KR100769111B1 - How to Pick Up Collets, Die Bonders and Chips - Google Patents

Abstract

The cracking of the semiconductor chip during pickup and bonding is prevented. The bonding tool 10 consists of the collet holder 20 and the collet 30. The collet holder 20 has a vacuum suction hole 21 in the center portion, fixing screws 22 and 23 for attaching the collet holder 20 to the support member, a recess 24 in the lower part and a recess in the mouth 24. It has a portion 25. The collet 30 abuts against the lower surface of the flat surface 31 at the lower end, the plurality of vacuum suction holes 32 penetrating up and down, the protrusion 33 penetrating into the concave portion 25, and the entrance portion 24. It has a flange part 34. The space portion 26 is formed by setting the depth H1 of the recess portion 25 and the height H2 of the protrusion portion 33 to H1> H2, and the vacuum suction holes 21 and 32 are formed in the space portion 26. Communicate via. The plurality of vacuum suction holes 32 vacuum suck the peripheral portions of the chip, and pick up and bond them.

Description

Pickup method of collet, die bonder and chip {COLLET, DIE BONDER, AND CHIP PICK-UP METHOD}

The present invention relates to a collet, a die bonder using the collet, and a chip pick-up method of the die bonder. For example, a flake-shaped semiconductor chip (die) is picked up from a wafer sheet and soldered to a substrate such as a lead frame, The present invention relates to a collet, a die bonder for bonding via a bonding material such as braze, silver paste, resin, and the like, and a pick-up method most suitable for a flake-shaped semiconductor chip.

Generally, the semiconductor device manufactures the back surface of a semiconductor chip (die) by bonding (bonding) it to board | substrates, such as a flint board | substrate and a lead frame, via bonding materials, such as soldering, brazing, silver paste, and resin.

In the die bonder which bonds such a semiconductor chip to a board | substrate, as shown in FIG. 4, the pick-up and bonding tool which moves between the pick-up position P1 and the bonding position P2 of a semiconductor chip (henceforth a tool) is called. 40 is used. Hereinafter, the operation will be described in detail. The tool 40 is lowered at the pick-up position P1 of the semiconductor chip (a), and the tool 40 which vacuum-adsorbs the semiconductor chip 65 at the semiconductor chip assembly 60 is raised. After (picking up) (b), it is moved horizontally (c) and the tool 40 is lowered at the bonding position P2 (d) and the semiconductor chip 65 is attached to the substrate 1 via the bonding material 2. After the bonding, the bonding is completed, the tool 40 is raised (e), then horizontally moved (f), and returned to the upper position of the original pickup position P1.

The semiconductor chip assembly 60 is horizontally moved by one pitch between the operations of (a) to (f) of the tool 40, and the semiconductor chip 65 to be picked up next is moved to the pickup position P1. . In addition, the substrate 1 is also horizontally moved by one pitch and moved to the next bonding region P2. Hereinafter, the same operation is repeated, and the semiconductor chip 65 is sequentially picked up and bonded to the substrate 1.

As shown in FIG. 5A and FIG. 5B, the tool 40 is configured such that the collet 42 is attached to the collet holder 41. The collet holder 41 has a vacuum suction hole 43 to which a vacuum system or a compressed gas system is connected at the center, a fixing screw 44 for attaching to a pipe connecting the collet holder 41, and a lower end portion ( 45) and the recessed part 46 in the said arrival part 45 is provided. The collet 42 has a vacuum suction hole 47 in the center, a protrusion 48 penetrating the recess 46, and a flange 49 joined to the lower end of the stock 45. In addition, the vacuum suction hole 43 of the collet holder 41 and the vacuum suction hole 47 of the collet 42 are the vacuum part formed between the front part of the recessed part 46, and the upper surface of the protrusion part 48. As shown in FIG. It communicates via 50. In addition, contrary to the illustration, the concave portion may be provided on the collet 42 side, and the protrusion may be provided on the collet holder 41 side.

In addition, in the pickup position P1 of the conventional die bonder mentioned above, the semiconductor chip assembly 60 as shown in FIG. 6C is normally arrange | positioned. In the semiconductor chip assembly 60, as shown in FIG. 6A, the semiconductor wafer 63 is attached to a wafer sheet 62 having an adhesive layer on a surface attached to the wafer ring 61, and the semiconductor wafer 63 is attached thereto. 6B is cut vertically and horizontally by the dicer 64 and divided into respective semiconductor chips 65, and then the wafer sheet 62 is fixed to the fixing ring 66 as shown in FIG. 6C. As the wafer ring 61 is placed on the upper side and the wafer ring 61 is pressed down (or the pressing ring 66 is pushed up), the wafer sheet 62 is pulled up to enlarge the interval of each semiconductor chip 65, The thing which reduced the adhesive force of the semiconductor chip 65 and the wafer sheet 62 has been used.

In the semiconductor chip assembly 60, when picking up the semiconductor chip 65, as shown in FIG. 4, the semiconductor chip 65 is pressed against the pressure pin 67 at the lower side of the semiconductor chip 65. As the wafer sheet 62 in the periphery of the semiconductor chip 65 is deformed downward by vacuum suction from the bottom, and the adhesion area between the semiconductor chip 65 and the wafer sheet 62 is reduced, the semiconductor chip 65 is reduced. The adhesion between the wafer sheet 62 and the wafer sheet 62 is reduced, and the collet 42 allows the semiconductor chip 65 to be reliably absorbed and picked up by a small vacuum suction force. Alternatively, the semiconductor chip 65 can be picked up from the wafer sheet 62 by suction fixing and fixing the semiconductor chip to the collet 42, and the lower surface of the wafer sheet is attracted and pulled down by the suction stage.

Here, the collet 42 has various configurations as shown in Figs. 7A to 7C. The collet 42A shown in FIG. 7A has a single large diameter vacuum suction hole 51 in the center portion, and a flat surface 52 is provided on the lower surface thereof. The collet 42B shown in FIG. 7B has a single large diameter vacuum suction hole 51 at the center portion, and an entrance portion 53 is provided at the periphery of the lower surface, and the vacuum suction hole ( The concave portion 54 communicating with 51 is provided. The collet 42C shown in FIG. 7C has a single large diameter vacuum suction hole 51 at the center portion, and an entrance portion 53 is provided at the periphery of the lower surface thereof, and the vacuum suction hole 51 is formed in the entrance portion 53. ), A concave portion 54 is provided, and an inclined surface 55 is formed between the concave portion 54 and the vacuum suction hole 51.

The collet 42A shown in FIG. 7A abuts the flat surface 52 of the lower surface on the semiconductor chip 65, applies a vacuum suction force to the vacuum suction hole 51, and adsorbs the chip 65. In addition, the collet 42B shown in FIG. 7B abuts the lower surface of the inlet portion 53 at the peripheral portion against the chip 65, applies a vacuum suction force to the vacuum suction hole 51, and adsorbs the chip 65. . In addition, the collet 42C shown in FIG. 7C abuts the upper shoulder of the chip 65 in the middle of the inclined surface 55, and applies the vacuum suction force to the vacuum suction hole 51 to adsorb the chip 65.

In recent years, in addition to miniaturization and weight reduction of semiconductor packages, as the capacity increases, the demand for thin semiconductor chips having a thickness of 50 μm or less (hereinafter referred to as flake chips) has been expanded, and technology for laminating such flake chips has been attracting attention.

Since flake chips have low mechanical strength, their handling requires close attention. However, the conventional collet 42 has a structure having a single large diameter vacuum suction hole 51 at the center as shown in 42B of FIGS. 7A and 7B and 42C of FIG. 7C, and at the time of picking up the flake chip. Due to the vacuum suction of the central portion of the semiconductor chip, excessive stress on the semiconductor chip cannot be avoided due to deformation of the wafer sheet occurring at the start of peeling or at the end of peeling of the wafer sheet at the time of pick-up, and the flake chips were easily broken. .

In addition, due to the adsorption by the vacuum suction hole at the time of bonding, not only the semiconductor chip after peeling can be stabilized and handled, but also the center part of the semiconductor chip floats and bubbles remain on the entire surface. There was a problem that can not be obtained.

Hereinafter, the problem will be described in detail for each collet. First, as shown in FIG. 8A, the collet 42A shown in FIG. 7A has the center portion of the thin chip 65a upward as shown in FIG. 8A at the start of peeling off when the thin chip 65a is picked up from the wafer sheet 62. Since the periphery of the flake chip 65a is subjected to the stress deformed downward together with the wafer sheet 62 due to the deformation force under the wafer sheet 62 and the deformation force under the wafer sheet 62, the flake chip 65a is Fragile

In addition, when the lamella chip 65a is bonded to the substrate 1 by the collet 42A, as shown in FIG. 8B, the lamella chip 65a is stressed upward by the reaction force of the bonding material 2. At this time, the presence of the vacuum suction hole 51 at the center portion causes the stress 3 to locally deform the central portion of the flake chip 65a, so that the flake chip 65a is easily broken.

In addition, when bonding the flake chip 65a to the substrate 1 with the collet 42A, as shown in FIG. 8B, the flake chip 65a is applied to the substrate 1 by applying a predetermined pressure with the collet 42A. Since the pressure is released upward from the vacuum suction hole 51 even if the flake chip 65a is not broken, the center portion of the flake chip 65a can be deformed upward and bonded. Such a phenomenon is the same also in the collet 42B of FIG. 7B mentioned later and the collet 42C of FIG. 7C.

In addition, in the case where there is a flake chip 65a that is difficult to detach from the collet 42A after the completion of the bonding, as shown in FIG. 8C, the compressed gas 4 is supplied to the vacuum adsorption hole 51, and the collet 42A is provided. Since the discharge pressure of the compressed gas 4 concentrates on the center portion of the flake chip 65a when the flake chip 65a is easily separated from the flake chip 65a, the center portion of the flake chip 65a is stressed to be deformed downward. There is a problem that the flake chip 65a is easily broken.

Since the collet 42B shown in FIG. 7B has a large recessed part 54 compared with the collet 42A shown in FIG. 7A, peeling start at the time of picking up the flake chip 65a from the wafer sheet 62 is shown. At the time, as shown in Fig. 9A, the presence of the recess 54 and the pressure of the pressure pin 67 cause the stress of the central portion of the flake chip 65a to be deformed upward, so that the flake chip 65a is provided. This is fragile

In addition, when bonding the lamella chip 65a to the substrate 1 with the collet 42B, as shown in FIG. 9B, the lamella chip 65a is stressed upward by the reaction force of the bonding material 2, At this time, the presence of the concave portion 54 causes a large stress 3 in which the central portion of the flake chip 65a is locally deformed upward, so that the flake chip 65a is easily broken.

In addition, when the compressed gas 4 is supplied to the vacuum suction hole 51 after completion of the bonding, as shown in FIG. 9C, since the center portion of the flake chip 65a is deformed downward, the flake chip 65a ) Is a fragile problem.

Although the collet 42C shown in FIG. 7C is usually for thick semiconductor chips, on the contrary, when applied to the flake chips 65a, peeling starts when picking up the flake chips 65a from the wafer sheet 62, although not shown. At the time, similarly to FIG. 9A, because of the presence of the recess 54 and the pressure of the pressure pin 67, the flake chip 65a is broken because the center portion of the flake chip 65a is subjected to a stress that is deformed upward. easy.

In addition, when bonding the lamella chip 65a to the substrate 1, similarly to FIG. 9B, the lamella chip 65a is subjected to a stress 3 upward by the reaction force of the bonding material 2, but at this time, Due to the presence of the concave portion 54 in the center portion, since the center portion of the flake chip 65a is subjected to a stress that is deformed upward, the flake chip 65a is easily broken.

In addition, when the compressed gas 4 is supplied to the vacuum suction hole 51 for bringing the flake chip 65a into close contact with the bonding material 2 after the completion of bonding, the center portion of the flake chip 65a is lowered as in FIG. 9C. Since it is stressed to deform, the flaky chip 65a is easily broken.

In addition to the above problem, the collet 42C shown in FIG. 7C has an inlet portion 53 at the periphery of the lower surface, and the inclined surface 55 in the concave portion 54 formed by the inlet portion 53. Since the shoulder of the flake chip 65a is abutted and adsorbed, it has the following peculiar problem at the time of pick-up.

That is, as shown in FIG. 10A, when the space | interval L1 of the four flake chips 65b and 65c adjacent to both sides of the flake chip 65a to adsorb | suck is smaller than the width L of the collet 42C, Since the clearance gap g between the flaky chip 65a and the flaky chips 65b and 65c which adjoin is too small, and the entry part 53 does not enter in such clearance gap g, The flaky chips 65b and 65c adjacent to the lower surface may be damaged or the flaky chips 65a to be adsorbed may not be adsorbed.

On the other hand, as shown in FIG. 10B, when the space | interval L2 of the four flake | chip chips 65b and 65c adjacent to both sides of the flake | chip chip 65a to adsorb is larger than the width L of the collet 42C, Between the flake chips 65a to be adsorbed and the adjacent flake chips 65b, 65c, an interval g1 as long as the entrance portion 53 enters is secured, and the flake chips 65a can be picked up. However, in order to form such a large gap g1, it is necessary to greatly expand the wafer sheet 62 at the time of stretching the wafer sheet 62 shown in Fig. 6C, and the number of the flake chips 65a is increased. It should be small, and the yield of the flaky chip 65a will become low. Or since the large diameter wafer ring 61 and the wafer sheet 62 are needed, the wafer ring 61 and the wafer sheet 62 become expensive. Moreover, since the horizontal moving distance of the semiconductor chip assembly 60 becomes large at the time of pick-up, not only the die bonder becomes large and expensive, but also there is a problem that the speed cannot be increased. In addition, even in combination with the needleless pick-up, the collet having a suction hole only in the center portion is also deformed around the chip due to the deformation of the sheet. This occurs when the adhesion between the sheet and the chip is relatively high with respect to the deformation recovery force of the chip. If the chip has a strain recovery force of 50 mg or less, it is particularly prone to occur, and in some cases, the flake chip may break. As a countermeasure against this, a collet provided with a plurality of vacuum bloods is effective. In addition, a mechanism for adjusting the vacuum pressure of each of the collet and the stage is provided to prevent chip breakage. For example, the chip holding force is increased by using the upper part (collet side) as the maximum vacuum pressure, and pressure control is performed so that the chip is not broken at the lower part (stage side).

An object of the present invention is to provide a collet in which a flake chip does not break, for example, when picking up and / or bonding a flake chip, a die bonder using the collet, and a method of picking up a chip.

In the collet according to the present invention, in order to solve the above-mentioned problem, in the collet for picking up and / or bonding the chip, the bottom surface of the collet is formed on a flat surface and a plurality of vacuum adsorption portions are formed on the flat surface of such a bottom surface. It is characterized in that it was installed (claim 1).

The term " collet for picking up and / or bonding a chip " refers not only to a collet of a die bonder of a so-called direct bonding method that picks up and bonds the chip as it is, but also picks up the chip and transfers it to a tray or a position fixing unit. It includes a transfer collet for pick-up of a die bonder of a so-called indirect bonding system or a collet for pick-up and bonding of chips from a tray or a position correction unit, which are mobilely mounted and pick up and bond chips from such a tray or a position correction unit.

In addition, the collet according to the present invention is mounted to a collet holder having a vacuum suction hole at the center thereof, and includes a plurality of vacuum suction holes penetrating up and down, and the vacuum suction hole of the collet holder and the plurality of vacuum suction holes of the collet are provided. It is characterized by providing a sealed space for communicating (claim claim 2).

In addition, the collet according to the present invention is mounted in a collet holder having a vacuum suction hole at the center thereof, and the collet has a single or a plurality of vacuum suction holes, and at the same time a lower surface has a groove communicating with the vacuum suction hole. And a sealed space portion for communicating the vacuum suction hole of the collet holder with a single or a plurality of vacuum suction holes of the collet is provided (claim 3).

Moreover, the die bonder which concerns on this invention is characterized by including the collet in any one of the above-mentioned collets (claim 4).

Further, in the method of picking up a chip according to the present invention, using the die bonder, the back side of the chip bonded to the wafer sheet is vacuum-adsorbed with a collet, and then the back side of the chip is placed relative to the pressure pin under the wafer sheet. Or the wafer sheet is deformed downward by a vacuum suction force from the bottom (claim 5).

According to the collet according to claim 1 of the present application, since the peripheral portion of the flake chip can be vacuum-adsorbed by the plurality of vacuum suction portions on the lower surface, the vacuum suction force acts only on the center portion of the flake chip as in the prior art so that the peripheral portion is not pulled out. For example, when the flake chip is peeled off from the wafer sheet and picked up, the circumferential portion of the flake chip is vacuumed to the collet even if the wafer sheet at the periphery of the flake chip is deformed downward by a vacuum suction force acting from below. Since it is adsorbed, the periphery of the flake chip is not deformed downward with the deformation of the wafer sheet, only the wafer sheet can be deformed downward, and the peeling start of the flake chip from the wafer sheet is performed smoothly, The crack at the time of picking up a flake chip can be prevented.

Further, for example, when the flake chip is bonded to the substrate, since the flake chip can be evenly pressed by the flat surface of the collet, the presence of a vacuum suction hole provided in the center of the conventional collet and the reaction force of the bonding material By this, the center portion of the flake chip is not subjected to the stress that is deformed upward, and thus cracking during bonding of the flake chip can be prevented.

In addition, after the bonding of the flake chips is completed, the compressed gas is supplied to the vacuum suction portion, and the flake chips are likely to fall out of the collet, and the compressed gas discharged from the plural vacuum suction portions is dispersed to the wide surface of the flake chips. As a collet having a vacuum suction hole in the center portion of the related art, the discharge pressure of the compressed gas is concentrated locally in the center portion of the flake chip, thereby eliminating the stress that the center portion of the flake chip is going to deform downward. Breaking from the collet can be prevented.

Moreover, according to the collet of Claim 2 of this application, the vacuum suction force which acts on the vacuum suction hole of the center part of a collet holder is a plurality of vacuum suctions of the said collet via the sealed space part between the said collet holder and the said collet. It can be uniformly dispersed in the ball, vacuum adsorbing the periphery of the flake chip, can receive the reaction force of the bonding material on a flat surface, and when the compressed gas is supplied, the compressed gas can be dispersed and supplied to the flake chip. It is possible to prevent the flake chip from being broken at the time of pick-up, at the time of bonding and at the time of detachment of the flake chip. In addition, the collet holder can share a vacuum suction hole only in the center portion in the same manner as in the prior art, and simply adopts a plurality of vacuum suction holes in the collet. As compared with the case of forming by, the configuration of each stage can be simplified, and the collet can be produced at low cost. In addition, since the plurality of vacuum suction holes of the collet can be formed at the time of casting molding of the collet, there is no increase in the number of processes or the cost due to the increase of the vacuum suction holes.

In addition, by varying the hole diameter or density of the vacuum suction hole of the collet at the center portion and the peripheral portion, it is possible to apply pressure to the peripheral portion from the center portion of the flake chip during bonding of the flake chip, It is possible to bond to the substrate while extruding the gas, and to bond the flake chips without drawing an atmosphere gas. Thereby, the gas attracted between a chip | tip and a base material can be removed reliably, and predetermined adhesive strength and product quality can be obtained.

Further, according to the collet according to claim 3 of the present application, since the vacuum suction force acting on the vacuum suction hole in the center of the collet holder is uniformly dispersed through the single or plural vacuum suction holes of the collet, the pickup It is possible to vacuum-adsorb the periphery of the flake chip at the time of dissipation, to receive the reaction force of the bonding material on the flat surface during bonding, and to discharge the compressed gas discharge pressure to the wider surface of the flake chip at the time of detachment of the flake chip. Since the stress which locally deforms the flake chip does not work at any time during pick-up, bonding and detachment, cracking of the flake chip can be prevented. In addition, since the collet holder can share a vacuum suction hole only in the center part in the same manner as in the related art, and simply adopts a groove portion communicating with the vacuum suction hole on the lower surface of the collet, a plurality of vacuum suction holes can be used. As compared with the case of forming by the groove | channel etc., the structure of each stage becomes simple and the said collet can be manufactured at low cost. In addition, since the vacuum suction hole and the groove part of the said collet can be formed simultaneously at the time of casting molding of a collet, as a groove part is provided, a process number or a cost increase does not occur.

Moreover, according to the die bonder of Claim 4 of this application, at the time of the pick-up which peels a flake chip from a wafer sheet, the flake chip adhered to a wafer sheet is pressurized with a pressure pin from the lower side, or the said wafer sheet is vacuum-absorbed, As it is deformed downward, when the adhesion area between the lamella chip and the wafer sheet is reduced to reduce the adhesive force, the peripheral portion of the upper surface of the lamella chip can be adsorbed by a plurality of vacuum suction holes or grooves of the collet, and the flake Since the chip is received from the flat surface, only the wafer sheet of the peripheral portion of the flake chip is deformed downward without the center portion of the flake chip deforming upwards, or the peripheral portion of the flake chip deforming downward with the deformation of the wafer sheet. The adhesive force between the flake chip and the wafer sheet is reduced, the peeling starts smoothly, and the flake chip is broken. You can definitely pick up without luggage.

In addition, since the reaction force of the bonding material is distributed to the flat surface of the collet when the flake chip is bonded to the substrate, the presence of the vacuum suction hole provided in the center of the collet and the reaction force according to the bonding material are used. The phenomenon that the central portion is deformed upward is eliminated, and the flake chip can be bonded without cracking.

In addition, in the case where the compressed gas is supplied to the vacuum suction hole after the bonding of the lamella chips, and the lamella chips are easily removed from the collet, the compressed gas is formed in the plurality of vacuum suction holes or grooves of the collet. As it is dispersed and discharged to the surface, the discharge pressure of the compressed gas is concentrated in the center of the flake chip, such as a collet having a vacuum suction hole in the conventional center, so that the center portion of the flake chip is not deformed downward, and the flake chip By preventing the cracking, the flake chip can be separated from the collet.

In addition, according to the chip pick-up method according to claim 5 of the present application, the wafer sheet is vacuum-adsorbed at the periphery of the chip in the collet, and the back surface of the chip is relatively compressed with a pressure pin or the wafer sheet is bonded to the chip. Since the vacuum suction is used to deform downward, the chip is not deformed downward or the wafer sheet of the peripheral portion of the chip is deformed downward in the state where the peripheral part of the chip is pulled, as in the conventional chip pickup method. It is possible to effectively prevent cracking when picking up the chip without stressing the chip.

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

FIG. 1B is a bottom view of the bonding tool of FIG. 1A.

1C is a collet front view of the bonding tool of FIG. 1A.

FIG. 2A is an enlarged longitudinal sectional view of a main portion of a state of pick-up of a flake chip for explaining the operation of the die bonder having the collet of FIG. 1C; FIG.

2B is an enlarged longitudinal sectional view of a main portion of a state at the time of flake chip bonding.

FIG. 2C is an enlarged longitudinal cross-sectional view of the main portion of the state in the state of detachment from the collet of the lamella chip for explaining the operation of bonding with the collet of FIG. 1C. FIG.

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

3B is a bottom view of the bonding tool of FIG. 3A.

3C is a collet front view of the bonding tool of FIG. 3A.

4 is an explanatory diagram of a pick-up and bonding operation of a die bonder.

5A is a longitudinal rear view of a bonding tool of a conventional die bonder.

5B is an enlarged fragmentary front view of the bonding tool of FIG. 5C.

It is explanatory drawing of the state which stuck the semiconductor wafer to the wafer sheet of the semiconductor chip assembly manufacturing process shown in FIG.

FIG. 6B is an explanatory diagram of a state in which a semiconductor wafer is divided into respective semiconductor chips by Dicer in the semiconductor chip assembly manufacturing step shown in FIG. 4.

It is explanatory drawing of the state which extended the wafer sheet in the semiconductor chip assembly manufacturing process shown in FIG.

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

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

7C is another collet longitudinal sectional view of a conventional die bonder.

FIG. 8A is an enlarged longitudinal sectional view of a main portion of a state at the time of picking up a thin chip for explaining the operation by the collet of FIG. 7A. FIG.

FIG. 8B is an enlarged longitudinal sectional view of a main portion of a state at the time of detachment of the lamella chip for explaining the operation by the collet of FIG. 7A; FIG.

FIG. 8C is an enlarged longitudinal sectional view of a main portion of a state of thin chip bonding for explaining the operation by the collet of FIG. 7A. FIG.

FIG. 9A is an enlarged longitudinal sectional view of a main portion of a state of thin chip pick-up for explaining the operation by the collet of FIG. 7B. FIG.

FIG. 9B is an enlarged longitudinal sectional view of a main portion of a state at the time of detachment of the flake chip for explaining the operation by the collet of FIG. 7B. FIG.

FIG. 9C is an enlarged longitudinal sectional view of the main portion in close contact with the bonding material of the lamella chip for explaining the operation by the collet of FIG. 7B. FIG.

Fig. 10A is an enlarged longitudinal sectional view for explaining the problem caused by the collet of Fig. 7C, which is a first problem explanatory diagram in the case where the chip spacing is small.

Fig. 10B is an enlarged longitudinal sectional view for explaining the problem caused by the collet shown in Fig. 7C, and is a second problem explanatory diagram in the case where the chip spacing is increased.

Hereinafter, embodiments of a die bonder having a collet according to 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 has a collet 30 mounted to the collet holder 20 and the collet holder 20, as shown in Figs. 1A to 1C. The collet holder 20 is, for example, made of stainless steel, has a vacuum suction hole 21 connected to a vacuum system at the center thereof, and has two fixing screw holes 22 for attaching the collet holder 20 to the support member. And 23, a recess 24 at the periphery of the lower end and a recess 25 surrounded by the recess 24.

The collet 30 is made of, for example, stainless steel, nitrile rubber, fluorine rubber, a heat resistant resin material, and the like, and a plurality of flat surfaces 31 on the lower surface penetrating up and down (as shown) A vacuum suction hole 32 having a predetermined diameter of 15 pieces (3 lengths 5 widths) for a rectangular thin chip, a protrusion 33 penetrating into the groove 25 of the collet holder 20, and a collet holder. The flange part 34 which abuts on the lower surface of the entrance part 24 of 20 is provided.

The depth H1 of the recess 25 of the collet holder 20 is set larger than the height H2 of the groove 33 of the collet 30, and the ceiling surface and the protrusion ( Between the upper surface of 33), a space portion 26 corresponding to H1-H2 is formed. For this reason, the vacuum suction hole 21 of the collet holder 20 and the vacuum suction hole 32 of the collet 30 are communicating through the space part 26. As shown in FIG. Accordingly, when the vacuum suction force is applied to the vacuum suction hole 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 portion 26. When the compressed gas is supplied to the vacuum suction hole 21 of the collet holder 20, the compressed gas is dispersed and discharged from the plurality of vacuum suction holes 32 of the collet 30 via the space part 26. do.

Next, the pick-up operation of the flake chip according to the tool 10, the bonding operation, and the detachment operation of the collet will be described with reference to the drawings.

First, the case of picking up the flake chip at the pick-up position P1 will be described. As shown in FIG. 2A, the flake chip 65a in which the collet 30 of the tool 10 is adhered to the wafer sheet 62 is shown. ) And a vacuum suction force is applied to the vacuum suction hole 21 of the collet holder 20. Therefore, such a vacuum suction force is distributed to the plurality of vacuum suction holes 32 of the collet 30 via the space portion 26, so that the peripheral portion of the flake chip 65a can be vacuum-adsorbed.

In such a state, when the center portion of the flake chips 65a is pressed by the pressure pin 67 under the wafer sheet 62 or the wafer sheet 62 is deformed downward by the vacuum suction force from the bottom, the flake chips 65a. ) Abuts on the flat surface 31, and the peripheral portion is adsorbed by the vacuum suction hole 32 of the collet 30, so that the central portion of the flake chip 65a is not bent upward by the pressure pin 67. At the same time, the peripheral portion of the lamella chip 65a does not deform downward with the deformation of the wafer sheet 62, and the peripheral portion of the lamella chip 65a can start peeling smoothly from the wafer sheet 62, and the flakes The adhesion area between the chip 65a and the wafer sheet 62 is reduced, and the adhesion force is reduced.

When the tool 10 is raised as it is in the above-mentioned state, as mentioned above, the flake | chip chip 65a by which the peripheral part is peeled from the wafer sheet 62 is the wafer sheet 62 toward the center part from this peeled peripheral part. It is completely peeled off in order to be peeled off. At this time, since the center portion of the flake chip 65a is adsorbed by the vacuum suction hole 32 of the collet 30, the center portion of the flake chip 65a is peeled off from the wafer sheet 62 smoothly without deforming downward. Then, the flake chip 65a is picked up without breaking.

Next, the case where the thin chip 65a adsorbed by the tool 10 is bonded to the substrate 1 will be described. As shown in FIG. 2B, the bonding material 2 supplied to the substrate 1 will be described. Thus, the flake chip 65a receives a reaction force upward, but has a flat surface 31 on the lower surface of the collet 30, so that the reaction force by the bonding material 2 is uniform across the entire back surface of the flake chip 65a. As a result of the dispersion, the flake chips 65a are not broken without receiving a local reaction force only in the center portion of the flake chips 65a as in the prior art.

In addition, in the case where compressed gas is supplied to the vacuum suction artificial 21 in order to detach the flake chip 65a from the tool 10 after the completion of bonding, as shown in FIG. 2C, the compressed gas 4 is a collet ( Since the plurality of vacuum suction holes 32 of 30 are dispersed and discharged into the flake chips 65a, the compressed gas concentrates only on the center portion of the flake chips 65a, as in the collet having a single vacuum suction hole in the conventional center portion. Since it is not discharged, the center portion of the flake chip 65a is not deformed downward, the crack of the flake chip 65a can be prevented, and the flake chip 65a can be detached.

Example 2

Next, the collet 10A according to the second embodiment of the present invention will be described with reference to FIGS. 3A, 3B, and 3C. The collet 10A includes a collet holder 20 and a collet 30A. Since the collet holder 20 according to the present embodiment is the same as the collet holder 20 shown in FIG. 1A, the same reference numerals are given to the same parts, and description thereof will be omitted.

The collet 30A has a flat surface 31 on the lower surface, a plurality of small-diameter vacuum suction holes 32, a protrusion 33 penetrating into the recess 25 of the collet holder 20, and a mouth portion of the collet holder 20. The point of having the flange part 34 which abuts on the lower surface of 24 is the same as the collet 30 shown in FIG. 1A, but the groove part 35 which communicates with the lower end of the several vacuum suction hole 32 in one direction. ) And a groove portion 36 communicating with the lower ends of the plurality of vacuum suction holes 32 in the other direction. The vacuum suction hole 24 and the grooves 35 and 36 which penetrate the collet 30A are formed in the production type, and the protrusions corresponding to the shapes of the vacuum suction hole 24 and the grooves 35 and 36 are formed in advance. At the time of casting molding of 30A, the vacuum suction hole 24 and the grooves 35 and 36 can be formed at the same time, so that the manufacturing process by forming the plurality of vacuum suction holes 32 or the grooves 35 and 36 is performed. The increase in number and cost can be prevented.

Next, operation | movement of the tool 10A provided with the collet 30A which has the said groove part 35 and 36 is demonstrated.

First, in the case where the tool 10A adsorbs the flake chip 65a, the collet 30A of the tool 10A is brought into contact with the upper surface of the flake chip 65a bonded to the wafer sheet 62, and the collet holder ( A vacuum suction force is applied to the vacuum suction hole 21 of 20). Accordingly, the vacuum suction force is distributed to the plurality of vacuum suction holes 32 of the collet 30A via the space portion 26 and to the groove portions 35 and 36 communicating with these vacuum suction holes 32. It is disperse | distributed and can adsorb | suck the peripheral part of flake chip 65a in a wider surface.

In such a state, when the center portion of the flake chip 65a is pressed with the pressure pin 67 under the wafer sheet 62 or the wafer sheet 62 is deformed downward by the vacuum suction force from the bottom, the flakes Since the chip 65a abuts on the flat surface 31 and the periphery is vacuum-adsorbed by the grooves 35 and 36 of the collet 30A, the center portion of the flake chip 65a is driven by the pressure pin 67. While not deforming upwards, the peripheral portion of the flake chip 65a does not deform downward with the deformation of the wafer sheet 62, and the peripheral portion of the flake chip 65a starts peeling smoothly from the wafer sheet 62. In addition, the adhesion area between the flake chip 65a and the wafer sheet 62 is reduced, and the adhesion force is reduced.

When the tool 10A is raised as it is, as described above, the flake chip 65a whose peripheral portion is peeled off the wafer sheet 62 is completely peeled off from the wafer sheet 62 toward the center from the peeled peripheral portion. Peel off. At this time, since the center portion of the lamella chip 65a is adsorbed by the grooves 35 and 36 of the collet 30A, the center portion of the lamella chip 65a does not deform downward, and is gently peeled off from the wafer sheet 62. Then, the flake chip 65a is picked up without breaking.

Next, the case where the flake chip 65a adsorbed by the tool 10A is bonded to the substrate 1 will be described. The flake chip 65a is provided by the bonding material 2 supplied to the substrate 1. Receives a reaction force 3 directed upward, but has a flat surface 31 on the lower surface of the collet 30A, so that the reaction force by the bonding material 2 is uniformly distributed on the entire back surface of the flake chip 65a. As a result, cracking of the flake chip 65a is eliminated without receiving a local reaction force only in the center portion of the flake chip 65a as in the prior art.

In addition, when the compressed gas 4 is supplied to the vacuum suction hole 21 in order to separate the flaky chip 65a from the tool 10A after completion | finish of bonding, the compressed gas 4 is a plurality of collet 30A. Since it is dispersed and discharged from the groove portions 35 and 36 to the wide surface of the flake chip 65a, the compressed gas is locally only at the center portion of the flake chip 65a, such as a collet having a single vacuum suction hole in the conventional center portion. Since it is not discharged in a concentrated manner, the center portion of the flake chip 65a is not deformed downward, and the crack of the flake chip 65a can be prevented and the flake chip 65a can be detached.

In addition, the above-described embodiments have been described with respect to specific forms of the present invention, and the present invention is not limited to these embodiments, and various modifications are possible.

For example, in Example 2 mentioned above, although the case where the some vacuum adsorption hole 32 was formed in 30A of collets was demonstrated, as with the collet 30A shown to FIG. 3A and FIG. 3B, the flat surface ( In the case where the grooves 35 and 36 are formed in the 31, the number of the vacuum suction holes 32 communicating with the grooves 35 and 36 can be made smaller than that shown, for example, a single vacuum suction. It is good also as a structure which has the ball 24.

In addition, the above-described embodiments have specifically described the pickup, bonding, and release from the collet of the flake chip, which exhibits a remarkable effect. However, the above-described embodiments are conventionally used for the pickup, bonding, and separation from the semiconductor chip having a thickness of about 50 μm or more. Applicability is also obvious.

In addition, although the above-mentioned embodiment demonstrated the case where the bonding material 2 is supplied to the board | substrate 1 by application | coating etc., and bonding a flake chip through this bonding material 2, previously, the back surface of a flake chip was carried out. The bonding material may be deposited and bonded through such a bonding material.

In addition, in Examples 1 and 2 mentioned above, the entrance part 24 and the recessed part 25 are provided in the collet holder 20 side, and it penetrates into the said recessed part 25 in the collet 30, 30A side. Although the case where the protrusion part 33 and the flange part 34 which abuts on the lower surface of the said arrival part 24 was provided was demonstrated, the granular part and recessed in the collet 30, 30A side contrary to the case shown in the figure. The part may be provided, and the flange part which abuts on the upper surface of the protrusion part and the granular part which fits in the said recessed part may be provided in the collet holder 20 side.

In addition, although the case where the size of the collet 30 is equivalent to the size of the flake chip 65a is shown in FIGS. 2A-2C, in order to vacuum-suck the peripheral part of the flake chip 65a, the collet 30 is carried out. May be larger than the flake chip 65a. Thus, by making the collet 30 larger than the flake chip 65a, the bubble of the bonding material of the peripheral part of the flake chip 65a can be removed more completely, and favorable bonding can be implement | achieved. The specific size (amount exceeded in the chip size) of the collet 30 depends on the chip size or the thickness of the tape when interposed between the chip and the lead frame or the substrate.

In addition, in Example 1 mentioned above, although the case where the several vacuum suction holes 32 of the collet 30 were formed uniformly in the same diameter was demonstrated, for example, the hole diameter of the vacuum suction hole of the center part is The pressure applied to the flake chip at the center and the periphery varies according to the size of the vacuum suction hole in the periphery, which is large and the hole diameter of the vacuum suction hole in the periphery is small, or the density of the vacuum suction hole in the periphery is increased. In this case, when bonding the lamella chip to the substrate, pressure is applied from the central portion of the lamella chip to the periphery in order to allow bonding while extruding the atmospheric gas below the lamella chip, and the bonding material does not contain air bubbles. Good bonding can be realized. In addition, although the contact surface with the chip | tip of the collet 30 is made into the flat surface in FIG. 1 and FIG. 2, the collet 30 is utilized using the deformation | transformation of the sheet | seat interposed between the chip lower surface and a pressure pin or a needleless slider. ), The center portion is formed into a curved surface with a slight protrusion downward, and the peeling property is improved by synergism with the plurality of vacuum suction holes 32, or the atmosphere gas at the time of bonding. Extrusion can be smoothed.

In addition, the above-described embodiments have described a so-called direct bonding die bonder in which chips are picked up and bonded as they are, but once the picked-up chip is moved to a tray or a position corrector, It is also applicable to the pick-up collet and bonding collet of a so-called indirect bonding die bonder which picks up and bonds a chip.

The present invention is particularly suitable for die bonders of semiconductor chips, but can also be applied to die bonders of various electronic components such as resistor chips and capacitor chips.

Although the above has been described with reference to preferred embodiments of the present invention, those skilled in the art have various modifications of the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. And can be changed.

Claims (6)

A collet for picking up and / or bonding chips, The bottom 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, and the suction force of the central portion of the flat surface is strong and the suction force of the peripheral portion is weak. Collet characterized by setting the diameter. The method of claim 1, The collet is mounted to a collet holder having a vacuum suction hole in the center, and has a plurality of vacuum suction holes penetrating up and down, And a closed space for communicating the vacuum suction hole of the collet holder and the plurality of vacuum suction holes of the collet. The method of claim 1, The collet is mounted to the collet holder having a vacuum suction hole in the center, The collet has a single or a plurality of vacuum suction hole, and at the same time has a groove portion communicating with the vacuum suction hole on the lower surface, And a closed space for communicating the vacuum suction hole of the collet holder with a single or a plurality of vacuum suction holes of the collet. The method of claim 1, The collet is mounted to a collet holder having a vacuum suction hole in the center, and has a vacuum suction hole, And a closed space for communicating the vacuum suction hole of the collet holder with the vacuum suction hole of the collet, wherein the width of the closed space part is larger than the width of the flat surface of the collet. A die bonder comprising the collet according to any one of claims 1 to 3. Using the die bonder according to claim 5, after vacuum suctioning the periphery of the chip whose back surface is bonded to the wafer sheet in a collet, the back surface of the chip is relatively pressed under pressure pins under the wafer sheet, or the wafer A method for picking up chips, characterized in that the sheet is vacuum sucked from the bottom and deformed downward.

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