JP3087233B2 - Measuring method of chip position shift - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a highly accurate method for measuring a chip displacement in flip-chip connection of an IC chip or the like used in a semiconductor device or the like.

[0002]

2. Description of the Related Art The flip-chip connection method is a mounting method effective for high-density electrode connection or electrode connection of minute dimensions in the opposing positioning connection between an IC chip and a substrate or between IC chips.

[0003] In recent years, this flip-chip connection method is represented in the 1987 National Institute of Electronics, Information and Communication Engineers Semiconductor and Materials Division National Convention Lecture Papers (Part 2), p. 338, S9-6 due to the improvement of positioning accuracy at the time of connection. It has been used for positioning and opposing connection between an optical device chip such as a light receiving element and a surface emitting laser and a substrate constituting an optical component such as a lens and an optical waveguide. In this case, a positional deviation between the two after flip-chip connection becomes a problem.

[0004] For this reason, it is necessary to accurately inspect the positional deviation at the time of flip chip connection. In this type, as a conventional method for measuring the positional deviation by flip-chip connection, measurement using a marker as shown in FIG. 4 has been common. In the figure, 1
Is a pseudo substrate made of a transparent glass material, 2 and 5 are bump electrode patterns, 3 is a bump, 4 is a chip, and 6a and 6b are markers.

[0005] In the conventional displacement measurement method, bump electrode patterns 2 and 5 are formed on the opposing surface of a pseudo substrate 1 and a chip 4 to be flip-chip connected on the pseudo substrate 1, respectively. , 5 have a certain positional relationship, and when viewed from above without any positional deviation, the marker 6a is placed on the pseudo substrate 1 side so as to completely overlap.
After forming the markers 6b on the chip 4 side and flip-chip connecting them using the bumps 3, the displacement L of the markers 6a and 6b is enlarged from the transparent pseudo substrate 1 side by a microscope (not shown). However, the method of reading with a length measuring device or the like was generally used. This method is an effective position deviation measurement method when the positional deviation L can be read with an accuracy larger than the width of the markers 6a and 6b.

[0006]

However, in the conventional position deviation measuring method, when the position deviation L is very small, particularly, the reading error of the markers 6a and 6b itself and the accuracy of the length measuring device used for the measurement. There was a possibility that the measurement error would increase due to the above factors.

That is, in the length measurement with an accuracy equal to or less than the width of the markers 6a and 6b, the deviation L must be measured by accurately judging the edge portion and the center of the markers 6a and 6b, and the reading error is reduced. There was a growing problem. Also, when a length measuring device that optically transmits and enlarges an object using a microscope and measures the length as image information is used, the transmitted and enlarged image is distorted due to the aberration of the microscope, etc. Length measurement was difficult.

On the other hand, in a length measuring device that moves an object by using a fine moving table and reads a marker, it may be difficult to obtain an accurate length measurement due to backlash of the fine moving table. In addition, in flip-chip connection, if the objects to be positioned and connected are twisted and connected, there is a problem that the arrangement of the markers themselves is twisted and the measurement error increases. SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention is to provide a chip position shift measuring method capable of accurately measuring a minute position shift of an IC chip in flip chip connection.

[0009]

The above object can be attained by adopting the following novel characteristic construction method of the present invention. That is, the first feature of the present invention is that the IC
In the flip-chip connection method in which a chip or a chip having a similar shape is positioned and connected to a substrate via a bump electrode pattern in a flip-chip connection method, a chip for performing the flip-chip connection is described. Alternatively, on one of the surfaces of the substrate opposed thereto, a plurality of concentric similar-shaped lines are arranged at equal pitches in a doubly overlapping manner from the bump electrode pattern and the center point of any predetermined positional relationship with the bump electrode pattern. A pattern of a main scale position shift detection pattern arranged at intervals is formed, and a bump electrode pattern having the same dimensions and the same position as the bump electrode pattern is formed on the surface of either the other chip or the substrate. In the same manner as described above, a plurality of concentric similarity lines are formed in a doubly overlapping manner from the center point of the arbitrary predetermined positional relationship with the bump electrode pattern before the same shape. A pattern of a vernier scale position shift detection pattern arranged at equal pitch intervals at intervals slightly shifted by a predetermined value compared to the opposed concentric similar shape line is formed, and via a bump formed on the bump electrode. After flip-chip connection, the chip or the substrate is optically transmitted, and the main scale scale position shift detection pattern formed on the chip and the substrate surface respectively, and from the superimposed state of the sub scale scale position shift detection pattern And a chip position shift measuring method for measuring a chip position shift with respect to the substrate.

A second feature of the present invention is that the concentric similarity lines of the main scale scale position shift detection pattern and the sub scale scale position shift detection pattern in the first feature are endless continuous or discontinuous patterns. This is a method for measuring a chip position shift.

A third feature of the present invention is that the first or the second
Concentric similarity lines of the main scale scale position shift detection pattern and the vernier scale scale position shift detection pattern in the features of the above are either a concentric pattern, a dot pattern, a part of a straight line pattern, or any of a plurality of these combination patterns. This is a method for measuring a chip position shift.

[0012]

According to the present invention, the above measures are taken, so that the main scale and the vernier scale used for the calipers are concentrically similar line patterns, and are separated by a predetermined distance from the bump electrode by a semiconductor manufacturing technique. It is read as a superposition information of the main scale scale pattern and the vernier scale scale pattern, so that it is not necessary to accurately read the edge or center of the pattern, and it is also possible to obtain aberrations and mechanical problems such as a microscope. The deviation does not affect the length measurement.

Therefore, even if the chip is displaced in any direction, accurate and accurate measurement of the positional deviation of the chip can be realized without using a precise length measuring device. Further, since the main scale scale pattern and the vernier scale scale pattern are similar to each other, the positional deviation of the twisted and rotated object can be easily measured.

[0014]

【Example】

(First Embodiment) A first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view of a displacement detection pattern used in the chip displacement measurement method of the present embodiment, wherein (a) is formed on a connection substrate and (b) is formed on a chip. In the figure, reference numeral 1 'denotes a connection board which is, for example, a ceramic wiring board, 2' and 5 'denote lower and upper bump electrode patterns respectively, 4' denotes a chip, and α denotes a position shift formed on the connection board 1 '. The detection pattern β is a misregistration detection pattern formed on the chip 4 ′.

As shown in FIG. 1A, on a connection board 1 ',
A 20 μmφ bump electrode pattern 2 ′ is formed one at each of the four corners, and the intersection of the oblique lines connecting the lower bump electrode patterns 2 ′ is defined as the center point 0, and the circumferential pitch a from the center point 0 is, for example, 10 μm. And at the same time, a plurality of concentric circles αa to αh having a uniform pattern width b of 5 μm are formed at the same time by a semiconductor forming technique such as a photolithography technique. I do.

On the other hand, the same arrangement and the same dimensions as the lower bump electrode pattern 2 'formed on the connection substrate 1' are provided on the opposite surface of the semiconductor wafer chip 4 'which can be cut into many chips by dicing. The lower bump electrode pattern 5 ′ is formed, and the intersection of the diagonal line of the upper bump electrode pattern 5 ′ is set as the center point 0 similarly to the connection board 1 ′ for each chip 4 ′. Are arranged such that the circumferential pitch c is equal to, for example, 9.9 μm, and the circumference of a plurality of concentric circles βa to βh whose pattern width d is uniformly set to, for example, 5 μm is a photo of the sub-scale scale position shift detection pattern β. It is formed simultaneously by a semiconductor formation technique such as a lithography technique.

Thereafter, for example, AuSn or SnPb bumps are formed on the upper bump electrode pattern 5 'corresponding to each chip on the wafer, and the wafer is cut into single chips 4'.
The connection substrate 1 ′ and the electrode patterns 2 ′ and 5 ′ for bumps formed on the opposing surface of the chip 4 ′ are precisely face-to-face aligned by face-down using a double-sided alignment device or the like, and the chip 4 ′ is Flip chip connection is performed by bonding on the connection substrate 1 '.

Next, the sample after the flip-chip connection has been completed is subjected to polymerization of two concentric misalignment detection patterns α and β formed on the surface facing the connection substrate 1 ′ and chip 4 ′ by an infrared microscope. It is transmitted through the tip 4 ′ and observed through magnification, and the overlapping position of the main scale scale position shift detection pattern α and the sub scale scale position shift detection pattern β is read. From the scale, the zero center, that is, the position shift is zero, the main scale scale position shift is zero. The positional deviation of the chip 4 'with respect to the connection substrate 1' is measured from the number of scales up to the center point 0 of the concentric circle, which is a scale in which the scale scale and the vernier scale completely overlap.

According to the chip position displacement measuring method of this embodiment, the main scale scale position displacement detection pattern α of the concentric circles αa to αh having the circumferential pitch a of 10 μm and the circumferential pitch c of 9.9.
Due to the vernier scale position shift detection pattern β of the concentric circles βa to βh of μm, even if the tip 4 ′ is shifted in any
The position deviation can be detected with a high accuracy of m, and even if the position deviation is smaller than 5 μm of the scale pattern widths b and d, the chip 4 ′ can be transmitted through the microscope without using a precise length measuring device. Then, simply by observing the polymerization of the position shift detection patterns α and β, the chip position shift can be easily measured. Also, since the main scale and vernier scale are formed in a circle,
Even if the connected chip 4 'and the connection board 1' have a mutually twisted positional relationship, the measurement can be performed with the same accuracy without any trouble.

In this embodiment, the circumferential pattern pitch a of the concentric circles αa to αh of the main scale scale position shift detection pattern α is set to 1
0 μm, concentric circle βa of vernier scale position shift detection pattern β
.Beta.h circumferential pattern pitch c was set to 9.9 .mu.m. However, in order to obtain the required measurement accuracy X by the chip position displacement measuring method of the present invention, the main scale scale position displacement detection pattern was obtained from the required measurement accuracy X. The concentric circles βa to βh of the vernier scale position shift detection pattern β are determined so as to have a pitch (X−a) obtained by subtracting the concentric circles αa to αh circumferential pattern pitch a of α, and the center of the scale is zero. Therefore, circular scales may be arranged and formed at equal intervals at the pitches a and c (= X−a). Further, in this embodiment, the main scale is arranged on the surface of the connection board 1 'and the vernier scale is arranged on the surface of the chip 4'. It goes without saying that a similar effect can be obtained even if a vernier scale is arranged on the side.

(Second Embodiment) A second embodiment of the present invention will be described in detail with reference to the drawings. FIG. 2 (a), (b), (c), (d)
FIG. 4 is a plan view showing a variation of a displacement detection pattern used in the present embodiment. In the first embodiment, the case where the main scale and the vernier scale scale are concentric patterns has been described. However, as in the present embodiment, one or both of the main scale and the vernier scale scale pattern form a concentric circle. It may be a cut discontinuous pattern.

Here, each of the variations of the displacement detection pattern shown in FIG. 2 will be described. FIG. 2A shows a positional deviation detection pattern γ obtained by cutting the circumferences of the concentric circles α and β at an interval. FIG. 2B shows a positional deviation detection pattern δ in which a circular dot pattern is arranged at positions around the concentric circles α and β shown in FIG.

FIG. 2C shows the concentric circles α and β shown in FIG.
Is a positional shift detection pattern ε in which a square dot pattern is arranged at a position on the circumference of. FIG. 2D shows a positional shift detection pattern ω in which triangular dot patterns are arranged at positions around the concentric circles α and β shown in FIG.

According to the displacement detection patterns γ, δ, ε, and ω shown in FIGS. 2A, 2B, 2C, and 2D, compared with the displacement detection patterns α and β in FIG. As a result, the visibility of the pattern polymerization is improved, and more accurate positional deviation detection becomes possible. The above pattern is a typical example, and FIGS. 2 (b), (c),
Any shape may be used for the dot pattern (d), or different types of dot patterns may be combined.

Further, the concentric pattern shown in FIG.
The cut concentric pattern of (a) and FIGS. 2 (b), (c),
It is obvious that the various dot patterns of (d) may be used in combination. As described above, in the first and second embodiments, only the example where the zero center of the scale (ie, the scale where the main scale and the vernier scale completely overlap when the positional deviation is zero) is the center of the concentric circle has been described. In the method of measuring a chip position deviation according to the present invention, the circumference of any concentric circle may be set as the zero center.

Also, in the first embodiment, the line widths b and d of the pattern are 5 μm, the dimensions of the bump electrode patterns 2 ′ and 5 ′ are four 50 μm φ, the wiring board 1 ′ is made of ceramic, and the bump material is made of AuSn. Or SnPb, but the present invention is not limited to this value or material, and furthermore, the displacement detection patterns α and β are defined by the four diagonal lines of the lower and upper bump electrode patterns 2 ′ and 5 ′. Although they are set at the intersections, they may be arranged and formed at any positions as long as they are at predetermined intervals with respect to the bump electrode patterns 2 'and 5'. Also, in the first embodiment,
The displacement detection patterns α and β and the bump electrode pattern 2 ′,
Although it has been described that 5 ′ is formed at the same time, it is not necessary to form them simultaneously if the displacement detection patterns α and β can be formed accurately at desired positions.

(Third Embodiment) A third embodiment of the present invention will be described in detail with reference to the drawings. FIGS. 3A and 3B are main scale and vernier scale position shift detection patterns used in the tip position shift measuring method of the present embodiment, and FIG. 3A shows the first scale shown in FIG.
The concentric pattern of the embodiment and a misregistration detection pattern in which a 5 μm orthogonal cross line passing through the center is arranged. FIG. 2B shows the concentric pattern of the first embodiment shown in FIG. These are misalignment detection patterns arranged concentrically. In the figure, θ and λ are positional shift detection patterns.

The displacement detection patterns θ and λ of the present embodiment are
After being formed on the surface facing the substrate 1 'and the chip 4', the first
As in the embodiment, by flip-chip connection and observation with an infrared microscope, not only positional deviation but also twist angle can be measured simultaneously. In the present embodiment, the orthogonal cross line θa and the dot pattern λa are respectively different patterns, but a composite pattern may be formed together with a concentric pattern.

Further, the concentric pattern with the orthogonal cross line θa and the concentric pattern with the dot pattern λa of the present embodiment may be formed such that one is a chip and the other is a substrate. still,
In these embodiments, an example in which a sample is transmitted and enlarged by an infrared microscope to measure a length is described. However, any microscope that can transmit and enlarge a substrate or a chip may be used. For example, an X-ray microscope Alternatively, the substrate or the chip may be formed of a transparent material, and the length may be measured with a normal microscope or the like from the transparent side.

Further, in these embodiments, the concentric patterns are drawn on the substrate and the chip. However, the present invention is not limited to the concentric circles, and the same applies to the use of concentric and similar line patterns having the same shape. In addition, in these embodiments, a sample in which a substrate and a chip are flip-chip connected is described. However, if a sample has a similar shape line pattern of the same shape, a sample in which a chip and a chip are flip-chip connected may be used. It goes without saying that the displacement can be measured.

[0031]

As described above, according to the present invention, the main scale and the vernier scale used for the calipers are concentric and similar line patterns of the same shape, and an arbitrary predetermined distance from the bump electrode pattern is obtained by the semiconductor manufacturing technology. Since it is formed at a distance, it is possible to read misalignment as a superimposed pattern of the main scale and the vernier scale, so it is not affected by the fine reading error of the marker or the accuracy of the length measuring instrument, and even if the chip is shifted in any direction It is possible to easily and accurately measure the displacement of the tip, and if the main scale and the vernier scale are particularly concentric, the same displacement can be measured with the same accuracy even when the position of the twisted and rotated object is changed. It has excellent practicality and usefulness such as having an effect.

[Brief description of the drawings]

FIG. 1 is a plan view of a displacement detection pattern used in a chip displacement measurement method according to a first embodiment of the present invention, and FIG.
Is formed on a connection substrate, and (b) is formed on a chip.

FIGS. 2 (a), (b), (c) and (d) are plan views showing variations of a displacement detection pattern used in a chip displacement measurement method according to a second embodiment of the present invention.

FIGS. 3 (a) and 3 (b) are main scale and vernier scale position shift detection patterns used in a tip position shift measuring method according to a third embodiment of the present invention.

FIG. 4 is an explanatory side view showing a conventional method for measuring a positional shift in flip chip connection.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Pseudo board 1 '... Connection board 2,5,2', 5 '... Bump electrode pattern 3 ... Bump 4,4' ... Chip 6a, 6b ... Marker 0 ... Center point α ... Formed on connection board Position shift detection patterns αa to αh, βa to βh: concentric circles β: position shift detection patterns formed on the chip γ, δ, ε, ω, θ, λ: position shift detection patterns

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-19312 (JP, A) JP-A-48-93270 (JP, A) JP-A-62-19856 (JP, A) 268415 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01B 11/00-11/30 102 H05K 3/32-3/34 H05K 13/00-13/04

Claims (3)

(57) [Claims] In a flip chip connection method in which an IC chip or a chip having a similar shape is positioned and connected to a substrate via an electrode pattern for bumps, a method for measuring a chip position shift after a positioning connection is used. A bump electrode pattern and a plurality of concentric similar shapes are formed on the surface of either one of the chip to be flip-chip connected or the substrate facing the same in a doubly double manner from a center point of an arbitrary predetermined positional relationship with the bump electrode pattern. A main scale scale position shift detection pattern for arranging the lines at equal pitches in the radial direction is formed in a pattern, and the same size and the same position as the bump electrode pattern are arranged on one surface of the other chip or the substrate. And a plurality of concentrically similar lines in a doubly overlapping manner from the center point of the predetermined predetermined positional relationship with the bump electrode pattern to be formed. A pattern of a vernier scale position shift detection pattern arranged at equal pitch intervals at intervals slightly shifted by a predetermined value compared to the opposed concentric similar shape line having the same shape as the above is formed on the bump electrode. After flip-chip connection via the formed bump, the chip or substrate is optically transmitted, and the main scale scale position shift detection pattern formed on the chip and the substrate facing surface respectively, and the sub scale scale position shift. From the polymerization state of the detection pattern,
A method for measuring a positional shift of a chip with respect to the substrate, comprising: 2. The chip position shift according to claim 1, wherein the concentric similar lines of the main scale scale position shift detection pattern and the sub scale scale position shift detection pattern are endless continuous or discontinuous patterns. Measuring method 3. The concentric similar lines of the main scale scale position shift detection pattern and the sub scale scale position shift detection pattern may be any one of a concentric pattern, a dot pattern, a partially linear pattern, and a combination of a plurality of these patterns. 3. The method according to claim 1, wherein: