JP2781787B2 - Bonding pad arrangement of semiconductor chip and optimization method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To find the minimum value of an area occupied by a pad and then find the arrangement position of the pad by selecting one pad in the m-th line as a reference one and finding cutting angles for the angles of the pads in the m-th line and the pads in the adjacent (m-1)-th line which face each other. SOLUTION: A distance between the center of a reference pad in an m-th line and the center of one of adjacent pads in the (m-1)-th line is found (a first process) and then a distance between the center of the reference pad in the m-th line and the center of the other adjacent pad in the (m-1)-th line is found (a second process). Then, the distance between a point where a line (m-11 ; m-12 ) connecting the center (m-11 ) of the one adjacent pad in the (m-1)-th line and the center (m-12 ) of the other adjacent pad in the (m-1)-th line and a vertical line from the center of the reference pad in the m-th line cross each other and the center of the one adjacent pad or the other adjacent pad in the (m-1)-th line is found. From the angle between the line (m-11 ; m-12 ) and the line by the first process and an angle between the line (m-11 ; m-12 ) and the line by the second process, cutting angles of the angles of the pads in the m-th line and in the (m-1)-th line which face each other are found. Based on the cutting angles, the pads are arranged at specified intervals. By this method, areas occupied by the pads can be made small.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a bonding pad arrangement structure of a semiconductor chip and a method of optimizing the same.

[0002]

2. Description of the Related Art Referring to FIG.
A description example of Japanese Patent Publication No. 1 will be described. Pad arrangement area 6
The pads 63 are arranged in two rows in a staggered manner, and the first row and the second row are arranged in two rows.
The row of pads 63 cuts the portions adjacent to each other in an inclined manner at an arbitrary angle. As a result, since the first-row and second-row pad side intervals are enlarged, the first-row and second-row intervals can be reduced to the minimum pad side interval 52 defined by the design standard. Although the method of determining the cut angle 83b of the corner of the pad adjacent to the second row and the first row is not described, in the example described in JP-A-4-36401, the cut angle of the corner of the pad is 83bα = 135. (Degree), one side of pad is 9
6 (μm), applied pad center interval 57Px in the x direction
= 150 (μm), minimum pad side interval dpp = 20 (μm)
m), the distance 58b between the centers of the pads in the y direction to be applied between the conventional second row and the first row is 116 (μm).
It can be reduced to about 90 (μm) and as small as 20 (μm).

A description will be given of an example described in Japanese Patent Publication No. 3-42496. According to the description example of Japanese Patent Publication No. 3-42496, it is described that the pad shape can be applied to a pad arrangement of three or more rows even if a pentagonal or more polygonal pad is used. . Using these conventional techniques, a staggered pad arrangement is determined. As shown in FIG.
Two rows of staggered pads are arranged to be arranged in the pad area width 62 in the pad arrangement area width direction (hereinafter, referred to as the x direction). However, as shown in FIG.
Is smaller than the pad area width 62 in the x direction. Therefore, as shown in FIG. 10, if the center coordinates of the pad in the x direction of the odd-numbered example and the even-numbered row are respectively combined to form three rows, the pad can be accommodated within the width of the input / output buffer row. This pad arrangement will be described with reference to FIGS. 5, 6, and 7. FIG. In the first step of FIG. 5, a limit value related to pad arrangement based on a pad design standard of a semiconductor chip and a set value related to a device based on a product condition of the semiconductor chip are stored.

In the second step shown in FIG. 5, a limit value related to pad arrangement based on a pad design standard of a semiconductor chip and a set value related to a device based on a product condition of the semiconductor chip are stored.

[0005] In the second step shown in FIG. 5, the pad arrangement area 6 in the semiconductor chip is considered in consideration of the conditions obtained in the first step.
The number n of pad rows, the maximum number of pads that can be arranged per row, and the center distance between adjacent pads are determined so that the number of pads specified by the set value can be arranged at 2. Since the center interval of the pads to be applied must pass n-1 wirings between the pads in the n-th column,
It may change depending on the value of the pad row number n. 5 in FIG.
The third step b is a pad arrangement position serving as a starting point from the n-th row to the first row of the pad row number n obtained in the second step;
The cutting angles of the corners of the adjacent pads in the m-th row and the (m-1) -th row are obtained. In the fourth step of FIG. 5, the pads are sequentially arranged at the center intervals of the pads obtained in the second step, starting from the pad arrangement positions starting from the n-th column to the first column.

In FIG. 6, 21, 22, 23, 231, 23
2,233,234,235,236,237,23
8, 239 and 24 are specific contents of the second step (2 in FIG. 5), and FIG. 7 is a specific content of 33b in FIG.
2b and 333b are a twenty-first procedure for calculating the distance from the center point of the pad serving as the starting point of the m-th row to the center point of the pad serving as the starting point of the (m-1) -th row. A twenty-second procedure for obtaining an angle formed by the distance obtained in the second procedure is a cutting angle of a corner of an adjacent pad in the m-th row and the (m-1) -th row from the angle obtained in the twenty-second procedure. The cut line segment of the corner of the pad shown is a contact point at the intersection of the line segment of the distance between the pad center point of the m-th row and the (m-1) -th row obtained in the twenty-first procedure and the pad inscribed circle. Is the tangent to the inscribed circle of the pad. Variable names used in expressions (1) to (11) described later will be described with reference to FIGS. 5, 6, 7, 8, 9, and 10.

Rp is the minimum pad radius 51, d _pp is the minimum pad side interval 52, d _ph is the minimum pad side-wiring interval 53,
d _hh is the minimum wiring interval 54, W _h is the minimum wiring width 55, P _x0
The same column of the minimum pad center spacing, P _x pad columns x-direction of the pad center distance 57 to be applied, P _y pad center distance 58, n in the y direction to be applied to apply, the total number of pads U are arranged, U _max is the maximum number of pads that can be arranged per row, m is the number of pad rows of interest, W _x is the pad arrangement area width 62 in the x direction, and P _xy is the center of the pad between the m-th row and the (m−1) -th row. intervals 81a, 81b, theta is the angle 82a, 82b formed by the x and P _xy, alpha denotes an ablation angle 83a, 83 b of the corner of the pads adjacent the first m columns and the m-1 column.

Equations (1) to (11) are shown in FIGS.
7 are expressed, and equation (1) is 232 in FIG. 6, equation (2) is 236 in FIG. 6, and equations (3), (4), and (5) are 23, Equation (6) is 2 in FIG.
4. Equation (7) is 332b in FIG. 7, and equation (8) is 33 in FIG.
b, equation (9) is 336b in FIG. 7, and equation (10) is 3 in FIG.
38b and equation (11) correspond to 339b in FIG.

P _x1 = rp × 2 + d _PP (1) P _x2 = rp × 2 + W _h × (n−1) + d _hh × (n−2) + d _ph × 2 (2) P _x2 > P _x0 and P when _{x2> P x1, P x =} P x2 ... (3) P x0> time of P _x2 and _{P x0> P x1, P x} = P x2 ... (4) P x1> P x2 and P _x1> P _x0 , P _x = P _x1 (5) When W _x / ((U / n) × (P _x + rp)) ≧ 1, U _max = U / n (6) P _xy (m ≧ 3) _{= rp × 2 + W h ×} (m-2) + d hh × (m-3) + d Ph × 2 ... (7) P xy (m = 2) = rp × 2 + d pp ... (8) θ = cos -1 · _{P x / 2 · P xy ...} (9) α = 90 ( degrees) + θ ... (10) P y = sinθ × P xy ... (11) 5 for pad row number n = 2 of the conventional example, FIG. 6, FIG. 7, a specific numerical value will be described. In 1 of FIG.
The minimum pad radius 51 of a circle inscribed in the pad with one side of the pad being 96 (μm), which is a limit value from the design standard, is rp = 48
(Μm), the minimum pad side interval 52 is d _pp 20 (μm),
The minimum pad side-wiring distance 53 is _dph = 15 (μm), the minimum wiring distance 54 is _dhh = 10 (μm), the product minimum wiring width 55 is _Wh = 24 (μm), and the minimum pad center distance in the same row is P _x0 = 120 (μm), set value based on product conditions, total number of pads to be arranged is U = 90, pad arrangement area 62 in x direction
Is obtained as W _x = 9000 (μm). 6 in FIG.
Then, the number of pad rows is initialized to zero. One is added to the number of pad rows applied at 22 in FIG. 6 to set the number of pad rows n = 1. In 231 of FIG. 6, the center spacing 57 between the pads in the x direction to be applied is set to P _x0 = 120 of the center spacing of the minimum pads in the same row.
(Μm). In 232 of FIG. 6, the center distance between the minimum pads obtained from the limit value of the design standard is obtained by using Expression (1).

P _x1 = 48 × 2 + 20 = 116 (μm) (12) At 233 in FIG. 6, since the branch condition is “No”, x to be applied
The pad center interval 57 in the direction becomes P _x = 120 (μm), and the process shifts to 235 in FIG. 6, and shifts to 24 in FIG. 6 because the number of pad rows n = 1 in 235 in FIG. 24 in FIG. 6 is obtained by applying the equation (6), and as a result, 9000 / ((90/1) × (120 + 48)) = 1.595 <1 (13) Since all pads cannot be arranged, 22 in FIG. Is added to the number of pad rows to be applied, and the number of pad rows is set to n = 2. 6 have the same result as when the number of pad rows n = 1, and the processing shifts to 235 in FIG. 6, where the number of pad rows n =
For 2, the process moves to 236 in FIG. In 236 of FIG. 6, the minimum pad center distance under the condition that one wiring is equal to the pad adjacent to the n-th column is determined using Expression (2).

P _x2 = 48 × 2 + 24 × (2-1) + 10 × (2-2) + 15 × 2 = 150 (μm) (14) At 237 in FIG. 6, since the branch condition is “Yes”, 6 of 2
At 38, the center distance 57 of the pad in the x direction to be applied is set to P _x2
= 150 (μm) and the process proceeds to 24 in FIG.

In FIG. 6, reference numeral 24 denotes a result of applying the equation (6). As a result, 9000 / ((90/2) × (150 + 48)) = 1.010 ≧ 1 U _max = 90/2 = 45 (15) Since the pads can be arranged, the maximum number of pads that can be arranged per row is U _max = 45, and the process proceeds to 31 in FIG. 5, and since the number of pad rows in the branch condition n = 2, the process proceeds to 32 in FIG. The number of target pad rows m is set to m = 2. Reference is made to FIG. 7 from 33b in FIG. In 331 of FIG. 7, since the branch condition is m = 2, the pad center distance 81b between the second row and the first row is obtained using Expression (8) in 333b of FIG. .

P _xy = 48 × 2 + 20 = 116 (μm) (16) At 336 b in FIG. 7, an angle 82 b formed between the x direction and P _xy
Is calculated using equation (9).

Θ = cos ⁻¹ · 150/2 · 116 = 49.7 (degrees) (17) At 338b in FIG. 7, the cutoff angle 83b of the corner of the adjacent pad in the second row and the first row is expressed by the following equation. Determined using (10).

Α = 90 + 49.7 = 139.7 (degrees) (18) At 339 b in FIG. 7, a pad center interval 5 in the y direction to be applied
8d is obtained by using equation (11). .

P _y = sin49.7 (degrees) × 116 = 88.5 (μm) (19) At 34 in FIG. 5, the number m of pad rows of interest is subtracted by 1, and the number m of pad rows is set to 1. At 35 in FIG. 5, since the branch condition m = 1, the process proceeds to 4 in FIG. 5, and in 4 in FIG. 5, the application is performed in the x direction from the pad center point which is the starting point from the second row to the first row. The pads are sequentially arranged at the pad center intervals 57 in the x direction to be performed. As a result, the minimum value of the center interval of the pads in the y direction is given by the equation (19).
From the equation (18), it is found that the cutting angle 83b of the pad corner at that time is 88.5 (μm).
7 (degrees). Therefore, if the optimum value of the cutting angle of the corner of the pad is obtained, it can be further reduced by 1.5 (μm) as compared with the embodiment of JP-A-4-364051.

Similarly, the number of pad rows n = 3 will be described with reference to FIGS. 5, 6, and 7 by setting specific numerical values. In 1 of FIG. 5, the limit value is set according to the design standard, the minimum pad radius 51 is rp = 48 (μm), and the minimum pad side interval 52 is d _pp = 2.
0 (μm), minimum pad side-interval spacing 53 is d _ph = 15
(Μm), the minimum wiring interval 54 is d _hh = 10 (μm), the minimum wiring width 55 is W _h = 24 (μm), the center distance between the minimum pads in the same row is P _x0 = 120 (μm), set according to product conditions. The value and the total number of pads to be arranged are obtained as U = 90, and the pad arrangement area width 62 in the x direction is obtained as W _x = 7000 (μm). At 21 in FIG. 6, the number of pad rows is initialized to zero. One is added to the number of pad rows to be applied, and the number of pad rows n = 1 is set. In 231 of FIG. 6, the center spacing 57 of the pad in the x direction to be applied is set to P _x0 = 120 of the center spacing of the minimum pads in the same row.
(Μm). In 232 of FIG. 6, the minimum pad center distance obtained from the limit value of the design standard is obtained using Expression (1).

P _x1 = 48 × 2 + 20 = 116 (μm) (20) At 233 in FIG. 6, since the branch condition is “No”, x to be applied
The center interval 57 of the pad in the direction becomes Px = 120 (μm), and the process shifts to 235 in FIG. 6, and shifts to 24 in FIG. 6 because the number of pad rows n = 1 in 235 in FIG. 24 in FIG.
As a result of applying (Equation 6), 7000 / ((90/1) × (120 + 48)) = 0.462 <1 (21) Since all pads cannot be arranged, the number of pad rows to be applied in 22 in FIG. , And 1 is set to the number of pad rows n = 2. 6 have the same result as when the number of pad rows n = 1, and the processing shifts to 235 in FIG. 6, where the number of pad rows n =
For 2, the process moves to 236 in FIG. In 236 of FIG. 6, the center spacing of the minimum pad that satisfies the condition for passing one wiring between pads in the second row adjacent to each other is calculated using Expression (2).

P _x2 = 48 × 2 + 24 × (2-1) + 10 × (2-2) + 15 × 2 = 150 (μm) (22) At 237 in FIG. 6, the branch condition is “Yes”, 6 of 2
At 38, the center distance 57 of the pad in the x direction to be applied is set to P _x2
= 150 (μm) and the process proceeds to 24 in FIG. 24 in FIG. 6 is obtained by applying the equation (6), and as a result, 7000 / ((90/2) × (150 + 48)) = 0.786 <1 (23) Since all pads cannot be arranged, 22 in FIG. Is added to the number of pad rows to be applied, and the number of pad rows is set to n = 3. 6 have the same result as when the number of pad rows n = 1, and the processing shifts to 235 in FIG. 6, where the number of pad rows n =
For 3, the process moves to 236 in FIG. In 236 of FIG. 6, the minimum center interval that satisfies the condition of passing two wires between the pads adjacent to each other in the third row is obtained using Expression (2).

P _x2 = 48 × 2 + 24 × (3-1) + 10 × (3-2) + 15 × 2 = 184 (μm) (24) At 237 in FIG. 6, since the branch condition is “Yes”, 6 of 2
At 38, the center distance 57 of the pad in the x direction to be applied is set to P _x2
= 184 (μm), and the routine proceeds to 24 in FIG. 24 in FIG. 6 is obtained by applying the equation (6). As a result, 7000 / ((90/3) × (184 + 48)) = 1.006 ≧ 1 U _max = 90/3 = 30 (25) All pads can be arranged. Therefore, the maximum number of pads U _max that can be arranged per row is U _max = 30, and the processing shifts to 31 in FIG. 5. Since the number of pad rows n = 3 in the branch condition, the processing shifts to 32 in FIG. Set several m = 3. Reference is made to FIG. 7 from 33b in FIG. In 331 of FIG. 7, since the branch condition is m = 3, the pad center distance 81a between the third row and the second row is obtained using Expression (7) in 332b of FIG.

P _xy = 48 × 2 + 24 × (3-2) + 10 × (3-3) + 15 × 2 = 150 (μm) (26) At 336b in FIG. 7, an angle 82a formed by the X direction and Pxy
Is calculated using equation (9).

Θ = cos ⁻¹ · 184/2 · 150 = 52.2 (degrees) (27) At 338b in FIG. 7, a pad corner cutting angle 83a is obtained using Expression (10).

Α = 90 + 52.2 = 142.2 (degrees) (28) At 339b in FIG. 7, a center interval 58c between pads to be applied in the y direction is obtained by using equation (11).

P ^y = sin 52.2 (degrees) × 150 = 18.5 (μm) (29) At 34 in FIG. 5, the number of pad rows m of interest is subtracted by 1, and the number of pad rows m = 2, At 35 in FIG. 5, because of the branch condition m = 2, the process shifts to 33b in FIG. 5 and refers to FIG. 3 in FIG.
At 31, since the branch condition is m = 2, the center distance 81 b between the pads of the second row and the first row is calculated by 333 b in FIG.
Is determined using

P _xy = 48 × 2 + 20 = 116 (μm) (30) At 336 b in FIG. 7, an angle 82 b formed by the x direction and P _xy
Is calculated using equation (9).

Θ = cos ⁻¹ · 184/2 · 116 = 37.5 (degrees) (31) At 338b in FIG. 7, the cutting angle 83b of the corner of the pad is obtained using Expression (10).

Α = 90 + 37.5 = 127.5 (degrees) (32) At 339b in FIG.
8d is obtained by using equation (11).

P _y = sin 37.5 (degrees) × 116 = 70.6 (μm) (33) At 34 in FIG. 5, the number m of pad rows of interest is subtracted by 1, and the number m of pad rows is set to 1. At 35 in FIG. 5, because of the branch condition m = 1, the process proceeds to 4 in FIG. 5, and at 4 in FIG. 5, the center point of the pad from the third row to the first row is shifted in the x direction from the center point of the pad. The pads are sequentially arranged at the center intervals 57 of the pads in the x direction to be applied.

As described above, the same processing is repeated even when the number of pad rows is n = 4 or more. The pad arrangement area 62 can be reduced by obtaining the optimum value of the conventional example. However, according to the equation (29), the distance 58c between the third row and the second row in the y direction is 118.5 (μm), and the equation (33) 2nd column-
The distance 58d in the y direction between the first rows is 70.6 (μm), and 4d between the third row and the second row and between the second row and the first row.
A difference of 7.9 (μm) appears.

[0030]

The first problem is that when the pads are arranged in three rows in a staggered pattern according to the regularity of the prior art,
The pad occupied area in the y-direction greatly increases between the third row and the second row as compared with that between the second row and the first row. The reason is,
As shown in FIG. 10, a wiring connecting the pads in the first row and the input / output buffer must be passed between the pads in the third row and the second row. When the wiring is passed between the two rows of pads, it is not necessary to pass the wiring between the third row of pads and the other adjacent second row of pads. This is because, since the pad arrangement positions are the same, the second row of pads adjacent to the third row of pads can be further approached.

The second problem is that the corners of the mating pads between the first row of pads and the adjacent second row of pads are cut obliquely at an arbitrary angle. As a result, the distance between the first row and the second row cannot be reduced so much, that is, the effect decreases. The reason is that in order to minimize the pad occupied area, not only the pad shape but also the cutting angle, the pad arrangement position, that is, the distance and angle between each pad must be determined.

It is an object of the present invention to provide a bonding pad arrangement configuration of a semiconductor chip and a method of optimizing the pad occupying area in which the pad occupying area is small and the minimum value of the pad occupying area and its pad arranging position can be obtained.

[0033]

SUMMARY OF THE INVENTION According to the present invention, there is provided a semiconductor chip bonding pad arrangement configuration and a method for optimizing the same, wherein a limit value relating to a pad arrangement according to a pad design standard of a semiconductor chip and a setting value relating to a device according to a product condition of the semiconductor chip. 1 (FIG. 1), and the number of pad rows and the number of pads per row can be arranged so that the number of pads specified by the set value can be arranged in the pad arrangement area in the semiconductor chip. A second step (2 in FIG. 1) for obtaining a maximum number of pads and a center distance between adjacent pads, and arbitrary pads in the first to n-th rows (where n is an integer) of the number of pad rows Determine the starting pad position to be the starting point in the row, and
Is a third step (3a in FIG. 1) for determining the cut-off angle of the opposing pad corner between the pad of n <m <1) and the adjacent pad of the (m-1) th row, and the nth row in the pad arrangement region. And a fourth step (4 in FIG. 1) of sequentially arranging the maximum number of pads that can be arranged per row in each of the rows from the first row to the first row at pad center intervals.

According to the present invention, in the first step, the limit value regarding the pad arrangement based on the pad design standard of the semiconductor chip and the set value regarding the device based on the product condition of the semiconductor chip are stored. The number of rows of pads, the maximum number of pads that can be arranged per row, and the center distance between adjacent pads are set so that the number of pads specified by the set value can be arranged in the pad arrangement area in the chip. In the third step, in the first procedure, the distance from the center point of the pad serving as the starting point of the m-th row to one pad center point of the adjacent (m-1) -th row is determined, and in the second procedure, , The distance between the center point of the pad serving as the starting point of the m-th row and the center point of the other pad of the (m-1) -th row is determined, and in the third procedure, one pad of the (m-1) -th row and the other The line connecting the center points of the pads A perpendicular line is drawn from the center point of the pad to obtain an intersection, a distance from the center point of one pad or the center point of the other pad to the intersection is obtained, and one pad and the other in the (m-1) th row are determined in the fourth procedure. The angle formed by the line segment connecting the center points of the pads with the line segment of the distance obtained in the first procedure is obtained, and in the fifth procedure, one pad and the other pad of the m-1 row are arranged. The angle formed by the line segment connecting the center points and the line segment of the distance obtained in the second procedure is obtained, and in the sixth procedure,
From the angles obtained in the fourth procedure and the fifth procedure, a cutting angle of the corner of the pad corresponding to the pad in the m-th row and the pad in the (m-1) -th row is obtained. The n-th
Pads are sequentially arranged at the pad center intervals determined in the second step, with the maximum number of pads that can be arranged per row in each of the rows from the first row to the first row.

[0035]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a flowchart for explaining a method of optimizing the arrangement of bonding pads of a semiconductor chip according to an embodiment of the present invention. FIG. 2 is a flowchart of 33a in FIG. 1, and FIG. 3 is a pad to which the flowchart of FIG. FIG. 4 is a plan view of three rows of pads arranged in a zigzag pattern to which the flowchart of FIG. 1 is applied.

The first step (1 in FIG. 1) and the second step (2 in FIG. 1) shown in the flowchart of FIG. 1 are the same as in the prior art. The third step (3a in FIG. 1) includes a pad arrangement position serving as a starting point from the n-th row to the first row of the pad row number n obtained in the second step, and a pad in the m-th row and the m-th pad. The cutting angle of the corner of the pad corresponding to the pad in one row is determined.
In the fourth step (4 in FIG. 1), pads are sequentially arranged from the pad arrangement positions that are the starting points from the nth row to the first row at the center intervals of the pads obtained in the second step. FIG. 2 is a sectional view of FIG.
A first procedure for determining a distance from a center point of a pad serving as a starting point of the m-th row to a center point of one pad in an adjacent (m-1) -th row; A second procedure for determining the distance from the center point of the pad serving as the starting point of the m-th row to the center point of the other pad in the adjacent (m-1) -th row; and one pad and the other pad in the (m-1) -th row A line is drawn from the center point of the pad serving as the starting point of the m-th row to a line segment connecting the center points of the first and second points, and an intersection is obtained, and a distance from the center of one pad or the center of the other pad to the intersection is obtained. And a fourth procedure for finding an angle formed by a line segment connecting the center point of one pad and the other pad in the m-1th row with the line segment of the distance obtained in the first procedure, A line segment connecting the center point of one pad and the other pad in the (m-1) th row with a line segment having the distance obtained in the second procedure A fifth step of obtaining an angle but which forms, from an angle determined by the fourth step and the fifth step, the m
A sixth procedure is described which determines the cut angle of the corner of the pad between the pad in the row and the pad in the (m-1) th row.
The cut line segment of the corner of the pad, which is indicated by the cut angle of the corner of the pad, is a line of the distance between the center points of the m-th row and the (m-1) -th row of pads determined in the first procedure and the second procedure. This is a tangent to the pad inscribed circle, with the intersection of the minute and the pad inscribed circle as the node.

The variable names used in equations (1) to (6) and in equations (34) to (42) described later are as shown in FIG.
This will be described with reference to FIGS. rp is a minimum pad radius 51, d _pp is a minimum pad side interval 52, d _ph is a minimum pad side-wiring interval 53, d _hh is a minimum wiring interval 54,
W _h is the minimum wiring width 55, P _x0 is the center spacing of the same row minimum pad, P _x is the x direction of the center distance 57 of the pad to be applied,
_Py is the center distance 58a, 58 of the pad in the y direction to be applied.
b, n pad columns to be applied, the total number of pads U are arranged, m pad columns of interest, W _x is the x-direction of the pad arrangement region width 62, P _xy2 is the m-th column and the m sandwiching the wire The center spacing 71a, 71b, _Pxy1 of the pad between the -1st row and the pad is the center spacing 72 between the mth row and the (m-1) th row without the wiring.
a, 72bΔP _x is the center spacing 73a, 73b, θ1 between the pads in the x direction of the m-th row and the (m-1) -th row, which do not sandwich the wiring, is x
The angle 74a, 74b, θ2 formed by the direction and P _xy1 is x
The angle 75a, 75b, α1 formed by the direction and P _xy2 is P
cutting angles 76a, 76b of the corners of the pad intersecting with xy1,
α2 is the cutting angle 77a of the corner of the pad that intersects _Pxy2 ,
77b.

Equations (34) to (42) express the functions of the flow shown in FIG. 2, and equation (34) represents the function 33 shown in FIG.
2a, equation (35) is 333a in FIG. 2, and equation (36) is FIG.
334a and equation (37) are 335a and equation (38) in FIG.
2 is 336a in FIG. 2, equation (39) is 337a in FIG. 2, and equations (40) and (41) are 338a in equation 2 and equation (42).
Corresponds to 339a in FIG.

P _xy2 (n ≧ 3) = rp × 2 + W _h × (n−2) + d _hh × (n−3) + d _ph × 2 (34) P _xy2 (n = 2) = rp × 2 + d _pp (35) P _xy1 (n ≧ 2) = rp × 2 + d _pp (36)

[0041]

[0042] alpha ₂ = 90 _{(degrees) + θ 2 ... (40)} α 1 = 90 ( _{degrees) + θ 1 ... (41)} P y = sinθ 1 × P xy1 = sinθ 2 × P xy2 ... (42) of the present invention Regarding the first embodiment, the number of pad rows n = 2
1 will be described with reference to FIGS. 1 and 2 by setting specific numerical values. In FIG. 1, the limit value is stored from the design standard and the set value is stored from the product condition. In FIG. 1B, the method of obtaining the center distance 57 of the pad in the x-direction and the number of pad rows to be applied in FIG. This is the same as the description of the pad row number n = 2.
At 31 in FIG. 1, since the number of pad rows n = 2 in the branch condition, FIG.
To 32, and sets the number of focused pad rows m = 2. Reference is made to FIG. 2 from 33a in FIG. 331 of FIG.
Since the branching condition is m = 2, the pad center distance 71b between the second row and the first row without interposing the wiring is set to 333a in FIG.
It is determined using equation (35).

P _xy2 = 48 × 2 + 20 = 116 (μm) (43) At 334 a in FIG. 2, the pad center distance 72 b between the second row and the first row, which do not sandwich the wiring, is calculated using the equation (36). Ask.

P _xy1 = 48 × 2 + 20 = 116 (μm) (44) In the 335a of FIG. 2, the x and y directions of the second and first columns, which do not sandwich the wiring of P _xy1, are obtained in 334a of FIG. The pad center interval 73b is obtained by using equation (37).

[0045]

[0046] In 336a in FIG. 2, the angle 74b of x and P _xy2 form, at 337a in FIG. 2, the angle 75b of x and P _xy1 form, respectively formula (38), formula (3
Determined using 9).

Θ2 = cos ⁻¹ (150−75.0) /116=49.7 (46) θ1 = cos ⁻¹ 75.0 / 116 = 49.7 (47) In FIG. center distance P _xy2 resection angle 76b of the corner of the pad that intersects the ablation angle 77b of the corner of the pad which intersects the pad center distance P _xy2, respectively, formula (40), determined using equation (41).

Α2 = 90 + 49.7 = 139.7 (degrees) (48) α1 = 90 + 49.7 = 139.7 (degrees) (49) y-direction pad center distance 58 to be applied at 339a in FIG.
b is obtained using equation (42).

P _y = sin49.7 (degrees) × 116 = 88.5 (μm) (50) At 34 in FIG. 1, the number m of pad rows of interest is subtracted by 1, and the number m of pad rows is set to 1. At 35 in FIG. 1, because of the branch condition m = 1, the process proceeds to 4 in FIG. 1, and in 4 in FIG. 1, from the center point of the pad which is the starting point from the second row to the first row, in the x direction, The pads are sequentially arranged at the pad center intervals 57 in the x direction to be applied.

The second embodiment of the present invention will be described with reference to FIGS. 1 and 2 by setting specific numerical values for the number of pad rows n = 3. In FIG. 1, a limit value is obtained from a design standard and a set value is obtained from a product condition. In FIG. 1B, a method of obtaining a center distance 57 between pads to be applied in the x direction and a number of pad rows to be applied is determined by a conventional pad. This is the same as the description for the number of columns n = 3. At 31 in FIG. 1, since the number of pad rows n = 3 in the branch condition,
The process proceeds to 32 in FIG. 1, and the number of pad rows of interest, m = 3, is set. Reference is made to FIG. 2 from 33a in FIG. 331 of FIG.
Since the branch condition m = 3, the center distance 71 between the pads of the third and second rows sandwiching the wiring shown in FIG.
a is obtained by using the equation (34).

P _xy2 = 48 × 2 + 24 × (3-2) + 10 × (3-3) + 15 × 2 = 150 (μm) (51) In 334a of FIG. The center distance 72a between the row and the pad is obtained by using equation (36).

[0052] In 335a of _{P xy1 = 48 × 2 + 20} = 116 (μm) ... (52) 2 was determined by 334a in FIG. 2, the x direction of the third and second columns not to pinch the wires P _xy1 The center distance 73a between the pads is obtained by using Expression (37).

[0053]

[0054] In 336a in FIG. 2, the angle 74a where x and P _xy2 form, at 337a in FIG. 2, the angle 75a which x and Pxy1 form, respectively, formula (38), formula (3
Determined using 9).

Θ2 = cos ⁻¹ (184-67.4) /150=39.0 (degrees) (54) θ1 = cos ⁻¹ 67.4 / 116 = 54.5 (degrees) (55) 2 of 338a, resection angle 76a of the corners of the pad which intersects the central interval P _xy2 pad, the resection angle 77a of the corner of the pad which intersects the pad center distance P _xy1, respectively, formula (40), formula (41) Is determined using

Α2 = 90 + 39.0 = 129.0 (degrees) (56) α1 = 90 + 54.5 = 144.5 (degrees) (57) At 339a in FIG. 2, the center distance between the pads in the y direction is applied. 58a is calculated using equation (42).

P _y = sin 54.5 (degrees) × 116 = sin 39.0 (degrees) × 150 = 94.4 (μm) (58) At 34 in FIG. 1, subtract 1 from the number m of pad rows of interest. , The number of pad rows is set to m = 2, and the branch condition m = 2 at 35 in FIG. 1 so that the processing shifts to 33a in FIG. 1 and refers to FIG. 2 of FIG.
At 31, the branch condition is m = 2, and therefore, at 333 a of FIG.
b is determined using equation (35).

P _xy2 = 48 × 2 + 20 = 116 (μm) (59) At 334 a in FIG. 2, the center distance 72 b between the pads of the second row and the first row that do not sandwich the wiring is calculated by using the equation (36). Ask.

P _xy1 = 48 × 2 + 20 = 116 (μm) (60) In the 335a of FIG. 2, the x-direction of the second and first columns, which do not sandwich the wiring of P _xy1 , is obtained by 334a in FIG. The center spacing 73b between the pads is determined using equation (37).

[0060]

[0061] In 336a in FIG. 2, the angle 74b of x and P _xy2 form, at 337a in FIG. 2, the angle 75b of x and P _xy1 form, respectively, formula (38), formula (3
Determined using 9).

Θ2 = cos ⁻¹ (184-92.0) /116=37.5 (degrees) (62) θ1 = cos ⁻¹ 92.0 / 116 = 37.5 (degrees) (63) 2 of 338a, resection angle 76b of the corner of the pad which intersects the central interval P _xy2 pad, the resection angle 77b of the corner of the pad which intersects the pad center distance P _xy1, respectively, formula (40), formula (41) Is determined using

Α ₂ = 90 + 37.5 = 127.5 (degrees) (64) α ₁ = 90 + 37.5 = 127.5 (degrees) (65) In FIG. The center interval 58b is obtained using Expression (42).

P _y = sin 37.5 (degrees) × 116 = 70.6 (μm) (66) At 34 in FIG. 1, the number m of pad rows of interest is calculated as one source, and the number m of pad rows is set to 1. At 35 in FIG. 1, because of the branch condition m = 1, the process shifts to 4 in FIG. 1, and in 4 in FIG. 1, from the pad center point which is the starting point from the third row to the first row, in the x direction, The pads are sequentially arranged at the pad center intervals 57 in the x direction to be applied. According to equation (58), the distance 58a in the y direction between the third row and the second row is 94.4 (μm), and from equation (66), the distance 58b in the y direction between the second row and the first row is 70.6. (Μm), the difference of 47.9 (μm) in the conventional example is reduced to 23.8 (μm), and the results of Expressions (33) and (66) are the same, but the third column -There is an effect between rows of the second row or more. As described above, even when the number of pad rows is n = 4 or more, the same processing is repeated to obtain the pad arrangement position that minimizes the pad position area.

[0065]

The first effect is that the pad occupation area can be made smaller than that of the conventional example, and is particularly remarkable in the third row and the second row or more. The reason is that the odd-numbered row and the even-numbered row do not have the same pad arrangement positions in the x direction, and the n-th row pad adjacent to the n-th row pad that does not pass the wiring connecting the pad and the input / output buffer is connected. This is to make the distance close to the center distance of the pad allowed by the design standard.

The second effect is that the minimum value of the pad occupied area and its pad arrangement position can be obtained. The reason is that the number of pad rows, the cut angle of the corner of the pad, the center interval between adjacent pads, are set for each pad row, and the line segment connecting the n-th row and the adjacent pad center point of the (n-1) -th row is set. Is set for each pad row.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating a method for optimizing a bonding pad arrangement of a semiconductor chip according to an embodiment of the present invention.

FIG. 2 is a flowchart of 33a in FIG.

FIG. 3 is a plan view of two rows of pads arranged in a zigzag pattern to which the flowchart of FIG. 1 is applied;

FIG. 4 is a plan view of three rows of pads arranged in a zigzag pattern to which the flowchart of FIG. 1 is applied;

FIG. 5 is a flowchart illustrating an example of a conventional method for optimizing the arrangement of bonding pads on a semiconductor chip.

FIG. 6 is a flowchart of FIG. 1 and FIG.

FIG. 7 is a flowchart of 33b in FIG. 5;

FIG. 8 is a plan view of a conventional pad arranged in a two-row staggered pattern.

FIG. 9 is a plan view of a staggered arrangement of two rows of pads that cannot be accommodated in the column width of a conventional input / output buffer.

FIG. 10 is a plan view of a conventional three-row staggered pad array of pads.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 1st process 2 2nd process 3a 3rd process 3b 3rd conventional process 4 4th process 332a, 333a 1st procedure 334a 2nd procedure 335a 3rd procedure 336a 4th procedure 337a Fifth procedure 338a Sixth procedure 332b, 333b Twenty first procedure 336b Twelfth procedure 338b Twelfth procedure 51 Minimum pad radius rp 52 Minimum pad side spacing dph 53 Minimum pad side-wiring spacing 54 Minimum wiring spacing 55 Minimum Wiring width 57 Applicable pad center distance in the x direction 58a, 58b Applicable pad center distance in the y direction between the third and second rows and between the second and first rows 58c, 58d Conventional third row -Between the second rows, the second row-
The center spacing of the pads in the y-direction to be applied between the first columns 61 The input / output buffer 62 The width of the pad arrangement area in the x-direction 63 The pads 64 Wirings 71a, 71b connecting the input / output buffers and the pads Third and second rows sandwiching the wiring Center spacing 72a, 72b between pads of first and second rows 72a, 72b Center spacing 73a, 73b of pads between third and second rows, and second row and first row not sandwiching wires 73a, 73b Do not sandwich wires Center spacing 74a, 74b between pads in x direction of third and second rows, and second and first rows 74a, 74b Third row and second row sandwiching wiring in x direction
The angle 75a, 75b formed by the line segment of the pad center distance 71a between the row, the second row, and the first row. 75% of the center distance 72a, 72b of the pad between the third row and the second row without interposing the wiring in the x direction. An angle 76a formed by the line segment A cut angle of a corner of a pad that intersects with a line segment of a center interval 71a between the pads of the third row and the second row that sandwich the wiring 76b The second row and the first row that do not sandwich the wiring Angle 77a of the corner of the pad intersecting with the line segment of the pad center interval b 77a The angle of the pad corner intersecting with the line segment of the center interval 72b between the third and second rows not interposing the wiring 81a Angles 83a, 83b formed by the line segments of the center intervals of the pads between the third row and the second row, and between the second row and the first row. Adjacent pads of the third row and the second row, and the second row and the first row. Corner resection angle

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-8-340017 (JP, A) JP-A-8-172109 (JP, A) JP-A-63-252434 (JP, A) JP-A-7-252 22460 (JP, A) JP-A-5-308137 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01L 21/60 301

Claims (6)

(57) [Claims] A first step of storing a limit value relating to a pad arrangement according to a bonding pad (hereinafter referred to as a pad) design standard of a semiconductor chip and a setting value relating to a device according to a product condition of the semiconductor chip; The number of pad rows, the maximum number of pads that can be arranged per row, and the center distance between pads between adjacent pads are determined so that the number of pads specified by the set value can be arranged in the pad arrangement area within the area. In the second step, a starting pad position to be a starting point is determined from an arbitrary pad row from the first row to the n-th row (n is a positive integer) of the number of previous pad rows, and an m-th row (m is n <m <)
M-1 adjacent to the center point of the pad which is the starting point of 1)
A third step of determining a cut angle of a corner of the pad facing the pad in a row, and a maximum pad which can be arranged per row in each of the n-th row to the first row in the pad placement area And a fourth step of sequentially arranging the number of pads at the center interval of the pads. 2. The first step of determining a distance from a center point of a pad serving as a starting point of an m-th row to a center point of one of the adjacent pads of the (m-1) -th row; The m-th
The m-th row adjacent to the center point of the pad which is the starting point of the row
Second means for determining the distance from the center point of the other pad in one row; and a line segment connecting the center point of the one pad and the center point of the other pad in the m-1 row, A third procedure in which a perpendicular is drawn from the center point of the pad which is the starting point of the row to determine an intersection, and a distance from the center point of the one pad or the center point of the other pad to the intersection is obtained; A fourth step of determining an angle formed by a line segment having the distance determined in the first step in a line segment connecting the center point of the one pad and the center point of the other pad in one row; and m
A fifth procedure for determining an angle formed by a line segment connecting the center point of the one pad in one row and the center point of the other pad with the line segment having the distance determined in the second procedure; The fourth
And a sixth procedure of calculating a cut-off angle of a corner of the pad corresponding to the m-th row pad and the (m-1) -th row pad from the angle obtained in the fifth procedure. 2. The method for optimizing the arrangement of bonding pads of a semiconductor chip according to claim 1. 3. A distance between a center point of a pad serving as a starting point of the m-th row and a center point of one of adjacent pads in an (m-1) -th row and a center point of a pad serving as a starting point of the m-th row. 3. The arrangement structure of bonding pads of a semiconductor chip, wherein the distance between the other pads of the adjacent m-rows is within the range determined according to claim 2. 4. A pad lead-out wiring (hereinafter, referred to as a wiring) passing between a pad serving as a starting point of the m-th row and an adjacent (m-1) -th row of pads is formed at a corner of the pad determined by claim 1. A semiconductor chip bonding pad arrangement structure wired in parallel with a cutting angle of the semiconductor chip. 5. The semiconductor chip according to claim 1, wherein all of the pads in the first to n-th rows of the pad row number have a pad shape obtained by cutting at a corner of the pad determined according to claim 1. Bonding pad arrangement structure. 6. The bonding of a semiconductor chip according to claim 1, wherein the shape of the pad determined according to claim 1 is a pad shape cut off at a tangent to an inscribed circle of each pad by a cutting angle of a corner of the pad. Pad arrangement structure.