JP2011134750A - Semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device for preventing separation or the like in an interface by efficiently reinforcing the interface between an end face of a semiconductor chip and a fillet against thermal stress generated by the warpage at low and high temperatures. <P>SOLUTION: In the semiconductor device for sealing an area between the semiconductor chip 2 and an interposer 7 by using an underfill 9, a plurality of linear irregular sections 5 along a horizontal direction having widths W<SB>1</SB>of 30-50 μm in depth directions are provided at least at one portion of an end face 3 of the semiconductor chip 2. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a flip chip mounting type semiconductor device.

  In recent years, resin-encapsulated semiconductor devices have a tendency of higher density, higher integration, and higher speed of operation, and there is a demand for semiconductor chip packages that can be made smaller and thinner than conventional packages. However, flip chip mounting is generally used to meet such a demand (see Patent Documents 1 and 2).

  FIG. 3 is a cross-sectional view showing a conventional flip chip mounting type semiconductor device. In this semiconductor device 100, a semiconductor chip 2 such as an IC or LSI is provided on an upper surface portion of an interposer 7 where a circuit is provided on both sides and a circuit on both sides is conducted through a through hole. An electronic component 11 such as a chip resistor or a chip capacitor may be mounted on the interposer 7 adjacent to the periphery of the semiconductor chip 2.

  A solder ball 8 is connected to the pad electrode on the lower surface portion of the interposer 7, and the semiconductor device 100 is connected to the circuit board 12 by the solder ball 8.

  In the semiconductor chip 2, a large number of bumps 6 are formed on the electrode on the surface, and then the bump 6 and the pad electrode on the upper surface of the interposer 7 are aligned and contacted, and the upper surface of the interposer 7 is face-down. Placed on the part. The bumps 6 are heated and melted and then solidified, whereby the electrodes of the semiconductor chip 2 and the pad electrodes on the upper surface of the interposer 7 are electrically connected.

  Further, the gap between the semiconductor chip 2 and the interposer 7 is sealed with an underfill 9 filled and cured with an underfill material of a liquid resin composition. The underfill 9 can protect the bumps 6, increase the bonding strength between the semiconductor chip 2 and the interposer 7, and prevent moisture in the atmosphere from entering between the semiconductor chip 2 and the interposer 7. The moisture resistance of the package of the semiconductor device 100 can be improved.

  The flip chip mounting type semiconductor device 100 having such a structure has a small mounting area, and the height of the bump 6 is usually as low as several hundred μm or less, and it is necessary to encapsulate the resin up to the wire as in the case of wire bonding connection. Therefore, it is possible to reduce the height after mounting, and to meet demands such as downsizing and thinning.

  When the underfill material 9 is filled with the underfill material, part of the underfill 9 oozes out from between the semiconductor chip 2 and the interposer 7, and the underfill 9 is formed outwardly from the end surface portion 3 of the semiconductor chip 2. Fillet 10 is formed. The fillet 10 has a shape in which the base end portion is attached to the end surface portion 3 of the semiconductor chip 2 by surface tension and extends while inclining outward.

  On the other hand, when heat is applied to the semiconductor device 100 after sealing between the semiconductor chip 2 and the interposer 7 with the underfill 9, particularly the interface between the semiconductor chip 2 and the fillet 10 and the interface between the interposer 7 and the fillet 10. Under stress.

  When stress is applied in this way, peeling may occur at these interfaces. Conventionally, countermeasures such as blending a low stress agent with the underfill material have been made. However, even with such measures, the improvement in reliability may not always be sufficient, and a technique for further improving the reliability of the semiconductor device 100 is required.

  As such a technique, as shown in FIG. 4, a plurality of linear concavo-convex portions 110 along the vertical direction are provided in the horizontal direction on the end surface portion 3 of the semiconductor chip 2, and the entire surface of the end surface portion 3 is wavy in the horizontal direction. It has been proposed to provide a concavo-convex portion 110 on the surface (see Patent Document 3).

  By providing such a wave-shaped uneven portion 110, the anchor effect improves the adhesion at the interface between the end face portion 3 of the semiconductor chip 2 and the fillet 10, and a constant reinforcing action against stress can be expected.

JP 2009-155405 A JP 2002-110735 A JP 2004-304081 A

  However, by providing the concavo-convex portion 110 as shown in FIG. 4, the anchor effect improves the adhesion at the interface between the end surface portion 3 of the semiconductor chip 2 and the fillet 10 to some extent, and a certain reinforcing action against stress can be expected. However, when stress due to thermal stress at low temperature or high temperature, for example, stress at the time of heat cycle, is considered, tearing stress is applied to the interface between the end face portion 3 of the semiconductor chip 2 and the fillet 10.

  That is, due to the difference in thermal expansion coefficient between the semiconductor chip 2 and the interposer 7, the semiconductor chip 2 is warped toward the convex side at a low temperature, and conversely, the interposer 7 is warped toward the convex side at a high temperature.

  Such warpage in the vertical direction toward the semiconductor chip 2 side and the interposer 7 side generates stress in a direction away from the interface, that is, tearing stress, at the interface between the end face portion 3 of the semiconductor chip 2 and the fillet 10. .

  However, with respect to such a tearing stress, the uneven portion 110 as shown in FIG. 4 is not reinforced in the tearing direction because the direction of the unevenness is vertical, and the semiconductor is caused by thermal stress at low or high temperatures. There is a problem that peeling at the interface between the end face portion 3 of the chip 2 and the fillet 10 cannot be sufficiently suppressed, and there is a possibility that the semiconductor chip 2 or the fillet 10 itself may be cracked.

  The present invention has been made in view of the circumstances as described above, and effectively reinforces the interface between the end surface portion of the semiconductor chip and the fillet against thermal stress caused by warping at low temperature or high temperature. It is an object of the present invention to provide a semiconductor device capable of preventing peeling and the like.

  The present invention is characterized by the following in order to solve the above problems.

  1stly, the semiconductor device of this invention is a semiconductor device which sealed between the semiconductor chip and the interposer by the underfill, Comprising: The width | variety of the depth direction is 30- in at least one part of the end surface part of a semiconductor chip. A plurality of linear concavo-convex portions along the horizontal direction of 50 μm are provided in the vertical direction.

  Second, in the first semiconductor device, the concavo-convex portion is formed by any method selected from etching, polishing, and grinding of the end surface portion.

  According to the first and second inventions, a plurality of linear concavo-convex portions along the horizontal direction having a width in the depth direction of 30 to 50 μm are provided in at least a part of the end surface portion of the semiconductor chip in the vertical direction. Thus, linear irregularities provided along the horizontal direction to effectively counter thermal stress caused by warping at low temperatures or high temperatures effectively act as anchors. Therefore, the interface between the end face portion of the semiconductor chip and the fillet is efficiently reinforced, and peeling or the like at this interface can be effectively prevented.

It is sectional drawing which shows the periphery of the end surface part of the semiconductor chip in which the fillet was formed in embodiment of the semiconductor device of this invention. FIG. 2 is a perspective view of the semiconductor device of FIG. 1. It is sectional drawing which shows the conventional flip-chip mounting type semiconductor device. It is a top view which shows the flip-chip mounting type semiconductor device which provided the linear uneven | corrugated | grooved part along the perpendicular direction in the end surface part of the semiconductor chip.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 is a cross-sectional view showing the periphery of an end surface portion of a semiconductor chip on which a fillet is formed in an embodiment of a semiconductor device of the present invention, and FIG. 2 is a perspective view of the semiconductor device of FIG. 1 (only a semiconductor chip and an interposer are shown) , And other components such as fillets are omitted.).

  As shown in FIG. 1, the semiconductor device of this embodiment is characterized in that a plurality of linear concavo-convex portions 5 along the horizontal direction are provided on the end surface portion 3 of the semiconductor chip 2 in the vertical direction.

  By providing the concavo-convex portion 5, when the end surface portion 3 is a smooth surface as in the prior art of FIG. 3, or as shown in FIG. 4, the linear concavo-convex portion 110 along the direction perpendicular to the end surface portion 3 is provided. Compared with the case where it is provided, the linear concavo-convex portion 5 provided along the horizontal direction effectively acts as an anchor against thermal stress caused by warping at low temperatures or high temperatures.

  That is, due to the difference in coefficient of thermal expansion between the semiconductor chip 2 and the interposer 7, the semiconductor chip 2 side warps to the convex side at low temperatures, while the interposer 7 side warps to the convex side at high temperatures. As shown in FIG. 1, by providing a linear concavo-convex portion 5 along the horizontal direction, a line is formed against tearing stress at the interface between the end surface portion 3 of the semiconductor chip 2 and the fillet 10 due to warpage to the convex side. The concavo-convex portion 5 acts to resist. Therefore, the uneven portion 5 provided in an appropriate direction to resist the tear stress effectively reinforces this interface, and can effectively prevent peeling at this interface.

As for the uneven | corrugated | grooved part 5, the width W ₁ of the depth direction of FIG. ₁ is 30-50 micrometers. If the width W ₁ is less than 30 μm, the reinforcing action against the tearing stress at the interface between the end face portion 3 of the semiconductor chip 2 and the fillet 10 may be insufficient. On the other hand, when the width W ₁ exceeds 50 μm, the mechanical strength of the concavo-convex portion 5 decreases, and the reinforcing action against the tear stress at the interface between the end face portion 3 of the semiconductor chip 2 and the fillet 10 may be insufficient.

  Although the method of forming the uneven | corrugated | grooved part 5 is not specifically limited, For example, the etching of the end surface part 3, grinding | polishing, grinding etc. are mentioned. In addition, the uneven portion 5 may be formed by dicing the semiconductor chip 2.

  The shape of the semiconductor chip 2 is not particularly limited, and may be any of a square, a rectangle, a circle, and the like. The concavo-convex portion 5 can be provided on the entire end surface portion 3 of the semiconductor chip 2, but also by providing at least a part of the end surface portion 3 at the interface between the end surface portion 3 of the semiconductor chip 2 and the fillet 10 due to thermal stress. Can be prevented. For example, when the shape of the semiconductor chip 2 is a square or a rectangle, the uneven portion 5 can be provided on at least one side of the semiconductor chip 2. When the shape of the semiconductor chip 2 is circular, it is preferable to provide the concavo-convex portion 5 in a range of 1/4 or more of the circumference.

  Further, the line-shaped uneven portion 5 may be continuous on one side of the end surface portion 3 of the semiconductor chip 2, but is a line shorter than the length of one side of the end surface portion 3 of the semiconductor chip 2. A plurality of concavo-convex portions 5 may be provided at various locations on one side of the end surface portion 3.

  The entire configuration of the semiconductor device of this embodiment can be the same as the conventional configuration as shown in FIG. 3, for example, except for the portion shown in FIG. The semiconductor device according to the present embodiment can be manufactured by sealing between the semiconductor chip 2 such as an IC or LSI and the interposer 7 such as an FR grade or ceramic substrate on which a circuit is formed with an underfill material. .

  For example, the semiconductor chip 2 is connected to the pad electrode on the upper surface portion of the interposer 7 via the bump 6, and then an underfill material is applied and filled in a gap between the bumps 6 using a dispenser or the like, and then heated and cured, Through a process such as resin-sealing the entire semiconductor chip 2, a semiconductor device by flip chip mounting can be manufactured.

  Although it does not specifically limit as an underfill material, A liquid thing can be used at normal temperature. The viscosity of the underfill material is preferably 0.1 to 100 Pa · s, more preferably 0.5 to 30 Pa · s at 25 ° C. Specifically, for example, an epoxy resin composition containing an epoxy resin, a curing agent, or the like can be used as the underfill material.

  The conditions for heat-curing the underfill material are not particularly limited, and may be set appropriately according to the type of the underfill material. For example, in the case of an epoxy resin composition, 120 to 170 ° C., 0 .5-5 hours.

  As a package form in the semiconductor device of the present invention, various flip chip mounting type packages, for example, in the case of a bear IC, WLCSP (Wafer Level Chip Size Package), BGA (Ball Grid Array), CSP (Chip Size Package) are used. ) And the like.

EXAMPLES Hereinafter, although an Example demonstrates this invention in more detail, this invention is not limited to these Examples at all.
<Examples 1-4, Comparative Examples 1-5>
An underfill material (CV5186S, manufactured by Panasonic Electric Works Co., Ltd.) between a semiconductor chip (TEG chip, 10 mm × 10 mm × 300 μm) in which Sn-Ag-Cu bumps having a diameter of 80 μm are arranged at a pitch of 200 μm and an interposer (FR-4). ]) At 80 ° C. and then cured at 150 ° C. for 1 hour.

  Note that a chip resistor and a chip capacitor were mounted and arranged in advance at a position spaced from the position of the end surface portion of the semiconductor chip on the upper surface portion of the interposer before filling with the underfill material.

  In Examples 1 to 4, a plurality of linear concavo-convex portions along the horizontal direction were provided in the vertical direction by grinding the end surface portion of the semiconductor chip on one side or all four sides of the end surface portion of the semiconductor chip. The width of the concavo-convex portion in the depth direction was 30 μm or 50 μm.

  On the other hand, in Comparative Example 1, a semiconductor chip was used in which all of the end surfaces of the four sides were smooth surfaces without providing uneven portions. In Comparative Examples 2 to 4, an uneven portion was provided on the end surface portion of the semiconductor chip in the same manner as in Examples 1 to 4, but the width in the depth direction of the uneven portion was 10 μm or 80 μm. In Comparative Example 5, a semiconductor chip was used in which a plurality of linear concavo-convex portions along the vertical direction as shown in FIG.

  As described above, 20 semiconductor device packages were produced for each of Examples 1 to 4 and Comparative Examples 1 to 5. This package was treated for 3000 cycles under the condition of Condition B (−55 ° C./+125° C.) in a liquid bath heat cycle.

The package after the heat cycle test was evaluated according to the following criteria depending on the presence or absence of peeling at the interface between the end face portion of the semiconductor chip and the fillet.
○: No peeling for all 20 packages Δ: Peeling for 1 to 4 packages in 20 packages ×: Peeling for 5 or more packages in 20 packages Table 1 shows the evaluation results Show.

  From Table 1, in Examples 1 to 4, in which at least part of the end surface portion of the semiconductor chip is provided with a plurality of linear concavo-convex portions along the horizontal direction having a width in the depth direction of 30 to 50 μm in the vertical direction, The portion reinforces the interface between the end face portion of the semiconductor chip and the fillet, and peeling at the interface was not observed.

  On the other hand, in Comparative Example 1 in which the end surfaces of the semiconductor chip are not provided with uneven portions and all of the end surfaces of the four sides are vertical surfaces, peeling is observed at the interface between the end surface of the semiconductor chip and the fillet in many packages. It was.

  In Comparative Examples 2 to 4, an uneven part having a width in the depth direction of less than 30 μm or more than 50 μm was provided on the end face part of the semiconductor chip, but peeling at the interface between the end face part of the semiconductor chip and the fillet was observed.

  In Comparative Example 5, linear uneven portions along the vertical direction were provided on the end surface portion of the semiconductor chip, but peeling at the interface between the end surface portion of the semiconductor chip and the fillet was observed.

2 Semiconductor chip 3 End face part 5 Uneven part 7 Interposer 9 Underfill W ₁ Width in depth direction

Claims (2)

  A semiconductor device in which a gap between a semiconductor chip and an interposer is sealed with an underfill, and at least part of an end surface portion of the semiconductor chip, linear irregularities along a horizontal direction with a depth of 30 to 50 μm A semiconductor device characterized in that a plurality of portions are provided in the vertical direction.   2. The semiconductor device according to claim 1, wherein the concavo-convex portion is formed by any method selected from etching, polishing, and grinding of the end face portion.

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