JP2006351589A - Semiconductor chip, electronic device and manufacturing method thereof - Google Patents

Abstract

A semiconductor chip, an electronic device, and a method of manufacturing the same are provided to improve the reliability of bump connection when a bump is miniaturized in a semiconductor chip and an electronic device on which the semiconductor chip is mounted.
A semiconductor chip 10 is mounted on a mounting board 20 having mounting board bumps 24 made of solder, the semiconductor chip body 11 on which an electronic circuit is formed, and the semiconductor chip body connected to the electronic circuit. The semiconductor chip bumps 12 are formed. The semiconductor chip bumps 12 are made of a metal having a melting point higher than that of solder, and are connected to the mounting substrate bumps 24 when mounted, and are smaller than the diameter of the mounting substrate bumps 24. Shall. Further, the electronic device has a configuration in which the semiconductor chip 10 is mounted on the mounting substrate 20 having the mounting substrate bumps 24 as described above.
[Selection] Figure 1

Description

  The present invention relates to a semiconductor chip, an electronic device, and a manufacturing method thereof, and more particularly, to a semiconductor chip, an electronic device, and a manufacturing method thereof corresponding to bump miniaturization.

  The demand for downsizing, thinning, and weight reduction of portable electronic devices such as digital video cameras, digital mobile phones, and notebook personal computers has been increasing. While an electronic circuit device in which such a semiconductor device is mounted on a printed wiring board has been realized by 70% reduction year by year, how can the component mounting density on the mounting substrate (printed wiring substrate) be improved? Has been researched and developed as an important issue.

  For example, a package form for mounting a semiconductor device has shifted from a lead insertion type such as DIP (Dual Inline Package) to a surface mounting type, and further bumps (projections) made of solder, gold, etc. on the pad electrode of a semiconductor chip. A flip chip mounting method has been developed in which an electrode is provided and connected to a wiring board through bumps face-down.

  For example, flip chip bonding in the case where fine bumps of about φ30 μm or less are provided on the upper and lower sides, as described in Patent Document 1, etc., on a chip with a lower bump (or a mounting substrate with a bump) adsorbed on a bonder stage After the chip with the upper bump adsorbed to the bonding tool is faced and the bumps are aligned, the bonding tool is lowered, the bump is brought into contact, the chip with the upper bump is mounted on the chip with the lower bump, and then heated under pressure. Bond the bumps. Such bonding is called local reflow bonding.

  However, local reflow bonding in which pressure heating is performed as described above has the disadvantage that it takes 60 to 90 seconds of heating and pressing time per chip in order to perform bonding reliably, resulting in a long bonding time. Had.

FIG. 4 is a schematic diagram for explaining the problems of local bonding in the conventional method.
The chip 110 with the upper bump is configured by connecting to an electronic circuit formed on the chip body 111, forming a pad electrode 112 on the chip body 111, and forming a spherical solder bump 113 so as to cover the pad electrode 112. Yes.
On the other hand, the chip (or mounting substrate) 120 with the lower bump is connected to an electronic circuit formed on the chip body (or substrate) 121, and the pad electrode 122 is formed on the chip body 121, and the spherical surface is formed so as to cover it. A solder bump 123 having a shape is formed.
In bonding the chip 110 with the upper bump and the chip 120 with the lower bump, when the fine bumps such as solder are bonded to each other, the bumps are slipped due to the spherical shape of the bumps. May have occurred.

FIGS. 5A and 5B are schematic diagrams for explaining the problems of the local bonding of the conventional method.
When bonding the chip 110 with the upper bump and the chip 120 with the lower bump as shown in FIG. 4, the chip 120 with the lower bump is held on the bonding stage BS as shown in FIG. 5A, and the upper bump is formed by the bonding head BH. The attached chip 110 is held, the bumps are aligned with each other, pressurized and heated to perform reflow bonding, cooled, and then removed from the bonding stage BS and the bonding head BH to be in the state shown in FIG.
In such local reflow bonding, bumps are aligned with each other and then bumps are heated under pressure to bond them. Therefore, the self-alignment effect that can be obtained by batch reflow with general soldering is obtained. If the position shift occurs, the state is maintained as it is.

FIG. 6 is a schematic diagram for explaining a problem of local bonding in the conventional method.
When bonding the chip 110 with the upper bump and the chip 120 with the lower bump as shown in FIG. 4, in the local reflow bonding by pressurizing and heating the solder bumps, the pressure is applied by the bonding head when the solder is melted. The solder bumps were crushed too much, and the chip was tilted, so that a desired gap between chips could not be secured, and there was a case where the solder was short-circuited. Further, due to this inclination, the bumps may not be in contact with each other at other portions Y, resulting in poor connection.
JP 2000-349123 A

  The problem to be solved by the present invention is that it is difficult to increase the certainty of bump connection when bumps are miniaturized in a semiconductor chip and an electronic device on which the semiconductor chip is mounted.

  The semiconductor chip of the present invention is a semiconductor chip mounted on a mounting board having mounting board bumps made of solder, the semiconductor chip body on which an electronic circuit is formed, and the semiconductor chip connected to the electronic circuit A bump formed on the main body and connected to the mounting substrate bump at the time of mounting, made of a metal having a melting point higher than that of solder and having a diameter smaller than the diameter of the mounting substrate bump .

  The semiconductor chip of the present invention is a semiconductor chip mounted on a mounting board having mounting board bumps made of solder, the semiconductor chip body on which an electronic circuit is formed, and the semiconductor chip connected to the electronic circuit A bump formed on the main body and connected to the mounting substrate bump at the time of mounting, which is made of a metal having a melting point higher than that of solder and has a diameter smaller than that of the mounting substrate bump.

  An electronic device according to the present invention includes a mounting substrate having mounting substrate bumps made of solder, a semiconductor chip body on which an electronic circuit is formed, and bumps formed on the semiconductor chip body so as to be connected to the electronic circuit. A bump for a semiconductor chip made of a metal having a melting point higher than that of the solder, and having a diameter smaller than that of the bump for the mounting substrate, and the bump for the semiconductor chip is connected to the bump for the mounting substrate, And a semiconductor chip mounted on a mounting substrate.

The electronic device according to the present invention includes a mounting substrate having mounting substrate bumps made of solder, and a semiconductor chip.
Here, the semiconductor chip is a semiconductor chip body on which an electronic circuit is formed, and bumps formed on the semiconductor chip body so as to be connected to the electronic circuit. The semiconductor chip bump is connected to the mounting substrate bump, and the semiconductor chip is mounted on the mounting substrate.

  According to another aspect of the present invention, there is provided a method of manufacturing an electronic device, wherein the mounting substrate bumps of the mounting substrate having solder mounting substrate bumps are connected to the semiconductor chip body on which an electronic circuit is formed and the electronic circuit. As described above, the semiconductor chip of the semiconductor chip having bumps formed on the semiconductor chip body and made of a metal having a melting point higher than that of solder and having a diameter smaller than that of the mounting substrate bump Aligning and piercing the bump for mounting, temporarily attaching the semiconductor chip to the mounting substrate, reflowing and solidifying the solder for the mounting substrate bump, and connecting the mounting substrate bump and the semiconductor chip bump And fixing the semiconductor chip to the mounting substrate.

In the manufacturing method of the electronic device according to the present invention, first, the mounting chip bump of the mounting board having the mounting board bump made of solder is connected to the semiconductor chip body on which the electronic circuit is formed and the electronic circuit. As described above, the semiconductor chip bump of the semiconductor chip having a bump formed on the semiconductor chip body and made of a metal having a melting point higher than that of the solder and having a diameter smaller than that of the mounting substrate bump. Are aligned and stabbed to temporarily attach the semiconductor chip to the mounting substrate.
Next, the solder of the mounting substrate bump is reflowed and solidified, and the mounting substrate bump and the semiconductor chip bump are connected to fix the semiconductor chip to the mounting substrate.

  According to the semiconductor chip of the present invention, in the semiconductor chip mounted on the mounting substrate, the bump on the chip side is used as the bump on the mounting substrate side by using the bump on the chip side having a smaller diameter than the bump on the mounting substrate side made of solder. Can be mounted by reflow, and when bumps are miniaturized, the reliability of bump connection can be improved.

  According to the electronic device of the present invention, in the electronic device in which the semiconductor chip is mounted on the mounting substrate, the bump on the mounting substrate side is used by using the bump on the chip side whose diameter is smaller than the bump on the mounting substrate side made of solder. The bumps on the chip side can be pierced and temporarily attached, and can be mounted by reflow. When the bumps are miniaturized, the reliability of bump connection can be improved.

  According to the method for manufacturing an electronic device of the present invention, in the method for manufacturing an electronic device in which a semiconductor chip is mounted on a mounting substrate, a chip-side bump having a smaller diameter than the bump on the mounting substrate side made of solder is used. When the bumps on the chip side are pierced and temporarily attached to the bumps and mounted by reflow, the reliability of the bump connection can be improved when the bumps are miniaturized.

  Hereinafter, a semiconductor chip, an electronic device, and a manufacturing method thereof according to embodiments of the present invention will be described with reference to the drawings.

FIG. 1A is a schematic cross-sectional view showing the configuration of the semiconductor chip according to the present embodiment.
The semiconductor chip 10 includes a semiconductor chip body 11 on which an electronic circuit is formed, and semiconductor chip bumps 12 formed on the semiconductor chip body 11 so as to be connected to the electronic circuit.
The semiconductor chip 10 is a semiconductor chip mounted on a mounting board having mounting board bumps made of solder, and the semiconductor chip bump 12 is a bump connected to the mounting board bump at the time of mounting, and is higher than the solder. It is made of a metal having a melting point and has a diameter smaller than the diameter of the bump for the mounting substrate.

The semiconductor chip bump is preferably in the shape of a substantially prism, a pyramid, a substantially cylinder, or a substantially cone.
For example, in the case of a substantially prismatic or substantially cylindrical shape, it can be formed by performing a plating process on the Al pad with Au or Cu, or by an Au stud bump forming process. Alternatively, in the case of a substantially pyramid or substantially conical shape, it can be formed by performing Zn substitution plating on the Al pad, forming a Ni core by Ni electroless plating, and further performing Au plating or the like. .
Preferably, the maximum diameter of the semiconductor chip bump 12 is 30 μm or less, for example, 10 μm, 15 μm,.

FIG. 1B is a schematic cross-sectional view showing the configuration of the mounting substrate on which the semiconductor chip according to this embodiment is mounted.
In the mounting substrate 20, for example, an insulating film 22 is formed on the surface of a semiconductor chip main body 21 for mounting substrate, and a pad electrode 23 connected to an electronic circuit or the like formed in the semiconductor chip main body 21 is formed thereon. A mounting substrate bump 24 made of spherical solder is formed so as to cover each pad electrode 23.
For example, the mounting substrate bump 24 can be formed by solder plating or the like, and its diameter is, for example, about 30 μm.
As the mounting substrate, as long as the mounting substrate bump 24 made of solder is formed on the pad electrode, a normal resin substrate, a substrate in which a resin layer is laminated, a ceramic substrate, or the like may be used as the main body portion.

The electronic device according to the present embodiment is configured by mounting the semiconductor chip shown in FIG. 1A on the mounting substrate shown in FIG. 1B, and a manufacturing method thereof will be described.
2A and 2B are schematic cross-sectional views illustrating a method for manufacturing an electronic device according to this embodiment.
First, as shown in FIG. 2A, the semiconductor chip body 11 in which an electronic circuit is formed on the mounting substrate bump 24 of the mounting substrate 20 having the mounting substrate bump 24 made of solder, and the electronic circuit A semiconductor chip 10 having bumps formed on the semiconductor chip body 11 so as to be connected, and made of a metal having a melting point higher than that of solder and having a diameter smaller than the diameter of the mounting board bump 24. The semiconductor chip bumps 12 are aligned and pierced, and the semiconductor chip 10 is temporarily attached to the mounting substrate 20.

The temporary attachment is possible because the diameter of the semiconductor chip bump 12 is smaller than the diameter of the mounting substrate bump 24. For example, the semiconductor chip bump 12 has a substantially prismatic shape, a substantially pyramid shape, and a substantially cylindrical shape. Alternatively, when the shape is substantially conical, the mounting substrate bumps 24 can be effectively pierced.
Here, bumping a semiconductor chip bump into a mounting substrate bump and temporarily attaching the semiconductor chip to the mounting substrate means pressing the semiconductor chip bump against the mounting substrate bump and deforming at least a part of the mounting substrate bump. In particular, this means that the oxide film on the surface of the solder constituting the mounting substrate bump 24 is broken through and the semiconductor chip bump and the mounting substrate bump are fixed to such an extent that they do not peel even if a certain amount of force is applied.
As described above, the semiconductor chip bump 12 is pierced into the mounting substrate bump 24 and fixed to such an extent that it does not peel off even if a certain amount of force is applied, thereby preventing the occurrence of misalignment between the semiconductor chip 10 and the mounting substrate 20. it can.

In the above-described temporary attachment, it is preferable that the mounting substrate 20 is preheated to such an extent that the solder constituting the mounting substrate bump 24 at about 200 ° C. does not melt.
In this case, it is easy to deform the mounting substrate bump 24 and break through the oxide film, and even if the semiconductor chip bump is columnar, it is easy to pierce the mounting substrate bump.

Next, as shown in FIG. 2B, the solder is melted by reflow treatment and cooled to solidify the solder, and the mounting substrate bump 24 and the semiconductor chip bump 12 made of solder are electrically and mechanically connected. The semiconductor chip 10 is fixed to the mounting substrate 20 by connecting.
As described above, the electronic device of this embodiment can be manufactured.

  In the solder reflow process described above, the semiconductor chip bump 12 reaches the pad electrode 23 through the mounting substrate bump 24 made of solder. The gap between the semiconductor chip and the mounting substrate may deviate from a predetermined value due to the crushing of the solder bumps. In this embodiment, the bump crushing during bonding is performed by adjusting the height of the bump for the semiconductor chip. Therefore, it is possible to adjust the crushing of the bumps and to control the gap between the semiconductor chip and the mounting substrate stably and constantly.

The step of reflowing and solidifying the solder for the mounting board bumps can be performed independently for one electronic device, but is preferably performed simultaneously for a plurality of electronic devices.
When manufacturing a plurality of electronic devices, processing time can be shortened by performing reflow processing in a lump.

In the step of reflowing the solder for the mounting substrate bump, it is preferable that the position of the semiconductor chip bump with respect to the mounting substrate bump is automatically adjusted by the surface tension of the solder.
3A and 3B are schematic cross-sectional views showing that the semiconductor chip bumps are positioned in a self-aligned manner with respect to the mounting substrate bumps.
FIG. 3A shows a state in which the semiconductor chip is temporarily attached to the mounting substrate in a state where the position of the semiconductor chip bump is shifted from the center with respect to the mounting substrate bump.
When the reflow process is performed in the above-described state, the semiconductor chip is not fixed by the bonding head as in the conventional example. Therefore, as shown in FIG. Is automatically moved to the center of the pad electrode 23 of the mounting substrate 20, and the semiconductor chip 10 can be positioned with respect to the mounting substrate 20 in a self-aligning manner.

In the above, it is preferable that the shape of the semiconductor chip bump 12 is a substantially prismatic shape, a substantially pyramid shape, a substantially cylindrical shape, or a substantially conical shape.
For example, it is preferable that the maximum diameter of the bump for a semiconductor chip be 30 μm or less.
By making the shape of the semiconductor chip bump 12b the above-described shape or by reducing the diameter, it becomes easier to stab and fix without slipping with respect to the mounting substrate bump.

As the mounting substrate 20, it is preferable to use a substrate having a semiconductor.
For example, the above method can be applied when a semiconductor chip is mounted on another semiconductor chip.

The electronic device according to the present embodiment manufactured by the above manufacturing method is configured by mounting the semiconductor chip 10 on which the semiconductor chip bumps 12 are formed on the mounting substrate 20 having the mounting substrate bumps 24 made of solder. Yes.
The semiconductor chip bump 12 is a bump formed on the semiconductor chip body 11 so as to be connected to the electronic circuit of the semiconductor chip body 11 and is made of a metal having a melting point higher than that of the solder, and is larger than the diameter of the mounting substrate bump 24. The semiconductor chip 10 has a small diameter, the semiconductor chip bump 12 is connected to the mounting substrate bump 24, and the semiconductor chip 10 is mounted on the mounting substrate 20.

In the electronic device according to the present embodiment, for the above reason, the semiconductor chip bump is preferably in the shape of a substantially prism, a pyramid, a substantially cylinder, or a substantially cone, and the largest of the semiconductor chip bumps. The diameter is preferably 30 μm or less.
Further, the present invention can be applied to a configuration in which a semiconductor chip is mounted on another semiconductor chip, in which the mounting substrate is a substrate having a semiconductor.

  According to the present embodiment, in flip chip mounting of a chip with bumps of φ30 μm or less, (1) short-time mounting by batch reflow processing for a plurality of electronic devices and (2) semiconductor chip for mounting substrate bumps by reflow It is possible to position the bumps in a self-aligned manner and (3) adjust the gap between the chip and the mounting substrate by adjusting the height of the bump for the semiconductor chip.

The present invention is not limited to the description of the above embodiment.
For example, as a mounting substrate, a normal mounting substrate such as a resin substrate or a ceramic substrate, an intermediate substrate, or the like can be used in addition to a semiconductor chip.
In addition, various modifications can be made without departing from the scope of the present invention.

FIG. 1A is a schematic cross-sectional view showing a configuration of a semiconductor chip according to the embodiment of the present invention, and FIG. 1B is a schematic view showing a configuration of a mounting substrate on which the semiconductor chip according to the embodiment of the present invention is mounted. It is sectional drawing. 2A and 2B are schematic cross-sectional views illustrating a method for manufacturing an electronic device according to an embodiment of the present invention. 3A and 3B are schematic cross-sectional views showing that the semiconductor chip bumps are positioned in a self-aligned manner with respect to the mounting substrate bumps. FIG. 4 is a schematic diagram for explaining the problems of local bonding in the conventional method. FIGS. 5A and 5B are schematic diagrams for explaining the problems of the local bonding of the conventional method. FIG. 6 is a schematic diagram for explaining a problem of local bonding in the conventional method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Semiconductor chip, 11 ... Semiconductor chip main body, 12 ... Semiconductor chip bump, 20 ... Mounting substrate, 21 ... Semiconductor chip main body for mounting substrate, 22 ... Insulating film, 23 ... Pad electrode, 24 ... Bump for mounting substrate, DESCRIPTION OF SYMBOLS 110 ... Chip with upper bump, 111 ... Chip body, 112 ... Pad electrode, 113 ... Solder bump, 120 ... Chip with lower bump (or mounting substrate), 121 ... Chip body (or substrate), 122 ... Pad electrode, 123 ... Solder bump , BH ... Bonding head, BS ... Bonding stage

Claims (13)

A semiconductor chip mounted on a mounting substrate having mounting substrate bumps made of solder,
A semiconductor chip body on which an electronic circuit is formed;
A bump formed on the semiconductor chip main body so as to be connected to the electronic circuit and connected to the mounting substrate bump at the time of mounting, made of a metal having a melting point higher than that of solder, and larger than the diameter of the mounting substrate bump A semiconductor chip having a bump for a semiconductor chip having a small diameter. The semiconductor chip according to claim 1, wherein the semiconductor chip bump has a substantially prismatic shape, a substantially pyramid shape, a substantially cylindrical shape, or a substantially conical shape. The semiconductor chip according to claim 1, wherein a maximum diameter of the bump for the semiconductor chip is 30 μm or less. A mounting board having mounting board bumps made of solder;
A semiconductor chip body on which an electronic circuit is formed, and a bump formed on the semiconductor chip body so as to be connected to the electronic circuit, and is made of a metal having a melting point higher than that of solder, which is larger than the diameter of the bump for the mounting substrate. An electronic device comprising: a semiconductor chip bump having a small diameter; and the semiconductor chip bump connected to the mounting substrate bump and mounted on the mounting substrate. The electronic device according to claim 4, wherein the semiconductor chip bump has a substantially prismatic shape, a substantially pyramid shape, a substantially cylindrical shape, or a substantially conical shape. The electronic device according to claim 4, wherein the semiconductor chip bump has a maximum diameter of 30 μm or less. The electronic device according to claim 4, wherein the mounting substrate is a substrate having a semiconductor. A semiconductor chip body on which an electronic circuit is formed and a bump formed on the semiconductor chip body so as to be connected to the electronic circuit with respect to the mounting board bump of the mounting board having a mounting board bump made of solder. The semiconductor chip bump of a semiconductor chip comprising a semiconductor chip bump made of a metal having a melting point higher than that of the solder and having a diameter smaller than that of the mounting substrate bump, and the semiconductor chip Temporarily attaching to the mounting substrate;
Reflowing and solidifying the solder of the mounting substrate bump, connecting the mounting substrate bump and the semiconductor chip bump, and fixing the semiconductor chip to the mounting substrate. The method for manufacturing an electronic device according to claim 8, wherein the steps of reflowing and solidifying the solder of the bumps for mounting substrate are simultaneously performed on a plurality of electronic devices. 9. The method of manufacturing an electronic device according to claim 8, wherein in the step of reflowing the solder of the mounting substrate bump, the position of the semiconductor chip bump with respect to the mounting substrate bump is automatically adjusted by the surface tension of the solder. . The method for manufacturing an electronic device according to claim 8, wherein a shape of the semiconductor chip bump is a substantially prismatic shape, a substantially pyramid shape, a substantially cylindrical shape, or a substantially conical shape. The method for manufacturing an electronic device according to claim 8, wherein a maximum diameter of the bump for the semiconductor chip is 30 μm or less. The method for manufacturing an electronic device according to claim 8, wherein a substrate having a semiconductor is used as the mounting substrate.

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