WO2005029574A1

WO2005029574A1 - Collet, die bonder, and chip pick-up method

Info

Publication number: WO2005029574A1
Application number: PCT/JP2003/011936
Authority: WO
Inventors: Nobuhiro Nagamoto
Original assignee: Nec Machinery Corporation
Priority date: 2003-09-18
Filing date: 2003-09-18
Publication date: 2005-03-31
Also published as: AU2003266534A1; CN1802735A; JPWO2005029574A1

Abstract

PROBLEM TO BE SOLVED: To prevent semiconductor chips from cracking during pick-up and during bonding. SOLUTION: A bonding tool (10) is constituted of a collet holder (20) and a collet (30). The collet holder (20) comprises a vacuum suction hole (21) at the center, attaching threaded holes (22, 23) for attaching the collet holder (20) to a support member, a depending section (24) at the bottom, and a recess (25) in the depending section (24). The collet (30) comprises a flat surface (31) at the lower end, a plurality of vertically extending vacuum suction through-holes (32), a projection (33) adapted to fit in the recess (25), and a flange (34) abutted against the lower surface of the depending section (24). A space (26) is defined such that the depth dimension H1 of the recess (25) and the height dimension H2 of the projection (33) are set H1 > H2, and communication is established between the vacuum suction holes (21, 32) through the space (26). The plurality of vacuum suction holes (32) vacuum-suck the periphery of a chip, whereby pick-up and bonding are effected.

Description

How to pick up collets, taps, i-bonders and chips

Technical field

The present invention relates to a collet, a die bonder using the collet, and a method of picking up a chip in the die bonder. For example, a flaky semiconductor chip (die) is picked up from a wafer sheet to be softened on a substrate such as a lead frame. TECHNICAL FIELD The present invention relates to a method of bonding, a die bonder, and a pick-up method particularly suitable for a semiconductor chip having a flake shape, which is bonded through a bonding material such as a hard solder, a silver paste, and a resin.

Background art

In general, semiconductor devices bond the back surface of a semiconductor chip (die) to a substrate such as a printed circuit board or a lead frame via a bonding material such as soft solder, hard solder, silver paste, or resin. ).

In such a die bonder for bonding a semiconductor chip to a substrate, as shown in FIG. 4, a big chip and a bonding tool (hereinafter referred to as a tool) that move between a pickup position P1 and a bonding position P2 of the semiconductor chip. 40) is used. Hereinafter, the operation will be described in detail. At the peak position P1 of the semiconductor chip, the column 40 descends (a), and the tool 40 which vacuum-adsorbs the semiconductor chip 65 from the semiconductor chip assembly 60 is moved. After raising (picking up) a little bit (b), it moves horizontally (c), and the tool 40 descends at the bonding position P2 (d) bonding the semiconductor chip 65 to the substrate 1 via the bonding material 2 Then, when the bonding is completed, the pile 40 rises (e), moves horizontally (f), and returns to the position above the original pickup position P1.

During the operation of a to f in the tool 40, the semiconductor chip assembly 60 is horizontally moved by one pitch 7 and the next semiconductor chip 65 to be picked up is moved to the peak position P1. Can be Substrate 1 also moves horizontally by one pitch, and the next bonding area Is moved to the bonding position P2. Hereinafter, the same operation is repeated, and the semiconductor chips 65 are sequentially picked up and bonded to the substrate 1.

As shown in FIGS. 5A and 5B, the above-mentioned rail 40 is configured by attaching a collet 42 to a collet holder 41. The collet holder 41 has a vacuum suction hole 43 at the center to which a vacuum or compressed gas system is connected, a set screw 44 for attaching to the pipe connecting the collet holder 41, and a lower end. It has a lower part 45 and a concave part 46 in the lower part 45. The collet 42 has a vacuum suction hole 47 at the center, a convex portion 48 fitted into the concave portion 46, and a flange portion 49 joined to the lower end of the standing portion 45. The vacuum suction hole 43 of the collet holder 41 and the vacuum suction hole 47 of the collet 42 form a space 50 formed between the ceiling of the recess 46 and the upper surface of the projection 48. Is communicated through. Contrary to the illustrated example, a concave portion may be provided on the collet 42 side and a convex portion may be provided on the collet holder 41 side.

Further, at the pickup position P1 in the conventional die bonder, a semiconductor chip assembly 60 as shown in FIG. 6C is usually arranged. As shown in FIG. 6A, the semiconductor chip assembly 60 has a semiconductor wafer 63 attached to a wafer 62 having an adhesive layer on the surface attached to the wafer ring 61 and a semiconductor wafer 63 attached thereto. As shown in FIG. 6B, the wafer 63 is cut lengthwise and breadthwise by a dicer 64 to divide it into individual semiconductor chips 65, and then, as shown in FIG. By disposing it on the fixing ring 6 6 and pushing down the wafer ring 6 1 (or pushing up the holding ring 6 6), the wafer hash 6 2 is stretched and the individual semiconductor chips 6 5 In addition, the distance between the semiconductor chip 65 and the wafer sheet 62 has been reduced while increasing the gap.

When the semiconductor chip 65 is to be picked up from the semiconductor chip assembly 60, as shown in FIG. 4, the semiconductor chip 65 is pushed up from below the semiconductor chip 65 with push-up pins 67, and the semiconductor chip 65 is pushed up. The wafer chip 62 in the peripheral portion of 5 is deformed downward by a vacuum suction force from below to reduce the bonding area between the semiconductor chip 65 and the wafer sheet 62, thereby reducing the semiconductor chip. The adhesive force between the wafer 65 and the wafer sheet 62 is reduced, so that the semiconductor chip 65 can be reliably attracted and picked up by the collet 42 with a small vacuum suction force. Alternatively, the semiconductor chip is sucked and fixed to the collet 42, and the wafer sheet is The semiconductor chip 65 can be picked up from the wafer sheet 62 by a method in which the lower surface of the semiconductor chip is sucked and pulled down by the suction stage.

Here, the collet 42 has various configurations shown in FIGS. 7A to 7C. The collet 42A shown in FIG. 7A has a single, large-diameter vacuum suction hole 51 at the center and a flat surface 52 provided on the lower surface. The collet 4 2B shown in FIG. 7B has a single, large-diameter vacuum suction hole 51 at the center, and a standing portion 53 around the lower surface. A concave portion 54 communicating with the vacuum suction hole 51 is provided (for example, see Patent Document 1). The collet 42C shown in FIG. 7C has a single, large-diameter vacuum suction hole 51 at the center, and a standing part 53 around the lower surface. A concave portion 54 communicating with the vacuum suction hole 51 is provided at the bottom, and an inclined surface 55 is formed between the concave portion 54 and the vacuum suction hole 51.

Then, the collet 42 shown in FIG. 7A has the lower flat surface 52 abutted against the semiconductor chip 65 and applies a vacuum suction force to the vacuum suction hole 51 to suck the chip 65. . In addition, the collet 42B shown in FIG. 7B is configured such that the lower surface of the lower part 53 of the peripheral portion is brought into contact with the chip 65, and a vacuum suction force is applied to the vacuum suction hole 51, so that the chip 65 is moved. Adsorb. Further, the collet 4 2 C shown in FIG. 7C is configured such that the upper surface shoulder of the chip 65 is brought into contact with the inclined surface 55, and a vacuum suction force is applied to the vacuum suction hole 51, so that the chip 6 Adsorb 5 Disclosure of the invention

Recently, in addition to the size and weight of the semiconductor package, as a large capacity proceeds, the thickness is 5 0〃M following thin semiconductor chips (hereinafter, flakes that the chip) is expanded demand force ^s, its thin pieces The technology of stacking chips has attracted attention.

Since flake tips have low mechanical strength, they must be handled with great care. However, as shown in 42A in FIG. 7A, 42B in FIG. 7B, and 42C in FIG. 7C, the conventional collect 42 has a single large diameter at the center. This structure has a vacuum suction hole 51, and the center of the semiconductor chip is vacuum-sucked at the time of picking up a flake chip. Therefore, it occurs at the start of peeling of the wafer sheet at the time of peak-up and at the end of peeling.ゥ Due to the deformation, can not ^S avoid giving excessive stress to the semiconductor chip, flake Chidzupu cracking was easy.

In addition, the semiconductor chip after peeling cannot be handled stably because of the suction by the vacuum suction hole at the center during bonding, and the semiconductor chip is lifted up at the center part and bubbles are left on the entire surface. There was a problem that quality could not be obtained. Hereinafter, those problems will be described in detail for each collet. First, as shown in FIG. 8A, at the beginning of peeling when the flake chip 65a is picked up from the wafer sheet 62, the center of the flake chip 65a is upward. And the peripheral portion of the flake tip 65a is subjected to a stress such that the peripheral portion of the flake chip 65a is deformed downward together with the flat sheet 62 by the downward deformation force of the wafer sheet 62. Therefore, the flake tip 65a is easily broken.

When bonding the thin chip 65a to the substrate 1 with the collet 42A, as shown in FIG. 8B, the reaction force of the bonding material 2 causes the thin chip 65a to receive upward stress. At this time, the presence of the vacuum suction hole 51 at the center causes a stress 3 that locally deforms the center of the thin chip 65a upward, so that the thin chip 65a is easily broken.

When bonding the thin chip 65a to the substrate 1 with the collet 42A, a predetermined pressure is applied by the collet 42A to press the thin chip 65a onto the substrate 1, as shown in FIG. 8B. Since the pressure is released from the vacuum suction hole 51 upward even if the flake tip 65a does not break, the central part of the flake tip 65a is deformed upward and bonded. There is. Such a phenomenon is the same in the later-described collect 42B in FIG. 7B and the collect 42C in FIG. 7C.

In addition, after bonding, if there is a thin chip 65a that is difficult to detach from the collet 42A, the compressed gas 4 is supplied to the vacuum suction hole 51 as shown in FIG. If the flake tip 65a is easily detached from the flake tip 65a, the compressed pressure of the compressed gas 4 is concentrated at the center of the flake tip 65a, so that the center of the flake tip 65a is deformed downward. There was a problem that the flake tip 65a was liable to crack due to the high stress.

The collet 42B shown in Fig. 7B has a larger recess compared to the collet 42A shown in Fig. 7A. As shown in FIG. 9A, when the thin chip 65 a starts to be separated from the wafer sheet 62 due to the presence of the recesses 54, the presence of the recesses 54 and the push-up pins 67 push up. Therefore, since the central portion of the thin chip 65a receives a large stress that deforms upward, the thin chip 65a is easily broken.

When bonding the flake chip 65a to the substrate 1 with the collet 42B, as shown in FIG. 9B, the flake chip 65a receives an upward stress due to the reaction force of the bonding material 2. At this time, the presence of the concave portion 54 receives a large stress 3 that locally deforms the central portion of the thin chip 65 a upward, so that the thin chip 65 a is easily damaged.

Further, when the compressed gas 4 is supplied to the vacuum suction holes 51 after the bonding is completed, as shown in FIG. 9C, a stress such that the central portion of the thin chip 65 a is deformed downward is applied. There was a problem that 5a was easily broken.

The collector 42 C shown in FIG. 7C is usually a thick semiconductor chip. If it is applied to the sliced chip 65a, it is not shown in the figure, but at the start of peeling when picking up the sliced chip 65a from the wafer sheet 62, similar to Fig. 9A. The presence of the concave portion 54 and the push-up pin 67 push up the central part of the thin chip 65a, so that the thin chip 65a is easily broken.

When bonding the thin chip 65 a to the substrate 1 ^: as in FIG. 9B, the thin chip 65 a receives an upward stress 3 due to the reaction force of the bonding material 2. Because of the presence of the concave portion 54, the center of the thin chip 65a receives a stress that deforms upward, so that the thin chip 65a is easily broken.

Further, after the bonding is completed, when the compressed gas 4 is supplied to the vacuum suction hole 51 to bring the flake chip 65a into close contact with the bonding material 2, as shown in FIG. 9C, the center of the flake chip 65a is lowered. However, there is a problem in that the thin chip 65 a is easily damaged by the stress that deforms the chip. Further, in addition to the above-described problems, the collet 42C shown in FIG. 7C has a lower portion 53 around the lower surface, and the inclination in the concave portion 54 formed by the lower portion 53. Since the suction is performed by bringing the shoulder of the thin chip 65 a into contact with the surface 55, there are the following specific problems during pickup. That is, as shown in Fig. 1OA, the distance between the four flake chips 65 b and 65 c adjacent to both sides of the flake chip 65 a to be adsorbed: L 1 is the collet 42 C If the width dimension L is smaller than the width dimension L, the gap g between the flake chip 65 a and the adjacent flake chips 65 b, 65 c is too small, and the rising portion 53 cannot enter the gap g. Adjacent flake chips 65 b and 65 c on the lower surface of 53 may be damaged, or flake chips 65 a to be adsorbed may not be adsorbed.

On the other hand, as shown in FIG. 10B, the distance L 2 between the four thin chips 65 b and 65 c adjacent to both sides of the thin chip 65 a to be adsorbed is set to the width of the collet 42 C. If it is larger than the dimension L, a gap g1 is secured between the flake chip 65a to be adsorbed and the adjacent flake chips 65b, 65c so that the standing portion 53 can enter. Although the thin chip 65 a can be picked up, in order to form such a large gap g 1, when the air sheet 62 shown in FIG. It is necessary to greatly expand, the number of flaked chips 65a must be reduced, and the yield of flaked chips 65a decreases. Alternatively, a large-diameter wafer ring 61 and an energy-saving sheet 62 are required, so that the cost of the wafer ring 61 and the wafer sheet 62 becomes high. In addition, since the horizontal movement distance of the semiconductor chip assembly 60 at the time of pickup is large, not only is the die bonder large and expensive, but also the speed cannot be increased. Also, even in combination with a $ 21 pick-up, the periphery of the chip is also deformed by the deformation of the sheet in a collet that has a suction hole only in the center. This occurs when the adhesive force between the sheet and the chip is relatively high with respect to the chip's deformation recovery force. If the chip has a deformation recovery force of 5 Omg or less, it is particularly likely to occur, and in some cases, the flaked chip may crack. As a countermeasure, a collet provided with multiple vacuum holes is effective. In addition, a mechanism for adjusting the vacuum pressure of the collect stage and each stage is provided to prevent chip cracking. For example, 上部 Set the maximum vacuum pressure at the upper part (collet side) to increase the chip holding force, and control the pressure at the lower part (stage side) so that the chip does not break.

Therefore, the present invention provides, for example, a collet that does not break the flake chip during the chip-up and / or bonding, a die bonder and a chip using the collet. The purpose is to provide a big-up method.

In order to solve the above-mentioned problems, a collet of the present invention includes a collet for picking up and / or bonding a chip, wherein a lower surface of the collet is formed on a flat surface, and a plurality of vacuum suction portions are formed on the flat surface of the lower surface. (Claim 1). The term “collet for picking up and / or bonding chips” above refers to not only the collect in a so-called direct bonding type die bonder that picks up the chip and bonds it as it is, but also Transfer to the position and position correction unit, and then pick up and bond the chip from the tray and position correction unit. This is a so-called indirect bonding type bonder for a big bond or tray. And from the position correction section. It includes a collection for bonding for picking up and bonding.

Further, the collet of the present invention is mounted on a collet holder having a vacuum suction hole at a central portion, and includes a plurality of vacuum suction holes penetrating vertically, and a plurality of the vacuum suction holes of the collet holder and the plurality of collets. A sealed space for communicating with the vacuum suction hole is provided (claim 2).

Further, the collet of the present invention is mounted on a collet holder having a vacuum suction hole in the center, and this collet has one or more vacuum suction holes and communicates with the vacuum suction hole on the lower surface. A groove is provided, and a closed space is provided for communicating a vacuum suction hole of the collect hood lid with a single or a plurality of vacuum suction holes of the collect (Claim 3).

Further, the die bonder of the present invention is provided with the collet described in any one of the above forces (Claim 4).

Further, the chip big-up method of the present invention: using the die bonder described above, the chip whose back surface is joined to the wafer sheet is vacuum-sucked with a collet, and then the back surface of the chip is placed below the seat sheet. The piston is relatively pushed up by a push-up pin from above, or the eave sheet is deformed downward by a vacuum suction force from below (claim 5).

According to the collet according to claim 1 of the present invention, a plurality of vacuum suction portions on the lower surface are used to form a lamella. Since the peripheral portion of the chip can be vacuum-sucked, the vacuum suction force acts only on the central portion of the flake chip as in the related art, so that the peripheral portion does not become free. —When peeling off the sheet and picking up, even if the wafer sheet around the thin chip is deformed downward by the vacuum suction force acting from below, the peripheral part of the thin chip is vacuum-adsorbed by the collect. As a result, the periphery of the book chip does not deform downward due to the deformation of the wafer sheet, and only the wafer sheet can be deformed downward, so that the thin chip can be smoothly separated from the wafer chip. It is possible to prevent cracking at the time of picking up the flake chips.

In addition, for example, when bonding a thin chip to a substrate, the flat surface of the collet can evenly press the thin chip, so that there is a vacuum suction hole provided in the center of the conventional collet and a counterpart of the bonding material. The force prevents the central portion of the thin chip from being stressed such that it deforms upward, so that cracking of the thin chip at the time of bonding can be prevented. Furthermore, when the compressed gas is supplied to the vacuum suction part after the bonding of the flake tip to make it easy for the flake chip to separate from the collet, the compressed gas ejected from the plurality of vacuum suction parts is applied to the wide surface of the flake chip. By being dispersed, the compressed pressure of the compressed gas is concentrated locally at the center of the flake tip, as in a conventional collet with a vacuum suction hole at the center, causing the center of the flake tip to deform downward. The stress at the time of removing the thin chip from the collet can be prevented.

According to the collet described in claim 2 of the present invention, the vacuum suction force acting on the vacuum suction hole at the center of the collet holder is transmitted through the closed space between the collet holder and the collet. It can be evenly distributed in the plurality of vacuum suction holes of the collet, and the peripheral part of the flake tip can be vacuum-sucked. Also, the reaction force of the bonding material can be dispersed and received on a flat surface. When the compressed gas can be supplied, the compressed gas can be dispersed and supplied to the flake chip, so that the flake chip can be prevented from being broken at any time during the pickup of the flake chip, the bonding, and the detachment of the flake chip. Moreover, as in the conventional case, a collet holder having a vacuum suction hole only in the center can be used in common, and a collet holder having a plurality of vacuum suction holes can be used simply. Compared to the case where it is formed by dovetails, The configuration is simple and the collet can be manufactured at low cost. Since a plurality of vacuum suction holes of the collet can be formed at the same time when the collet is formed by molding, there is no increase in man-hour and cost due to an increase in the number of vacuum suction holes.

In addition, by making the hole diameter and density of the vacuum suction holes of the collet different between the central portion and the peripheral portion, pressure is applied from the central portion to the peripheral portion of the thin chip when bonding the thin chip. This makes it possible to bond the substrate to the substrate while extruding the atmosphere gas below the flake chip, and to bond the flake chip without involving the atmosphere gas. As a result, gas trapped between the chip and the base material can be reliably removed, and a predetermined bonding strength and product quality can be obtained.

According to the collet according to the third aspect of the present invention, the vacuum suction force acting on the vacuum suction hole at the center of the collet holder is applied to the groove through one or more vacuum suction holes of the collet. Since it is evenly distributed, the periphery of the thin chip can be vacuum-sucked during pick-up, and the reaction force of the bonding material can be dispersed and received on the flat surface during bonding, and compressed gas is ejected when the thin chip is detached Since the pressure can be spread over a wider surface of the flaked chip, no stress that locally deforms the flaked chip at the time of pick-up, bonding, or detachment is applied. Cracks can be prevented. In addition, as in the conventional case, a collet holder having a vacuum suction hole only at the center can be used in common, and a collet holder having a groove communicating with the vacuum suction hole on the lower surface of the collet simply needs to be adopted. Compared to the case where a plurality of vacuum suction holes are formed by dovetails or the like, the configuration is much simpler, and the collet can be manufactured at low cost. Since the vacuum suction hole and the groove of the collet can be formed at the same time when the collet is formed by injection molding, the provision of the groove does not increase the man-hour and cost.

Further, according to the die bonder according to the fourth aspect of the present invention, at the time of pick-up in which the thin chip is peeled off from the wafer sheet, the thin chip attached to the wafer sheet is pushed up from below by a push-up pin, or When the adhesive force is reduced by reducing the bonding area between the thin chip and the wafer sheet by, for example, deforming the chip downward by vacuum suction, the periphery of the upper surface of the thin chip is Suction can be achieved with multiple vacuum suction holes or grooves and thin Since the chip is received on a flat surface, the center of the chip does not deform upward, and the periphery of the chip does not deform downward due to the deformation of the wafer sheet. Only the wafer sheet of the part is deformed downward, the adhesive force between the thin chip and the wafer sheet is reduced, the peeling starts smoothly, and the thin chip can be reliably picked up without breaking.

In addition, when bonding the thin chip to the substrate, the reaction of the bonding material is dispersed and received on the flat surface of the collet. By the force, the phenomenon that the central portion of the thin chip is not deformed upward is eliminated, and the bonding can be performed without breaking the thin chip.

In addition, after bonding the flake tip, if the compressed gas is supplied to the vacuum suction hole to make the flake tip easily separate from the collet, the compressed gas is supplied from the plurality of vacuum suction holes or grooves of the collet to the wide surface of the flake tip. By being dispersed and ejected, the compressed gas ejection pressure is concentrated at the center of the flake tip, such as a conventional collet with a vacuum suction hole at the center, and the center of the flake tip is deformed downward The flake tip is prevented from cracking, and the flake tip can be separated from the collet.

Further, according to the chip pick-up method according to the fifth aspect of the present invention, the periphery of the chip is vacuum-adsorbed by the collet, and then the back surface of the chip is relatively pushed up by the push-up pin, or the chip is pushed up. Since the wafer sheet joining the chips is deformed downward by vacuum suction, the center of the chips is relatively free while the periphery of the chips is free, as in the conventional method of picking up chips. This prevents the chip from being lifted up and the chip around the chip from deforming downward, effectively preventing chip breakage during chip pickup without stressing the chip. Brief description of the drawings

FIG.1A is a longitudinal sectional side view of a bonding tool according to a first embodiment of the present invention,

Figure 1B is a bottom view of the bonding tool of Figure 1A,

FIG. 1C is a front view of the collect at the bonding tool of FIG. 1A, FIG. 2A is an enlarged vertical sectional view of a principal part of a die bonder provided with the collect of FIG. 1 in a state of pick-up of a thin chip for explaining operation,

FIG. 2B is an enlarged vertical cross-sectional view of a main part in a state of bonding a thin chip,

FIG. 2C is an enlarged vertical sectional view of a main part of the die bonder provided with the collet shown in FIG. 1 in a state where the thin chip is detached from the collet for explaining the operation.

FIG. 3A is a longitudinal sectional side view of a bonding tool according to a second embodiment of the present invention,

Figure 3B is a bottom view of the bonding tool of Figure 3A,

FIG. 3C is a front view of the collect in the bonding tool of FIG. 3A,

FIG. 4 is an explanatory view of a pick-up and bonding operation in a die bonder, and FIG. 5A is a longitudinal rear view of a bonding tool in a conventional die bonder.

FIG. 5B is a front view of a large vertical section of a portion of the bonding tool shown in FIG. 5A.

FIG. 6A is an explanatory view showing a state in which a semiconductor chip is attached to an ash in a manufacturing process of the semiconductor chip assembly shown in FIG. 4;

FIG. 6B is an explanatory view showing a state where the semiconductor wafer is divided into individual semiconductor chips by a dicer in a manufacturing process of the semiconductor chip assembly shown in FIG. 4,

FIG. 6C is an explanatory view showing a state where a sheet is stretched in a manufacturing process of the semiconductor chip assembly shown in FIG. 4,

Fig. 7A is a longitudinal sectional view of a collet in a conventional die bonder.

Fig. 7B is a longitudinal sectional view of another collet in the conventional die bonder.

FIG. 7C is a longitudinal sectional view of still another collet in the conventional die bonder,

FIG. 8A is an enlarged vertical sectional view of a main part of a state of a thin chip for explaining operation by the collector of FIG. 7A in a big cup state,

FIG. 8B is an enlarged longitudinal sectional view of a main part in a state of bonding a thin chip for explanation of operation using the collet of FIG. 7A,

FIG. 8C is an enlarged longitudinal sectional view of an essential part in a state at the time of detachment of the thin chip for explanation of the operation by the collect of FIG.

FIG. 9A shows a state in which a thin chip for pick-up operation by the collet of FIG. 7B is picked up. Main part enlarged longitudinal sectional view of

FIG. 9B is an enlarged longitudinal sectional view of an essential part in a state in which the thin chip is detached for explanation of operation by the collet of FIG. 7B,

Fig. 9C is an enlarged vertical cross-sectional view of the main part when the thin chip is adhered to the bonding material for explaining the operation by the collet of Fig. 7B. Fig. 1OA is the main part for explaining the problem with the collet of Fig. 7C. Explanatory drawing of the first problem when the chip spacing is small in the enlarged longitudinal sectional view,

FIG. 10B is an enlarged vertical cross-sectional view of a main part for describing a problem caused by the collet shown in FIG. 7C, and is an explanatory diagram of a second problem when the chip interval is increased. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of a die bonder including a collet of the present invention will be described with reference to the drawings.

(Example 1)

The tool 10 according to the first embodiment of the present invention includes a collet holder 20 and a collet 30 mounted on the collet holder 20, as shown in FIGS. 1A to 1C. The collect holder 20 is made of, for example, stainless steel and has a vacuum suction hole 21 connected to a vacuum system at the center, and two mounting screw holes 22 for attaching the collect holder 20 to a support member.

23, a lower portion 24 around the lower end portion, and a concave portion 25 surrounded by the lower portion 24.

The collet 30 is made of, for example, stainless steel, nitrile rubber, fluoro rubber, heat-resistant resin, or the like depending on the application, and has a flat surface 31 on the lower surface and a plurality of vertically penetrating (in the illustrated example, a rectangular A small-diameter vacuum suction hole 32 of 3 pieces in length and 5 pieces in width and 5 pieces for a thin chip, a convex part 3 3 fitted into the concave part 25 of the collet holder 20, and a collet holder 20. Lower surface 24 of lower portion 24: has flange portion 34 to be in contact with.

The depth dimension H1 of the concave portion 25 of the collet holder 20 is set larger than the height dimension H2 of the convex portion 33 of the collet 30. A space 26 between H 1 and H 2 is formed between the upper surface and the upper surface. Therefore, the vacuum suction holes 2 1 and the vacuum suction hole 32 of the collet 30 communicate with each other through a space 26. Thereby, when a vacuum suction force is applied to the vacuum suction 21 of the collet holder 20, the vacuum suction force is applied to the plurality of vacuum suction holes 32 of the collet 30 via the space 26. When a compressed gas is supplied to the vacuum suction holes 21 of the collet holder 20, the compressed gas is dispersed and ejected from the plurality of vacuum suction holes 32 of the collet 30 via the space 26.

Next, the pick-up operation, the bonding operation, and the detachment operation from the collet of the thin chip by the above rule 10 will be described with reference to the drawings.

First, the case of picking up a flake chip at the pick-up position P 1 will be described. As shown in FIG. 2A, the collet 30 of the roll 10 is attached to the flake tip 65 a bonded to the wafer sheet 62. And a vacuum suction force is applied to the vacuum suction holes 21 of the collet holder 20. Then, the vacuum suction force is dispersed to the plurality of vacuum suction holes 32 of the collet 30 via the space 26, and the peripheral portion of the thin chip 65a can be suctioned by vacuum.

In this state, if the push-up pin 67 pushes up the center of the flake chip 65a from below the wafer sheet 62, or the wafer sheet 62 is deformed downward by the vacuum suction force from below. Since the flake tip 65 a is in contact with the flat surface 31 and the peripheral portion is sucked by the vacuum suction hole 32 of the collet 30, the center of the flake tip 65 a is pushed up by the push-up pin 6. 7 does not bend upward, and the periphery of the flake tip 65 a does not deform downward with the deformation of the evacuation sheet 62, and the periphery of the flake tip 65 a does not deform. Peeling starts smoothly from the sheet 6 2, and the adhesive area between the thin chip 65 a and the wafer sheet 62 decreases, thereby reducing the adhesive strength.

When the level 10 is raised as it is, as described above, the thin chip 65 a whose peripheral portion is peeled off from the wafer sheet 62 is moved from the peeled peripheral portion to the central portion as described above. It is gradually peeled off from the hasheet 62 and completely peeled off. At this time, since the central portion of the flake tip 65 a is sucked by the vacuum suction hole 32 of the collet 30, the central portion of the flake tip 65 a does not deform downward, and the wafer sheet 6 2 smoothly. The flake tip 65a is broken up without cracking. Next, a description will be given of a case where the flake chip 65a adsorbed on the plate 10 is bonded to the substrate 1. As shown in FIG. 2B, the lamella is supplied by the bonding material 2 supplied to the substrate 1. The chip 65a receives a reaction force directed upward, but since the collet 30 has a flat surface 31 on the lower surface, the reaction force due to the bonding material 2 is uniformly distributed over the entire back surface of the thin chip 65a. As a result, the local reaction force is not applied only to the central portion of the thin chip 65a as in the related art, and the crack of the thin chip 65a is eliminated.

After the bonding is completed, if compressed gas is supplied to the vacuum suction hole 21 to detach the thin chip 65a from the tool 10, the compressed gas 4 is collected as shown in FIG. 2C. To be scattered and ejected from the plurality of vacuum suction holes 32 into the flake chip 65a, as in a conventional collet having a single vacuum suction hole in the center, the center of the flake tip 65a Since the compressed gas does not concentrate and blow out only at the portion, the center of the flake tip 65a does not deform downward, preventing the flake tip 65a from cracking and detaching the flake tip 65a. It can be done.

(Example 2)

Next, a collect 1OA according to a second embodiment of the present invention will be described with reference to FIGS. 3A, 3B, and 3C. The collet 1OA includes a collet holder 20 and a collet 3OA. Since the collet holder 20 is the same as the collet holder 20 shown in FIG. 1A, the same parts are denoted by the same reference numerals and the description thereof will be omitted.

The collet 3 OA has a flat surface 31 on the lower surface, a plurality of small-diameter vacuum suction holes 32, a convex portion 33 fitted into the concave portion 25 of the collet holder 20, and a rising portion 24 of the collet holder 20. The point having a flange portion 34 in contact with the lower surface is the same as that of the collet 30 in FIG. 1A, but further includes a groove portion 35 communicating in one direction with the lower ends of the plurality of vacuum suction holes 32. A different point is that it has a lower end of the vacuum suction hole 32 and a groove 36 communicating with the other direction. The vacuum suction holes 24 and the grooves 35, 36 penetrating the collet 30A can be formed in advance in the production mold by forming protrusions corresponding to the shapes of the vacuum suction holes 24 and the grooves 35, 36. Since the vacuum suction holes 24 and the grooves 35, 36 can be formed at the same time during the molding of the collet 3OA, by forming a plurality of vacuum suction holes 32, grooves 35, 36 There is no increase in manufacturing man-hours or cost. Next, the operation of the reel 1 OA including the collet 3 OA having the grooves 35 and 36 will be described.

First, when adsorbing the flake tip 65 a with the tool 1 OA, the collet 3 OA of the tool 10 A is brought into contact with the upper surface of the flake chip 65 a joined to the wafer sheet 62, A vacuum suction force is applied to the vacuum suction holes 21 of the collet holder 20. Then, the vacuum suction force is distributed to the plurality of vacuum suction holes 32 of the collet 3 OA through the space 26, and further, the grooves 35, 36 communicating with these vacuum suction holes 32 are formed. The peripheral portion of the thin chip 65a can be vacuum-adsorbed on a wider surface.

In this state, if the push-up pin 67 pushes up the center of the thin chip 65a from below the wafer sheet 62, or if the wafer sheet 62 is deformed downward by the vacuum suction force from below, 6a is in contact with the flat surface 31 and the periphery is vacuum-sucked by the grooves 3 5 and 36 of the collet 3OA. As a result, the peripheral portion of the thin chip 65 a is not deformed downward due to the deformation of the ha sheet 62, and the peripheral portion of the thin chip 65 a is not deformed. The peeling starts smoothly from the sheet 6 2, and the adhesive area between the thin chip 65 a and the wafer sheet 62 decreases, and the adhesive strength decreases.

When the roll 1 OA is raised as it is, as described above, the flake chips 65 a peeled off from the peripheral sheet 62 from the peripheral part toward the center from the peeled peripheral part as described above.ゥ The film is gradually peeled off from the wafer sheet 62 and completely peeled off. At this time, since the central portion of the thin chip 65a is adsorbed by the grooves 35, 36 of the collet 3OA, the central portion of the thin chip 65a does not deform downward, so that it is smooth. Peeled from wafer sheet 62, thin chip 65a is picked up without cracking.

Next, a description will be given of a case where the flake chip 65a adsorbed on the tool 1OA is bonded to the substrate 1. The bonding material 2 supplied to the substrate 1 causes the flake chip 65a to move upward. Although the force 3 is received, the collet 3 has a flat surface 3 1 on the lower surface of the OA, so the reaction force due to the bonding material 2 is evenly distributed over the entire back surface of the thin chip 65 a, so that the conventional thin chip 6 5a no longer receives a local reaction force only at the center, thin section chip 6 5 The crack of a disappears.

After the bonding is completed, if compressed gas 4 is supplied to the vacuum suction holes 21 to separate the thin chip 65 a from the roll 1 OA, the compressed gas 4 is supplied to the plurality of grooves 3 5, 3 of the collet 3 OA. Because it is dispersed and ejected on the wide surface of the flake chip 65a from 6, it is localized only at the center of the flake chip 65a, like a conventional collet with a single vacuum suction hole at the center. Since the compressed gas does not concentrate and blow out, the center of the flake tip 65a does not deform downward, preventing the flake tip 65a from cracking and allowing the flake tip 65a to separate. it can.

Each of the embodiments described above describes a specific embodiment of the present invention. The present invention is not limited to these embodiments, and various modifications are possible.

For example, in Embodiment 2 described above, a case was described in which a plurality of vacuum suction holes 32 were formed in the collet 3 OA. However, as in the collet 3 OA shown in FIGS. 3A and 3B, the flat surface 31 was formed. When the grooves 35 and 36 are formed, the number of the vacuum suction holes 32 communicating with the grooves 35 and 36 can be made smaller than that in the illustrated example. A configuration having 24 may be adopted.

In the above embodiment, the description has been given of the pick-up, bonding and detachment from the collage of a thin chip, which exerts a particularly remarkable effect, but the pick-up and bonding of a semiconductor chip having a thickness of 50 zm or more are usually performed. Needless to say, the present invention can also be applied to the withdrawal from the collet.

Further, in the above embodiment, the case where the bonding material 2 is supplied to the substrate 1 by coating or the like and the flake chips are bonded through the bonding material 2 has been described. After being adhered, bonding may be performed via this bonding material. In the first and second embodiments, the lower portion 24 and the concave portion 25 are provided on the collet holder 20 side, and the convex portion 33 fitted into the concave portion 25 is provided on the collet 30 or 30A side. The case where the flange portion 34 is provided to contact the lower surface of the rising portion 24 has been described. Contrary to the illustrated example, a rising portion and a concave portion are provided on the collets 30 and 3OA, and the collet holder 20 is provided. A side may be provided with a convex portion that fits into the concave portion and a flange portion that contacts the upper surface of the rising portion. 2A to 2C show the case where the size of the collet 30 is equal to the size of the thin chip 65a, but in order to vacuum-adsorb the peripheral portion of the thin chip 65a, The size of the collet 30 may be larger than the flake tip 65a. By making the collet 30 larger than the thin chip 65a, air bubbles of the bonding material around the thin chip 65a can be more completely removed, and good bonding can be realized. The specific size of the collet 30 (the amount of protrusion from the chip size) varies depending on the chip size and the thickness of the bonding tape interposed between the chip and the lead frame or substrate.

In the first embodiment, the case where the plurality of vacuum suction holes 32 of the collet 30 have the same diameter and are formed uniformly has been described.For example, the diameter of the central vacuum suction hole is large. By reducing the diameter of the vacuum suction holes in the peripheral area, or increasing the density of the vacuum suction holes in the central area and decreasing the density of the vacuum suction holes in the peripheral area, If the pressure applied to the flake chips is made different, bonding is performed while pushing the gas under the flake chips by gradually applying pressure from the center to the periphery of the flake chips when bonding the flake chips to the substrate. It is possible to realize good bonding without bubbles in the bonding material. Also, in FIGS. 1 and 2, the contact surface of the collet 30 with the chip is a flat surface, but the deformation of the sheet interposed between the lower surface of the chip and the push-up pin or the 21 dollarless slider is used. By forming the central part of the lower surface of the collet 30 into a curved surface that is slightly convex downward, synergistic action with the plurality of vacuum suction holes 32 improves the releasability and extrudes the atmosphere gas during bonding. It can be smooth.

In the above-described embodiment, a so-called direct bonding type die bonder in which a chip is picked up and bonded as it is has been described. However, the picked up chip is temporarily transferred to a tray or a position correcting section, and the tray and the position corrected are transferred. The present invention can also be applied to a so-called indirect bonding type die bonder in which a chip is picked up from a part and bonded, and is used for a pickup collet and a bonding collet. Industrial applicability

The present invention is particularly suitable for a die bonder for a semiconductor chip. It can also be applied to die bonders for various electronic components such as chips and capacitor chips

Claims

The scope of the claims

1. In the collet for picking up and / or bonding chips,

A collet, wherein the lower surface of the collet is formed as a flat surface, and a plurality of vacuum suction portions are provided on the flat surface of the lower surface.

2. The collet is mounted on a collet holder having a vacuum suction hole in the center, and includes a plurality of vacuum suction holes penetrating vertically.

2. The collet according to claim 1, wherein a closed space is provided for communicating a vacuum suction hole of the collet holder with a plurality of vacuum suction holes of the collet.

3. The collet is mounted on a collet holder having a vacuum suction hole in the center, and the collet has a single or a plurality of vacuum suction holes, and a groove communicating with the vacuum suction hole on the lower surface. Prepare,

2. The collet according to claim 1, wherein a closed space is provided for communicating a vacuum suction hole of the collet holder with one or more vacuum suction holes of the collet.

4. A die bonder comprising the collet according to any one of claims 1 to 3.

5. After using a die bonder according to claim 4, the periphery of the chip whose back surface is joined to the sheet is vacuum-sucked with a collet, and the back surface of the chip is pushed up from below the wafer sheet with a pin. A chip big-chip method characterized in that the chip is relatively pushed up or the wafer sheet is vacuumed from below and deformed downward.