JP2001244405A - Semiconductor device and its junction structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device that is capable of high-density packaging and speedy, electric transmission to other electrical circuit elements. SOLUTION: In a semiconductor device 1, semiconductor chips 5 and 6 are joined to an electric in the upper and lower surfaces of a circuit substrate 4 having a plurality of electrodes 2 and 10 on both surfaces. A metal ball 7 of an external terminal is provided near a region where the lower-surface semiconductor chip 6 is joined, and the active area of the semiconductor chip 6 that is joined to a lower surface is provided at the circuit substrate side 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device and a joining structure between the semiconductor device and a printed circuit board.

[0002]

2. Description of the Related Art Conventionally, semiconductor devices such as QFP (Quad Flat Package), TCP (Tape
Carrier Package), BGA (Ball Grid Array), CSP
(Chip Scale or Size Package), CCB (Controlled Co
llapsed bonding) is known.

[0003] The mounting method using the BGA is described, for example, in US Pat.
9,198, USP 5,285,352, USP 5,381,307, USP 5,397,921.

The BGA has a structure in which a semiconductor chip is bonded onto a circuit board and then sealed, and solder balls are mounted on a wiring electrode portion on a surface opposite to the semiconductor chip mounting surface of the circuit board, and are melted. belongs to. In order to mount the BGA on the printed circuit board, the solder ball of the BGA and the wiring electrode portion of the printed circuit board are soldered via the solder ball.

[0005] The structure of a semiconductor device using a conventional BGA will be described with reference to FIGS. FIG. 3A is a cross-sectional view of a semiconductor device, and FIG. 3B is a cross-sectional view of a bonding structure in which the semiconductor device is bonded to a printed circuit board.

In FIG. 3A, reference numeral 101 denotes a circuit board having circuit patterns and electrode portions on both surfaces. Circuit board 1
The semiconductor element 102 is die-bonded to one surface of the semiconductor device 102. Die-bonded semiconductor device 1
02 is transfer-molded with resin 103 and sealed.

[0007] Solder paste is printed on the electrode portion 104 on the surface opposite to the surface to which the semiconductor element 102 is bonded. After the solder balls are mounted on the solder paste, the solder paste and the solder balls are melted through a reflow process. A spherical terminal 105 is formed. The solder paste flux is removed by washing, and the semiconductor device 10 is removed.
6 are formed.

Next, a joint structure between the semiconductor device and the printed circuit board will be described with reference to FIG. Electrode part 10 of printed circuit board 107 having circuit pattern and electrode part 108 on both sides
8, a solder paste is applied, the electrode portion 104 of the semiconductor device 106 and the electrode portion 108 of the printed board 107 are positioned, and the spherical terminal 105 of the semiconductor device 106 is mounted on the solder paste of the electrode portion 108 of the printed board 107. . Thereafter, the soldering is performed by melting the spherical terminal 105 and the solder paste through a reflow process. Thus, the electrode portion 104 of the semiconductor device 106 and the electrode portion 108 of the printed board 107 are electromechanically joined.

[0009] The method using the CSP is described, for example, in USP 5,346,8.
61, USP 5,592,025.

[0010] The CSP prints cream solder on the electrode portion on the opposite side of the semiconductor chip mounting surface of the flexible substrate on which the semiconductor chip has been bonded and resin-sealed, and places a solder ball on the solder paste to flow into a reflow soldering process. And the solder ball is integrally formed with the electrode portion of the flexible substrate. A cream solder is applied to the wiring electrodes of the printed circuit board, the solder balls are positioned and mounted, and the electrodes of the flexible board of the CSP and the electrodes of the printed circuit board are electrically and mechanically joined through a reflow soldering process.

The method using CCB is described, for example, in US Pat. No. 3,292,2.
40, USP 3,303,393.

US Pat. No. 3,303,393 discloses a ball-shaped terminal for electromechanically connecting a circuit board on which a circuit pattern for electrically connecting an electric circuit element is formed and a chip element board on which a semiconductor is mounted. There is a disclosure of a configuration in which an element is mounted on the chip element via solder coating, a terminal portion of a circuit pattern of the circuit board is aligned with the terminal element, and a solder reflow process is performed to join the solder.

[0013]

In the case of the conventional semiconductor device bonding structure of the BGA system and the CSP system, there is a problem that a high-density mounting structure cannot be obtained because the semiconductor device is one chip.

[0014] Further, when electric transmission between the BGA, CSP and other electric circuit elements is performed at high speed, problems related to electricity such as generation of delay and noise occur.

Semiconductor devices having a junction structure of the BGA system and the CSP system are used by being incorporated in many products such as electric equipment, communication equipment, and office machines. The demand is increasing.

In order to achieve high-density mounting of BGA and CSP,
Although the distance from other electric circuit elements has been reduced, or other electric circuit elements have been mounted on the back surface of the circuit board to increase the density, there has been a limit.

In the case where high-speed electric transmission is performed between the BGA, CSP and another electric circuit element, a signal is transmitted by narrowing the interval between the electric circuit element and the other electric circuit element or mounting the electric circuit element on the back surface of the other electric circuit element. The pattern of the circuit board to be made is made as short as possible, and the circuit pattern is determined by the transmission circuit simulation, and the circuit board is made difficult to generate noise.However, the speeding up of electric signals in recent years has also caused limitations. .

An object of the present invention is to provide a semiconductor device capable of high-density mounting and capable of high-speed electric transmission with another electric circuit element, and a bonding structure thereof.

[0019]

As a result of intensive studies conducted by the present inventors, they have found that the above-mentioned problems can be solved by packaging a semiconductor device into two chips and one package, and have completed the present invention. .

That is, the present invention described in claim 1 provides:
A semiconductor device in which a semiconductor chip is bonded to an electrode portion on each of an upper surface and a lower surface of a circuit board having a plurality of electrode portions on both surfaces, and a metal sphere serving as an external terminal is provided near a region on the lower surface where the semiconductor chip is bonded. The present invention relates to a semiconductor device, wherein an active area of a semiconductor chip bonded to a lower surface is provided on a circuit board side.

According to a second aspect of the present invention, in the semiconductor device, an active area of a semiconductor chip to be bonded to an upper surface is provided on a circuit board side.

According to a third aspect of the present invention, there is provided a bonding structure of a semiconductor device, wherein a metal ball as an external terminal of the semiconductor device and an electrode portion of a printed circuit board are soldered. .

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment FIGS. 1A and 1B show a first embodiment. FIG.
FIG. 1A is a diagram illustrating a semiconductor device 1, and FIG. 1B is a diagram illustrating a bonding structure in which the semiconductor device 1 is solder-bonded to a printed circuit board 13, both of which are cross-sectional views.

First, a semiconductor device 1 of the present invention will be described with reference to FIG.

In a semiconductor device 1 of the present invention, a semiconductor chip 5 is joined to an electrode portion 2 on an upper surface of a circuit board 4 having a plurality of electrode portions 2, 10 and a pattern (not shown) on the upper and lower surfaces. The semiconductor chip 6 has an electrode portion 10
Is joined to. An electrode portion 3 of an external terminal is provided on the lower surface of the circuit board 2, and the electrode portion 3 is provided with a solder ball, so that the semiconductor chips 5, 6 can be electrically connected to the outside. ing.

The position of the electrode portion 3 of the external terminal is
And the vicinity of the region where the semiconductor chip 6 is mounted. The semiconductor chip 6 is mounted so that its active area is in contact with the circuit board 4 side. The active area in the present invention refers to an area where a circuit element is formed on a semiconductor chip.

Since the semiconductor chip 6 is mounted so that its active area is in contact with the circuit board 4 side, since the electrode portions 10 of the circuit board 4 can be set to the outer dimensions of the semiconductor chip 6, the number of solder balls 7 is reduced. Since the number of pins can be increased, the number of pins of the semiconductor device 1 can be increased.

The semiconductor chip 5 and the semiconductor chip 6 are sealed with resins 8 and 11, respectively. Semiconductor chip 5
Is bonded to the electrode 2 on the upper surface of the circuit board 4 by wire bonding, and the semiconductor chip 6 has a solder bump 9 provided on the semiconductor chip 6 and an electrode portion 10 of the circuit board 4 soldered.

One embodiment of the method for manufacturing the semiconductor device 1 of the present invention will be described below.

A semiconductor chip 5 is wire-bonded to an upper surface of a circuit board 4 provided with a plurality of electrodes 2 and 10 and a pattern on the upper and lower surfaces and an electrode portion 3 of an external terminal on the lower surface, and is transfer-molded with a resin 8. . Thereafter, a solder paste is applied to the electrode portion 10 on the lower surface of the circuit board 4, and the semiconductor chip 6 having the solder bump 9 is positioned and mounted.
The solder ball 7 is also mounted on the electrode portion 3 of the external terminal at the same time,
In the reflow process, the solder paste, the solder bumps 9 and the solder balls 7 are heated and melted and joined. Next, the flux of the solder paste is removed by washing, and the semiconductor chip 6 is sealed with the resin 11 to obtain the semiconductor device 1.

Next, referring to FIG. 1B, a description will be given of a joint structure between the semiconductor device 1 and the printed circuit board 13. FIG.

First, after the solder paste is applied to the electrode portion 12 of the printed board 13 by printing or dispensing, the electrode portion 3 of the semiconductor device 1 and the printed board 13 are positioned, and the solder balls 7 of the semiconductor device 1 are attached to the printed board 13. Mounted on the solder paste. Thereafter, the solder paste and the solder balls 7 are heated and melted by a reflow heating process to achieve electromechanical connection to obtain a joint structure. In this reflow heating process, the solder bumps 9 of the semiconductor chip 6 are formed.
Melted, but there was no problem.

Thereafter, the electric characteristics were measured, and good electric characteristics were obtained. From the conventional two-chip two-package configuration,
Electromagnetic noise has also been reduced. Second Embodiment FIGS. 2A and 2B show a second embodiment. FIG.
2A shows the semiconductor device 26, and FIG.
6 is a view showing a joint structure in which the printed circuit board 27 is joined by soldering, and both are sectional views.

The semiconductor device 26 of the present invention comprises a circuit board 22 having a plurality of electrode portions 29, 31 and a pattern (not shown) on the upper and lower surfaces and further having an electrode portion 32 for external terminals on the lower surface.
The semiconductor chip 21 is mounted on the upper surface and the semiconductor chip 23 is mounted on the lower surface. Solder ball 2 is applied to electrode part 32 of the external terminal.
4 for connection to the outside. The position of the electrode portion 32 of the external terminal is on the lower surface of the circuit board 22 and near the region where the semiconductor chip 23 is mounted.

The semiconductor chips 21 and 23 are mounted so that their active areas are in contact with the circuit board 22.

The semiconductor chip 21 and the semiconductor chip 23
Each is sealed with resin 25. Semiconductor chip 21
Are solder-bonded between the solder bumps 28 provided on the semiconductor chip 21 and the electrode portions 29 of the circuit board 22. In the semiconductor chip 23, the solder bumps 30 provided on the semiconductor chip 23 and the electrode portions 31 of the circuit board 22 are soldered in the same manner as in the first embodiment.

The size of the semiconductor device 26 can be reduced by mounting the semiconductor chips mounted on the upper and lower surfaces so that the active areas thereof are in contact with the circuit board 22 side.

In order to manufacture the semiconductor device shown in FIG. 2A, for example, the semiconductor chip 21 on the upper surface of the circuit board 22 is reflow-connected in the same manner as in the first embodiment, and then the lower surface of the circuit board 22 is manufactured. Semiconductor chip 23 and solder ball 2
4 is subjected to reflow connection in the same manner as in the first embodiment, and thereafter, the flux of the solder paste is removed by washing, and the semiconductor chips 21 and 23 are sealed with a resin 25 to obtain a semiconductor device 26.

FIG. 2B shows a connection structure between the semiconductor device 26 and the printed circuit board 27 shown in FIG. FIG.
The connection structure of (b) is the same as that of the first embodiment, and the description is omitted.

In this embodiment, the upper surface and the lower surface of the circuit board 22 are separately subjected to reflow processing.
The semiconductor chip 21 on the upper surface, the semiconductor chip 23 on the lower surface, and the solder ball 24 may be simultaneously subjected to reflow heating to perform solder joining.

In this example, the semiconductor device 26 has good electrical characteristics. In addition, the structure joined to the semiconductor device 26 and the circuit board 27 also has good electrical characteristics, and has lower noise than the conventional two-chip two-package structure.

[0042]

According to the first aspect of the present invention, the conventional two-chip, two-package package is made into two-chip, one-package, and the apparent number of components in one package is reduced. Densification was obtained. Also,
By providing the active area of the semiconductor chip mounted on the lower surface on the circuit board side, the number of pins of the semiconductor device can be increased.

Conventionally, signal transmission between packages has been performed via a printed circuit board. However, since the signal can be processed in one package and the wiring length is shortened, the delay of electric signals is reduced, and the noise is reduced. It was planned. This has a remarkable effect as the electric signal speed increases.

According to the second aspect of the present invention, in addition to the above effects, the size of the semiconductor device can be reduced.

According to the third aspect of the present invention, it is possible to provide a bonding structure capable of high-density mounting, high-speed electric signal and low noise.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view of a semiconductor device according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view illustrating a bonding structure between the semiconductor device of the present invention and a printed circuit board.

FIG. 2A is a cross-sectional view of a semiconductor device showing another embodiment of the present invention, and FIG. 2B is a cross-sectional view showing a joint structure between the semiconductor device of the present invention and a printed circuit board.

FIG. 3A is a sectional view of a conventional semiconductor device,
FIG. 3B is a cross-sectional view illustrating a conventional bonding structure between a semiconductor device and a printed circuit board.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor device 2, 10 Electrode part 3 External terminal electrode part 4 Circuit board 5, 6 Semiconductor chip 7 Solder ball 8, 11 Resin 12 Electrode part 13 Printed board 26 Semiconductor device 29, 31 Electrode part 32 External terminal electrode part 22 Circuit boards 21, 23 Semiconductor chip 24 Solder balls 25 Resin 27 Printed board 33 Electrode unit 101 Circuit board 102 Semiconductor chip 103 Resin 104 Electrode unit 105 Solder ball 106 Semiconductor device 107 Printed board

Claims (3)

[Claims] 1. A circuit board having a plurality of electrode portions on both surfaces, a semiconductor chip is bonded to an electrode portion on each of an upper surface and a lower surface, and a metal ball as an external terminal is provided near a region on the lower surface where the semiconductor chip is bonded. Wherein an active area of a semiconductor chip bonded to a lower surface is provided on a circuit board side. 2. The semiconductor device according to claim 1, wherein an active area of the semiconductor chip bonded to the upper surface is provided on the circuit board side. 3. A bonding structure for a semiconductor device, wherein a metal ball as an external terminal of the semiconductor device according to claim 1 and an electrode portion of a printed circuit board are soldered.