Polishing apparatus

A polishing apparatus,

• comprising:
• a polishing plate having an upper face, on which a polishing cloth is adhered;
• a holding head having a lower face, on which a workpiece is held so as to press the workpiece onto the polishing cloth;
• and
• a driving mechanism for relatively moving said polishing plate with respect to said holding head so as to polish a lower face of the workpiece,
• wherein said holding head comprises:
• a head base;
• a main head section being attached on the lower side of the head base with a first diaphragm and capable of moving toward said polishing plate, said main head section having a press ring, which is provided on the lower side thereof and capable of pressing the polishing cloth;
• a press plate being provided in the main head section with a second diaphragm and capable of moving toward said polishing place;
• an elastic sheet member being attached on a lower face of the press plate;
• a first fluid chamber being formed between the head base and the main head section and closed by the first diaphragm;
• a second fluid chamber being formed between the main head section and the press plate and closed by the second diaphragm;
• a third fluid chamber being formed between the lower face of the press plate and the elastic sheet member;
• first pressing means for introducing a pressurized fluid into the first fluid chamber and pressing the main head section downward;
• second pressing means for introducing a pressurized fluid into the second fluid chamber and pressing the press plate downward;
• and
• third pressing means for introducing a pressurized fluid into the third fluid chamber and pressing the workpiece downward, and
• whereby the workpiece is held on the lower side of the elastic sheet member, and the lower face of the workpiece can be polished;
• wherein:
• a rotary shaft is connected to the head base,
• the head base and the main head section are engaged by a first transmitting member so as to allow the main head section to move upward and downward,
• the main head section and the press plate are engaged by a second transmitting member so as to allow the press plate to move upward and downward,
• the head base is rotated by rotating the rotary shaft,
• the main head section is rotated with the first transmitting member, and
• the press plate is rotated with the second transmitting member.

A polishing apparatus,

• comprising:
• a polishing plate having an upper face, on which a polishing cloth is adhered;
• a holding head having a lower face, on which a workpiece is held so as to press the workpiece onto the polishing cloth;
• and
• a driving mechanism for relatively moving said polishing plate with respect to said holding head so as to polish a lower face of the workpiece,
• wherein said holding head comprises:
• a head base;
• a main head section being attached on the lower side of the head base with a first diaphragm and capable of moving toward said polishing plate, said main bead section having a press ring, which is provided on the lower side thereof and capable of pressing the polishing cloth;
• a press plate being provided in the main head section with a second diaphragm and capable of moving toward said polishing plate;
• an elastic sheet member being attached on a lower face of the press place;
• a first fluid chamber being formed between the head base and the main head section and closed by the first diaphragm;
• a second fluid chamber being formed between the main head section and the press plate and closed by the second diaphragm;
• a third fluid chamber being formed between the lower face of the press plate and the elastic sheet member;
• first pressing means for introducing a pressurized fluid into the first fluid chamber and pressing the main head section downward;
• second pressing means for introducing a pressurized fluid into the second fluid chamber and pressing the press plate downward;
• and
• third pressing means for introducing a pressurized fluid into the third fluid chamber and pressing the workpiece downward, and
• whereby the workpiece is held on the lower side of the elastic sheet member, and the lower face of the workpiece can be polished;
• wherein:
• the head base and the main head section respectively have engaging parts, which engage each other when the bead base is moved upward and disengage each other when the head base is moved downward, and
• the engaging parts are slope faces, which are capable of correctly positioning the main head section with respect to the head base.

A polishing apparatus,

• comprising:
• a polishing plate having an upper face, on which a polishing cloth is adhered;
• a holding head having a lower face, on which a workpiece is held so as to press the workpiece onto the polishing cloth;
• and
• a driving mechanism for relatively moving said polishing plate with respect to said holding head so as to polish a lower face of the workpiece,
• wherein said holding head comprises:
• a head base;
• a main head section being attached on the lower side of the head base with a first diaphragm and capable of moving toward said polishing plate, said main head section having a press dug, which is provided on the lower side thereof and capable of pressing the polishing cloth;
• a press plate being provided in the main head section with a second diaphragm and capable of moving toward said polishing plate;
• an elastic sheet member being attached on a lower face of the press plate;
• a first fluid chamber being formed between the head base and the main head section and closed by the first diaphragm;
• a second fluid chamber being formed between the main head section and the press plate and closed by the second diaphragm;
• a third fluid chamber being formed between the lower face of the press plate and the elastic sheet member;
• first pressing means for introducing a pressurized fluid into the first fluid chamber and pressing the main head section downward;
• second pressing means for introducing a pressurized fluid into the second fluid chamber and pressing the press plate downward;
• and
• third pressing means for introducing a pressurized fluid into the third fluid chamber and pressing the workpiece downward, and
• whereby the workpiece is held on the lower side of the elastic sheet member, and the lower face of the workpiece can be polished;
• wherein;
• the main head section and the press plate respectively have engaging parts, which engage each other when the press plate is axially moved in a first direction relative to the main head section and which disengage each other when the press plate is axially moved in a second direction that opposes the first direction, and
• the engaging parts are slope faces, which are capable of correctly positioning the press plate with respect to the main head section.