JP2001223291A - Semiconductor device package and its mounting board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance reliability of connection after mounting a CSP while sustaining arrangement of lands, wiring rule and effective number of connection terminals. SOLUTION: A plurality of approximately elliptical electrodes 21 are formed in matrix, while inclining the direction of long axis against the longitudinal/ lateral directions of the matrix, on the ball terminal bonding face 3a of the interposer 3 of a CSP 1. According to a wiring rule, a wiring pattern 5 is formed at a specified distance L from the electrodes 21. The electrodes 21 and the wiring pattern 5 are covered with an insulating protective film 9. Approximately elliptical openings of smaller dimensions than the ball terminal 11 are made in the insulating protective film 9 above the electrodes 21 thus forming primary lands 21a. The primary land 21a is formed obliquely to the row and column directions of the matrix while aligning the direction of long axis with the electrode 21. The ball terminal 11 is bonded to each primary land 21a of the electrode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device package having a plurality of spherical metal lands (referred to as ball terminals) fixed to a back surface thereof, and a mounting substrate on which the semiconductor device package is mounted.

[0002]

2. Description of the Related Art At present, BGA (see U.S. Pat. No. 5,148,265) and .mu.BGA (terminal pitch) are known as those having ball terminals arranged in a matrix on a back surface of a semiconductor device package in which a semiconductor chip is sealed. Is a BGA of 0.8 mm or less, and the CSP (Chip Scale P
ackage). Hereinafter, these semiconductor device packages are collectively referred to as CSP.

FIG. 1 is a schematic configuration diagram showing a CSP.
(A) is a front view, (B) is a plan view seen from below.
2A and 2B are enlarged views of a portion surrounded by a dashed circle in FIG. 1B, wherein FIG. 2A shows a state after ball terminal bonding, and FIG. 2B shows a state before ball terminal bonding. A plurality of circular electrodes 7 are formed in a matrix in the vertical and horizontal directions on a ball terminal bonding surface (rear surface) 3a of a base substrate (hereinafter referred to as an interposer) 3 of a CSP 1 in which a semiconductor chip is arranged and sealed. The wiring pattern 5 is also formed on the ball terminal joining surface 3a at a predetermined distance L from the electrode 7 according to the wiring rule. The electrode 7 and the wiring pattern 5 are covered with an insulating protective film 9. A circular opening having a size smaller than that of the ball terminal 11 is formed in the insulating protective film 9 on the electrode 7, and a primary land (exposed surface portion of the electrode 7) 7a is formed. One ball terminal 11 made of solder etc.
It is joined to the next land 7.

FIGS. 3A to 3E are process diagrams when the ball terminal 11 is fixed to the CSP 1, and FIGS.
FIGS. 4A and 4B are cross-sectional views showing enlarged portions surrounded by broken-line circles in FIGS. In general, the ball terminals 11 are bonded to the primary lands 7a by placing the ball terminals 11 on the primary lands 7a with the ball terminal bonding surface 3a of the interposer 3 facing upward ((A), (B), and ( D)), heat is applied once in a reflow oven or the like to temporarily heat the ball terminal 11 above its melting point (eutectic point if the ball terminal 11 is made of an alloy material) (hereinafter referred to as primary reflow), and the primary land is heated. This is performed by alloying the ball terminal 7a with the ball terminal 11a.

FIGS. 4A to 4E are process diagrams for mounting the CSP 1 on the mounting board 13. FIGS.
(E) is a sectional view showing, in an enlarged manner, a portion surrounded by a broken-line circle in (B) and (C). The mounting substrate 13 on which the CSP 1 is mounted is a substrate 1 made of glass epoxy or the like.
5 is provided. CSP1 is mounted on the mounting surface 15a of the substrate 15.
The circular electrodes 17 are formed at positions corresponding to the ball terminals 11 connected to the electrodes, that is, in a matrix in the vertical and horizontal directions. A wiring pattern (not shown) is also formed on the mounting surface 15a of the substrate 15 at a predetermined distance from the electrode 17 according to a wiring rule. Wiring pattern and electrode 1
7 is covered with an insulating protective film 19. A circular opening having a size smaller than that of the ball terminal 11 is formed in the protective film 19 on the electrode 17, and a secondary land (exposed surface portion of the electrode 17) 17a is formed.

The mounting of the CSP 1 on the mounting board 13 is performed by the CS
The CSP 1 is arranged on the mounting substrate 13 so that the ball terminal 11 fixed to P1 corresponds to the secondary land 17a ((A), (B) and (D)), and heat is applied in a reflow oven or the like to apply the ball terminal 11 to the ball terminal. This is performed by heating (hereinafter referred to as secondary reflow) above the melting point of 11 (eutectic point if ball terminal 11 is made of an alloy material) and alloying ball terminal 11 and secondary land 17a.

The diameters of the primary land 7a and the secondary land 17a are generally equal to or smaller than the diameter of the ball terminal 11. This is because, as shown in FIGS. 1 to 4, the insulating protective films 9 and 19 forming the primary land 7a and the secondary land 17a have a thickness, and the ball terminals 11 are arranged on the primary land 7a. , And the ball terminals 11 fixed to the CSP 1 greatly contribute to the positioning when the ball terminals 11 are arranged on the secondary lands 17a. Furthermore, the shape of the ball terminal 11 after the primary reflow and the mounting substrate 13 of the CSP 1
This is also to maintain the required height and size of the ball terminal 11 in consideration of the mountability to the ball terminal 11.

In the CSP and its mounting board, the arrangement (position and quantity) of the ball terminals is currently determined by EIAJ (Elec).
The standardization is in progress by the TRON (Tronics Industries Association of Japan), etc., but they are arranged in a matrix at an equal pitch, the size of the ball terminal material is uniform for each CSP, and the shape of the ball terminal material Is generally spherical.

The wiring pattern on the ball terminal bonding surface of the interposer and the mounting surface of the mounting board are formed in accordance with the wiring rules. For example, the CSP1 of FIG. 2 will be described as an example. As shown in FIG.
Are formed in accordance with a wiring rule having a certain distance L or more from the electrode 7 so as not to make electrical contact with the electrode 7. Also in the mounting board, the wiring pattern formed in the secondary land formation region is formed according to a wiring rule that does not make electrical contact with the secondary land.

[0010]

The CSP 1 is mounted on the mounting board 1
3 and interposer 3 at the time of secondary reflow
Mechanical stress is concentrated on the ball terminal 11 due to stress generated by the difference in thermal expansion coefficient between the ball terminal 11 and the substrate 15, and cracks occur at the joints between the primary land 7 a and the secondary land 17 a and the ball terminal 11, and the connection is made. It is generally known that defects occur. It is also well known that the mechanical stress varies depending on the positions of the ball terminals 11 arranged in a matrix, and the mechanical stress increases as the ball terminals 11 on the outer peripheral side of the interposer 3 increase. This is because the mechanical stress due to the difference between the thermal expansion coefficients of the interposer 3 and the substrate 15 is accumulated from the center of the interposer 3 toward the outer periphery.

As a conventional technique, a large ball terminal is used in the outer peripheral portion to improve the reliability after mounting (Japanese Patent Laid-Open No.
No. 0-247700) and a ball member made of the same size and material as a ball terminal (effective connection terminal).
Some are used not as connection terminals but as reinforcement members (non-connection terminals) for improving reliability. However, in the former case, the wiring rules of the interposer and the mounting board are hindered due to the large ball terminals, and when the size of the ball terminals is significantly different, the above is contradictory. Needless to say, the latter is directly linked to a decrease in the number of effective connection terminals. If the number of non-connection terminals is increased, the reliability after mounting is improved accordingly, but there is a large risk that the number of effective connection terminals is reduced.

Therefore, the present invention provides an arrangement of primary lands and secondary lands, a wiring density of an interposer and a mounting board, that is, a wiring rule, and an effective number of connection terminals, even if the thermal expansion coefficients of the interposer and the mounting board are different. While maintaining durability, the durability against heat shrinkage stress concentrated on the ball terminals is improved, cracks at the joint between the interposer and the ball terminals and the joint between the ball terminals and the mounting board are suppressed, and the It is an object of the present invention to provide a CSP capable of improving connection reliability and a mounting board thereof.

[0013]

SUMMARY OF THE INVENTION According to the present invention, in order to withstand a stress caused by a difference in thermal expansion coefficient between an interposer after a CSP is mounted on a mounting board and a mounting board, a portion where a ball terminal is disposed on the interposer (primary land). ) And the shape of the mounting portion (secondary land) on the mounting board side have characteristics, so that the arrangement of the primary land and the secondary land and the wiring rules of the interposer and the mounting board are the same, but after mounting. To improve the connection reliability.

[0014] The semiconductor device package according to the present invention comprises:
A semiconductor device package in which a semiconductor chip is mounted and sealed on a surface of a base substrate, and ball terminals are fixed to primary lands arranged in a matrix on the back surface of the base substrate. The primary land has a uniform shape, and at least a part of the primary land includes a non-circular shape having a portion projecting obliquely to the vertical and horizontal directions of the matrix with respect to the circular shape.

The wiring rules for the primary land formation area are as follows:
Since the distance between the center of the next land and the wiring pattern is used as a reference, when the shape of the primary land is circular, there is a margin in the distance between the primary land and the wiring pattern in the vertical and horizontal directions of the matrix. In the CSP according to the present invention, at least a part of the primary land includes a non-circular shape having a portion protruding obliquely with respect to the vertical and horizontal directions of the matrix with respect to the circular shape. As a result, the area of the non-circular primary land is larger than that of the circular primary land even if the same wiring rule as that of the circular primary land is applied. The joint area increases.

In the mounting board according to the present invention, a semiconductor chip is mounted on the surface of a base substrate and sealed, and ball terminals are fixed to primary lands arranged in a matrix on the back surface of the base substrate. A mounting substrate on which a semiconductor device package is mounted, on which a secondary land arranged in a matrix corresponding to the arrangement of the ball terminals of the semiconductor device package is formed, and at least a part of the secondary land is Non-circular shapes having portions protruding obliquely with respect to the vertical and horizontal directions of the matrix are included.

In the mounting board according to the present invention, the aforementioned CS
Similarly to P, at least a part of the secondary land includes a non-circular shape having a portion projecting obliquely to the vertical and horizontal directions of the matrix on the basis of the circle with respect to the circle. As a result, the area of the non-circular secondary land is larger than that of the circular secondary land even if the same wiring rule as that of the circular secondary land is applied.
The bonding area between the secondary land and the ball terminal increases.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION In a CSP and a mounting board thereof according to the present invention, the shape of a non-circular land (refers to a primary land and a secondary land, hereinafter simply referred to as both lands) is elliptical. Alternatively, it is preferable that the shape is formed based on a square. When the ellipse is used as a reference, the major axis of the ellipse is formed in an oblique direction. When the rectangle is used as a reference, sides are formed in the vertical and horizontal directions. As a result, the land can be formed in a non-circular shape having a portion projecting obliquely with respect to the matrix.

The reliability after mounting the CSP on the mounting board is as follows:
As described above, a large factor is caused by mechanical stress due to a difference in thermal expansion coefficient between the CSP and the mounting board. It can be easily inferred from a physical point of view that the mechanical stress accumulates and increases from the center of the CSP interposer toward the outer periphery. In fact, it is already well known that, even in a temperature cycle test after mounting the CSP on the mounting board, a connection failure first occurs at the joint between the outermost land and the ball terminal.

Therefore, the land shape is preferably circular at the center of the matrix arrangement and non-circular at the outer periphery. As a result, the bonding area between the land and the ball terminal is larger in the land on the outer peripheral portion than in the land in the central portion, so that the mechanical stress on the bonding portion between the land and the ball terminal can be dispersed.

The ball terminal is fixed to the primary land at the time of primary reflow. In the prior art, the bonding position of the ball terminal is determined by the circular shape of the primary land. When arranging the ball terminal material on the circular primary land, even if the ball terminal moves within the primary land, since the contour of the primary land is circular, the ball terminal material melted at the time of the primary reflow is removed. The force is evenly applied to the side wall of the opening on the primary land. Further, the moving range of the ball terminal in the primary land is smaller than the volume of the ball terminal. Therefore, no matter where the ball terminal material exists on the primary land, the shape and joint position of the ball terminal after the ball terminal and the primary land are alloyed by applying heat by primary reflow or the like. Is almost uniform. Therefore, in the prior art, the primary land shape has not been regarded as a problem with respect to the variation in the arrangement position of the ball terminals and the dropout of the ball terminals until the completion of the primary reflow.

When the primary land shape is non-circular as in the CSP according to the present invention, the arrangement position varies due to the movement of the ball terminal, and after the primary reflow or the like is performed due to the variation. There is a possibility that the shape of the ball terminal will vary, or the rate of occurrence of dropping of the ball terminal will increase. Therefore, it is preferable that the non-circular primary land is formed with a projection in which the profile of the primary land protrudes inward to guide the ball terminal to the vicinity of the center of the land. As a result, the arrangement position accuracy of the ball terminals can be improved, and variations in the shape of the ball terminals after primary reflow or the like are performed and the ball terminals can be prevented from falling off.

In the mounting board according to the present invention, the non-circular secondary land is formed with a protruding portion in which the contour of the secondary land protrudes inward for guiding the ball terminal near the center of the land. Is preferred. As a result, it is possible to improve the placement position accuracy of the CSP before the secondary reflow, and it is possible to suppress the variation in the shape of the ball terminal after the secondary reflow or the like and the bonding failure between the ball terminal and the secondary land. .

In the CSP and the mounting board, the land may include a land having a larger area than other lands. In that case, in the prior art, the land and the ball terminal are joined by preparing a ball terminal material for a large area land and arranging a plurality of types of ball terminal materials having different sizes. I will be forced. Therefore, in the CSP and the mounting board according to the present invention, a plurality of ball terminals are fixed to the large area land, and the contour of the land faces inward to guide the plurality of ball terminals to the large area land. It is preferable that a protruding projection is formed. When a larger ball terminal volume is required for joining the large area land and the ball terminal than the other land, a plurality of ball terminal materials identical to the ball terminal material arranged on the other land are arranged on the large area land. As a result, a plurality of types of ball terminal volumes can be achieved with a single ball terminal material without increasing the number of production steps, and it is easy to respond to mass production lines.

[0025]

FIG. 5 is a plan view showing a primary land according to an embodiment of the CSP. FIG.
(B) shows a state before ball terminal bonding. The overall configuration of the CSP is the same as in FIG. A plurality of electrodes 21 having an approximate elliptical shape are formed in a matrix in the vertical and horizontal directions on the ball terminal bonding surface 3a of the interposer 3 of the CSP 1.
The wiring pattern 5 is formed at a predetermined distance L from the electrode 21 according to the wiring rule. The electrodes 21 are arranged with the major axis direction oblique to the vertical and horizontal directions of the matrix.

The electrode 21 and the wiring pattern 5 are covered with a protective material such as a resist or an insulating protective film 9 made of a base material such as polyimide. An approximately elliptical opening having a size smaller than that of the ball terminal 11 is formed in the insulating protective film 9 on the electrode 21, and a primary land (exposed surface portion of the electrode 21) 21a is formed. Primary land 21a
Are formed obliquely to the vertical and horizontal directions of the matrix, with the major axis direction aligned with the electrodes 21. The ball terminals 11 made of solder or the like are joined to the respective electrode primary lands 21a.

In one embodiment of the mounting board, although not shown, a secondary land is formed in the same configuration as that of FIG. 5B. For example, the wiring rules of the interposer and the mounting board are set as follows: wiring pattern width = 100 μm, distance L between land and wiring pattern = 100 μm, dimension from the center of the land in the vertical and horizontal directions (see dimension r in FIG. 5B). = 500
If μm and land pitch = 800 μm, only one wiring pattern can be wired between adjacent lands.

In the embodiment of the CSP shown in FIG. 5 and the embodiment of the mounting board having the same structure as that of FIG. 5B, a portion protruding in the vertical and horizontal directions of the matrix is smaller than that of a circular land having a radius r. Therefore, the same wiring rule (inter-land wiring 1
The area of the land, that is, the bonding area between the land and the ball terminal is improved by about 14% while maintaining the above condition. The connection strength is improved by the increase in the bonding area. Also, since there is no need to change the wiring rules between the interposer and the mounting board, the reliability after mounting can be obtained simply by changing the primary land shape in the interposer, and by changing the secondary land and secondary land shape in the mounting board. Can be improved.

FIGS. 6A and 6B are plan views showing a primary land according to another embodiment of the CSP. FIG. 6A shows a state after ball terminal bonding, and FIG. 6B shows a state before ball terminal bonding. The overall configuration of the CSP is the same as in FIG. A plurality of substantially rectangular electrodes 23 are formed in a matrix shape in the vertical and horizontal directions on the ball terminal bonding surface 3a of the interposer 3 of the CSP 1. The wiring pattern 5 is formed at a predetermined distance L from the electrode 23 according to the wiring rule, and is connected to the electrode 23. The electrodes 23 have their sides arranged in the vertical and horizontal directions of the matrix. The electrode 2 is formed on the insulating protective film 9 on the electrode 21.
An approximately rectangular opening having a size smaller than 1 is formed, and the primary land 23a is formed so that the direction of the side is aligned with the electrode 23. In other embodiments of the mounting board, although not shown, a secondary land is formed by a configuration similar to that of FIG. 6B.

Assuming that the same wiring rule as that of the embodiment shown in FIG. 5, that is, wiring pattern width = 100 μm, distance L = 100 μm, dimension r = 500 μm, land pitch = 800 μm, and one wiring pattern that can be wired between adjacent lands,
In the embodiment of the CSP of FIG. 6 and the embodiment of the mounting board having the same configuration as that of FIG. 6B, the connection between the land and the ball terminal is maintained while maintaining the same wiring rule as compared with the land having the circular shape with the radius r. The area can be improved by about 27%.

FIG. 7 is a plan view of another embodiment of the CSP as viewed from below, and shows a state before ball terminals are fixed. CS
A plurality of primary lands 25 and 27 are formed in a matrix in the vertical and horizontal directions on the ball terminal joining surface of the interposer 3 of P1. 1 arranged at the outermost periphery of the matrix arrangement
Like the primary land 21a shown in FIG. 5, the shape of the next land 25 is formed in an approximate elliptical shape with a dimension r. The shape of the primary land 27 excluding the outermost periphery is formed in a circular shape with a radius r. In this embodiment, the outermost primary lands 25 are formed so that the bonding area of the primary lands 25 with the ball terminals is larger than that of the central lands 27.

When the CSP of FIG. 7 is mounted on a secondary land having the same configuration as that of FIG. 7 and a mounting substrate having the secondary land, the bonding area of the outermost land with the ball terminal is larger than that of the land on the center side. Therefore, the bonding strength between the outermost land and the ball terminal is larger than that of the center land. As a result, due to the difference in thermal expansion coefficient between the interposer and the mounting board,
In particular, it is possible to disperse the mechanical adaptation force to the joint between the land and the ball at the outermost periphery, and it is possible to improve the reliability after mounting.

In the embodiment shown in FIG. 7 where the land shape is circular at the center of the matrix arrangement and non-circular at the outer periphery, only the outermost primary land is elliptical. However, the present invention is not limited to this. The change in the land shape for each position is determined by the size of the package and the required connection reliability. Therefore, various modes are possible, for example, a shape in which the center portion is circular and gradually changes to an elliptical shape whose area gradually increases toward the outer peripheral side, and a shape in which the shape differs for each land position. Stress due to thermal shrinkage is applied radially from the center of the package. Therefore, for example, when an elliptical land is used as shown in FIGS. 5 and 7, it is preferable to arrange the land so that the major axis direction of the land is radially oriented from the center of the package.
This is more effective against such stress.

FIGS. 8A to 8C are plan views showing examples of land shapes. FIGS. 8A to 8C show the state after ball terminal bonding from FIGS. 8A to 8C. FIG. As shown in (A), an approximate elliptical opening having a smaller size than the electrode 29 is formed on the approximate elliptical electrode 29, and the land 29a is aligned with the electrode 29 in the major axis direction. It is formed. In the land 29a, two protruding portions 29b each having a contour protruding inward are formed at four positions in the vicinity of both ends of the long axis.

As shown in FIG. 3B, an approximate rectangular opening having a size smaller than that of the electrode 31 is formed on the approximate rectangular electrode 31, and a land 31 a is formed so that the sides of the land 31 a are aligned with the electrode 31. Have been. On the land 31a, there are formed projection portions 31b, each of which has a contour protruding inward, at two locations on each side, for a total of eight locations. As shown in (C), an approximate rectangular opening having a smaller size than the electrode 33 is formed on the approximate rectangular electrode 33, and a land 33 a is formed so that the sides of the land 33 a are aligned with the electrode 33. Land 3
3a, a projection protrudes inward, and a protruding portion 33b having a concave shape at the tip thereof is provided at one position on each side, for a total of 4 parts.
It is formed in several places.

In the lands 29a, 31a and 33a, the movement range of the ball terminal 11 can be suppressed by providing the protruding portions 29b, 31b and 33b. When arranging the material of the ball terminal 11 on the primary land, it is possible to reduce variation in the arrangement position of the material of the ball terminal 11. As a result, the variation in the shape of the ball terminals 11 after the primary reflow or the like is performed can be suppressed, and it is possible to contribute to improvement in the mounting efficiency on the mounting substrate and the connection reliability.

The shape of the land in which the projection of the land protrudes inward for guiding the ball terminal to the vicinity of the center of the land is not limited to the embodiment shown in FIG. Any shape may be provided as long as the ball terminal can be positioned near the center of the land, and any number of locations may be provided.

FIGS. 9A to 9D are plan views showing examples of large-area land shapes. FIGS. 9A to 9D are views after ball terminal bonding of FIGS. 9A to 9D. It is a top view showing a state. As shown in (A), an approximate rectangular opening having a size smaller than that of the large-area electrode 35 is formed on the large-area electrode 35 with the large-area land 35a. Are formed together. In the large-area land 35a, protruding portions 35b whose contours protrude inward are formed at a total of four locations near each pair of two opposite corners, one location on each side. As shown in (B), an approximate elliptical opening having a size smaller than that of the large-area electrode 37 is formed on the large-area electrode 37 of the approximate elliptical shape, and the large-area land 37a is formed by the large-area electrode 37. Is formed in such a manner that the direction of the major axis direction is adjusted. Large area land 37
In FIG. 4A, two protruding portions 37b each having a contour protruding inward are formed in the vicinity of both ends of the long axis at a total of four locations.

As shown in (C), an approximate elliptical opening having a size smaller than that of the large land 39 is formed on the large elliptical large area electrode 39, and the large area land 39a becomes large. It is formed so as to be aligned with the area electrode 39 in the major axis direction. In the large area land 39a, two projecting portions 39b each having a contour protruding inward are formed near the both ends of the short axis at a total of two locations.
As shown in (D), on the large square land 41 of the approximate square, an opening of an approximate square shape having a size smaller than that of the large land 41 is formed. It is formed in the same direction. On the large-area land 41a, projections 41b whose contours protrude inward are formed at four locations, one at the center of each side.

As shown in FIGS. 9A to 9D, by forming the projecting portions 35b, 37b, 39b, and 41b, two large-area lands 35, 37, and 39 and four large-area lands 41 have four projections. The positions of the materials of the ball terminals 11 can be limited to some extent. Thus, even if a larger ball terminal volume is required than the other lands, the ball terminals 11 arranged on the other lands can be used.
The CSP can be arranged on the mounting substrate by using the same ball terminal material 11 as the material of the above. As a result, a plurality of types of ball terminal volumes can be achieved with a single ball terminal material without increasing the production process, It is easy to respond to mass production lines.

In the embodiments shown in FIGS. 5 to 9, the primary land shape and the secondary land shape are the same as the electrode shape. However, the present invention is not limited to this. The land shape and the electrode shape may be different.
Further, the CSP and the land of the mounting board on which the CSP is mounted need not be the same, and may have different shapes. Although the lands are formed smaller than the electrodes in the embodiments of FIGS. 5 to 9, the present invention is not limited to this, and the electrodes and the lands may have the same size. Further, as a mounting structure for realizing high-density arrangement, there is a flip-chip connection structure in which an active element surface of a semiconductor chip is directly connected to a mounting substrate via lands such as solder balls.
The flip-chip connection structure, like the BGA mounting structure,
Suitable for high-density arrangement because the arrangement area can be reduced. The present invention can be applied to this flip chip connection structure.

[0042]

In the CSP according to the present invention, the size of the ball terminals is uniform, and at least a portion of the primary land has a portion projecting obliquely to the vertical and horizontal directions of the matrix with respect to the circular shape. Because the non-circular shape has a non-circular shape, the bonding area between the non-circular shape primary land and the ball terminal is increased, and even if the thermal expansion coefficients of the interposer and the mounting board are different, the primary land Improves durability against heat shrinkage stress concentrated on ball terminals while maintaining placement, wiring rules, and effective number of lands, suppresses cracking at the junction between the interposer and ball terminals, and Connection reliability can be improved.

In the mounting board according to the present invention, the size of the ball terminal is uniform, and at least a part of the secondary land has a portion projecting obliquely to the vertical and horizontal directions of the matrix with respect to the circle. Since a non-circular shape is included, the bonding area between the non-circular shape secondary land and the ball terminal is increased, and even if the thermal expansion coefficients of the interposer and the mounting board are different, the secondary land is arranged. While maintaining the wiring rules and the effective number of lands, the durability against heat shrinkage stress concentrated on the ball terminals has been improved, and the occurrence of cracks at the joints between the ball terminals and the mounting board has been suppressed. Connection reliability can be improved.

In the CSP and the mounting board thereof according to the present invention, if the non-circular land shape is formed in a shape based on an ellipse or a square, the land can be inclined in the matrix shape. It can be formed to have a protruding portion.

If the land shape is circular at the central portion of the matrix arrangement and non-circular at the outer peripheral portion, the land shape may be changed from the central portion of the interposer to the outer peripheral portion due to the difference in thermal expansion coefficient between the interposer and the mounting board. The mechanical stress on the joint between the land and the ball terminal accumulated toward the side can be dispersed, and the connection reliability after mounting can be improved.

In the CSP according to the present invention, the non-circular primary land is formed with a protruding portion in which the profile of the primary land projects inward for guiding the ball terminal near the center of the land. With such a configuration, it is possible to improve the positioning accuracy of the ball terminals, suppress variations in the shape of the ball terminals after primary reflow or the like, and prevent the ball terminals from falling off. Performance can be improved.

In the mounting board according to the present invention, the non-circular secondary land is formed with a protruding portion in which the contour of the secondary land projects inward for guiding the ball terminal near the center of the land. By doing so, the positioning accuracy of the CSP before the secondary reflow can be improved, and the variation in the shape of the ball terminal after the secondary reflow or the like is performed and the joint failure between the ball terminal and the secondary land are suppressed. The connection reliability after mounting can be improved.

When a land has a larger area than other lands, a plurality of ball terminals are fixed to the large land and a plurality of balls are fixed to the large land. If a protrusion is formed so that the contour of the land protrudes inward to guide the terminal, a larger ball terminal volume is required for joining the large area land and the ball terminal than other lands. Even if a plurality of ball terminal materials are arranged on a large area land, the same ball terminal material as the ball terminal material arranged on another land can be used. Terminal volume can be achieved, and it is easy to respond to mass production lines.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a CSP, (A) is a front view, and (B) is a plan view seen from below.

FIGS. 2A and 2B are enlarged views of a portion surrounded by a broken-line circle in FIG. 1B, wherein FIG.
Indicates a state before ball terminal bonding.

FIGS. 3 (A) to 3 (E) are process diagrams when a ball terminal is fixed to a CSP, and FIGS. 3 (D) and 3 (E) are (B) and FIG.
It is sectional drawing which expands and shows each part enclosed with the broken-line circle in (C).

4 (A) to 4 (E) are process diagrams when mounting a CSP on a mounting board, and FIGS. 4 (D) and 4 (E) are (B) and (E).
It is sectional drawing which expands and shows each part enclosed with the broken-line circle in (C).

FIG. 5 is a plan view showing a primary land according to an embodiment of the CSP, wherein (A) shows a state after ball terminal bonding, and (B) shows a state before ball terminal bonding.

FIG. 6 is a plan view showing a primary land according to another embodiment of the CSP, in which (A) shows a state after ball terminal bonding, and (B) shows a state before ball terminal bonding. The overall configuration of the CSP is the same as in FIG.

FIG. 7 is a plan view of another embodiment of the CSP as viewed from below.

FIGS. 8A to 8C are plan views showing examples of land shapes, and FIGS. 8A to 8C show states after ball terminal joining of FIGS. 7A to 7C. It is a top view.

FIGS. 9A to 9D are plan views showing examples of large-area land shapes, and FIGS. 9A to 9D show states after ball terminal bonding of FIGS. 9A to 9D. FIG.

[Explanation of symbols]

Reference Signs List 1 CSP (semiconductor device package) 3 interposer (base substrate) 3a ball terminal bonding surface (back surface) 5 wiring pattern 7, 17, 21, 23, 28, 31, 33, 35, 3
7, 41 Electrode 7a, 21a, 23a, 25, 27 Primary land 9, 19 Insulating protective film 11 Ball terminal 13 Mounting substrate 13 15 Substrate 15a Mounting surface 17a Secondary land 29a, 31a, 33a, 35a, 37a, 39a , 4
1a Land

Claims (10)

[Claims] In a semiconductor device package in which a semiconductor chip is mounted and sealed on the surface of a base substrate and ball terminals are fixed to lands arranged in a matrix on the back surface of the base substrate, The size is uniform, and at least a part of the lands includes a non-circular shape having a portion projecting in an oblique direction with respect to the vertical and horizontal directions of the matrix with respect to a circular shape. Semiconductor device package. 2. The semiconductor device package according to claim 1, wherein the non-circular land shape is formed in a shape based on an ellipse or a square. 3. The semiconductor device package according to claim 1, wherein the land shape is circular at a central portion of the matrix arrangement and non-circular at an outer peripheral portion. 4. The non-circular land is formed with a protruding portion in which the contour of the land protrudes inward for guiding a ball terminal near the center of the land. 13. A semiconductor device package according to 5. The land includes a land having a larger area than other lands, a plurality of ball terminals are fixed to the land, and the land has a large area. The semiconductor device package according to any one of claims 1 to 4, wherein a projecting portion whose profile of the land protrudes inward to guide the plurality of ball terminals is formed. 6. The arrangement of ball terminals of a semiconductor device package in which a semiconductor chip is mounted on a surface of a base substrate and sealed, and ball terminals are fixed to lands arranged in a matrix on the back surface of the base substrate. In a mounting substrate on which a land arranged in a matrix corresponding to the shape is formed on the surface and a semiconductor device package is mounted, at least a part of the land is oblique to a circle with respect to the vertical and horizontal directions of the matrix. A non-circular shape having a protruding portion. 7. The mounting board according to claim 6, wherein the non-circular land shape is formed in a shape based on an ellipse or a square. 8. The mounting substrate according to claim 6, wherein the land shape is circular at a central portion of the matrix arrangement and non-circular at an outer peripheral portion. 9. The non-circular land is formed with a protruding portion whose land contour protrudes inward for guiding a ball terminal near the center of the land. A mounting board according to any of the above. 10. The land includes a land having a larger area than other lands, a plurality of ball terminals are fixed to the large land, and the land has a large area. The mounting substrate according to claim 6, wherein a projection is formed such that a contour of the land projects inward to guide the plurality of ball terminals.