JPS62281343A - Semiconductor device - Google Patents

Abstract

PURPOSE:To connect a semiconductor chip and a mounting substrate electrically and to make it possible to align both parts highly accurately, by making a restoring force, which is yielded after the reflow of protruded electrodes, act in the direction, where the central point of the semiconductor chip and the central point of the mounting substrate substantially agree. CONSTITUTION:An arranging position of an electrode 5A of a semiconductor chip 5 is set at a position, where the electrode 5A is deviated by a specified amount alpha in the direction of the central point P1 of the semiconductor chip 5 with respect to the arranging position of an electrode 4A of a mounting substrate 4. In other words, the arranging position of the electrode 4A of the mounting substrate 4 is set at a position, where the electrode 4A is deviated in the reverse direction to the direction of the central point P1 of the semiconductor chip 5 (or the central point P2 of the mounting substrate 4) by the specified amount alpha with respect to the arranging position of the electrode 5A of the semiconductor chip 5. A protruded electrode 6, which is connected to the electrode 4A and the electrode 5A, whose arranging positions are deviated, is formed in a slant state (having an angle theta, which is formed with a horizontal plane that will be described later).

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a semiconductor device, and is particularly applicable to a semiconductor device in which a semiconductor chip is mounted on a mounting substrate with protruding electrodes interposed therebetween. related to effective techniques.

[Prior art]

A semiconductor device employing the face-down bonding method is configured as shown in FIG. 15 (cross-sectional view of main parts). That is, in the semiconductor device, the protruding electrode 3 is interposed between the electrode IA on the mounting surface of the mounting substrate 1 and the electrode 2A on the element surface of the semiconductor chip 2, and the semiconductor chip 2 is mounted on the mounting substrate l. protrusion? ii The circle 3 is made of, for example, a solder material.

This type of semiconductor device is formed using a primary manufacturing method.

First, the protruding electrode 3 is formed on the electrode 2A of the semiconductor chip 2 with a barrier metal layer (not shown) interposed therebetween. The protruding electrodes 3 are formed by a solder plating method, a solder dipping method, or a solder evaporation method.

Next, the protruding electrode 3 is brought into contact with the electrode IA of the mounting substrate 1, and the center point of the element surface of the semiconductor chip 2 is aligned with the center point of the mounting surface of the mounting substrate 1, so that the mounting substrate 1 and the semiconductor chip 2 are connected. Perform alignment. The electrode IA and the protruding electrode 3 are brought into contact with each other with a barrier metal layer (not shown) interposed therebetween, as described above.

Next, a reflow step, that is, heating the entire protruding electrode 3
A heat treatment process is performed to melt the Through this reflow step, the protruding electrode 3 and each of the electrodes IA and 2A are electrically connected, and the semiconductor chip 2 is mounted on the mounting substrate 1. In the reflow step, the aligned mounting substrate 1 and semiconductor chip 2 are automatically conveyed by a conveyor belt, and are carried out in an electric furnace provided during this conveyance.

[Problem that the invention seeks to solve]

In the above-mentioned reflow process, the flux used to prevent the protruding electrode 3 from oxidizing flows and boils.
An external force F shown in FIG. 16 (cross-sectional view of main parts) is applied to the semiconductor chip 2.
occurs. Further, in the reflow step, an external force F is generated due to vibration of the conveyor belt. Therefore, after one reflow process, a deviation of δ occurs between the electrode IA and the electrode 2A,
The center point of the mounting surface of the mounting substrate 1 and the center point of the element surface of the semiconductor chip 2 cannot be precisely aligned.

The deviation and δ, that is, the amount of deviation between the center points of the mounting substrate 1 and the semiconductor chip 2, depend on the dimensions and shape of the protrusion ff1f43, but reach approximately tens to hundreds of micrometers.

This amount of deviation δ does not pose a problem in a semiconductor device whose purpose is simply to electrically connect the mounting substrate 1 and the semiconductor chip 2. However, this becomes a problem when the semiconductor chip 2 has a light emitting element such as a laser or a light receiving element such as a photodiode, and the mounting substrate 1 has an optical signal transmission path such as an optical fiber or a guiding waveguide. This is because positioning accuracy on the order of several [μm] is required to transmit optical signals between the light emitting element or the light receiving element and the transmission path. In other words, as described above, since a large slippage δ occurs, the semiconductor device can perform electrical connection, but there is a problem that alignment cannot be performed with high precision.

An object of the present invention is to electrically connect a half-quad chip and a mounting board and to align one imager with high precision in a semiconductor device in which a semiconductor chip is mounted on a mounting board by interposing a protruding ffi pole. The goal is to provide technology that enables

Another object of the present invention is to provide a technique that can achieve the above object with a simple configuration.

The above and other objects and novel features of the present invention are explained by the following description of the specification and the accompanying drawings.

[Means for solving problems]

A brief overview of typical inventions disclosed in this application is as follows.

The present invention provides a first electrode of a semiconductor chip and a second electrode of a mounting substrate.
I! In a semiconductor device in which the semiconductor chip is mounted on a mounting substrate with a protruding electrode interposed between the protruding electrode and the protruding electrode, the restoring force generated after the protruding electrode glue flows causes the first mti; The center point of the semiconductor chip and the center point of the mounting board are shifted relative to the arrangement position of the second electrode of the mounting board so that the center point of the semiconductor chip and the center point of the mounting board substantially coincide with each other. .

[For production]

According to the above-mentioned means, even if the center point of the semiconductor chip and the center point of the mounting board are misaligned due to an external force generated in one reflow process, the restoring force of the protruding electrode allows the respective center points to substantially coincide. Therefore, it is possible to electrically connect one and the other and to perform highly accurate positioning.

Hereinafter, one embodiment of the present invention will be specifically described using the drawings.

In all the figures for explaining the embodiments, parts having the same functions are given the same reference numerals, and repeated explanations will be omitted.

[Example 1 of the invention] Example of the invention! The schematic configuration of a semiconductor device is shown in FIG. 1 (a plan view seen from the single-core chip side), and I
A cross section taken along line I-II is shown in FIG.

As shown in FIGS. 1 and 2, the semiconductor device includes a protruding electrode 6 interposed between an electrode 4A formed on the mounting surface of the mounting substrate 4 and an electrode 5A formed on the element surface of the semiconductor chip 5. Then, the semiconductor chip 5 is mounted on the mounting board 4.

The semiconductor chip 5 includes a light emitting element such as a laser, or a light receiving element such as a photodiode or a phototransistor. The semiconductor chip 5 is made of, for example, silicon, gallium arsenide, or the like.

The part of the mounting substrate 4 on which the semiconductor chip 5 is mounted is configured with an optical signal receiving section or an optical signal emitting section of an optical signal transmission path consisting of an optical fiber and a leading waveguide for transmitting an optical signal. This optical signal receiving section or optical signal emitting section is configured to input an optical signal from the light emitting element of the semiconductor chip S or to output an optical signal to the light receiving element. The mounting substrate 4 is made of, for example, silicon, silicon carbide, ceramic, or the like.

The protruding electrode 6 has a drum-shaped shape in which the cross-sectional area of the center portion is larger than that of the portion connected to each of the electrodes 4A and 5A, and the cross-sectional shape is circular. The protruding electrode 6 is made of, for example, a solder material containing each of Su and Pb, or each of Su, Pb, and In as a main component.

Mounting board 4? Ti electrode 4A, electrode 5A of semiconductor chip 5
As shown in FIG. 3 (enlarged sectional view of the main part), the connection between each of these and the protrusion 146 is made using barrier metals FW4B and 5, respectively.
This is done through B. The barrier metal layers 4B and 5B are
For example, it has a three-layer structure in which Au, Cu, and Ti are sequentially stacked from the protruding electrode 6 side. Au is mainly Cu
oxidation prevention and improves wettability with the protruding electrode 6. Cu
Mainly.

Improves the wettability between Au and Ti. Ti is mainly.

1[Works as a barrier metal layer to prevent corrosion of 4A and 5A.

As shown in FIGS. 1 and 2, in this semiconductor device, the arrangement position of the electrode 5A of the semiconductor chip 5 is set at the center of the semiconductor chip 5 with respect to the arrangement position of the electrode 4A of the mounting substrate 4. It is configured to be shifted by a predetermined shift amount α in the direction of point P. In other words, the arrangement position of the electrode 4A on the mounting board 4 is as follows.
With respect to the arrangement position of the electrode 5A of the semiconductor chip 5, the center point P of the half-quad chip 5 (or the center point P2 of the mounting board 4)
It is configured to be shifted by a predetermined shift amount α in the opposite direction. The protruding electrodes 6 connected to the electrodes 4A and m-poles 5A whose arrangement positions are shifted are arranged in an inclined state (having an angle of 0 with a horizontal plane, which will be described later).

The semiconductor device configured in this manner can be replaced with a simple spring-based model, as shown in FIG. 4 (reproduction diagram of the semiconductor device).

The protrusion electron microscope 6 denoted by the reference numeral 6 and replaced with a spring shows a state in which it is melted during one reflow process. Mounting board 4. Each of the semiconductor chips 5 can be considered a rigid body. The spring constant of the protruding electrode 6 in the direction of the mounting surface of the mounting board 4 or the element surface of the semiconductor chip 5, that is, in the horizontal plane direction, is the angle between the spring and the horizontal plane. When O, it can be expressed by the following formula (1).

k' = k cos20 -...
Q> The modeled semiconductor device shown in FIG. 4 has two springs with spring constants ′ connected in parallel in the horizontal direction, and the overall spring constant in the horizontal direction is expressed by the following equation
〉

K = 2 k' ・・・・・・〈
2> Therefore, the amount of deviation δ between the center point Pi of the mounting board 4 and the center point Pl of the semiconductor chip 5 is expressed by the following equation <3>, where the external force acting in the horizontal direction that occurs in one reflow process is d. can be expressed.

δ = F/K ・・・・・・ Equations 1 to 3 show that when the external force F is constant, the larger the angle θ with the horizontal plane, the larger the spring constant K, and the amount of deviation. This means that δ can be made small. In other words, the arrangement position of the electrode 5A of the semiconductor chip 5 is changed to the position of the electrode 5A of the semiconductor chip 5.
The larger the shift in the direction of the center point P1 of the half-quad chip 5 with respect to the arrangement position of A (the larger the shift itα is), the smaller the shift amount δ caused by the external force F can be. Therefore, in the semiconductor device, the restoring force of the protruding electrode 6 (the force acting in the direction of the arrow in FIG. ) is configured to work. The restoring force of the protruding electrode 6 automatically acts after one reflow process.

Amount of deviation α between the arrangement position of electrode 4A and the arrangement position of electrode 5A
FIG. 5 shows the relationship between this and the restoring force of the protruding electrode 6 that acts in the opposite direction to the external force F when the external force F is applied. FIG. 5 shows the results of a wt dense analysis using a solder material as the protruding electrode 6 and taking into account the shape of the protruding electrode 6.

As shown in FIG. 5, as the amount of deviation α between the arrangement position of the 'rtL pole 4A of the mounting board 4 and the arrangement position of the electrode 5A of the semiconductor chip 5 is increased, the restoring force of the protruding electrode 6 (external force F Reduce the amount of deviation δ caused by the center point p.

(the force acting in the direction of substantially matching each of P2) increases.

In this way, in the semiconductor device, the restoring force generated after the reflow process of the protruding electrode 6 changes the arrangement position of the electrode 5A of the semiconductor chip 5 between the center point P of the semiconductor chip 5 and the center point P2 of the mounting substrate 4. By shifting the position of the electrode 4A of the mounting board 4 so that it acts in the direction substantially -fi.

The center point P0. P
Even if each of the projections 11it and 2 is shifted by the amount of shift δ,
The restoring force A of 6 acts to substantially align the respective center points P, , P2, so that both are electrically connected and the mounting board 4 and semiconductor chip 5 are positioned with 1H'6 accuracy. Can be combined. Mounting board 4 and semiconductor chip 5
This means that the respective center points P0 and P2 can be aligned with a high precision of several CA trn].

Moreover, the semiconductor device configured in this way.

The restoring force A can be automatically generated after one reflow process with respect to the external force F generated during one reflow process.

In the first embodiment, in a semiconductor device having four protruding electrodes 6, all the protruding electrodes 6 are tilted to actively create the restoring force A. 6, the restoring force A may be positively constructed by tilting all or at least four protruding electrodes 6.

[Embodiment of the invention■]

This embodiment (2) is another embodiment of the present invention in which the restoring force of the protruding electrode is further increased compared to the above-mentioned embodiment I.

FIG. 6 (a plan view seen from the semiconductor chip side) shows a schematic configuration of a semiconductor device which is Embodiment 2 of the present invention.

FIG. 7 shows a cross section taken along the line ■-■ in FIG. 6.

The semiconductor device of this embodiment (2) is constructed as shown in FIGS. 6 and 7. In other words, in the semiconductor device, the electrodes 5A of the half-six-piece chip 5 are arranged at the center point I of the semiconductor chip 5 with respect to the arrangement position of the electrode 5A of the mounting substrate 4, as in the above-mentioned embodiment (2). ) It is constructed with only a predetermined shift scene α in the i direction. Along with this, the semiconductor device has dimensions of the electrode 5A (connection area with the protruding 8 electrodes 6).
is configured to be smaller (or conversely larger) than the dimensions of the electrode 4A (the connection area with the protruding electrode 6).

Figure 8 (cross-sectional view of main parts of a semiconductor device) shows electrode 4A and electrode 5.
A semiconductor device in which each dimension of A is configured to be the same is shown. FIG. 9 (a sectional view of a main part of a semiconductor device) shows a semiconductor device in which the dimensions of the electrode 5A are smaller than the dimensions of the electrode 4A. Figure 8.

The protruding electrodes 6 of the semiconductor device shown in each of FIGS.
It is composed of a drum shape drawn with a radius R centered on two points. The semiconductor device shown in FIG. 8 includes electrodes 4A, 'iY
! In the semiconductor device shown in FIG. 9, in which the radius ratio of each pole 5A is 1:1, the electrode 4A, the electrode Vi! The radius ratio of each of the 5A is 1.5:L. The semiconductor device shown in FIG. 9 constructed under such conditions can obtain a restoring force approximately 2.5 times higher than the restoring force of the semiconductor device shown in FIG. 8, which is 1.

In this way, in the semiconductor device, the arrangement position of the electrode 5A of the semiconductor chip 5 is shifted by a predetermined deviation α in the direction of the center point P1 of the semiconductor chip 5 with respect to the arrangement position of the electrode 4A of the mounting substrate 4. As well as composing - electric tM 5 A
, By configuring the electrodes 4A with different dimensions, the mounting substrate 4 and the semiconductor,
Since it is possible to electrically connect the body chip 5 and align the two with high precision, and to increase the restoring force A, it is possible to align the two with high precision.

[Embodiment of the invention■]

This Example (2) is the same as that of Example 1. This is another embodiment of the present invention in which the restoring force of the protruding electrode is further increased compared to each of II.

The schematic structure of the semiconductor device which is Embodiment ① of the present invention is shown in 10th
(a plan view seen from the semiconductor chip side), and FIG. 11 shows a cross section taken along the line XI-X in FIG. 10.

The semiconductor device of Example 2 is constructed as shown in FIGS. 10 and 11. In other words, the semiconductor device of Example 1 is the same as that of Example 1 above. Compared to each of the electrodes H, more electrodes 4A□ to 4A are provided on the mounting substrate 4, and more electrodes 5A and 5As are provided on the semiconductor chip 5.

Each is connected by a protruding electrode 6. In the semiconductor device, the electrodes 5A and 5A2 of the semiconductor chip 5 are arranged in the same manner as in the above embodiments (1) and (2).

In the direction of the center point P of the semiconductor chip 5 with respect to the respective arrangement positions of the electrodes 4A1 and 4A of the mounting board 4.

A predetermined deviation amount α1. It is configured to be shifted by α2. Each deviation amount α1. α2, that is, the arrangement positions of the electrodes 5A and 4A, and the arrangement positions of the electrodes tIIi5A and 4A2 are configured to become smaller as they approach the direction of the center point P1. Each restoring force A1gA2 is configured to increase from the center point P toward the periphery of the semiconductor chip 5.

Furthermore, the positions of the electrodes 4A, 5A are not shifted because they coincide with the center point P1.

In this way, in the semiconductor device, the mounting substrate 4 is provided with many electrodes 4A, 4A, and the semiconductor chip 5 is also provided with many atisA electrodes 5A, each connected by the protruding electrode 6, and the electrode 5A. , 5A2, the respective installation positions are as follows.
A predetermined deviation amount α4 is applied to the respective arrangement positions of the electrodes 4A and 4A2 in the direction of the center point P1 of the semiconductor chip 5.
．． By shifting by α2, the above embodiment I
Similarly, it is possible to electrically connect the mounting substrate 4 and the semiconductor chip 5 and align them with high precision, and the restoring force can be increased by the plurality of protruding electrodes 6. Therefore, both can be aligned with high precision.

Also, the respective arrangement positions of the electrodes 4A1 and 4A2.

With respect to the respective arrangement positions of the electrodes 5A, 5A2, each deviation amount α1. By configuring α2 to be small, it is possible to reduce short circuits between the protruding electrodes 6 in contact with each other, particularly on the center point P side where the density of the protruding electrodes 6 is high.

[Embodiment IV of the invention] This embodiment
This is another embodiment of the present invention in which the direction in which the restoring force of the protruding electrode acts is changed.

The schematic structure of the semiconductor device which is the embodiment (1) of the present invention is shown in the 12th
13 and 14L7I (a plan view seen from the semiconductor chip side).

The semiconductor device of this embodiment (■) is shown in FIGS. 12, 1.3, and @
The configuration is as shown in each of FIGS.

The semiconductor device shown in FIG. 12 is configured so that the positions of the electrodes 4A and 5A are shifted in a direction perpendicular to the sides of the semiconductor chip 5, and a restoring force A acts in that direction. .

The semiconductor device shown in FIG. 13 is configured so that the positions of the electrodes 4A and 5A are shifted in a direction parallel to the sides of the semiconductor chip 5, and a restoring force A acts in that direction. .

In the semiconductor device shown in FIG. 14, the positions of the electrodes 4A and 5Δ are shifted in a direction forming an angle of 45 degrees with respect to the side of the semiconductor chip 5, and a restoring force A acting in that direction It is configured to have.

In any of the semiconductor devices, the direction in which the restoring force A acts does not directly match the direction toward the center point P of the semiconductor chip 5, but when predetermined restoring forces A are combined, the direction in which the restoring force A acts is It coincides with the direction toward P. That is, each semiconductor device is configured so that the restoring force A acts in the direction of aligning the center point P1 of the semiconductor chip 5 with the center point P2 of the mounting substrate 4, similarly to the above embodiment.

Although the present invention has been specifically described above based on Examples, it goes without saying that the present invention is not limited to the above-mentioned Examples and can be modified in various ways without departing from the gist thereof.

For example, the present invention may combine the above-mentioned embodiment (2) and embodiment (III).

Further, in the present invention, the groove bottom of the protruding electrode 6 may be made of a material other than solder material.

Further, in the present invention, the protruding electrode 6 may have a circular cross-sectional shape.

Further, the present invention is not limited to a semiconductor device that includes a semiconductor chip having one light-emitting element or a light-receiving element and a mounting board having an optical signal transmission path, but is particularly applicable to electrical connections between the semiconductor chip and the mounting board. It can be applied to semiconductor devices that require highly accurate alignment. A semiconductor device configured in this manner can increase the packaging density of semiconductor chips.

〔Effect of the invention〕

As described above, according to the present invention, the following effects can be obtained.

In a semiconductor device in which a protruding electrode is interposed between a first electrode of a semiconductor chip and a second electrode of a mounting substrate, and the semiconductor chip is mounted on the mounting substrate, the arrangement position of the first electrode of the semiconductor chip is set as described above. The position of the second electrode on the mounting board is adjusted so that the restoring force generated after the reflow process of the protruding electrode acts in a direction in which the center point of the semiconductor chip and the center point of the mounting board substantially coincide. Even if the center point of the semiconductor chip and the center point of the mounting board are misaligned due to external force generated during the reflow process, the restoring force of the eight oil-shaped electrodes will maintain the respective center points. Since they act to match, they are electrically connected, and
High-precision alignment can be performed.

[Brief explanation of the drawing]

FIG. 1 shows an outline a8 of a semiconductor device which is Embodiment I of the present invention.
A plan view showing the configuration. FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1. 3 is an enlarged cross-sectional view of a main part of the semiconductor device shown in FIG. 2, and FIG. 4 is a replica of the semiconductor device shown in FIG. 2. FIG. 5 is a diagram showing the relationship between the amount of deviation in the arrangement position of the electrode and the restoring force of the protruding electrode in the semiconductor devices shown in each of FIGS. 1 to 4, and FIG. Example 411 of semiconductor device (■)
FIG. 3 is a plan view showing the III8 configuration. FIG. 7 is a cross-sectional view taken along the line ■-■ in FIG. 6, FIGS. 8 and 9 are cross-sectional views of main parts of a semiconductor device for explaining the effects of Example (■), and FIG. , FIG. 11 is a sectional view taken along the line XI-X in FIG. 10, FIGS. Example! FIG. 2 is a plan view showing a schematic configuration of a semiconductor device; FIGS. 15 and 16 are sectional views of essential parts of a semiconductor device for explaining the conventional technology. In the figure, 4...mounting board, 5...semiconductor chip, 6...protruding electrodes, 4A, 4A, 4A, 5A, 5A. 5A, electrode, Pl, P2, center point, α, α1. α2
゜δ is the amount of deviation, F is the external force.

Claims (7)

[Claims] (1) In a semiconductor device in which a protruding electrode is interposed between a first electrode of a semiconductor chip and a second electrode of a mounting substrate, and the semiconductor chip is mounted on the mounting substrate, the arrangement position of the first electrode of the semiconductor chip The second electrode of the mounting substrate is arranged so that the restoring force generated after the reflow process of the protruding electrode acts in a direction in which the center point of the semiconductor chip and the center point of the mounting substrate substantially coincide. A semiconductor device characterized by being shifted in position. (2) The semiconductor according to claim 1, wherein the first electrode is arranged at a position shifted toward the center of the semiconductor chip with respect to the second electrode. Device. (3) The semiconductor according to claim 1, wherein the arrangement position of the second electrode is shifted toward the center point of the semiconductor chip with respect to the arrangement position of the first electrode. Device. (4) A patent claim characterized in that the arrangement position of the first electrode and the arrangement position of the second electrode are shifted in all or some connection parts with the protruding electrode interposed therebetween. Each of the semiconductor devices according to the ranges 1 to 3 above. (5) Each of the semiconductors according to claims 1 to 4, wherein the area of the first electrode is approximately equal to or different from the area of the second electrode. Device. (6) The amount of deviation between the arrangement position of the first electrode and the arrangement position of the second electrode is configured to become smaller as it approaches the center point of the semiconductor chip. Each of the semiconductor devices described in Items 1 to 5. (7) The semiconductor chip is configured with a light emitting element or a light receiving element, and the mounting board is provided with optical signal transmission for inputting an optical signal from the light emitting element of the semiconductor chip or outputting an optical signal to the light receiving element. 7. Each of the semiconductor devices according to claim 1, wherein a path is formed.