JP2006319211A - Packaging structure of semiconductor chip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a packaging structure of a semiconductor chip which can prevent lowering of yield caused by damage of the semiconductor chip in supersonic flip chip junction without changing design of the semiconductor chip, and can improve junction strength between each connection pad located in both ends of a vibration direction and each projection electrode facing each connection pad. <P>SOLUTION: Supersonic vibration is applied to a semiconductor chip 31 with a projection electrode 33 of the semiconductor chip 31 pressed to a substrate side connection pad 34 of a circuit substrate 32, and the projection electrode 33 and the substrate side connection pad 34 are joined. A plurality of projection electrodes 33 and a plurality of substrate side connection pads 34 are arranged along a vibration direction A, and each projection electrode 33 and each substrate side connection pad 34 are opposed. An extension 47 extending from each substrate side connection pad 34 along the vibration direction A to directions far from each other continues to each substrate side connection pad 34 at both ends. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a semiconductor chip mounting structure in which a semiconductor chip is mounted on a circuit board, and more specifically, a semiconductor chip mounting structure in which a semiconductor chip and a circuit board are bonded by ultrasonic flip chip bonding. About.

  In recent years, electronic devices such as mobile devices typified by mobile phones are rapidly spreading. One of the driving forces for the spread of electronic devices is the dramatic reduction in size, weight and thickness of electronic devices. With the reduction in size, weight, and thickness of electronic devices, semiconductor devices used in electronic devices are required to be reduced in size and thickness.

  A semiconductor device is configured by mounting a semiconductor chip on a circuit board. The semiconductor chip and the circuit board are bonded by, for example, flip chip bonding. In flip-chip bonding, the active element surface of a semiconductor chip is directed to a circuit board, and the connection pads of the semiconductor chip and the connection pads of the circuit board are bonded via protruding electrodes that are conductive connection members. According to such flip chip bonding, it is possible to meet the demands for miniaturization and thinning of the semiconductor device, and to increase the production efficiency.

  As one of flip chip bonding, there is an ultrasonic flip chip bonding using ultrasonic vibration together. Ultrasonic flip chip bonding has the advantage that the time required for bonding can be shortened. Such ultrasonic flip chip bonding has been frequently used nowadays.

  FIG. 14 is a cross-sectional view showing a conventional semiconductor chip mounting structure. FIG. 15 is a front view showing the circuit board 1. A semiconductor device 2 having a conventional mounting structure includes a semiconductor chip 3 and a circuit board 1. The semiconductor chip 3 has a protruding electrode 4. The circuit board 1 is configured by providing connection pads 5 on an insulating base 6. In the semiconductor device 2, the semiconductor chip 3 is disposed at a position indicated by a virtual line 7 in FIG. 15 with respect to the circuit board 1, and the protruding electrode 4 of the semiconductor chip 3 and the connection pad 5 of the circuit board 1 are joined. Composed.

  The insulating base 6 is a ceramic substrate or an organic substrate. The organic substrate is made of a resin material and is less expensive than a ceramic substrate. In order to reduce the cost of the circuit board 1, an organic substrate tends to be used as the insulating base 6.

  FIG. 16 is a cross-sectional view showing a state in which a pressing force and ultrasonic vibration are applied to the semiconductor chip 3. The protruding electrodes 4 of the semiconductor chip 3 and the connection pads 5 of the circuit board 1 are bonded by ultrasonic flip chip bonding.

  More specifically, first, the semiconductor chip 3 is mounted on the bonding tool 8, and the semiconductor chip 3 and the circuit board 1 are positioned so that the protruding electrode 4 of the semiconductor chip 3 and the connection pad 5 of the circuit board 1 face each other. Match. Next, the semiconductor chip 3 is placed on the circuit board 1, and the protruding electrodes 4 of the semiconductor chip 3 and the connection pads 5 of the circuit board 1 are brought into contact with each other. Thereafter, a pressing force in a direction 9 from the semiconductor chip 3 toward the circuit board 1 is applied to the semiconductor chip 3 via the bonding tool 8 and an ultrasonic vibration that vibrates in a direction 10 parallel to the circuit board 1 is applied. . As a result, the protruding electrode 4 and the connection pad 5 are rubbed with each other, the contamination layer between the protruding electrode 4 and the connection pad 5 is removed, and the protruding electrode 4 and the connection pad 5 are joined.

  FIG. 17 is a cross-sectional view showing a state of the insulating substrate 6 at the time of ultrasonic flip-chip bonding. At the time of ultrasonic flip chip bonding, the insulating base 6 is deformed due to the pressing force and ultrasonic vibration on the semiconductor chip 3, and the connection pad 5 bites into the insulating base 6 as shown in FIG. May end up. In this case, there is a problem that relative vibration between the protruding electrode 4 and the connection pad 5 is reduced, and it becomes difficult to join the protruding electrode 4 and the connection pad 5. Since the organic substrate is more easily deformed than the ceramic substrate, the above problem becomes more pronounced when the organic substrate is used as the insulating base 6 than when the ceramic substrate is used as the insulating base 6. .

  In order to solve such a problem, the ultrasonic vibration applied to the semiconductor chip may be strengthened. However, in this case, there is a high possibility that cracks will occur in the input / output electrodes of the semiconductor chip.

  In consideration of this point, in the technique disclosed in Patent Document 1, a dummy electrode is formed near the outer periphery of the semiconductor chip as viewed from the input / output electrodes, and bumps that are protruding electrodes are also provided on the dummy electrode. . With this technique, cracks are generated in the dummy electrodes during ultrasonic flip chip bonding, thereby preventing cracks in the input / output electrodes. Therefore, even if the ultrasonic vibration is increased, it is possible to prevent the yield from being reduced due to the damage of the semiconductor chip. By using such a technique, it is possible to prevent the yield of the semiconductor device 2 from being lowered and to improve the bonding strength between the protruding electrode 4 and the connection pad 5.

JP-A-8-330880

  In the technique disclosed in Patent Document 1, since a dummy electrode is provided in order to improve the bonding strength, the size of the semiconductor chip is inevitably increased, and the semiconductor device including the semiconductor chip is increased in size. is there. Moreover, it is necessary to redesign a semiconductor chip, and there is a problem that the cost increases.

  As a result of examination by the inventors of the present application, a plurality of protruding electrodes are arranged along the vibration direction of ultrasonic vibration, and a plurality of connection pads are arranged along the vibration direction, and each protruding electrode and each connection pad face each other. It was found that the bonding strength between the protruding electrode and the connection pad tends to vary depending on the position in the vibration direction.

  FIG. 18 is a diagram showing the bonding strength between each protruding electrode and each connection pad arranged along the vibration direction of ultrasonic vibration. In FIG. 18, the horizontal axis indicates the position of the connection pad, and the vertical axis indicates the bonding strength. Here, for convenience of explanation, it is assumed that four connection pads are arranged along the vibration direction. FIG. 18 shows the bonding strength between each connection pad located at both ends P1 and P4 in the vibration direction and each protruding electrode facing each connection pad, and intermediate P2 and P3 between both ends P1 and P4 in the vibration direction. The bonding strength between each connection pad located at と and each protruding electrode facing each connection pad is shown.

  As shown in FIG. 18, in the conventional technique, the bonding strength varies depending on the position in the vibration direction. Specifically, each connection pad at both ends P1, P4 has a lower bonding strength with the protruding electrode than each connection pad at the intermediate P2, P3. That is, the connection pads at both ends P1, P4 are inferior in bonding property to the protruding electrodes as compared with the connection pads at the intermediate points P2, P3, and as a result, the reliability of electrical connection is lowered.

  In consideration of such points, it is desired to improve the bonding strength between the connection pads at both ends P1 and P4 and the protruding electrodes facing the connection pads.

  FIG. 19 is a schematic diagram showing the behavior of the connection pad 5 at the time of ultrasonic flip-chip bonding. The reason for the variation in bonding strength will be described with reference to FIG. Here, for convenience of explanation, it is assumed that four connection pads 5 are arranged along the vibration direction A of ultrasonic vibration. Hereinafter, the four connection pads 5 may be referred to as first to fourth connection pads 11 to 14 in order from the vibration direction one A1 side. The first and fourth connection pads 11 and 14 correspond to the connection pads at both ends P1 and P4, and the second and third connection pads 12 and 13 correspond to the connection pads at the intermediate points P2 and P3. Each connection pad 11-14 is regarded as a rigid body, and the insulating base 6 is regarded as an elastic body.

  At the time of ultrasonic flip chip bonding, the connection pad 5 receives a pressing force and a frictional force from the protruding electrode 4. As a result, a rotational moment around a predetermined axis acts on the connection pad 5. The predetermined axis is an axis that extends in a direction perpendicular to the vibration direction A and is located at the center of the vibration direction A of the connection pad 5 within the surface of the connection pad 5 that faces the insulating substrate 6.

  For example, attention is focused on the second connection pad 12. When the semiconductor chip 3 is displaced in the other vibration direction A <b> 2 with respect to the circuit board 1, the end of the second connection pad 12 on the other vibration direction A <b> 2 side is brought close to the insulating base 6. A rotational moment 16 acts in the direction. As a result, the end of the second connection pad 12 on the one side in the vibration direction A1 side tends to float from the insulating base material 6, and the end of the second connection pad 12 on the other side in the vibration direction A2 side sinks into the insulating base material 6. Try to include.

  At this time, the rotational moment 17 similarly acts on the first connection pad 11. As a result, the end of the first connection pad 11 on the other vibration direction A2 side tends to sink into the insulating substrate 6. Similarly, the rotational moment 18 acts on the third connection pad 13. As a result, the end of the third connection pad 13 on the one vibration direction side A <b> 1 side tends to float up from the insulating base material 6.

  Therefore, in the second connection pad 12, the rotational moment 16 acting on the second connection pad 12 is canceled by the presence of the first and third connection pads 11 and 13 adjacent to each other. Thereby, the rotational moment 16 is apparently reduced, and the displacement of the second connection pad 12 is suppressed.

  As for the third connection pad 13, as in the case of the second connection pad 12, although the rotational moment 18 works, the third connection pad 13 works due to the presence of the adjacent second and fourth connection pads 12 and 14. The rotational moment 18 is canceled out. Thereby, the rotational moment 18 is apparently reduced, and the displacement of the third connection pad 13 is suppressed.

  Regarding the first connection pad 11, the second connection pad 12 exists on the other side A <b> 2 in the vibration direction, but there is no connection pad on the one side A <b> 1 in the vibration direction, and therefore the rotational moment 17 acting on the first connection pad 11 is not present. It cannot be offset. Accordingly, the first connection pad 11 is displaced. Specifically, the end portion on the one side A <b> 1 side in the vibration direction of the first connection pad 11 is lifted from the insulating base material 6.

  Regarding the fourth connection pad 14, the third connection pad 13 exists on the one side A <b> 1 in the vibration direction, but there is no connection pad on the other side A <b> 2 in the vibration direction. It cannot be offset. Accordingly, the fourth connection pad 14 is displaced. Specifically, the end of the fourth connection pad 14 on the other vibration direction A2 side sinks into the insulating substrate 6.

  Thus, when the semiconductor chip 3 is displaced in the other vibration direction A2 with respect to the circuit board 1, the displacement of the second and third connection pads 12, 13 is suppressed, but the first and fourth connection pads 11, 14 are suppressed. Is displaced. Further, when the displacement is made in one vibration direction A1, the displacement of the second and third connection pads 12, 13 is suppressed as in the case of displacement in the other vibration direction A2, but the first and fourth connection pads 11, 14 are suppressed. Is displaced.

  When ultrasonic vibration is applied to the semiconductor chip 3, the semiconductor chip 3 is alternately displaced in the vibration direction one A1 and the other A2 with respect to the circuit board 1. At this time, as described above, the displacement of the second and third connection pads 12 and 13 is suppressed, but the first and fourth connection pads 11 and 14 are constantly displaced.

  Therefore, relative vibration between the first and fourth connection pads 11 and 14 and the protruding electrode 4 is smaller than that of the second and third connection pads 12 and 13. As a result, in the first and fourth connection pads 11 and 14, the contamination layer between the protruding electrodes 4 is not sufficiently removed, and the bonding strength with the protruding electrodes 4 is lowered.

  An object of the present invention is to prevent a decrease in yield due to breakage of a semiconductor chip at the time of ultrasonic flip chip bonding without changing the design of the semiconductor chip, and to connect each of the connection pads positioned at both ends in the vibration direction. It is an object to provide a semiconductor chip mounting structure capable of improving the bonding strength with each protruding electrode facing each connection pad.

The present invention includes a semiconductor chip having a protruding electrode and a circuit board configured with a connection pad provided on an insulating base material. The semiconductor chip is placed on the circuit board, and the protruding electrode is pressed against the connection pad. In this state, ultrasonic vibration is applied to the semiconductor chip, and the protruding structure and the connection pad are bonded to each other.
A plurality of protruding electrodes are arranged at predetermined intervals along the vibration direction of ultrasonic vibration, and a plurality of connection pads are arranged along the vibration direction, and each protruding electrode and each connection pad face each other.
Of the connection pads arranged along the vibration direction, each connection pad located at both ends in the vibration direction has an extending portion extending in a direction away from each other along the vibration direction from each connection pad located at both ends. The semiconductor chip mounting structure is characterized in that each extending portion is provided on an insulating substrate.

Further, the present invention provides a vibration direction dimension combining a connection pad located at one end of the vibration direction and an extension portion connected to the connection pad, a connection pad located at the other end of the vibration direction, and an extension portion connected to the connection pad. And the vibration direction dimension is selected from 2 times to 3 times the vibration direction dimension of the connection pad.
In the invention, it is preferable that the insulating base material is made of a resin material.

The present invention also includes a semiconductor chip having a first connection pad, and a circuit board configured such that the second connection pad is provided on the insulating base and the protruding electrode is provided on the second connection pad. A mounting structure of a semiconductor chip that is placed on a circuit board and in which ultrasonic waves are applied to the semiconductor chip in a state where the protruding electrodes are pressed against the first connection pads, and the protruding electrodes and the first connection pads are bonded to each other. Because
The plurality of protruding electrodes are arranged at predetermined intervals along the vibration direction of the ultrasonic vibration, and the plurality of first connection pads and the plurality of second connection pads are arranged along the vibration direction. 1 connection pad is facing,
Among the second connection pads arranged along the vibration direction, the second connection pads located at both ends in the vibration direction are separated from each other along the vibration direction from the second connection pads located at both ends. Each of the extending portions extends continuously, and each extending portion is provided on an insulating base material.

  According to the present invention, the ultrasonic vibration is applied to the semiconductor chip in a state where the semiconductor chip is placed on the circuit board and the protruding electrode of the semiconductor chip is pressed against the connection pad of the circuit board. As a result, the bump electrode and the connection pad rub against each other, the contamination layer between the bump electrode and the connection pad is removed, and the bump electrode and the connection pad are joined. By such ultrasonic flip-chip bonding, the semiconductor chip is mounted on the circuit board, and the semiconductor chip mounting structure is realized.

  At the time of ultrasonic flip chip bonding, the connection pad receives a pressing force and a frictional force from the protruding electrode. As a result, a rotational moment acts on the connection pad. As described above, since the rotational moment acts on the connection pad, the connection pad gives the insulating base material a pressing force for pushing down the insulating base material and a pulling force for pulling up the insulating base material.

  When the semiconductor chip is displaced in one direction of vibration with respect to the circuit board, the end on one side of the connection pad in the direction of vibration gives a pressing force to the insulating base material, and the end of the connection pad in the direction of vibration on the other side is A pulling force is applied to the insulating substrate. When the semiconductor chip is displaced in the other vibration direction with respect to the circuit board, the end on one side of the connection pad in the vibration direction gives a pulling force to the insulating base, and the end on the other side of the connection pad in the vibration direction is insulated. A pressing force is applied to the substrate.

  In the mounting structure of the present invention, the plurality of protruding electrodes are arranged at predetermined intervals along the vibration direction of the ultrasonic vibration, and the plurality of connection pads are arranged along the vibration direction. Each of these protruding electrodes and each connection pad face each other.

  Since each protruding electrode and each connection pad are arranged in this way, the pressing force exerted on the insulating base material by the two inner ends among the ends in the vibration direction of each connection pad adjacent in the vibration direction And the pulling force is offset. Therefore, the deformation of the insulating base material due to the pressing force and the pulling force from the two inner ends is suppressed, and thereby the displacement of the two inner ends is suppressed.

  In the mounting structure of the present invention, among the connection pads arranged along the vibration direction, the connection pads positioned at both ends of the vibration direction are separated from each other along the vibration direction from the connection pads positioned at both ends. The extending portions extending in the direction are continuous. Each of these extending portions is provided on the insulating base material.

  Thus, since each extension part is provided, the displacement of two outer edge parts is suppressed among each edge part of the vibration direction in each connection pad located in the said both ends. More specifically, since the extending portions are connected to the two outer ends, the pressing force and the pulling force from the two outer ends are distributed and given to the insulating base material. Therefore, deformation of the insulating base material due to the pressing force and pulling force from the two outer ends is suppressed, and thereby the displacement of the two outer ends is suppressed.

  As described above, since displacement of each end portion in the vibration direction in each connection pad arranged along the vibration direction is suppressed, each connection pad located at both ends and each of these connection pads are connected to each other at the time of ultrasonic flip chip bonding. Relative vibration with each protruding electrode facing each other can be increased. As a result, the contamination layer between the connection pads located at both ends and the protruding electrodes can be reliably removed. Therefore, it is possible to improve the bonding strength between the connection pads located at both ends and the protruding electrodes.

  In the present invention, since it is not necessary to increase the ultrasonic vibration in order to improve the bonding strength, the semiconductor chip is damaged during the ultrasonic flip chip bonding as in the technique disclosed in Patent Document 1. There is no need to change the design of the semiconductor chip in order to prevent the resulting yield loss. Therefore, without changing the design of the semiconductor chip, it is possible to prevent the yield from being reduced due to breakage of the semiconductor chip at the time of ultrasonic flip chip bonding, and to increase the bonding strength between each connection pad and each protruding electrode located at both ends. Can be improved.

  Further, according to the present invention, the vibration pad dimension located at one end in the vibration direction and the extension portion connected to the connection pad are combined, and the connection pad located at the other end in the vibration direction is connected to the connection pad. The vibration direction dimension combined with the existing portion is selected to be two to three times the vibration direction dimension of the connection pad. By selecting 2 times or more and 3 times or less, it is possible to reliably improve the bonding strength between the connection pads located at both ends and the protruding electrodes. If it is less than 2 times, the bonding strength cannot be sufficiently improved. If it exceeds 3 times, the effect of improving the bonding strength is saturated.

  According to the present invention, an insulating substrate made of a resin material is used. An insulating base made of a resin material is less expensive than a ceramic substrate. Therefore, the cost of the circuit board can be reduced. Since an insulating base made of a resin material is more easily deformed than a ceramic substrate, when such an insulating base is used, the bonding strength between each connection pad and each protruding electrode located at both ends is reduced. Although it is easy, it is possible to prevent a decrease in bonding strength by providing the extending portion as described above.

  According to the present invention, the ultrasonic vibration is applied to the semiconductor chip in a state where the semiconductor chip is placed on the circuit board and the first connection pads of the semiconductor chip are pressed against the protruding electrodes of the circuit board. As a result, the first connection pad and the protruding electrode rub against each other, the contamination layer between the first connection pad and the protruding electrode is removed, and the first connection pad and the protruding electrode are joined. By such ultrasonic flip-chip bonding, the semiconductor chip is mounted on the circuit board, and the semiconductor chip mounting structure is realized.

  At the time of ultrasonic flip chip bonding, the second connection pad receives a pressing force and a frictional force from the protruding electrode. As a result, a rotational moment acts on the second connection pad. As described above, since the rotational moment acts on the second connection pad, the second connection pad gives the insulating base material a pressing force for pushing down the insulating base material and a pulling force for pulling up the insulating base material.

  When the semiconductor chip is displaced in one direction of vibration with respect to the circuit board, the end of one side of the second connection pad in the direction of vibration gives a pressing force to the insulating base, and the other side of the second connection pad in the direction of vibration The end portion provides a pulling force to the insulating base material. When the semiconductor chip is displaced in the other vibration direction with respect to the circuit board, the end on the one side in the vibration direction of the second connection pad gives a pulling force to the insulating base, and the end on the other side in the vibration direction of the second connection pad. The portion gives a pressing force to the insulating base material.

  In the mounting structure of the present invention, the plurality of protruding electrodes are arranged at predetermined intervals along the vibration direction of the ultrasonic vibration, and the plurality of first connection pads and the plurality of second connection pads are arranged along the vibration direction. The protruding electrodes and the first connection pads face each other.

  Since each protruding electrode, each first connection pad, and each second connection pad are arranged in this way, two inner ends of each end in the vibration direction of each second connection pad adjacent to each other in the vibration direction The pressing force and the pulling force applied to the insulating substrate by the part are canceled out. Accordingly, deformation of the insulating base material due to the pressing force and pulling force from the two inner end portions is prevented, thereby preventing displacement of the two inner end portions.

  In the mounting structure of the present invention, among the second connection pads arranged along the vibration direction, the second connection pads positioned at both ends of the vibration direction are connected to the vibration direction from the second connection pads positioned at the both ends. The extending portions extending in the direction away from each other along are connected. Each of these extending portions is provided on the insulating base material.

  Thus, since each extension part is provided, the displacement of two outer edge parts is prevented among each edge part of the vibration direction in each 2nd connection pad located in the said both ends. More specifically, since the extending portions are connected to the two outer ends, the pressing force and the pulling force from the two outer ends are distributed and given to the insulating base material. Therefore, deformation of the insulating base material due to the pressing force and pulling force from the two outer ends is prevented, thereby preventing displacement of the two outer ends.

  As described above, since the displacement of the end portions in the vibration direction of the second connection pads arranged along the vibration direction is prevented, the displacement of the protruding electrodes provided in the second connection pads located at both ends is prevented. Can be removed. As described above, since the displacement of each protruding electrode is prevented, relative vibration between each protruding electrode located at both ends and the first connection pad facing each protruding electrode can be increased during ultrasonic flip chip bonding. it can. As a result, the contamination layer between each protruding electrode and each first connection pad located at both ends can be reliably removed. Therefore, it is possible to improve the bonding strength between the protruding electrodes located at both ends and the first connection pads.

  In the present invention, since it is not necessary to increase the ultrasonic vibration in order to improve the bonding strength, the semiconductor chip is damaged during the ultrasonic flip chip bonding as in the technique disclosed in Patent Document 1. There is no need to change the design of the semiconductor chip in order to prevent the resulting yield loss. Therefore, without changing the design of the semiconductor chip, it is possible to prevent the yield from being reduced due to breakage of the semiconductor chip at the time of ultrasonic flip chip bonding, and the bonding strength between each protruding electrode and each first connection pad located at both ends. Can be improved.

  FIG. 1 is a cross-sectional view schematically showing a semiconductor chip mounting structure according to an embodiment of the present invention. The semiconductor device 30 having the mounting structure of the present embodiment is a semiconductor device used for electronic equipment such as a mobile phone. The semiconductor device 30 includes a semiconductor chip 31 and a circuit board 32. The semiconductor device 30 is configured by mounting a semiconductor chip 31 on a circuit board 32.

  The semiconductor chip 31 has a protruding electrode 33. The circuit board 32 has connection pads 34. In the present embodiment, the ultrasonic vibration is applied to the semiconductor chip 31 in a state where the semiconductor chip 31 is placed on the circuit board 32 and the protruding electrode 33 of the semiconductor chip 31 is pressed against the connection pad 34 of the circuit board 32. Is done. As a result, the protruding electrode 33 and the connection pad 34 are joined. By such ultrasonic flip chip bonding, the semiconductor chip 31 is mounted on the circuit board 32, and the mounting structure of the present embodiment is realized.

  FIG. 2 is a front view showing the semiconductor chip 31 in a simplified manner. The semiconductor chip 31 will be described with reference to FIG. 2 and FIG. The semiconductor chip 31 includes a chip body 36, connection pads (hereinafter referred to as “chip-side connection pads”) 37, and protruding electrodes 33.

  A semiconductor element is formed on the chip body 36. The semiconductor chip 31 is made of silicon (Si) or the like. The semiconductor chip 31 has a plate shape, and the shape viewed from the thickness direction is, for example, a quadrangular shape, specifically a square shape. The semiconductor chip 31 is, for example, 10 mm square and has a thickness of 0.1 mm.

  The chip-side connection pad 37 is provided on the chip body 36, specifically, the surface 38 on one side in the thickness direction of the chip body 36. The chip side connection pad 37 has conductivity and is electrically connected to the semiconductor element of the chip body 36. The chip-side connection pad 37 is made of aluminum (Al) -silicon (Si). The chip-side connection pad 37 is, for example, 45 μm square and has a thickness of 1 μm. The chip-side connection pad 37 is formed by sputtering.

  The protruding electrode 33 is provided on the chip-side connection pad 37. The protruding electrode 33 protrudes from the chip-side connection pad 37 in the thickness direction of the chip body 36. The protruding electrode 33 has conductivity and is electrically connected to the chip-side connection pad 37. The protruding electrode 33 is made of gold (Au). The protruding electrode 33 is, for example, 50 μm square and 20 μm in height. The protruding electrode 33 is formed by electrolytic plating. The protruding electrode 33 is a so-called plated bump.

  In the present embodiment, the plurality of protruding electrodes 33 are formed at a predetermined interval (hereinafter referred to as “protruding electrode interval”) L1 along the vibration direction A of ultrasonic vibration applied to the semiconductor chip 31 during ultrasonic flip chip bonding. line up. The protruding electrode interval L1 is a distance between adjacent protruding electrodes 33. The protruding electrode interval L1 is selected to be less than twice the vibration direction dimension W11 of the protruding electrode 33. The protruding electrode interval L1 is, for example, 50 μm. In this case, the distance L3 between the centers of the adjacent protruding electrodes 33 is 100 μm.

  More specifically, the chip-side connection pad 37 is provided along each edge 40a-40d along each edge 39a-39d of the surface (hereinafter referred to as "chip-side pad forming surface") 38 on one side in the thickness direction of the chip body 36. Are arranged in a line. Each chip-side connection pad 37 is provided with a protruding electrode 33. The protruding electrodes 33 are arranged along the respective edges 40a to 40d of the chip-side pad forming surface 38 so as to be arranged at intervals of 50 μm, for example.

  The extending direction of the pair of opposing edges 40a and 40c among the edges 40a to 40d is parallel to the vibration direction A of the ultrasonic vibration. In other words, at the time of ultrasonic flip chip bonding, ultrasonic vibration is applied so that the extending direction of the pair of opposing edges 40a and 40c and the vibration direction A are parallel.

  FIG. 3 is a front view showing a part of the circuit board 32 in a simplified manner. The circuit board 32 will be described with reference to FIG. 3 and FIG. The circuit board 32 includes an insulating base material 45, connection pads (hereinafter referred to as “board-side connection pads”) 34, wiring portions 46, and extending portions 47.

  The insulating base material 45 is made of an insulating material having electrical insulating properties. Specifically, the insulating base material 45 is an organic substrate made of a resin material serving as an insulating material. Examples of the resin material include glass cloth epoxy resin, aramid fiber nonwoven fabric epoxy resin, and liquid crystal polymer resin. The insulating base material 45 is plate-shaped, and the shape seen from the thickness direction is, for example, a quadrangular shape, specifically a square shape. The insulating base 45 is, for example, 15 mm square and has a thickness of 0.1 mm.

  The board-side connection pads 34 are provided on the insulating base 45, specifically, the surface 48 on one side in the thickness direction of the insulating base 45. The board-side connection pad 34 has conductivity. The board-side connection pad 34 is made of copper (Cu). The substrate-side connection pad 34 is, for example, 60 μm square and has a thickness of 18 μm.

  For example, a layer made of nickel (Ni) and a layer made of gold (Au) may be sequentially stacked on the substrate-side connection pad 34. In this case, a portion including the substrate-side connection pad 34, a layer made of nickel (Ni), and a layer made of gold (Au) will be referred to as a substrate-side connection pad 34. The thickness of the layer made of nickel (Ni) is, for example, about 2 μm, and the thickness of the layer made of gold (Au) is, for example, about 0.5 μm.

  The wiring portion 46 continues to the board-side connection pad 34. The wiring portion 46 is provided on the insulating base material 45, specifically, a surface 48 on one side in the thickness direction of the insulating base material 45 (hereinafter referred to as “substrate-side pad forming surface”). The wiring portion 46 has conductivity and is electrically connected to the board-side connection pad 34. The wiring portion 46 is made of copper (Cu). The thickness of the wiring portion 46 is, for example, about 18 μm. A solder resist may be applied on the wiring portion 46.

  In the present embodiment, a plurality of substrate-side connection pads 34 at a predetermined interval (hereinafter referred to as “pad interval”) L2 along the vibration direction A of ultrasonic vibration applied to the semiconductor chip 31 during ultrasonic flip-chip bonding. Lined up. The pad interval L2 is a distance between adjacent substrate side connection pads 34. The pad interval L2 is 40 μm, for example. Each substrate-side connection pad 34 faces each protruding electrode 33 of the semiconductor chip 31.

  In the present embodiment, among the board-side connection pads 34 arranged along the vibration direction A, the board-side connection pads 34 located at both ends of the vibration direction A include the board-side connection pads located at both ends. Extending portions 47 extending in a direction away from each other along the vibration direction A from 34 are connected. In other words, among the board-side connection pads 34 arranged along the vibration direction A, the board-side connection pad (hereinafter referred to as “one-side board-side connection pad”) 34 that is located closest to the vibration direction one A1 includes the vibration direction one A1. An extended portion 47 extending in the vibration direction is connected to a board-side connection pad (hereinafter referred to as “substrate-side connection pad at the other end”) 34 that is located most in the other vibration direction A 2. .

  The extending portion 47 is provided on the insulating base material 45, specifically, the substrate-side pad forming surface 48 of the insulating base material 45. The extending portion 47 is made of copper (Cu). The extension portion 47 has a thickness of about 18 μm, for example.

  For example, a layer made of nickel (Ni) and a layer made of gold (Au) may be sequentially stacked on the extended portion 47. In this case, a portion including the substrate side connection pad 34, a layer made of nickel (Ni), and a layer made of gold (Au) will be referred to as an extending portion 47. The thickness of the layer made of nickel (Ni) is, for example, about 2 μm, and the thickness of the layer made of gold (Au) is, for example, about 0.5 μm.

  Further, in the present embodiment, the vibration direction dimension (hereinafter referred to as “one-part pad part dimension”) W1 of the substrate-side connection pad 34 at one end and the extending portion 47 connected to the substrate-side connection pad 34 is the substrate side. The vibration pad dimension of the connection pad 34 (hereinafter referred to as “pad dimension”) W is selected to be 2 to 3 times. The vibration direction dimension (hereinafter referred to as “pad part dimension at the other end”) W2 of the other end board-side connection pad 34 and the extended portion 47 connected to the board-side connection pad 34 is at least twice the pad dimension W. 3 times or less is selected.

  More specifically, when a square 49 corresponding to the chip-side pad formation surface 38 is drawn on the substrate-side pad formation surface 48 of the insulating base material 45, the substrate-side connection pad 34 is connected to each edge portion 50a of the square 49. ˜50d so as to be aligned along the respective edges 51a to 51d. The board-side connection pads 34 are arranged along the respective edges 51a to 51d of the square 49, for example, at intervals of 40 μm.

  The extending direction of a pair of opposing edges 51a and 51c among the edges 51a to 51d is parallel to the vibration direction A of ultrasonic vibration. In other words, at the time of ultrasonic flip chip bonding, ultrasonic vibration is applied so that the extending direction of the pair of opposing edges 51a and 51c and the vibration direction A are parallel.

  Of the board-side connection pads 34 arranged along one edge 51a of the pair of opposing edges 51a and 51c, the extended portions 47 are connected to the board-side connection pads 34 at both ends. Of the board-side connection pads 34 arranged along the other edge 51c of the pair of opposing edges 51a and 51c, the extended portions 47 are connected to the board-side connection pads 34 at both ends.

  Each substrate-side connection pad 34 is connected to a wiring portion 46. Each wiring portion 46 extends from each board-side connection pad 34 toward the outside of the square 49.

  The vibration direction dimension W31 of the wiring part 46 connected to the board-side connection pad 34 at one end is the same as the pad part dimension W1 at one end. The vibration direction dimension W32 of the wiring part 46 connected to the board-side connection pad 34 at the other end is the same as the pad part dimension W2 at the other end.

  In manufacturing such a circuit board 32, first, for example, a double-sided copper-clad board is prepared. The double-sided copper-clad substrate is a substrate in which copper foil is provided over the entire surface of both sides in the thickness direction of the insulating base material 45. Next, the copper foil provided on the surface on one side in the thickness direction of the insulating substrate 45 is etched into a predetermined wiring pattern. As a result, the substrate-side connection pads 34, the wiring portions 46, and the extending portions 47 are formed at the same time. Thereafter, a layer made of nickel (Ni) and a layer made of gold (Au) are sequentially stacked on the substrate-side connection pad 34 by plating. The layer made of gold (Au) is formed by electroless plating. In this way, the circuit board 32 can be manufactured.

  The board-side connection pad 34, the wiring part 46, and the extending part 47 are made of the same material and are simultaneously formed by the same method. Therefore, the extended portion 47 can be formed without increasing the number of steps.

  4 is a diagram for explaining a mounting procedure for mounting the semiconductor chip 31 on the circuit board 32. FIG. 4A shows a state in which the semiconductor chip 31 is brought close to the circuit board 32, and FIG. 2) shows a state in which a pressing force and ultrasonic vibration are applied to the semiconductor chip 31, and FIG. 4 (3) shows a state in which the bonding tool 56 is separated from the semiconductor chip 31.

  This mounting procedure is executed by, for example, a joining apparatus. In general, the joining apparatus includes a stage, a joining tool 56, tool driving means, and ultrasonic vibration applying means. The stage holds the circuit board 32 horizontally and moves the circuit board 32. The bonding tool 56 is provided above the stage and holds the semiconductor chip 31 by vacuum suction with a negative pressure. The joining tool 56 is made of, for example, iron (Fe), and an adsorption hole for adsorbing the semiconductor chip 31 is formed. The tool driving means moves the bonding tool 56 in the vertical direction and applies a pressing force to the semiconductor chip 31 via the bonding tool 56. The ultrasonic vibration applying unit applies ultrasonic vibration to the semiconductor chip 31 via the bonding tool 56.

  When the semiconductor chip 31 shown in FIG. 2 and the circuit board 32 shown in FIG. 3 are prepared, the semiconductor chip 31 is mounted on the bonding tool 56, and the circuit board 32 is placed on the stage, the mounting operation is started. When the mounting operation is started, the circuit board 32 is aligned with the semiconductor chip 31 by the stage so that the protruding electrodes 33 of the semiconductor chip 31 and the board-side connection pads 34 of the circuit board 32 face each other. The

  Next, as shown in FIG. 4A, the welding tool 56 is lowered by the tool driving means. The tool driving means lowers the joining tool 56 to a predetermined position. As a result, the semiconductor chip 31 is placed on the circuit board 32, and the protruding electrodes 33 of the semiconductor chip 31 and the board-side connection pads 34 of the circuit board 32 come into contact with each other.

  Next, as shown in FIG. 4B, the application of the pressing force to the semiconductor chip 31 by the tool driving means is started, and the application of the ultrasonic vibration to the semiconductor chip 31 by the ultrasonic vibration applying means is started. The

  A pressing force is uniformly applied to the semiconductor chip 31 in the direction B from the semiconductor chip 31 toward the circuit board 32 throughout. The semiconductor chip 31 is applied with ultrasonic vibration that vibrates in a vibration direction A parallel to the extending direction of the pair of opposing edges 40 a and 40 c of the semiconductor chip 31.

  The pressing force to the semiconductor chip 31 is selected from 70 to 90 MPa, for example. The amplitude of the ultrasonic vibration is selected from 2 to 5 μm, for example. The frequency of the ultrasonic vibration is selected to be 60 kHz, for example.

  When a predetermined time has elapsed since the start of application of ultrasonic vibration, the application of ultrasonic vibration to the semiconductor chip 31 by the ultrasonic vibration application means is terminated, and the application of the pressing force to the semiconductor chip 31 by the tool driving means. Is terminated. The application time for applying the ultrasonic vibration is selected from 0.2 to 1.0 seconds, for example. Thereafter, the semiconductor chip 31 is detached from the joining tool 56, and the joining tool 56 is raised by the tool driving means as shown in FIG.

  As described above, in a state where a pressing force is applied to the semiconductor chip 31, that is, in a state where each protruding electrode 33 of the semiconductor chip 31 is pressed against each board-side connection pad 34 of the circuit board 32, ultrasonic vibration is generated in the semiconductor chip. 31 is applied. As a result, the protruding electrodes 33 and the substrate-side connection pads 34 rub against each other, and the contamination layer between the protruding electrodes 33 and the substrate-side connection pads 34 is removed. The contamination layer is a layer formed on the surface of each protruding electrode 33 and the surface of each substrate-side connection pad 34 and includes an oxide film or the like.

  In the state where the contamination layer is removed, each projection electrode 33 is further pressed against each substrate-side connection pad 34, whereby the projections and depressions of each projection electrode 33 and each substrate-side connection pad 34 are completely crushed. The opposing surfaces of the electrode 33 facing the substrate-side connection pads 34 are bonded to the substrate-side connection pads 34 throughout. By such ultrasonic flip chip bonding, the semiconductor chip 31 is mounted on the circuit board 32, and the mounting structure of the present embodiment is realized.

  FIG. 5 is a diagram showing the bonding strength between the protruding electrodes 33 and the substrate-side connection pads 34 arranged along the vibration direction A. As shown in FIG. In FIG. 5, the horizontal axis indicates the position of the board-side connection pad 34, and the vertical axis indicates the bonding strength.

  After each protruding electrode 33 and each substrate side connection pad 34 were joined by ultrasonic flip chip bonding, the semiconductor chip 31 was removed leaving each protruding electrode 33. Thereafter, the shear strength of the joint portion between each substrate side connection pad 34 arranged along the vibration direction A and each projection electrode 33 remaining on each substrate side connection pad 34 was measured using a shear tool. The shear strength of the joint corresponds to the joint strength.

  Here, for convenience of explanation, it is assumed that four substrate-side connection pads 34 are arranged along the vibration direction A. FIG. 5 shows the bonding strength between the board-side connection pads 34 positioned at both ends P1 and P4 in the vibration direction A and the protruding electrodes 33 facing the board-side connection pads 34, and the both ends in the vibration direction A. The bonding strength between each board-side connection pad 34 located in the middle P2, P3 between P1 and P4 and each protruding electrode 33 facing each connection pad 34 is shown.

  As shown in FIG. 5, in this embodiment, variation in bonding strength due to the position in the vibration direction A is suppressed. Specifically, the bonding strengths of the substrate-side connection pads 34 at both ends P1, P4 are the same as the bonding strengths of the protruding electrodes 33 compared to the substrate-side connection pads 34 of the intermediate P2, P3. Compared with FIG. 18, the bonding strength between the board-side connection pads 34 and the protruding electrodes 33 at both ends P1 and P4 is improved.

  FIG. 6 is a schematic diagram showing the behavior of each substrate-side connection pad 34 during ultrasonic flip-chip bonding. With reference to FIG. 6, the reason why the variation in bonding strength is suppressed will be described. Each board-side connection pad 34 is regarded as a rigid body, and the insulating base material 45 is regarded as an elastic body.

  At the time of ultrasonic flip chip bonding, the substrate side connection pad 34 receives a pressing force and a frictional force from the protruding electrode 33. As a result, a predetermined rotational moment around the axis L31 acts on the board-side connection pad 34. The predetermined axis L31 is an axis L31 that extends in a direction perpendicular to the vibration direction A in a plane facing the insulating base 45 of the board side connection pad 34 and is located at the center of the vibration direction A of the board side connection pad 34. is there.

  As described above, since the rotational moment acts on the board-side connection pad 34, the board-side connection pad 34 gives the insulating base material 45 a pressing force that pushes down the insulating base material 45 and a pulling force that pulls up the insulating base material 45. . The pressing force is a force in a direction from the board-side connection pad 34 toward the insulating base material 45 and is a compressive force that compresses the insulating base material 45. The pulling force is a force in a direction from the insulating base material 45 toward the board-side connection pad 34 and is a pulling force that pulls the insulating base material 45. This pulling force is a force in the direction opposite to the pressing force.

  When the semiconductor chip 31 is displaced in the vibration direction one A1 with respect to the circuit board 32, the substrate side connection pad 34 is brought close to the insulating base material 45 at the end on the vibration direction one A1 side of the substrate side connection pad 34. A rotational moment works in the direction. At this time, the end on the one side A1 in the vibration direction of the board-side connection pad 34 gives a pressing force to the insulating base 45, and the end on the other side A2 in the vibration direction of the board-side connection pad 34 is the insulating base 45. Gives a pulling force.

  When the semiconductor chip 31 is displaced in the other vibration direction A <b> 2 with respect to the circuit board 32, the substrate side connection pad 34 is separated from the insulating base material 45 at the end of the substrate side connection pad 34 on the one vibration direction A <b> 1 side. A rotational moment works in the direction. At this time, the end on the one side A1 in the vibration direction of the board-side connection pad 34 gives a pulling force to the insulating base 45, and the end on the other side A2 in the vibration direction of the board-side connection pad 34 applies to the insulating base 45. Give a pressing force.

  In the mounting structure of the present embodiment, the plurality of protruding electrodes 33 are arranged at the protruding electrode interval L1 along the vibration direction A of ultrasonic vibration, and the plurality of substrate-side connection pads 34 are arranged along the vibration direction A. . Each of these protruding electrodes 33 and each board-side connection pad 34 face each other.

  Since each protruding electrode 33 and each board-side connection pad 34 are arranged in this way, two inner ends of each end in the vibration direction A of each board-side connection pad 34 adjacent to the vibration direction A. The pressing force and the pulling force applied to the insulating base material 45 are canceled out. Therefore, the deformation of the insulating base material 45 due to the pressing force and the pulling force from the two inner ends is suppressed, and thereby the displacement of the two inner ends is suppressed.

  The two inner end portions are the end portions on the other vibration direction A2 side of the board-side connection pads 34 on the one side in the vibration direction among the board-side connection pads 34 adjacent in the vibration direction A, and the other side in the vibration direction. The vibration direction of the board-side connection pad 34 on the A2 side means one end on the A1 side.

  Further, in the mounting structure of the present embodiment, each of the board-side connection pads 34 at both ends has extended portions 47 that extend from the board-side connection pads 34 at both ends in directions away from each other along the vibration direction A, respectively. The extended portions 47 are continuously provided on the insulating base material 45.

  Thus, since each extended part 47 is provided, the displacement of two outer edge parts is suppressed among each edge part of the vibration direction A in each board | substrate side connection pad 34 of both ends. More specifically, since the extending portions 47 are connected to the two outer ends, the pressing force and the pulling force from the two outer ends are distributed and applied to the insulating base material 45. It is done. Therefore, the deformation of the insulating base material 45 due to the pressing force and the pulling force from the two outer ends is suppressed, and thereby the displacement of the two outer ends is suppressed.

  The two outer ends are the one on the vibration direction side A1 of the board-side connection pads 34 on the one side A1 in the vibration direction and the board on the other side A2 on the vibration direction side. It means the vibration direction in the side connection pad 34 and the other end portion on the A2 side.

  As described above, since the displacement of each end portion in the vibration direction A in each substrate side connection pad 34 arranged along the vibration direction A can be suppressed, each of the substrate side connection pads 34 at both ends and these at the time of ultrasonic flip chip bonding. The relative vibration with each protruding electrode 33 facing each substrate-side connection pad 34 can be increased. As a result, the contamination layer between the board-side connection pads 34 and the protruding electrodes 33 at both ends can be reliably removed. Accordingly, the bonding strength between the board-side connection pads 34 and the bump electrodes 33 at both ends can be improved.

  In this embodiment, since it is not necessary to increase the ultrasonic vibration in order to improve the bonding strength, the semiconductor chip 31 at the time of ultrasonic flip-chip bonding as in the technique disclosed in Patent Document 1 above. It is not necessary to change the design of the semiconductor chip 31 in order to prevent a decrease in yield due to the damage of the semiconductor chip 31. Therefore, without changing the design of the semiconductor chip 31, it is possible to prevent the yield from being reduced due to the damage of the semiconductor chip 31 during the ultrasonic flip chip bonding, and to connect the substrate-side connection pads 34 and the protruding electrodes 33 at both ends. Bonding strength can be improved.

  Here, it is assumed that four substrate-side connection pads 34 are arranged along the vibration direction A. Hereinafter, the four board-side connection pads 34 may be referred to as first to fourth board-side connection pads 61 to 64 in order from the vibration direction one A1 side. The first and fourth board-side connection pads 61 and 64 correspond to the board-side connection pads at both ends P1 and P4, and the second and third board-side connection pads 62 and 63 are the board sides of the intermediate P2 and P3. Corresponds to the connection pad.

  For example, focus on the second substrate-side connection pads 62. When the semiconductor chip 31 is displaced in the vibration direction other side A2 with respect to the circuit board 32, the second substrate side connection pad 62 has an end on the vibration direction other side A2 side of the second substrate side connection pad 62 as an insulating base material. Rotational moment 66 acts in the direction of approaching 45. As a result, the end on the one side A1 in the vibration direction of the second board side connection pad 62 tries to float up from the insulating base material 45, and the end on the other side in the vibration direction of the second board side connection pad 62 is on the insulating base. Trying to sink into the material 45.

  At this time, the rotational moment 67 similarly acts on the first substrate-side connection pad 61. As a result, the end on the other side A <b> 2 of the vibration direction of the first substrate side connection pad 61 tends to sink into the insulating base material 45. Similarly, the rotational moment 68 acts on the third substrate-side connection pad 63. As a result, the end of the third substrate side connection pad 63 on the one vibration direction side A <b> 1 side tends to float up from the insulating base material 45.

  Therefore, in the second substrate side connection pad 62, the rotational moment 66 acting on the second substrate side connection pad 62 is canceled by the presence of the first and third substrate side connection pads 61 and 63 adjacent to each other. As a result, the rotational moment 66 is apparently reduced, and the displacement of the second substrate side connection pad 62 is suppressed.

  As with the second substrate-side connection pad 62, the third substrate-side connection pad 63 also has a rotational moment 68, but the second and fourth substrate-side connection pads 62 and 64 are adjacent to each other. The rotational moment 68 acting on the three board side connection pads 63 is canceled out. As a result, the rotational moment 68 is apparently reduced, and the displacement of the third substrate side connection pad 63 is suppressed.

  With respect to the first board side connection pad 61, the second connection pad 62 exists on the other side A2 in the vibration direction, but there is no board side connection pad on the one side A1 in the vibration direction. It is not possible to cancel the rotational moment 67 acting on the. Even in such a first substrate side connection pad 61, since the extended portion 47 is connected to the end portion on the one side A1 in the vibration direction, the extended portion 47 suppresses the displacement due to the rotational moment 67.

  Regarding the fourth substrate side connection pad 64, the third connection pad 63 exists on the one side A1 in the vibration direction, but there is no substrate side connection pad on the other side A2 in the vibration direction. It is not possible to cancel the rotational moment 69 acting on the. Even in such a fourth substrate side connection pad 64, the extended portion 47 is connected to the end portion on the other side A <b> 2 in the vibration direction, so that the displacement due to the rotational moment 69 is suppressed by the extended portion 47.

  Thus, when the semiconductor chip 31 is displaced in the other vibration direction A2 with respect to the circuit board 32, the displacement of the first to fourth board-side connection pads 61 to 64 is suppressed. Further, when the displacement is made in the vibration direction one A1, the displacement of the first to fourth substrate side connection pads 61 to 64 is suppressed as in the case of the displacement in the other vibration direction A2.

  When ultrasonic vibration is applied to the semiconductor chip 31, the semiconductor chip 31 is displaced alternately with respect to the circuit board 32 in one vibration direction A1 and the other A2. At this time, as described above, the displacement of the first to fourth substrate side connection pads 61 to 64 is suppressed, and thereby the first to fourth substrate side connection pads 61 to 64 can behave in the same manner. In other words, the first and fourth substrate side connection pads 61 and 64 at both ends can behave in the same manner as the intermediate second and third substrate side connection pads 62 and 63.

  Accordingly, the magnitude of relative vibration between the first and fourth substrate-side connection pads 61 and 64 at both ends and the respective projection electrodes 33 is set to be equal to that between the second and third substrate-side connection pads 62 and 63 and the respective projection electrodes 33. The magnitude of the relative vibration can be set to the same level. As a result, the bonding strength between the first and fourth substrate-side connection pads 61 and 64 at both ends and the protruding electrodes 33 is set so that the bonding between the intermediate second and third substrate-side connecting pads 62 and 63 and the protruding electrodes 33 is performed. It can be as strong as the strength. Therefore, in all the substrate-side connection pads 61 to 64, good bonding with the protruding electrode 33 is achieved, and the semiconductor device 30 with high reliability for electrical connection can be realized.

  FIG. 7 is a diagram showing the relationship between the pad part dimension W1 at one end and the bonding strength. Since the relationship between the pad part dimension W2 at the other end and the bonding strength is the same as the relationship between the pad part dimension W1 at one end and the bonding strength, the description thereof is omitted. In FIG. 7, the horizontal axis indicates the pad part dimension W <b> 1 at one end, and the vertical axis indicates the bonding strength between the substrate-side connection pad 34 and the protruding electrode 33 at one end. In FIG. 7, the bonding strength value S indicates the bonding strength between the intermediate substrate-side connection pad 34 and the protruding electrode 33.

  FIG. 7 shows the bonding strength when the pad dimension W is 60 μm and the pad part dimension W1 at one end is changed to 60 μm, 120 μm, 180 μm, 240 μm, and 300 μm. That is, the bonding strength when the pad part dimension W1 at one end is changed to 1, 2, 3, 4, and 5 times the pad dimension W is shown. The measuring method is the same as the measuring method of the bonding strength shown in FIG.

  As shown in FIG. 7, when the pad part dimension W1 at one end is selected to be not less than 2 times and not more than 3 times the pad dimension W, the bonding strength between the substrate-side connection pad 34 at one end and the protruding electrode 33 is reliably improved. This bonding strength is equal to the bonding strength between the intermediate substrate-side connection pad 34 and the protruding electrode 33. If it is less than twice, the bonding strength between the substrate-side connection pad 34 at one end and the protruding electrode 33 cannot be sufficiently improved, and this bonding strength is the bonding between the intermediate substrate-side connecting pad 34 and the protruding electrode 33. It will be smaller than the strength. If it exceeds three times, the effect of improving the bonding strength between the substrate-side connection pad 34 at one end and the protruding electrode 33 is saturated.

  The bonding strength varies depending on the ultrasonic bonding condition parameters such as the pressing force to the semiconductor chip 31 and the amplitude and frequency of ultrasonic vibration. In the present embodiment, the pad part dimensions W1 and W2 are determined based on all the ultrasonic welding condition parameters.

  According to the present embodiment, the insulating base material 45 made of a resin material is used. The insulating base material 45 made of a resin material is less expensive than a ceramic substrate. Therefore, the cost of the circuit board 32 can be reduced. Since the insulating base material 45 made of a resin material is more easily deformed than a ceramic substrate, when such an insulating base material 45 is used, the bonding strength between the board-side connection pads 34 at both ends and the protruding electrodes 33 is used. However, it is possible to prevent the bonding strength from being lowered by providing the extending portion 47 as described above.

  Further, according to the present embodiment, it is possible to obtain good bonding with the protruding electrodes 33 in all the substrate side connection pads 34 arranged along the vibration direction A only by providing the extending portion 47 as described above. Can do. As a result, the yield of the semiconductor device 30 can be improved while maintaining the current manufacturing cost of the circuit board. In addition, the yield of the semiconductor device 30 can be improved without changing the distance between the centers of the substrate-side connection pads 34. Furthermore, the circuit board 32 is not only suitably used for ultrasonic flip chip bonding, but can also be applied as a circuit board for other flip chip bonding, so that versatility can be enhanced.

  FIG. 8 is a cross-sectional view schematically showing a semiconductor chip mounting structure according to another embodiment of the present invention. Since the semiconductor device 70 having the mounting structure of the present embodiment is similar to the semiconductor device 30 of the above-described embodiment, the corresponding parts are denoted by the same reference numerals, and the description of common points is omitted. The semiconductor device 70 includes a semiconductor chip 71 and a circuit board 72.

  FIG. 9 is a front view showing the semiconductor chip 71 in a simplified manner. The semiconductor chip 71 will be described with reference to FIG. 9 and FIG. In the present embodiment, there are two protruding electrode groups 73 and 74 constituted by a plurality of protruding electrodes 33 arranged at the protruding electrode interval L1 along the vibration direction A, and a predetermined interval along the vibrating direction A (hereinafter referred to as “electrode”). L11) (referred to as “group spacing”).

  Hereinafter, among the protruding electrode groups 73 and 74 arranged along the vibration direction A, the protruding electrode group 73 on the one side A1 in the vibration direction is referred to as a first protruding electrode group 73, and the protruding electrode group on the other side A2 in the vibration direction. 74 is referred to as a second protruding electrode group 74.

  The electrode group interval L11 is the distance between the inner two protruding electrodes 33 among the protruding electrodes 33 in the protruding electrode groups 73 and 74 arranged along the vibration direction A. The inner two protruding electrodes 33 are the protruding electrode 33 located in the other vibration direction A2 in the first protruding electrode group 73 and the protruding electrode located in the most vibration direction one A1 in the second protruding electrode group 74. 33. The electrode group interval L11 is at least twice the protruding electrode interval L1. The electrode group interval L11 is, for example, 400 μm.

  FIG. 10 is a front view showing a part of the circuit board 72 in a simplified manner. The circuit board 72 will be described with reference to FIG. 10 and FIG. In the present embodiment, two substrate-side connection pad groups 75 and 76 constituted by a plurality of substrate-side connection pads 34 arranged at the pad interval L2 along the vibration direction A are arranged along the vibration direction A. Each substrate-side connection pad 34 faces each protruding electrode 33 of the semiconductor chip 71.

  Hereinafter, among the board-side connection pad groups 75 and 76 arranged along the vibration direction A, the board-side connection pad group 75 on the one side A1 in the vibration direction is referred to as a first board-side connection pad group 75, and the other vibration direction is on the other side. The board-side connection pad group 76 on the A2 side is referred to as a second board-side connection pad group 76.

  Among the board-side connection pads 34 of the first board-side connection pad group 75, the board-side connection pads 34 at both ends in the vibration direction A are mutually connected along the vibration direction A from the board-side connection pads 34 at both ends. The extending portions 47 extending in the separating direction are connected to each other. That is, among the board-side connection pads 34 of the first board-side connection pad group 75, the board-side connection pad located in the most vibration direction A1 (hereinafter referred to as “the board side of one end in the first board-side connection pad group 75”). An extension portion 47 extending in one direction A1 in the vibration direction is connected to the connection pad 34), and is connected to the board-side connection pad (hereinafter referred to as "the first board-side connection pad group 75" in the other vibration direction other side A2). An extended portion 47 extending in the vibration direction other side A2 is connected to the board 34).

  Of the board-side connection pads 34 of the second board-side connection pad group 76, the board-side connection pads 34 at both ends in the vibration direction A are mutually connected along the vibration direction A from the board-side connection pads 34 at both ends. The extending portions 47 extending in the separating direction are connected to each other. That is, among the board-side connection pads 34 of the second board-side connection pad group 76, the board-side connection pad located in the most vibration direction A1 (hereinafter referred to as “the board side of one end in the second board-side connection pad group 76”). An extension portion 47 extending in one direction A1 in the vibration direction is connected to the connection pad 34), and is connected to a board-side connection pad (hereinafter referred to as “the second board-side connection pad group 76” in the other direction A2). An extended portion 47 extending in the vibration direction other side A2 is connected to the board 34).

  The vibration direction dimension W21 of the first board-side connection pad group 75 including the board-side connection pad 34 at one end and the extending portion 47 connected to the board-side connection pad 34 is two to three times the pad dimension W. Chosen. The vibration direction dimension W22 of the second board-side connection pad group 76 including the board-side connection pad 34 at the other end and the extending portion 47 connected to the board-side connection pad 34 is two to three times the pad dimension W. Selected below.

  The vibration direction dimension W23 of the first substrate-side connection pad group 75 including the substrate-side connection pad 34 at the other end and the extending portion 47 connected to the substrate-side connection pad 34 is, for example, 235 μm. A vibration direction dimension W24 of the second substrate-side connection pad group 76 including the substrate-side connection pad 34 at one end and the extending portion 47 connected to the substrate-side connection pad 34 is, for example, 235 μm. In the first substrate-side connection pad group 75, an extended portion 47 that is continuous with the substrate-side connection pad 34 at the other end, and in the second substrate-side connection pad group 76, an extended portion 47 that is continuous with the substrate-side connection pad 34 is provided. The distance L41 between is, for example, 40 μm.

  FIG. 11 is a diagram showing a comparative example of the bonding strength between the protruding electrodes 33 and the substrate side connection pads 34 arranged along the vibration direction A. FIG. FIG. 12 is a diagram showing the bonding strength between the protruding electrodes 33 and the substrate-side connection pads 34 arranged along the vibration direction A. 11 and 12, the horizontal axis indicates the position of the board-side connection pad 34, and the vertical axis indicates the bonding strength. In the present embodiment, the extended portion 47 is provided as described above, but in the comparative example, the extended portion 47 is not provided. The measuring method is the same as the measuring method of the bonding strength shown in FIG.

  Here, for convenience of explanation, a case where two board-side connection pad groups 75 and 76 constituted by three board-side connection pads 34 arranged at the pad interval L2 along the vibration direction A are arranged along the vibration direction A is shown. Suppose.

  In FIG. 11 and FIG. 12, the bonding strength between each substrate-side connection pad 34 located at both ends P <b> 1 and P <b> 3 of the first substrate-side connection pad group 75 and each protruding electrode 33 facing each of these substrate-side connection pads 34. And shows the bonding strength between the substrate-side connection pad 34 located in the middle P2 of the first substrate-side connection pad group 75 and the protruding electrode 33 facing the substrate-side connection pad 34. In addition, the bonding strength between each board-side connection pad 34 located at both ends P4 and P6 of the second board-side connection pad group 76 and each protruding electrode 33 facing each board-side connection pad 34 is shown. The bonding strength between the board-side connection pad 34 located in the middle P5 of the board-side connection pad group 76 and the protruding electrode 33 facing the board-side connection pad 34 is shown.

  In the comparative example, as shown in FIG. 11, the bonding strength varies depending on the position in the vibration direction A. Specifically, in the first board-side connection pad group 75, each board-side connection pad 34 at both ends P1, P3 has a lower bonding strength with the protruding electrode 33 than the board-side connection pad 34 at the intermediate P2. . In the second substrate-side connection pad group 76, each substrate-side connection pad 34 at both ends P4 and P6 has a lower bonding strength with the protruding electrode 33 than the substrate-side connection pad 34 at the intermediate P5.

  On the other hand, in this Embodiment, as shown in FIG. 12, the dispersion | variation in joining strength by the position regarding the vibration direction A can be suppressed. Specifically, in the first board-side connection pad group 75, each board-side connection pad 34 at both ends P1, P3 has the same bonding strength with the protruding electrode 33 as compared with the board-side connection pad 34 at the intermediate P2. Degree. In the second substrate-side connection pad group 76, the substrate-side connection pads 34 at both ends P4 and P6 have the same bonding strength with the protruding electrode 33 as compared with the substrate-side connection pad 34 at the intermediate P5.

  According to this embodiment, it is possible to achieve the same effect as the above-described embodiment.

  Each of the embodiments described above is merely an example of the present invention, and the configuration can be changed within the scope of the present invention. The present invention can be widely applied to mounting a semiconductor chip having protruding electrodes on a circuit board.

  FIG. 13 is a perspective view showing the board-side connection pad 34 at one end and the extending portion 100 connected to the board-side connection pad 34. The extending portion 100 connected to the board-side connection pad 34 at one end may include a first extending portion 101 extending in one vibration direction A1 and a second extending portion 102 extending in the direction opposite to the wiring portion 46. Good. In this case, the displacement of the substrate-side connection pad 34 at one end can be further reliably prevented, and the bonding strength between the substrate-side connection pad 34 at one end and the protruding electrode 33 can be improved. The same applies to the board-side connection pad 34 at the other end.

  Instead of the plating bumps, ball bumps may be provided on the chip-side connection pads 37 of the semiconductor chip 31. Moreover, the structure of the insulating base material 45 may be any of a single layer, both surfaces, and multiple layers. The insulating base 45 is not limited to an organic substrate made of a resin material, and may be a ceramic substrate, for example.

  Furthermore, although the case where the protruding electrode is provided on the chip-side connection pad has been described, in still another embodiment of the present invention, the protruding electrode is not the chip-side connection pad that is the first connection pad, but the second connection. You may provide in the board | substrate side connection pad which is a pad.

  Even in this case, the displacement of the end portions in the vibration direction of the substrate-side connection pads arranged along the vibration direction is prevented, so that the displacement of the protruding electrodes provided on the substrate-side connection pads located at both ends is prevented. It is. As described above, since the displacement of each protruding electrode is prevented, it is possible to increase the relative vibration between each protruding electrode located at both ends and the chip-side connection pad facing each protruding electrode at the time of ultrasonic flip chip bonding. it can. As a result, the contamination layer between the protruding electrodes located at both ends and the chip-side connection pads can be reliably removed. Therefore, it is possible to improve the bonding strength between the protruding electrodes located at both ends and the first connection pads.

  In this embodiment, since it is not necessary to increase the ultrasonic vibration to improve the bonding strength, the semiconductor chip at the time of ultrasonic flip-chip bonding as in the technique disclosed in Patent Document 1 is not required. There is no need to change the design of the semiconductor chip in order to prevent a decrease in yield due to breakage. Therefore, without changing the design of the semiconductor chip, it is possible to prevent a decrease in yield due to breakage of the semiconductor chip during ultrasonic flip chip bonding, and the bonding strength between each protruding electrode and each chip side connection pad located at both ends. Can be improved.

It is sectional drawing which simplifies and shows the mounting structure of the semiconductor chip of one Embodiment of this invention. 3 is a front view showing a simplified semiconductor chip 31. FIG. FIG. 3 is a front view showing a part of a circuit board 32 in a simplified manner. 5 is a diagram for explaining a mounting procedure for mounting a semiconductor chip 31 on a circuit board 32. FIG. It is a figure which shows the joint strength of each projection electrode 33 and each board | substrate side connection pad 34 which are located in a line along the vibration direction A. It is a schematic diagram which shows the behavior of each board | substrate side connection pad 34 at the time of ultrasonic flip chip joining. It is a figure which shows the relationship between the pad part dimension W1 of one end, and joining strength. It is sectional drawing which simplifies and shows the mounting structure of the semiconductor chip of the other form of implementation of this invention. It is a front view which simplifies and shows the semiconductor chip 71. It is a front view which simplifies and shows a part of circuit board 72. It is a figure which shows the comparative example of the joint strength of each projection electrode 33 and each board | substrate side connection pad 34 which are located in a line with the vibration direction A. It is a figure which shows the joint strength of each projection electrode 33 and each board | substrate side connection pad 34 which are located in a line along the vibration direction A. FIG. 3 is a perspective view showing a substrate-side connection pad 34 at one end and an extending portion 100 connected to the substrate-side connection pad 34. It is sectional drawing which shows the mounting structure of the semiconductor chip of a prior art. 1 is a front view showing a circuit board 1. FIG. 3 is a cross-sectional view showing a state in which a pressing force and ultrasonic vibration are applied to the semiconductor chip 3. FIG. It is sectional drawing which shows the state of the insulating base material 6 at the time of ultrasonic flip chip joining. It is a figure which shows the joining strength of each projection electrode and each connection pad which are located in a line along the vibration direction of ultrasonic vibration. It is a schematic diagram which shows the behavior of the connection pad 5 at the time of ultrasonic flip chip joining.

Explanation of symbols

30, 70 Semiconductor device 31, 71 Semiconductor chip 32, 72 Circuit board 33 Projection electrode 34 Substrate side connection pad 45 Insulating base material 47 Extending part

Claims (4)

Including a semiconductor chip having a protruding electrode and a circuit board configured with a connection pad provided on an insulating base, the semiconductor chip being placed on the circuit board, and the protruding electrode being pressed against the connection pad, A mounting structure of a semiconductor chip in which ultrasonic vibration is applied to the semiconductor chip and the protruding electrode and the connection pad are joined,
A plurality of protruding electrodes are arranged at predetermined intervals along the vibration direction of ultrasonic vibration, and a plurality of connection pads are arranged along the vibration direction, and each protruding electrode and each connection pad face each other.
Of the connection pads arranged along the vibration direction, each connection pad located at both ends in the vibration direction has an extending portion extending in a direction away from each other along the vibration direction from each connection pad located at both ends. A mounting structure of a semiconductor chip, characterized in that each extending portion is provided on an insulating substrate.   Vibration direction dimension combining the connection pad located at one end of the vibration direction and the extension part connected to the connection pad, and vibration combining the connection pad located at the other end of the vibration direction and the extension part connected to the connection pad 2. The semiconductor chip mounting structure according to claim 1, wherein the direction dimension is selected to be not less than 2 times and not more than 3 times the vibration direction dimension of the connection pad.   3. The semiconductor chip mounting structure according to claim 1, wherein the insulating base is made of a resin material. A semiconductor chip having a first connection pad; and a circuit board configured such that the second connection pad is provided on the insulating base and the protruding electrode is provided on the second connection pad, and the semiconductor chip is mounted on the circuit board. The semiconductor chip mounting structure in which the ultrasonic vibration is applied to the semiconductor chip in a state where the protruding electrode is pressed against the first connection pad, and the protruding electrode and the first connection pad are joined.
The plurality of protruding electrodes are arranged at predetermined intervals along the vibration direction of the ultrasonic vibration, and the plurality of first connection pads and the plurality of second connection pads are arranged along the vibration direction. 1 connection pad is facing,
Among the second connection pads arranged along the vibration direction, the second connection pads located at both ends in the vibration direction are separated from each other along the vibration direction from the second connection pads located at both ends. A mounting structure of a semiconductor chip, wherein extending portions are connected to each other, and each extending portion is provided on an insulating substrate.

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