JPH11284004A - Semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain a semiconductor device from being tilted, even if a solder bump is made to melt when mounting the semiconductor device on a head board. SOLUTION: A large number of output terminals 2 are arranged in rows on the main surface of a rectangular silicon board in the length wise direction, and solder bumps are each formed on the output terminals 2 for the formation of a semiconductor device. The output terminals 2 are arranged in plural rows A and B, and the outermost rows A and B are arranged on each side of a center line H, which separates the silicon board 1 in two halves in a crosswise direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flip-chip type semiconductor device mounted as a head driving IC on a printer head such as a thermal printer head or an LED printer head.

[0002]

2. Description of the Related Art Conventionally, a semiconductor element mounted as a head driving IC such as a thermal printer head is provided on one principal surface of a rectangular silicon substrate 21 as shown in FIG. A number of output terminals 22 are arranged along the long side, and a ground terminal 23, a data input terminal 24, a latch input terminal 25 and the like are arranged along the other long side, and solder bumps are formed on these terminals 22 to 25. (Not shown).

When the above-described semiconductor element is used as a driver IC for a thermal printer head, the output terminal 22 selectively selects each heating element of the thermal printer head based on image data supplied from the outside. They produce an output for generating Joule heat, and they are arranged in a staggered manner along the long side of the thermal print head near the heating element. Here, the reason why the output terminals 22 are arranged in a staggered manner is to reduce the size of the semiconductor element itself by shortening the silicon substrate 21 in the length direction. The output terminal 22 and the other terminals 23, 24, 25
And the central space S ₅ of the silicon substrate 1 located between
Electronic circuits such as switching transistors are formed at a high density (shaded area).

Since the output terminals 22 of such semiconductor elements are provided in one-to-one correspondence with the heating elements of the thermal printer head, the number thereof is extremely large, and most of the terminals 22 to 25 (80% or more) ) Is occupied by the output terminal 22.

[0005] Such conventional semiconductor elements are classified into so-called flip-chip types, and are mounted and mounted on a head substrate such as a thermal printer head by employing a conventionally known face-down bonding method. That is, FIG.
As shown in FIG. 3, the above-described semiconductor element 20 is mounted on the head substrate 31 such that the solder bumps 26 are in contact with the circuit wirings 32 on the head substrate 31. Thereafter, the solder bumps 26 are placed in a furnace. Then, the terminals 22, 23, 24, and 25 of the semiconductor element 20 are soldered to the corresponding circuit wirings 32 on the head substrate 31 to complete the mounting operation of the semiconductor element 20.

[0006]

However, in this conventional semiconductor device, the output terminals 22 occupying most of the terminals are intensively distributed on one long side of the silicon substrate 21, whereas the output terminals 22 occupy the other. There are only a few ground terminals 23 and some input terminals 24 and 25 on the long side. For this reason, when the semiconductor element 20 is mounted on the head substrate 31 such as a thermal printer head when the semiconductor element 20 is mounted on the head substrate 31,
The magnitude of the load applied to the solder bumps 26 on 2, 23, 24, and 25 is significantly different between the one long side of the semiconductor element 20 and the other long side, and the solder bump on the other long side is different. 2
6, an excessive load is applied. Therefore, when the solder bumps 26 are heated and melted in a furnace, the solder bumps 26 located on the other long side of the silicon substrate 21 are crushed by the above-mentioned load, and the semiconductor element 20 is placed on the upper surface of the head substrate 31. Implemented in an inclined state. In this case, the solder joint may be easily damaged by the application of a heat cycle, or the crushed solder bump 2
6 spreads around and causes short-circuiting between adjacent solder bumps, which has the disadvantage of significantly reducing the connection reliability of the solder joint.

[0007]

SUMMARY OF THE INVENTION The present invention has been devised in view of the above-mentioned drawbacks, and a semiconductor element of the present invention is provided along one main surface of a rectangular silicon substrate along the length direction of the substrate. A plurality of output terminals arranged in a row, and solder bumps formed on each of the output terminals, wherein the output terminals are arranged in a plurality of rows, and two outermost rows are provided. Are arranged on both sides of a center line which divides the width direction of the silicon substrate into two.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a plan view of a semiconductor device according to one embodiment of the present invention, and FIG. 2 is a cross-sectional view showing a state where the semiconductor device of FIG. 1 is mounted on a head substrate such as a thermal printer head. Is an output terminal, 6 is a solder bump, and a dotted line H is a center line that bisects the silicon substrate in the width direction. In FIG. 1, solder bumps are not shown for easy understanding of the arrangement of the output terminals 2.

The silicon substrate 1 has a thickness of 50 μm to 525.
μm, for example, 0.7 mm long × 6.0 m wide
It is formed to have a rectangular shape of m.

On one main surface of the silicon substrate 1, electronic circuits (not shown) such as shift registers, latch circuits, and switching transistors, a large number of terminals, and solder bumps 6 are provided.
It functions as a supporting base material for supporting the like.

Such a silicon substrate 1 is prepared by, for example, slicing single-crystal silicon manufactured by the well-known CZ method or the like to a thickness of 480 μm to 600 μm and polishing the same to a predetermined thickness and a predetermined shape. It is formed.

A large number of terminals provided on one main surface of the silicon substrate 1 are composed of an output terminal 2, a ground terminal 3, a data input terminal 4, and a latch input terminal 5. The solder bump 6 is formed.

The number of the output terminals 2 is 64 to 2
56, which account for the majority (87.5% to 97.0%) of all terminals. When the semiconductor element 10 is used for a thermal printer head, the output terminal 2 is used for externally supplied image data or the like. On the basis of the output, the heat generating elements of the thermal printer head individually generate Joule heat.

Such a large number of output terminals 2 are further divided into two groups by about half (approximately ± 2), and each group has a 90 μm length substantially parallel to the length direction of the silicon substrate 1. They are arranged at a pitch of １２０120 μm.

The two output terminal rows A and B are 50 μm on both sides from a center line H that bisects the silicon substrate 1 in the width direction.
The center lines H are arranged at positions separated by ２００200 μm, respectively, so that the output terminals 2 are substantially evenly distributed on both sides of the center lines H.

Therefore, the magnitude of the load applied to the solder bump 6 on one long side and the other long side of the silicon substrate 1 is substantially constant (± 10%), and the semiconductor element 10
When mounting on a head substrate 11 such as a thermal printer head, it is possible to effectively prevent a part of the melted solder bump 6 from being crushed by an excessive load. Therefore, the semiconductor element 10 can be arranged substantially parallel to the upper surface of the head substrate 11,
The terminals 2, 3, 4, and 5 of the semiconductor element 10 are connected to the head substrate 11
Satisfactorily connected to the circuit wiring 12.

In this case, if the distance between the output terminal rows A and B and the center line H is set to be substantially equal (± 5 μm), the semiconductor element 10 is mounted on the head substrate 11. In this case, the balance of the semiconductor element 10 can be kept optimal, and the collapse of the solder bump 6 and the inclination of the semiconductor element 10 can be more reliably prevented. Therefore, it is preferable that the distance between the output terminal rows A and B and the center line H be substantially equal.

The space formed by arranging the output terminal rows A and B as described above, that is, the silicon substrate 1
One of the electronic circuit of the switching transistor, such as the previously described in region S ₂ between the regions S ₁ and the output terminal sequence A-B between the long side and the output terminal row A are formed at high density, the output terminal By changing the arrangement of 2, the empty space is used efficiently.

On the other hand, terminals other than the output terminal 2 described above, that is, the ground terminal 3, the data input terminal 4, and the latch input terminal 5
Is near the long side of the silicon substrate 1 (200 μm from the edge).
m). These terminals 3,
4 and 5 are 8 to 30 and 3.0% of all terminals
Since they are about 12.5%, there is no great problem in mounting the semiconductor element 10 on the head substrate 11 regardless of where they are arranged.

The output terminal 2, the ground terminal 3, the data input terminal 4, and the latch input terminal 5 are made of a metal such as chromium or copper, and are conventionally known thin-film techniques, specifically, a sputtering technique or a photolithography technique. By adopting such a method, a predetermined pattern and a predetermined thickness are applied and formed.
Each of these terminals 2, 3, 4, 5 has a diameter of, for example, 50 μm or more.
It has a size of 200 μm and is formed in a rectangular or circular shape.

The solder bumps 6 formed on the terminals 2 to 5 are formed in a hemispherical shape with a height of 45 μm to 85 μm.

The solder bump 6 is made of a predetermined eutectic solder or the like. When the semiconductor element 10 is heated in a furnace when the semiconductor element 10 is mounted on a head substrate 11 such as a thermal printer head, a predetermined temperature (190 ° C. (250 ° C.) and acts to join the circuit wiring 12 of the head substrate 11 and the terminals 2, 3, 4, 5.

Such solder bumps 6 are attached and formed so as to individually cover the terminals 2, 3, 4, and 5 by employing a conventionally known electroless plating method or the like of eutectic solder or the like. You.

When the above-described semiconductor element 10 is mounted on a head substrate 11 such as a thermal printer head, a conventionally well-known face-down bonding method is employed. That is, the above-described semiconductor element 10 is mounted on the head substrate 11 such that the solder bumps 6 are in contact with the circuit wirings 12 on the head substrate 11, and then the solder bumps 6 are heated in a furnace. Melting and soldering the terminals 2, 3, 4, and 5 of the semiconductor element 10 to the corresponding circuit wirings 12 on the head substrate 11, thereby completing the mounting operation of the semiconductor element 10.

It should be noted that the present invention is not limited to the above-described embodiment, and various modifications and improvements can be made without departing from the gist of the present invention.

For example, in the above-described embodiment, a large number of output terminals 2 are divided into two groups, and the output terminals 2 of each group are arranged along the length direction of the silicon substrate 1, respectively. 3 output terminals
Even if the output terminals 2 of each group are arranged in one or more groups along the length direction of the silicon substrate 1 or are arranged in four or more columns, By arranging the two outermost rows on both sides of the center line H that bisects the silicon substrate in the width direction, the same effect as in the above-described embodiment can be obtained. For example, when the output terminals are arranged in three rows, as shown in FIG. 3, the output terminal row C in the center row is on the center line H, and the two outermost rows A and B located on both sides of the center are H. It is arranged at a position substantially equal to the distance from the terminal row C. Also in this case, the space (region S ₃ ) on one long side of the silicon substrate 1 or the output terminal array B
An electronic circuit such as a switching transistor is formed at a high density in a space (region S ₄ ) formed between the terminal and terminals 3, 4, and 5 other than the output terminal.

In the above embodiment, the silicon substrate 1
The ground terminal 3, the data input terminal 4, and the latch input terminal 5 are provided on one main surface in addition to the output terminal, but other terminals such as the data output terminal, the latch output terminal,
It goes without saying that an IC power supply terminal (V _DD ), an IC ground terminal and the like may be provided.

[0028]

According to the semiconductor device of the present invention, a large number of output terminals are arranged in a plurality of rows, and the outermost rows are arranged on both sides of a center line that divides the width direction of the silicon substrate into two. The output terminals are almost evenly distributed on both sides of the center line, and the magnitude of the load applied to the solder bumps on each terminal is determined on one long side and the other long side of the silicon substrate. It can be almost constant. Thus, when the semiconductor element is mounted on the printer head, a part of the melted solder bump is effectively prevented from being crushed by an excessive load, and the semiconductor element can be mounted satisfactorily.

[Brief description of the drawings]

FIG. 1 is a plan view of a semiconductor device according to one embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part showing a state where the semiconductor element of FIG. 1 is mounted on a head substrate such as a thermal printer head.

FIG. 3 is a plan view of a semiconductor device according to another embodiment of the present invention.

FIG. 4 is a plan view showing a conventional semiconductor device.

FIG. 5 is an enlarged sectional view of a main part showing a state where the semiconductor element of FIG. 4 is mounted on a head substrate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Silicon substrate 2 ... Output terminal 6 ... Solder bump H ... Center line which divides the width direction of silicon substrate 1 into two

Claims (1)

[Claims] A first silicon substrate having a rectangular shape,
A semiconductor device comprising a plurality of output terminals arranged in a row along the length direction of the substrate, and a solder bump formed on each of the output terminals, wherein the output terminals are arranged in a plurality of rows. And two outermost rows are arranged on both sides of a center line that bisects the width direction of the silicon substrate.