JP2001177226A - Printed-wiring board and/or back-surface electrode type electrical component and electrical component device provided with printed-wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent cracks from being generated at a solder connection part by increasing the size of the soldering part of the electrode terminal of a mounted BGA. SOLUTION: In back-surface electrode type electric components connected via a printed-wiring board and a bump electrode, specific electrodes that can be integrated by an integration land 5 of the wiring board are gathered at a position, where stresses at a connection part to the printed-wiring board is generated easily. In a substrate for mounting the back-surface electrode type electric components, the back-surface electrode type electric components are equipped with the integration land for allowing the specific electrodes that can be integrated to be subjected to bump connection.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed wiring board in which bump electrodes such as solder balls are arranged on the back surface of a component, and a back electrode type electrical component and an electrical component device including the printed wiring board.

[0002]

2. Description of the Related Art With the miniaturization of products such as those of portable information terminals in recent years, the back electrodes (Bal
1 Grid Array (hereinafter referred to as “BGA”) type electric components have also been miniaturized, and the BGA electrode terminals provided have also become smaller. With these miniaturization, BGA
Since the soldered connection for conducting the electrode terminals of the die-shaped electric component and the printed wiring board is also reduced, the resistance to thermal cycle stress and external stress is reduced.

FIG. 8 is a sectional view showing a conventional BGA type electric component and a printed wiring board substrate to which the BGA type electric component is attached. 8, reference numeral 11 denotes a BGA, 12 denotes a BGA-side terminal land, 13 denotes a solder connection, 14 denotes a corner connection,
Reference numeral 15 denotes a substrate, and 16 denotes a land of the substrate.

Japanese Patent Application Laid-Open No. H10-56093 discloses that a dummy electrode is provided at a corner of a BGA terminal array (one terminal corresponds to one substrate land), so that cracks are formed in a solder connection portion of the dummy electrode during a heat cycle. The description describes a semiconductor device in which the connection of signal electrodes is protected even if a crack occurs, and an electronic device incorporating the semiconductor device.

Japanese Patent Application Laid-Open No. 9-330993 discloses a semiconductor device having a BGA structure. In this semiconductor device, first, solder bump formation lands are divided and formed, and wirings connected between semiconductor chips are separated and separately drawn to divided lands. Thereafter, a semiconductor chip is mounted, testing is performed using the divided lands, and solder bumps are formed with solder balls or the like. This facilitates testing of a semiconductor device formed by mounting a plurality of semiconductor chips.

[0006]

In general, when a thermal cycle stress is applied to a printed wiring on which a BGA is mounted due to a change in environmental temperature or a change in the heat generated by the BGA itself, a BGA is generated.
Distortion occurs due to the difference between the GA and the coefficient of thermal expansion of the printed wiring board. This distortion often concentrates on the square connection portion located on the outer periphery of the BGA terminal, and when the solder connection portion cannot withstand this distortion, cracks are likely to occur in the solder connection portion.

Further, when an external force such as bending of a substrate is applied to a printed wiring board on which a BGA is mounted, the most susceptible to stress deformation is that there are few adjacent (possible to disperse stress) connection terminals, These are the four corners of the BGA terminal array where the amount of deformation of the printed wiring board is the largest, and the destruction of the electrode connection portion due to stress deformation often proceeds from the four corners to the inside of the electrode array.

Therefore, in order to improve the connection reliability of the BGA, it is necessary to improve the solder connection strength at the four corners of the terminal arrangement.

Even if the solder bump formation land is divided and formed, the size of the connection portion between the semiconductor bump formation land and the solder ball does not change, so that cracks do not occur in the solder connection portion. .

Accordingly, an object of the present invention is to increase the size of the soldered portion of the electrode terminal of the mounted BGA so that cracks are not generated at the soldered portion.

[0011]

According to the present invention, there is provided a printed wiring board on which a back electrode type electric component having a plurality of BGA (ball grid array) electrode terminals is mounted.
It is characterized in that it comprises an integrated land which is integrally connected to a plurality of BGA electrode terminals existing at the corners of the back electrode type electrical component among the GA electrode terminals.

The present invention also provides a back electrode type electric component,
An electrical component device comprising a combination with a printed wiring board, wherein the back electrode type electrical component has a plurality of BGA (ball grid array) electrode terminals, and the printed wiring board is one of the BGA electrode terminals. It is characterized by comprising an integrated land integrally connected to a plurality of BGA electrode terminals present at the corners of the back electrode type electric component. Further, the present invention is an electric component device comprising a combination of a back electrode type electric component and a printed wiring board, wherein the back electrode type electric component is a BGA (ball grid array).
A plurality of electrode terminals;
Among the GA electrode terminals, the integrated circuit has an integrated land integrally connected to a plurality of BGA electrode terminals present at the corners of the back electrode type electric component, wherein the back electrode type electric component and the printed wiring board are connected to each other. It is characterized by being connected.
The present invention is also an electric component device comprising a combination of a back electrode type electric component and a printed wiring board, wherein the back electrode type electric component includes a plurality of BGA (ball grid array) electrode terminals, The printed wiring board includes an integrated land integrally connected to a plurality of BGA electrode terminals present at the corners of the back electrode type electric component among the BGA electrode terminals, and One of the integrated lands of the printed wiring board is connected in a many-to-one correspondence to a plurality of BGA electrode terminals present at the corners, and arranged at a position other than the corners of the back electrode type electric component. A plurality of lands arranged at positions other than the integrated lands on the printed wiring board are connected to the plurality of BGA electrode terminals in a one-to-one correspondence. To.

Further, the electric component device of the present invention includes a back electrode type electric component and a printed wiring board.

That is, in the present invention,
The number of lands on the printed wiring board on which the GA is mounted is one for each electrode terminal of the BGA, whereas the integrated terminal group of the BGA is soldered on the integrated land of the board. The soldered portion of the electrode terminal becomes large, and thus the solder connection portion becomes large.
For this reason, the connection strength of the soldered portion is increased, so that the crack due to the thermal cycle stress and the destruction due to the external stress as described above are prevented, and the mounting reliability of the BGA is improved.

[0015]

FIG. 1 shows a first embodiment of the present invention. In the drawing, reference numeral 1 denotes a BGA, 2 denotes a specific electrode which can be integrated, and 3 denotes a general electrode.

In this embodiment, the BGA1
In this embodiment, four ground electrode terminals are provided at the corners as the specific electrodes 2 that can be integrated, respectively.

Alternatively, the electrodes or terminals that can be integrated may take the form of the following (1) to (7).

(1) Assemble ground electrode terminals.
(Or newly provided) (2) Collect non-contact electrode terminals. (Or newly provided) (3) Collect the same signal terminals. (Or newly provided) (4) Collect power supply terminals. (Or newly provided) (5) Assemble the ground electrode terminal and the non-contact electrode terminal.

(6) The same signal terminals and non-contact electrode terminals are assembled.

(7) A power supply terminal and a non-contact power supply terminal are assembled.

FIG. 2 shows a printed circuit board substrate on which the BGA 1 shown in FIG. 1 is mounted. In FIG. 2, reference numeral 4 denotes a substrate, 5 denotes an integrated land, and 6 denotes a general land.
The substrate 4 of this embodiment is characterized in that it has an integrated land 5, and the BGA 4 of the first embodiment shown in FIG.
The corner electrodes 2 are integrated on the same land as an integrated land 5. This makes it possible to increase the size of the soldered portion and improve the connection strength between the soldered BGA type component and the printed wiring board.

FIG. 3 shows a state in which the BGA shown in FIG. 1 is soldered to the substrate 4 shown in FIG. BG
The group of integrated terminals A1 is soldered on the integrated lands 5 of the substrate 4.

As shown in FIG. 4, since the integrated terminals 2 of the BGA of the present invention are soldered on the integrated lands 5 of the substrate 4, the soldered portions of the square electrode terminals of the mounted BGA are: It is much larger than when one terminal and one land are soldered.

That is, a solder connection is made at a large connection portion between the BGA terminal 2 and the integrated land 5 of the board, and the connection strength of the soldered portion at the square portion is greatly improved. Cracks due to thermal cycle stress and destruction due to external stress can be prevented, and the mounting reliability of the BGA can be improved.

In the present invention, the number of specific terminals to be collected at the four corners is not limited to four each, but may be any number.

For example, as shown in FIG. 5, the terminal 2 located at each of the four corners of the BGA 1 and the two terminals 2 arranged along the edge of the BGA 1 and adjacent to each terminal 2 can be integrated. It can be an electrode.

The board 4 for mounting the BGA 1 shown in FIG. 5 is provided with a square integrated land 10 as shown in FIG. This integrated land 10 is connected to each specific electrode 2 of the BGA 1 shown in FIG. 5 by soldering.

The integrated land provided on the substrate integrates the four-sided collective terminals by an arbitrary shape such as an ellipse or an ellipse in addition to the circle shown in FIGS. 2 and 3 and the square shown in FIG. It can be a land shape.

In this embodiment, the case where the BGA 1 is square is described as an example. However, the BGA 1 may have an arbitrary shape such as an octagon or a circle as shown in FIG. B
When the GA 1 is formed in a circular shape, for example, the specific electrodes 2 that can be integrated may be collected at a position where stress is likely to occur.

Here, the position where the stress of the BGA 1 is likely to occur is specified, for example, as follows. That is, a BGA 1 solder-connected to a printed wiring board via bump electrodes
Is inspected for strength after manufacture. This test is B
A stress is applied to a printed wiring board to which GA1 is connected by soldering, or a BGA1 main body, whereby it is checked which of the connection portions between BGA1 and printed wiring board is bent. Incidentally, this bent portion is a position where stress is likely to occur. Therefore, the specific electrode 2 may be collected at a bent portion.

[0031]

According to the present invention, the land of the printed wiring board on which the BGA is mounted is one for each electrode terminal in the conventional BGA. Because of the soldering, the soldered portion of the electrode terminal of the mounted BGA becomes large. Therefore, the size of the solder connection portion is increased, the connection strength of each soldered portion is increased, and the crack due to the thermal cycle stress and the destruction due to the external stress are prevented, and the mounting reliability of the BGA is improved.

[Brief description of the drawings]

FIG. 1 is a plan view showing a component electrode arrangement of a BGA according to a first embodiment of the present invention.

FIG. 2 is a partial plan view showing one example of a substrate for mounting the BGA of FIG. 1;

FIG. 3 is a transparent plan view showing a state in which the BGA of FIG. 1 is mounted on the substrate of FIG. 2;

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a plan view showing a component electrode arrangement of a BGA according to another embodiment of the present invention.

6 is a transparent plan view showing a state where the BGA of FIG. 5 is mounted on a substrate.

FIG. 7 is a plan view showing a shape example of a BGA.

FIG. 8 is a cross-sectional view showing a mounting state of a conventional BGA and a printed wiring board.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 BGA 2 Specific electrode which can be integrated 3 General electrode 4 Substrate 5 Integrated land 6 General land 7 Integrated land solder connection part 8 General land solder connection part 9 BGA side terminal land 10 Integrated land

Claims (22)

[Claims] 1. A printed wiring board on which a back electrode type electric component having a plurality of BGA (ball grid array) electrode terminals is mounted, wherein a corner portion of the back electrode type electric component among the BGA electrode terminals is provided. A printed wiring board comprising an integrated land integrally connected to a plurality of existing BGA electrode terminals. 2. A plurality of BGAs present at corners of the back electrode type electrical component, wherein the back electrode type electrical component has a quadrangular shape.
The electrode terminals are a plurality of BGAs existing at the corners of the square.
The printed wiring board according to claim 1, wherein the printed wiring board is an electrode terminal. 3. A plurality of BGAs, wherein the back electrode type electric component has a polygonal shape and exists at a corner of the back electrode type electric component.
The electrode terminals are a plurality of BGAs existing at the corners of the polygon.
The printed wiring board according to claim 1, wherein the printed wiring board is an electrode terminal. 4. The printed wiring board according to claim 1, wherein said plurality of BGA electrode terminals are composed of only ground electrode terminals. 5. The device according to claim 1, wherein the plurality of BGA electrode terminals are composed of only non-contact electrode terminals.
A printed wiring board according to any one of claims 1 to 3. 6. The printed wiring board according to claim 1, wherein the plurality of BGA electrode terminals include only the same signal terminal. 7. The printed wiring board according to claim 1, wherein the plurality of BGA electrode terminals include only power supply terminals. 8. The printed wiring board according to claim 1, wherein the plurality of BGA electrode terminals include only a ground electrode terminal and a non-contact electrode terminal. 9. The printed wiring board according to claim 1, wherein the plurality of BGA electrode terminals include only the same signal terminal and a non-contact electrode terminal. 10. The printed wiring board according to claim 1, wherein the plurality of BGA electrode terminals include only a power supply terminal and a non-contact electrode terminal. 11. An electric component device comprising a combination of a back electrode type electric component and a printed wiring board, wherein the back electrode type electric component has a plurality of BGA (ball grid array) electrode terminals. The electric component device, wherein the wiring board includes an integrated land that is integrally connected to a plurality of BGA electrode terminals existing at the corners of the back electrode type electric component among the BGA electrode terminals. 12. An electrical component device comprising a combination of a back electrode type electrical component and a printed wiring board, wherein the back electrode type electrical component includes a plurality of BGA (ball grid array) electrode terminals, The wiring board includes an integrated land integrally connected to a plurality of BGA electrode terminals present at the corners of the back electrode type electrical component among the BGA electrode terminals, wherein the back electrode type electrical component; An electrical component device comprising a printed wiring board connected thereto. 13. An electrical component device comprising a combination of a back electrode type electrical component and a printed wiring board, wherein the back electrode type electrical component has a plurality of BGA (ball grid array) electrode terminals, The wiring board includes an integrated land integrally connected to a plurality of BGA electrode terminals at the corners of the back electrode type electrical component among the BGA electrode terminals; Multiple B's in the part
A plurality of BGA electrode terminals are connected to the GA electrode terminals in such a manner that one of the integrated lands of the printed wiring board is connected in a many-to-one correspondence, and arranged at positions other than the corners of the back electrode type electric component. A plurality of lands arranged at positions other than the integrated lands on the printed wiring board in a one-to-one correspondence. 14. A plurality of BGAs present at corners of the back electrode type electrical component, wherein the back electrode type electrical component has a quadrangular shape.
The electrode terminals are a plurality of BGAs existing at the corners of the square.
The electrical component device according to claim 11, wherein the electrical component device is an electrode terminal. 15. A plurality of BGAs, wherein the back electrode type electric component has a polygonal shape and exists at a corner of the back electrode type electric component.
The electrode terminals are a plurality of BGAs existing at the corners of the polygon.
The electrical component device according to claim 11, wherein the electrical component device is an electrode terminal. 16. The semiconductor device according to claim 11, wherein said plurality of BGA electrode terminals comprise only ground electrode terminals.
16. The electric component device according to any one of items 15 to 15. 17. The electric component device according to claim 11, wherein the plurality of BGA electrode terminals are formed only of non-contact electrode terminals. 18. The apparatus according to claim 11, wherein said plurality of BGA electrode terminals are composed of only the same signal terminal.
An electrical component device according to any one of the above. 19. The electric component device according to claim 11, wherein the plurality of BGA electrode terminals are composed of only a power supply terminal. 20. The electric component device according to claim 11, wherein the plurality of BGA electrode terminals include only a ground electrode terminal and a non-contact electrode terminal. 21. The electric component device according to claim 11, wherein the plurality of BGA electrode terminals include only the same signal terminal and a non-contact electrode terminal. 22. The electric component device according to claim 11, wherein the plurality of BGA electrode terminals include only a power supply terminal and a non-contact electrode terminal.