JPH0332537A - Universal chuck table - Google Patents

Abstract

PURPOSE:To prevent the shapes of partition portions from being copied on the surfaces of processed matters, by making a constitution so that a suction sphere may be divided and partitioned by means of ringlike partition potions in opposition to processed matters whose sizes are different, and exposure may not occur on the mounting surfaces of processed matters. CONSTITUTION:A recessed cave-in portion 6 is provided at the center portion of the bottom portion 2b of the recessed portion 5 of a frame member 2, and ringlike groove portions 7-10 are formed in a concentric circle, and air suction holes 11-15 are respectively provided. A division member 3 as a whole is formed out of an inorganic matter having a ventilation quality, and ringlike partition portions 16-19 are formed out of powder of small mesh which is integrally sintered and has little ventilation. A surface member 4 is formed of a ventilation material, and provided in layers with the division member 3 within the recessed portion 5. Air suction means are provided connectingly at air suction holes 11-15 and connection with depressurizing means is made, and suction spheres are set in opposition to the sizes of processed matters by opening/closing selectively a valve.

Description

Detailed Description of the Invention [Industrial Application Field 1] According to the present invention, workpieces such as semiconductor wafers of different sizes are selectively placed, and the workpieces are appropriately placed in accordance with the respective sizes of the workpieces. This invention relates to a universal chuck table which is held by suction by a vacuum means and whose surface is subjected to, for example, polishing (grinding) or grinding. (Prior art) This type of chuck table, for example,
The structures disclosed in Japanese Patent Nos. 1-182738 are well known as conventional examples. The structure of the tick mechanism in this conventional example is that tables corresponding to the size of the workpiece, that is, porous ceramics, are arranged concentrically in multiple stages, and a ring-shaped partition is provided at the V4 section of each porous ceramic. It has a structure that exists on the surface. [Problem to be Solved by the Invention 1] In the conventional example described above, when a particularly large workpiece is mounted and adsorbed and subjected to cinder processing, ring-shaped partitions corresponding to each size are created on the table. Because it has an exposed structure, when the workpiece is held by vacuum suction and the surface is FA-polished using a suitable grinder with a predetermined pressure blade, the pressing force and the vacuum suction will cause the The workpiece is strongly pressed onto the table surface, and due to the difference in material or slight step between the partition and the table, that is, the porous ceramic, the surface of the polished workpiece is The shape of the partition, that is, the concentric pattern is projected. Such phenomena are generally referred to as "transcription"
Not only is the transferred pattern visible, but the steps in the pattern can be several microns wide. Therefore, in this type of free-size or universal table, the above-mentioned "transfer" problem has become a problem that must be solved. [Means for Solving the Problems] As a specific means for solving the problems in the conventional example, the present invention provides a suction area in which a plurality of suction areas are divided by ring-shaped partitions corresponding to objects to be treated of different sizes. The present invention provides a universal chuck table characterized in that the partition part is configured so that it is not exposed to the surface on which the workpiece is placed, and more specifically, it has a ring-shaped partition part and has air permeability. A suction area partitioning member having a suction area and a surface member having a flat and air permeable surface are arranged in an overlapping manner, the suction area partitioning member is formed of an inorganic material, and the ring-shaped partition is made of a finer mesh. A material formed of powder and bonded with a binder or integrally sintered is used, and thereby no one-transfer phenomenon occurs on the object to be processed. [Embodiment 1] Next, the present invention will be explained in more detail with reference to the illustrated embodiment. Reference numeral 1 indicates the entire chuck table, and the chuck table includes a disc-shaped frame member 2 and a suction area section. It is composed of a member 3 and a surface member 4. The disk-shaped frame member 2 has four circular portions 5 of a predetermined depth formed on its upper surface, and a ring-shaped portion 2 on the periphery of the upper surface.
a is formed. A recess 6 is provided at the center of the bottom 2b of the recess 5, and a plurality of ring-shaped grooves 7 to 10 are formed concentrically around the recess. An intake hole 11 is provided, and a plurality of intake holes 12 to 15 are provided in each of the grooves. The suction area dividing member 3 has a disk shape that fits into the recess 5 of the frame member 2, and is made of a material that has air permeability as a whole. A plurality of ring-shaped partitions 16 to 19 are provided concentrically so that the suction area is divided according to the size of the workpiece. These partition parts 16 to 19 are the ring-shaped groove part 7.
. The partition portions 18 and 19 are also formed following this pattern. Although the partitioning member 3 in this case has air permeability as a whole, the partitions 16 to 19 have almost no air permeability. For example, each partition is made of metal or ceramic, and the other parts are made of sintered inorganic material such as ceramic to improve air permeability. In particular, in the embodiment of the present invention, when the entire structure is made of an iridium-free material, the partitions 16 to 19 are made of #60
0 mesh ceramic powder such as carborundum and alumina is used, and the other parts are formed into a disk shape using #36 mesh ceramic powder, and then sintered to form an integral sintered product. Just do it. By forming it in this way, especially since the partition portion is made of fine mesh powder, the structure is such that the air permeability is greatly suppressed even if it is sintered. Further, the diameter of the ring-shaped partitions 16 to 19 is made to correspond to the size of the object to be processed. That is, the partition portion 16 is approximately 3 inches, the partition portion 17 is approximately 4 inches, and the partition portion 1 is approximately 4 inches.
8 is about 5 inches, the partition part 19 is about 6 inches, and the diameter of the dividing member 3 of the suction area is about 8 inches.
The thickness is approximately 3#. By forming in this way, the objects to be processed 11 to 15...Intake holes 16 to 19...Ring-shaped partitions 21 to 25
...Intake means 26-30...Valve a-e...Suction area

Claims (3)

[Claims] (1) The suction area is divided into a plurality of ring-shaped partitions to accommodate objects of different sizes, and the partition is configured so that it is not exposed to the surface on which the objects are placed. Universal chuck table. (2) The universal chuck according to claim (1), wherein a suction area dividing member having a ring-shaped partition portion and having air permeability and a surface member having a flat surface and having air permeability are arranged in an overlapping manner. table. (3) The universal chuck table according to claims (1) and (2), wherein the suction area partitioning member is formed of an inorganic material, and the ring-shaped partition is formed of finer mesh powder and integrally sintered.