JP4802593B2 - Collet - Google Patents

Description

  The present invention relates to a collet used in a pickup device that picks up a diced semiconductor chip adhered and held on an adhesive tape from the adhesive tape.

JP-A-9-141585 JP 2003-273136 A Japanese Patent Laid-Open No. 2002-338771 JP 2005-1117019 A

  In semiconductor packages compatible with high-density mounting, semiconductor chips with a thickness of 100 μm or less are stacked, and it is expected that semiconductor chips with a thickness of about 50 μm will be used in the future. As for IC tags, miniaturization of semiconductor chips has been attempted in order to achieve cost reduction, and the size of semiconductor chips has also become 1 mm square or less. In the method of assembling a thin semiconductor chip or a micro thin semiconductor chip, it is important to pick up the semiconductor chip reliably and without damage before mounting the semiconductor chip.

  As a method for picking up semiconductor chips individually divided by dicing from a dicing film (adhesive sheet), the needle push-up method shown in FIGS. 5 and 6 is based on a chip mounting device such as a die bonder or a flip chip bonder or a chip on a chip tray. Widely used in tray packing machines. 5 and 6, the semiconductor chips 1 are individually divided by dicing and are stuck on the adhesive sheet 2 at equal intervals. The semiconductor chip 1 is sequentially conveyed onto the pickup main body 4 of the pickup device 3 in a state where the semiconductor chip 1 is stuck on the adhesive sheet 2 having elasticity.

  The pickup main body 4 has a negative pressure portion 5 therein and is formed in a cylindrical shape, and the upper surface 6 of the negative pressure portion 5 has a flat guide surface 7 for supporting the lower surface of the adhesive sheet 2. Blocked by the portion 8. A through-hole 9 is formed in the central portion of the top wall 8 that is slightly larger than the bottom surface dimension of the semiconductor chip 1 and smaller than the width dimension of the adhesive sheet 2. Further, a pickup needle 10 that is in contact with the lower surface of the adhesive sheet 2 through the through hole 9 is provided in the pickup body 4 so as to be movable in the vertical direction. The tip of the pickup needle 10 has a sharp and sharp shape.

  A collet 11 is disposed above the pickup body 4 at a position corresponding to the through hole 9. The collet 11 has a suction hole 12 connected to a vacuum suction machine (not shown), and a chuck for adsorbing the semiconductor chip 1 to the tip of the collet 11 at the periphery of the opening of the suction hole 12. A portion 13 is formed. The collet 11 has a structure in which the semiconductor chip 1 adsorbed by the chuck portion 13 is peeled off from the adhesive sheet 2 and picked up and conveyed to a predetermined position on a lead frame (not shown) where die bonding is performed.

  The operation of the pickup device configured as described above will be described. The adhesive sheet 2 to which the semiconductor chip 1 is adhered is disposed so as to be transported while sliding on the guide surface 7 of the pickup body 4. The chip 1 is intermittently transported to a state where it is transferred to the central portion of the through hole 9. The pressure-sensitive adhesive sheet 2 disposed on the guide surface 7 is adsorbed through the through-hole 9 when the negative pressure portion 5 is set to a negative pressure, and is restrained by the guide surface 7 by this adsorption force. When the back surface of the adhesive sheet 2 is in close contact with the guide surface 7 and restrained, this is confirmed by a negative pressure sensor (not shown) and the position of the semiconductor chip 1 is detected by an image position detecting means (not shown). The

  Next, the collet 11 is lowered, the semiconductor chip 1 is vacuum-sucked by the chuck portion 13 and simultaneously the pickup needle 10 is raised, the tip breaks through the adhesive sheet 2 and pushes up the semiconductor chip 1, and the semiconductor chip 1 is removed from the adhesive sheet 2. Peel off. The collet 11 rises while adsorbing the semiconductor chip 1 and the semiconductor chip 1 is picked up.

  In the pickup device 3 described above, the tip of the picked-up pickup needle 10 has a structure that pushes through the adhesive sheet 2 and pushes the semiconductor chip 1, so that dust (adhesive sheet dust) is generated when the adhesive sheet 2 is pierced. There is a problem that this dust is scattered on the upper surface of the peripheral semiconductor chip 1, which causes a defect of the semiconductor chip 1. Further, when the tip of the pickup needle 10 breaks through the adhesive sheet 2, the tip contacts the back surface of the semiconductor chip 1 to generate dust (silicon dust) of the semiconductor chip 1, and the semiconductor as in the case of the adhesive sheet dust. This causes a defect of the chip 1.

  In order to solve the problem of generation of the adhesive sheet dust and silicon dust of the pickup device 3 described above, Patent Document 1 is a porous material that has a negative pressure portion inside and guides the lower surface of the adhesive sheet on the upper surface. A pickup main body provided with a formed sheet guide surface, and adsorbing the pressure-sensitive adhesive sheet by the negative pressure of the negative pressure portion acting through the sheet guide surface; and the sheet disposed at a position facing the sheet guide surface Pickup chuck means for holding the semiconductor chip conveyed on the guide surface and peeling it from the adhesive sheet, and provided in the pickup main body facing the pickup chuck means, and the tip shape is flat or It is made as a curved surface and the tip is formed on the sheet guide surface Through the guide hole is abutted against the lower surface of the adhesive sheet semiconductor chip pickup apparatus and a pickup needle pushing up the semiconductor chip has been proposed that.

  Further, in Patent Document 2, a chip holding unit that holds and holds a dicing semiconductor chip by an adsorption unit, a plurality of minute holes of a porous material provided in the adsorption unit, and the minute holes A pickup device including a vacuum pump for evacuating has been proposed.

  Incidentally, both of the pickup devices in Patent Documents 1 and 2 solve the problem of generation of adhesive sheet dust and silicon dust of the conventional pickup device, but the semiconductor chip is adsorbed and peeled from the adhesive sheet by a collet. In this case, depending on the size of the vacuum suction hole (suction hole) provided in the collet, the semiconductor chip may be deformed due to the warping of the semiconductor chip in relation to the suction force of the collet to the semiconductor chip. When the thickness of the film becomes a very small thickness of, for example, about 50 μm or less, this problem of adsorption warpage can become more prominent. Further, the vacuum suction hole has a problem that a collet having a vacuum suction hole having a size suitable for the size of the semiconductor chip must be manufactured.

  The present invention has been made in view of the above-mentioned points, and the object of the present invention is to prevent the semiconductor chip from being warped when adsorbing and peeling the semiconductor chip from the pressure-sensitive adhesive sheet and having various dimensions. An object of the present invention is to provide a collet that can be used for a semiconductor chip.

  The collet according to the present invention is flush with a collet body having a concave portion provided at one end and a suction hole communicating with the concave portion, and provided at the concave portion of the collet main body and one end surface of the collet main body. Or a porous sintered metal body having an exposed surface protruding from the one end surface.

  According to the collet of the present invention, for example, by suction operation of a vacuum suction machine, the semiconductor chip attached to the pressure-sensitive adhesive sheet can be picked up and picked up from the exposed surface of the porous sintered metal body through the suction hole. In order to eliminate the adsorption warpage of the semiconductor chip by applying an even adsorption force to the semiconductor chip to be adsorbed in this way, and to hold the semiconductor chip by adsorption on the exposed surface of the porous sintered metal body It is possible to adsorb semiconductor chips of various sizes, for example, even a semiconductor chip having a size smaller than the size (diameter) of the suction hole of the collet can be adsorbed and retained. Accordingly, it is possible to eliminate the need to make a collet. The exposed surface of the porous sintered metal body of the collet of the present invention may protrude from one end face of the collet body, but is preferably flush with the one end face. In some cases, the semiconductor chip can be adsorbed without requiring a large suction force.

  In a preferred example of the collet of the present invention, the suction hole communicates with a part of the bottom surface of the recess, and the remaining part of the bottom surface of the recess except the part is in contact with the porous sintered metal body. According to such a preferred example, for example, when the porous sintered metal body is press-fitted and fixed in the recess, the porous sintered metal body can be easily positioned with respect to the collet body, and thus the collet body. It is possible to easily make one end face of the metal and the exposed face of the porous sintered metal body flush with each other.

  In a preferred example of the collet of the present invention, the collet body has a caulking portion provided on the collet body at the opening edge of the concave portion in order to prevent the porous sintered metal body from falling off the concave portion. According to such a preferred example, mechanical fixing by caulking of the collet body can be applied to the porous sintered metal body, and the porous sintered metal body can be firmly fixed to the collet body. For example, when the porous sintered metal body is in contact with the bottom surface of the recess, the exposed surface of the porous sintered metal body and the one end surface of the collet body can be maintained more reliably. it can.

  The collet body of the collet of the present invention may be selected from carbon steel for mechanical structure, stainless steel, and pure copper. Specifically, such a collet body includes a carbon steel for machine structure defined in JIS-G-4501, such as S45C, stainless steel defined in JIS-G-4303, particularly martensitic stainless steel. Steel, for example, SUS420J2, oxygen-free copper defined by JIS-H-2123, and tough pitch copper also defined by JIS-H-2123 may be used.

  In a preferred example of the collet of the present invention, the porous sintered metal body contains inorganic substance particles at a ratio of 1 wt% to 5 wt%. In such a preferable example, the inorganic substance particles may be made of at least one of graphite, boron nitride, graphite fluoride, calcium fluoride, aluminum oxide, silicon oxide, and silicon carbide.

  The porous sintered metal body fixed to the concave portion of the collet of the present invention is a sintered metal body composed of 8% by weight or more and 11% by weight or less of tin and the balance of copper, or the above component composition with graphite, boron nitride, A sintered metal body in which inorganic substance particles composed of at least one of graphite fluoride, calcium fluoride, aluminum oxide, silicon oxide, and silicon carbide are dispersed and contained at a ratio of 1 wt% to 5 wt%. Also good.

  In the case where the porous sintered metal body contains inorganic substance particles dispersedly, the inorganic substance particles dispersedly contained in the sintered metal body itself are not plastically deformed by machining, and in addition, the porous sintered metal body Since the plastic deformation of the metal part of the base material is divided and reduced, clogging of the pores on the surface of the porous sintered metal body in machining is suppressed, and the pore opening end becomes a drawn structure, The semiconductor chip at the time of adsorbing and holding the semiconductor chip has an even and strong adsorbing force, and can be easily peeled from the adhesive sheet without causing problems such as adsorbing warpage.

  According to the present invention, it is possible to provide a collet that can be used for semiconductor chips of various dimensions without causing suction warpage of the semiconductor chip when the semiconductor chip is peeled from the adhesive sheet.

  Next, an example of an embodiment of the present invention will be described in more detail based on an example shown in the figure. The present invention is not limited to these examples.

  1 and 2 are longitudinal sectional explanatory views of the pickup device 3 including the collet 50 according to the embodiment of the present invention. FIG. 3 is an explanatory longitudinal sectional view of the collet 50. FIG. It is longitudinal cross-sectional explanatory drawing of the collet 50 in which the crimping part 67 was formed.

  The semiconductor chips 1 are individually separated by dicing and are stuck on the adhesive sheet 2 at equal intervals. The semiconductor chip 1 is sequentially conveyed onto the pickup main body 4 of the pickup device 3 while being stuck on the adhesive sheet 2. In this example, the pickup body 4 is formed in a cylindrical shape with a negative pressure portion 5 provided therein, and the upper surface 6 of the negative pressure portion 5 has a flat guide surface 7 for supporting the lower surface of the adhesive sheet 2. It is closed by the ceiling wall 8 having it.

  A through-hole 9 that is slightly larger than the bottom surface dimension of the semiconductor chip 1 and smaller than the width dimension of the adhesive sheet 2 is formed at the center of the top wall portion 8. A pickup needle 10 that is in contact with the lower surface of the adhesive sheet 2 through the through hole 9 is provided in the pickup body 4 so as to be movable in the vertical direction. Note that the tip of the pickup needle 10 has a hemispherical curved shape.

A collet 50 is disposed above the pickup body 4 at a position corresponding to the through hole 9. As shown in FIG. 3 in particular, the collet 50 is made of metal and has a cylindrical shape having a recess 64 provided at one end 82 and a suction hole 61 having a circular cross section extending in the vertical direction communicating with the recess 64. And a porous sintered metal body 70 provided in the recess 64 and having an exposed surface 71 that is flush with the one end surface 66 of the collet body 60. The suction hole 61 communicates with a part 62 of the bottom surface 81 of the recess 64, and the remaining part 63 except the part 62 of the bottom surface 81 is in contact with the porous sintered metal body 70. The part 62 is a central part of the bottom surface 81, and the remaining part 63 is annular. The recess 64 is circular in cross section and has a diameter larger than the diameter of the suction hole 61. The collet body 60 has an annular wall surface that defines the remaining portion 63 excluding a part 62 of the bottom surface 81 of the recess 64, and a cylindrical wall surface that defines the peripheral surface 65 of the recess 64. Porous sintered metal body 70 is press-fitted into the recess 64 in contact with a cylindrical wall defining a peripheral surface 65 of the annular wall and the recessed portion 64 defining the remainder 63 excluding a portion 62 of the bottom surface 81 of the concave portion 64 Is provided . The exposed surface 71 made of a flat surface is exposed on the one end surface 66 side.

  As the porous sintered metal body 70, a sintered body comprising 8 to 11% by weight of tin and the remaining copper, or the above-described component composition including graphite, boron nitride, graphite fluoride, calcium fluoride, aluminum oxide, silicon oxide, and A sintered body in which inorganic substance particles made of at least one of silicon carbide are dispersed and contained in a proportion of 1 wt% or more and 5 wt% or less is preferably used. Since the porous sintered metal body 70 is flush with the flat one end face 66, the semiconductor chip 1 can be reliably adsorbed without requiring a large suction force. In the present example, the exposed surface 71 is flush with the one end surface 66, but may be disposed at a position protruding from the one end surface 66, for example.

  In particular, the porous sintered metal body 70 in which the inorganic substance particles are dispersedly dispersed does not cause plastic deformation of the inorganic substance particles dispersedly contained in the sintered body by machining, and in addition, the porous sintered metal body 70 The function of dividing and reducing plastic deformation of the metal portion of the substrate is shown, clogging of pores on the surface of the porous sintered metal body in machining is suppressed, and the pore opening end has a drawn structure. As a result, an even and strong adsorption force acts on the semiconductor chip when adsorbing and holding the semiconductor chip, and the semiconductor chip can be easily peeled off from the adhesive sheet without causing problems such as adsorption warpage. Can do.

  The suction hole 61 of the collet 50 is connected to a vacuum suction machine (not shown), and a chuck portion for the exposed surface 71 of the porous sintered metal body 70 of the collet 50 to adsorb the semiconductor chip 1 and Become.

  Next, the operation of the pickup device 3 having the above configuration will be described. The adhesive sheet 2 to which the semiconductor chip 1 is adhered is transferred while sliding on the guide surface 7 of the pickup body 4, and the semiconductor chip 1 is intermittently conveyed to the central portion of the through hole 9 of the pickup body 4. When it is recognized that the pressure-sensitive adhesive sheet 2 has been conveyed to a predetermined position, the inside of the negative pressure part 5 is set to a negative pressure. If the inside of the negative pressure part 5 is made into a negative pressure, the adhesive sheet 2 will be adsorb | sucked to the guide surface 7 side through the through-hole 9 by this negative pressure, and will be restrained by the guide surface 7 with this adsorption force.

  When the back surface of the adhesive sheet 2 is brought into close contact with the guide surface 7 and restrained, this is confirmed by a negative pressure sensor (not shown), and the position of the semiconductor chip 1 is detected by an image position detecting means (not shown). . Next, the collet 50 is lowered, the semiconductor chip 1 is vacuum-adsorbed on the exposed surface 71 of the porous sintered metal body 70, and at the same time the pickup needle 10 is raised, the tip abuts against the back surface of the adhesive sheet 2, and the semiconductor chip 1 is attached. While pushing up, the collet 50 is once lifted, and the semiconductor chip 1 is peeled off from the adhesive sheet 2. Thereafter, the collet 50 itself rises while holding the semiconductor chip 1 by suction, whereby the semiconductor chip 1 is picked up. The pick-up needle 10 of this example is designed not to make a hole in the pressure-sensitive adhesive sheet 2 when the semiconductor chip 1 is pushed up. Even if the pickup needle has a mode in which a hole is formed in the adhesive sheet 2 when the semiconductor chip 1 is pushed up, the pickup device can be formed by combining the collet 50 of this example.

  In the pick-up operation of the semiconductor chip 1, the semiconductor chip 1 is adsorbed and held by the exposed surface 71 of the porous sintered metal body 70 press-fitted and fixed to the concave portion 64 of the collet body 60 that forms the collet 50. Since uniform suction force acts on the entire surface of the semiconductor chip 1, there is no inconvenience such as suction warpage in the semiconductor chip 1. Moreover, since the semiconductor chip 1 is adsorbed and held on the exposed surface 71 of the porous sintered metal body 70, the semiconductor chip 1 having a size smaller than the size (diameter) of the exposed surface 71 of the porous sintered metal body 70, for example. Can also be adsorbed and held, and there is an advantage in terms of economy that it is not necessary to manufacture a collet according to the semiconductor chip 1 of various dimensions.

  For example, as shown in FIG. 4, the collet main body 60 has a caulking portion 67 provided on the collet main body 60 at the opening edge 83 of the concave portion 64 in order to prevent the porous sintered metal body 70 from falling off the concave portion 64. And may be mechanically fixed to the peripheral portion of the exposed surface 71 of the porous sintered metal body 70 that is press-fitted and fixed to the recess 64 by the caulking portion 67. Since the upper surface of the sintered metal body 70 facing the bottom surface 81 is in contact with the remaining portion 63, the porous sintered metal body 70 is more firmly fixed to the concave portion 64, and the concave portion of the porous sintered metal body 70 is It is possible to eliminate problems such as coming out of 64.

  In addition to the needle push-up method described above, the collet 50 of the present example includes a needleless pickup method (see Patent Document 2), a low adhesion film method (see Patent Document 3), and a multi-stage push-up pickup method (see Patent Document 3) that have been developed in recent years. (See Patent Document 4).

  According to the collet 50 of this example, the collet body 60 having the recess 64 provided at one end 82 and the suction hole 61 communicating with the recess 64, and the collet body 60 are provided in the recess 64 of the collet body 60. Since the porous sintered metal body 70 having the exposed surface 71 that is flush with the one end face 66 of the main body 60 is provided, the porous body is made porous through the suction hole 61 by, for example, a suction operation of a vacuum suction machine. The semiconductor chip 1 adhered to the pressure-sensitive adhesive sheet 2 can be picked up by holding from the exposed surface 71 of the sintered metal body 70, and an even suction force is applied to the semiconductor chip 1 thus sucked. In addition, it is possible to eliminate the adsorption warp of the semiconductor chip 1 and to adsorb and hold the semiconductor chip 1 on the exposed surface 71 of the porous sintered metal body 70, it is possible to adsorb the semiconductor chip 1 of various dimensions. For example, even the semiconductor chip 1 having a size smaller than the size (diameter) of the suction hole 61 of the collet 50 can be sucked and held, and there is no need to manufacture the collet 50 according to various dimensions of the semiconductor chip 1. obtain.

  According to the collet 50, the suction hole 61 communicates with a part 62 of the bottom surface 81 of the recess 64, and the remaining part 63 except for the part 62 of the bottom surface 81 of the recess 64 is formed in the porous sintered metal body 70. For example, when the porous sintered metal body 70 is press-fitted and fixed in the recess 64, the porous sintered metal body 70 can be easily positioned with respect to the collet body 60. The one end surface 66 of the main body 60 and the exposed surface 71 of the porous sintered metal body 70 can be easily made flush.

  According to the collet 50, the collet body 60 has the caulking portion 67 provided at the opening edge 83 of the concave portion 64 in order to prevent the porous sintered metal body 70 from falling off the concave portion 64. Mechanical fixing by caulking of the collet body 60 can be applied to the porous sintered metal body 70, and the porous sintered metal body 70 can be firmly fixed by the recess 64, for example, porous sintering. When the metal body 70 is in contact with the bottom surface 81 of the concave portion 64, the state where the exposed surface 71 of the porous sintered metal body 70 and the one end surface 66 of the collet body 60 are flush with each other is more reliably maintained. Can do.

It is longitudinal section explanatory drawing of the pick-up apparatus to which the collet of the example of embodiment of this invention is applied. It is a longitudinal cross-sectional explanatory drawing of the pick-up apparatus to which the collet of the example shown in FIG. 1 is applied. It is a longitudinal cross-sectional explanatory drawing of the example shown in FIG. It is a longitudinal cross-sectional explanatory drawing of the other example of embodiment of this invention. It is longitudinal cross-sectional explanatory drawing of the conventional pick-up apparatus. FIG. 6 is a longitudinal cross-sectional explanatory diagram of the example shown in FIG. 5.

Explanation of symbols

50 collet 60 collet body 61 suction hole 64 recess 70 porous sintered metal body

Claims (4)

A collet body having a recess provided at one end and a suction hole communicating with the recess, and a porous body provided in the recess of the collet body and having an exposed surface flush with one end surface of the collet body The suction hole is in communication with a part of the bottom surface of the recess, and the remaining part of the bottom surface of the recess is in contact with the porous sintered metal body. The collet body has a crimped portion provided on the collet body at the opening edge of the concave portion to prevent the porous sintered metal body from falling off the concave portion, and the collet body is a part of the bottom surface of the concave portion. And the cylindrical wall surface defining the peripheral surface of the recess, and the porous sintered metal body is provided in the recess in contact with the annular wall surface and the cylindrical wall surface of the collet body. in which the collet.   The collet according to claim 1, wherein the collet body is selected from carbon steel for mechanical structure, stainless steel, and pure copper.   The collet according to claim 1 or 2, wherein the porous sintered metal body contains inorganic substance particles in a proportion of 1 wt% to 5 wt%.   The collet according to claim 3, wherein the inorganic substance particles are made of at least one of graphite, boron nitride, graphite fluoride, calcium fluoride, aluminum oxide, silicon oxide, and silicon carbide.

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