for protecting the metal wire 7 that electrically connects the semiconductor device 4 and the wiring board 1 with a wire bonding apparatus. Reference numeral 9 denotes a second protective resin formed on the first protective resin 8 for planarization so that an automatic surface mounter can be used, and further protecting the semiconductor device 4.
Reference numeral 3 denotes a metal ball formed immediately below the connection conductor filled in the via hole. Here, a eutectic solder is used for each of the connection conductor as the through-hole conductor 6 and the metal ball 3, and the melting point of the solder as the connection conductor is higher than the melting point of the solder as the metal ball 3. The melting point of the solder for the connection conductor is 290 degrees, and the metal balls 3
The melting point of the solder used is 250 degrees.

On the other hand, a conductive material for a via hole is printed on one side of a ceramic wiring board 1 provided with a plurality of holes for a via hole using an Ag-Pd-based paste, and a wiring electrode 12 is printed on the other side. Is printed with a conductive material for via holes using an Ag-Pd-based paste. Thereafter, baking is performed at 850 degrees to bake the Ag-Pd based paste. Next, eutectic solder is filled into each via hole of the wiring board 1 to form connection conductors, and then metal balls 3 are formed by eutectic solder immediately below the connection conductors.
To form At this time, the plurality of metal balls 3 are arranged in a plane with a predetermined dimension from the surface of the wiring board 1. Next, the semiconductor device 4 is mounted on the wiring board 1, the processing of the metal wires 7 is performed by the wire bonding method, the resin is sealed with the first and second protective resins 8 and 9, and a desired semiconductor package is formed. It is said.

In this semiconductor device, the metal balls 3
Since the melting point of the solder as the connection conductor is higher than that of the solder as above, there is no re-melting of the connection conductor previously formed when the metal ball 3 is formed, and disconnection of the connection conductor can be prevented.

The semiconductor device having the above configuration is surface-mounted on a circuit board (not shown) by a surface automatic mounting machine, and an external voltage is applied from the electrode pads of the circuit board through the metal balls 3 of the wiring board 1 to the connection conductors, The semiconductor device 4 is electrically connected to the semiconductor device 4 through a metal wire 7, performs a specific circuit process in the semiconductor device 4, and is output to a circuit board through the electrical connection path. At this time, the heat generated in the semiconductor device 4 is conducted from the semiconductor device 4 to the wiring board 1 through the high heat conductive insulating adhesive 5, and then from the metal ball 3 to the circuit board via the connection conductor. Further, it is released from the surface of the wiring board 1 into the air.

(Embodiment 2) FIG. 2 is a sectional view of a semiconductor package according to a second embodiment of the present invention. FIG.
In the figure, the same reference numerals are given to the same components as those in the first embodiment, and the description will be omitted. In a second embodiment,
The difference from the first embodiment is that a multilayer wiring board 21 made of ceramic having a hole 22 opened downward is used. Here, the wiring board 21 is formed by bonding an aluminum plate 30 as a metal foil band at the upper opening of the through hole, and the semiconductor device 4 is die-bonded in the hole 22 to form the semiconductor device 4. The plurality of electrode pads 11 are located on the first
To the ball electrodes 13 electrically connected to the wiring electrodes 12 provided on the surface of the wiring board 21 by the metal wires 7 and arranged in a plane on one surface of the wiring board 21 by the through-hole conductors 6 and the wiring conductors 14. Connected, each ball electrode 1
3 is that the metal ball 3 is formed. Here, the aluminum plate 30 is configured to also serve as either the power supply path or the ground path, and
Needless to say, one of the ball electrodes 13 is electrically connected to the ball electrode 13 by the through-hole conductor 6.

In this embodiment, the case where the wiring substrate is made of a ceramic substrate has been described, but a resin substrate may be used instead of the ceramic substrate. In this case as well, solder is buried in a via hole that electrically connects the surface on which the semiconductor device is mounted on the resin substrate and the surface on which the metal balls facing the surface are arranged and formed, and the solder ball is placed immediately below the via hole. With the configuration that forms
As well as sufficient heat dissipation as a semiconductor package,
The bonding strength of the solder ball can be increased.

Although the semiconductor device is mounted by the wire bonding method, the semiconductor device may be mounted on the wiring board by a flip chip bonding method or the like.

[0023]

As described above, in the semiconductor package of the present invention, a wiring board having excellent heat dissipation, a surface on which a semiconductor device is mounted on the wiring board, and metal balls facing the surface are arranged. By embedding the connection conductor in the via hole that electrically connects the surfaces, making it a through-hole conductor, and forming metal balls directly under this connection conductor, it has excellent heat dissipation properties for heat generating components such as bare chips for high power. Semiconductor package can be realized.

[Brief description of the drawings]

FIG. 1 is a sectional view of a semiconductor package according to an embodiment of the present invention.

FIG. 2 is a sectional view of a semiconductor package according to a second embodiment of the present invention;

[Explanation of symbols]

 1, 21 Wiring board 2 Depression 3 Metal ball 4 Semiconductor device 5 High heat conductive insulating adhesive 6 Through hole conductor 7 Metal wire 8 First protective resin 9 Second protective resin 10, 30 Metal foil strip 11 Electrode pad 12 Wiring electrode 13 Ball electrode 14 Wiring conductor

Claims (10)

[Claims] A wiring board provided with a concave portion having a metal foil band at a bottom portion; a semiconductor device die-bonded in the concave portion of the wiring substrate; and a semiconductor device provided on one surface of the wiring substrate, A plurality of wiring electrodes connected to the plurality of electrode pads by a metal wire, and a number of wiring electrodes smaller than the number of the electrode pads; and a wiring electrode provided on the other surface of the wiring substrate and provided on the one surface. A semiconductor package comprising the same number of ball electrodes as the above-mentioned wiring electrodes connected to each other through a through-hole conductor, and metal balls bonded to each of these ball electrodes. 2. A wiring board provided with a hole having an upper opening closed by a metal foil strip, a semiconductor device die-bonded in the hole of the wiring board, and a semiconductor device provided on one surface of the wiring board, A wiring electrode connected to a device electrode pad with a metal wire, and a through-hole conductor is provided on one surface of the wiring board so as to be set on the outer periphery of the wiring electrode, and between the wiring electrode and the wiring electrode. A semiconductor package including a ball electrode connected through the ball electrode and a metal ball joined to the ball electrode. 3. The semiconductor device according to claim 1, wherein said wiring board is provided on another surface of said wiring board,
A wiring electrode electrically connected to the metal foil strip, and connecting the wiring electrode to one of ball electrodes to which a metal ball provided on one surface of the wiring board is bonded via a through-hole conductor; The semiconductor package according to claim 1, wherein the semiconductor package is connected. 4. A metal foil strip provided on the wiring board is thermally coupled to a heat sink provided on the parent board when the metal foil strip is surface-mounted on the parent board via the metal ball. The semiconductor package according to claim 1, wherein the semiconductor package is configured. 5. The semiconductor package according to claim 1, wherein the metal ball is made of solder. 6. The semiconductor package according to claim 1, wherein the through-hole conductor is made of a material having good heat conductivity. 7. The semiconductor package according to claim 1, wherein the through-hole conductor is made of solder. 8. The semiconductor package according to claim 1, wherein the metal ball and the through-hole conductor are made of the same solder. 9. The wiring board according to claim 1, wherein the wiring board is made of ceramic.
Or the semiconductor package according to 2. 10. The semiconductor package according to claim 1, wherein the metal balls and the through-hole conductors are made of the same material solder, and the solders have different melting points.