JP2970755B2 - Semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device having a semiconductor integrated circuit chip having a center pad arrangement.
In particular, bonding pads of the semiconductor integrated circuit chip,
For example, like the inner lead on the lead frame side,
The present invention relates to a semiconductor device having a structure in which terminals of an external connection lead wire of a package are electrically connected by wire bonding.

[0002]

2. Description of the Related Art In recent years, the area for arranging bonding pads on a semiconductor integrated circuit chip has become narrower with the increasing integration of LSIs. Therefore, when the same number of bonding pads as in the related art are arranged on a semiconductor integrated circuit chip, the distance between adjacent bonding pads is reduced.

In particular, in a semiconductor integrated circuit chip 1 having a center pad arrangement as shown in FIG. 5, bonding pads 2 are arranged in a line at the center of the chip 1 from inner leads 4 on the lead frame side arranged on the left and right sides. In this case, the interval between the bonding pads 2 is very small, and accordingly, the tip diameter of the bonding tool 5 is reduced as shown in FIGS. However, in this case, the bonding length of the 2nd bonding shape (indicated by reference numeral 7) in the wire bonding process in the bonding tool 5 is reduced, and the bonding stability at the time of the 2nd bonding is reduced. Had led to a decline in sex.

[0004] Here, "2nd bonding" refers to the bonding pad 2 on the semiconductor integrated circuit chip 1.
To join the bonding wire 3 to "1st
In contrast to "bonding", for example, it refers to bonding a bonding wire 3 to a terminal of a lead for external connection of a package, such as an inner lead 4 of a lead frame.

When the distance between the bonding pads 2 is small, when performing wire bonding, FIG.
In (b), in the operation pattern of the bonding tool 5 as indicated by reference numeral 8, particularly, in the region indicated by reference numeral 9 (reverse operation), the tip of the bonding tool 5 is connected to the previously connected adjacent bonding wire 3. Contact
There is a risk of breaking the bonding wire 3 and
At the time of use, there is a possibility that an electrical short or the like may be caused between the bonding wires having different signals or potentials.

[0006]

As described above, when the distance between the bonding pads 2 on the semiconductor integrated circuit chip 1 is reduced, it is necessary to reduce the diameter of the tip of the bonding tool 2. In this case, however, 2nd is required. If the bonding stability in bonding decreases (for example, poor bonding), and if the tip diameter of the bonding tool 2 is not changed, the tip diameter becomes too large relative to the distance between the bonding pads 2. In the wire bonding operation, a problem such as cutting of the existing bonding wire adjacent thereto occurs.

The present invention has been made on the basis of the above circumstances, and provides a semiconductor device having a semiconductor integrated circuit chip having a center pad arrangement, which can be highly integrated without impairing the yield of wire bonding. The purpose is to do.

[0008]

Therefore, in the present invention,
A semiconductor device in which bonding wires are connected alternately to the left and right between terminals of external connection lead wires arranged on the left and right sides of the semiconductor integrated circuit chip and bonding pads arranged at the center of the semiconductor integrated circuit chip.
The bonding pads are arranged in a staggered manner so as to be displaced left and right with respect to the entire arrangement direction,
The positional displacement of the bonding pad is set so that the direction in which the bonding wire is drawn from the bonding pad to the terminal and the direction of a line connecting the centers of the adjacent bonding pads are at right angles or acute angles. It is characterized by having done.

Further, the arrangement of the terminals on the left and right with respect to the entire arrangement direction of the bonding pads may be defined by the direction of the bonding wire and the direction of a line connecting the centers between adjacent pads with respect to the bonding order. The angle is set to be a right angle or an acute angle.

[0010] Therefore, by shifting the position of the bonding pads left and right by a required amount in the direction of the entire arrangement, the necessary spacing between the bonding pads is substantially secured, and the tip diameter of the bonding tool is forcibly reduced. Without the need for wire bonding, it is possible to easily perform wire bonding, and in the operation pattern of wire bonding, accidents such as disconnection of adjacent existing bonding wires can be avoided. A good bonding state similar to that described above can be obtained.

[0011]

(Embodiment 1) Next, Embodiment 1 of the present invention will be specifically described with reference to FIGS. In the semiconductor integrated circuit chip 1 of the memory system, the bonding pads 2 may be arranged in a line at the center of the semiconductor integrated circuit chip 1 as described above. In this case, the inner leads 4 are connected to the semiconductor integrated circuit chip 1. Providing on both upper sides, the bonding wires 3 are usually arranged alternately (see FIG. 5). In this case, the adjacent bonding pad 2
Is L = L1.

In the embodiment of the present invention, adjacent bonding pads 2 are shifted left and right with respect to the direction of the overall arrangement of the bonding pads 2, forming a so-called staggered arrangement. Therefore, the distance L between the adjacent bonding pads 2
2 is L2 = L1 / cos θ (θ is the inclination angle with respect to the direction of the entire arrangement of the bonding pads), whereby the wire bonding can be performed without difficulty without forcibly reducing the tip diameter of the bonding tool. You can do it. Further, in use, there is no possibility that an electrical short-circuit or the like may be caused between bonding wires having different signals or potentials.

As shown in FIGS. 2A and 2B, the bonding wires 3 to be bonded from the respective bonding pads 2 to the corresponding left and right inner leads 4 are arranged from the upper side to the lower side in the figure. When the bonding is performed alternately on the left and right, the direction in which the bonding wire 3 is pulled out from the bonding pad 2 to the inner lead 4 and the direction of the line connecting the centers between the adjacent bonding pads 2 are at right angles or acute angles (in the drawing, α = right angle) is shown.
The left and right misalignment is set.

That is, in FIG. 2A, when the adjacent bonding pads 2 are arranged at an angle θ with respect to the direction of the overall arrangement of the bonding pads 2 (the vertical direction in the drawing), the bonding pads 2 At the time of wire bonding from 2 to the left inner lead 4, the reverse operation area 9 at the tip of the bonding tool 5 secures a sufficient interval L2 and does not approach the bonding wire 3 in the preceding stage.

In FIG. 2B, when performing wire bonding from the bonding pad 2 to the inner lead 4 on the right side, the reverse operation area 9 at the tip of the bonding tool 5 depends on the operation stroke. The distance L3 (L3 = L1 · sin θ) or more is ensured, and there is no further approach to the bonding wire 3 in the preceding stage.

In the embodiment shown in FIGS. 1 and 2, for convenience of explanation, the pitch dimension L in the direction of the entire arrangement of the bonding pads 2 is set to L = L1, and the intervals are equal, but as described above. Considering that L3 = L1 · sin θ <L1, the distance L in the entire direction of the bonding pad 2 in the case of FIG. 2B is L3 = L · sin θ> L
It is better to set it to 1. For example, L = L2 //
Assuming sin θ, L3 = L2. The reverse operation area 9 at the tip of the bonding tool 5 has a sufficient distance L
3 will be secured.

Accordingly, in the operation pattern 8 of the bonding tool 5, the reverse operation area 9 does not approach the adjacent bonding wire 3 connected immediately before, and the tip of the bonding tool 5 contacts. Therefore, there is no risk of disconnection.

(Embodiment 2) FIGS. 3 and 4 illustrate Embodiment 2 of the present invention. Here, the pitch of the left and right arrangement of the inner leads 5 with respect to the entire arrangement direction of the bonding pads 2 is shifted up and down in the drawing, and the other directions are the same as in the first embodiment. The direction of the line connecting the centers of the bonding pads 2 adjacent to each other is set to be a right angle or an acute angle with respect to the bonding order direction (from top to bottom in the drawing) (see FIG. 3).

That is, FIG. 4A shows a case where α = right angle, and FIG. 4B shows a case where α = acute angle. The operation and effect at this time are the same as those of the first embodiment,
Even if the pitch dimension L in the direction of the entire arrangement of the bonding pads 2 is equal, as shown in FIG. 4C, the direction of the reverse operation area 9 at the tip of the bonding tool 5 is different from that of the bonding wire 3 in the preceding stage. It has an angle away from it and does not approach it (here, α '= a sharp angle). Therefore, there is no possibility that the leading end of the bonding tool 5 comes into contact and breaks.

In the first and second embodiments, the case where the left and right inner leads 4 are wire-bonded alternately from top to bottom in the drawings (FIGS. 1 and 3) will be described. However, for example, for one inner lead, in the order from top to bottom, first wire bonding, and conversely, for the other inner lead, wire bonding in the order from bottom to top The good thing is, of course.

[0021]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. That is, as in the conventional example (see FIG. 5), when the pad spacing is 100 μm when the bonding pads 2 are arranged in a single row, in the present invention, a bonding tool similar to the case where the pad spacing is 120 μm is used. 5 is designed as follows in order to be usable.

First, the bonding pads 2 are shifted in a staggered manner so that the distance between the adjacent bonding pads 2 is one.
It should be 20 μm. Therefore, in this case, it is sufficient to shift the bonding pads 2 by about 67 μm left and right with respect to the direction of the entire arrangement. Next, for example, FIG.
(A), the inner leads 4 are arranged such that the longitudinal direction of the bonding wire 3 and the direction of the line connecting the centers of the bonding pads 2 adjacent to each other intersect at right angles. It may be arranged so as to intersect at an acute angle as in b)).

This eliminates the need to use the bonding tool 5 having a small tip diameter, which is required when the interval between the bonding pads 2 is 100 μm, and at least uses the bonding tool when the pad interval is 120 μm as it is. Can be done.

[0024]

According to the present invention, as described in detail above, the terminals of the external connection leads arranged on the left and right sides of the semiconductor integrated circuit chip and the bonding pads arranged at the center of the semiconductor integrated circuit chip are described. In a semiconductor device having left and right bonding wires connected alternately between the bonding pads, the bonding pads are arranged in a staggered manner so as to be shifted left and right with respect to the entire arrangement direction, and the bonding pads are connected to the terminals. The bonding pad is shifted left and right so that the direction in which the bonding wire is drawn out of the bonding pad and the direction of the line connecting the centers of the bonding pads adjacent to each other are at right angles or acute angles. Wire bonding can be performed easily without forcibly reducing the tip diameter of the tool. In addition, in the operation pattern of wire bonding, accidents such as breakage of adjacent existing bonding wires can be avoided, and even if the integration of chips is advanced, the yield of wire bonding is not impaired, and the same as before A good joint state can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing Embodiment 1 of the present invention.

FIG. 2 is an enlarged view of a main part for explaining wire bonding in (a) and (b).

FIG. 3 is a schematic plan view showing Embodiment 2 of the present invention.

FIG. 4 is an enlarged view of a main part for explaining wire bonding in (a) to (c).

FIG. 5 is a schematic plan view of a conventional example.

FIG. 6A is an external side view of a bonding tool,
(B) is an enlarged sectional view of the tip, and (c) is a plan view of a second bonding shape.

FIGS. 7A and 7B are a side view and a plan view for explaining wire bonding in a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Semiconductor integrated circuit chip 2 Bonding pad 3 Bonding wire 4 Inner lead (terminal) 5 Bonding tool 6 Part forming 2nd bonding shape bonding length 7 2nd bonding shape bonding length 8 To form a bonding wire loop shape Trajectory 9 of the bonding tool in the reverse operation area on that trajectory

Claims (2)

(57) [Claims] 1. The method according to claim 1, further comprising: connecting between terminals of external connection leads arranged on the left and right sides of the semiconductor integrated circuit chip and bonding pads arranged at the center of the semiconductor integrated circuit chip.
In a semiconductor device in which bonding wires are connected alternately to the left and right, the bonding pads are arranged in a staggered manner so as to be shifted left and right with respect to the entire arrangement direction, and bonding from the bonding pads to the terminals is performed. The semiconductor device according to claim 1, wherein the position of the bonding pad is shifted left and right so that the direction in which the wire is drawn out and the direction of a line connecting the centers of the adjacent bonding pads are at right angles or acute angles. 2. The arrangement of the terminals on the left and right with respect to the entire arrangement direction of the bonding pads, the direction of the bonding wire and the direction of a line connecting the centers between adjacent bonding pads are determined with respect to the bonding order direction. 2. The semiconductor device according to claim 1, wherein the angle is set to be a right angle or an acute angle.