Mold release film and process for producing semiconductor package

Patent metadata

Field	Value
Publication number	US-2016189985-A1
Application number	US-201615061044-A
Country	US
Kind code	A1
Filing date	Mar 4, 2016
Priority date	Nov 7, 2013
Publication date	Jun 30, 2016
Grant date	—

Abstract

To provide a mold release film which is excellent in releasability and capable of suppressing contamination of a mold or a resin-encapsulation portion by the mold release film and which is capable of forming a resin-encapsulation portion excellent in adhesion to an ink layer, and a process for producing a semiconductor package using the mold release film. A mold release film to be disposed on a cavity surface of a mold in a method for producing a semiconductor package wherein a semiconductor element is disposed in the mold and encapsulated with a curable resin to form a resin-encapsulation portion, characterized in that it has a first surface to be in contact with the curable resin at the time of forming the resin-encapsulation portion, and a second surface to be in contact with the cavity surface, at least the first surface is made of a fluororesin, and in a specific test method, F/Al is from 0.2 to 4, or F/(C+F+O) is from 0.1 to 0.3.

First claim

What is claimed is:

1 . A mold release film to be disposed on a cavity surface of a mold in a method for producing a semiconductor package wherein a semiconductor element is disposed in the mold and encapsulated with a curable resin to form a resin-encapsulation portion, characterized in that
it has a first surface to be in contact with the curable resin at the time of forming the resin-encapsulation portion, and a second surface to be in contact with the cavity surface, at least the first surface is made of a fluororesin, and F/Al in the following test method A is from 0.2 to 4, or F/(C+F+O) in the following test method B is from 0.1 to 0.3:
<Test method A>
A 1 mm thick cardboard, the mold release film, a 0.1 mm thick aluminum plate made of A1N30H—H18 material in accordance with JIS H4160 and a 1 mm thick cardboard are piled in this order so that the first surface and the aluminum plate are in contact with each other, and pressed for 5 minutes under conditions of 180° C. and 5 MPa, whereupon the mold release film is peeled off from the aluminum plate, and the surface of the aluminum plate which was in contact with the mold release film, is analyzed by an X-ray photoelectron spectroscopy to obtain the ratio (F/Al) of fluorine atoms to aluminum atoms,

<Test method B>
On a 3 mm thick first metal plate of a square shape with a size of 15 cm×15 cm, a 100 μm thick aluminum foil of a square shape with a size of 15 cm×15 cm is placed, on the aluminum foil, a 100 mm thick spacer of a square shape with a size of 15 cm×15 cm having a rectangular hole of 10 cm×8 cm opened at its center, is placed, in the vicinity of the center of the hole, 2 g of the following epoxy resin is placed, further thereon, the mold release film of a square shape with a size of 15 cm×15 cm is placed to let the first surface be on the spacer side, and thereon, a 3 mm thick second metal plate of a square shape with a size of 15 cm×15 cm is placed, to prepare a laminated sample; the laminated sample is pressed for 5 minutes under conditions of 180° C. and 10 MPa to cure the epoxy resin; after the pressing, the second metal plate, the mold release film and the spacer are removed, and the surface of the cured product of the epoxy resin that was in contact with the mold release film, is analyzed by an X-ray photoelectron spectroscopy to obtain the ratio (F/(C+F+O)) of fluorine atoms to the sum of carbon atoms, fluorine atoms and oxygen atoms:
Epoxy resin: epoxy granular resin for encapsulating semiconductors, trade name: SUMIKON EME G770H type F ver. GR, manufactured by Sumitomo Bakelite Co., Ltd.

2 . The mold release film according to claim 1 , which has a thickness of from 16 to 200 μm.

3 . The mold release film according to claim 1 , which is a film of a single-layer structure made of the fluororesin.

4 . The mold release film according to claim 1 , wherein the fluororesin is a fluoroolefin type polymer.

5 . The mold release film according to claim 4 , wherein the fluoroolefin type polymer is an ethylene/tetrafluoroethylene copolymer.

6 . The mold release film according to claim 5 , wherein the ethylene/tetrafluoroethylene copolymer comprises units based on tetrafluoroethylene, units based on ethylene and units based on a third monomer other than tetrafluoroethylene and ethylene, and the molar ratio (TFE/E) of the units based on tetrafluoroethylene to the units based on ethylene in the ethylene/tetrafluoroethylene copolymer, is from 80/20 to 40/60.

7 . The mold release film according to claim 5 , wherein the ethylene/tetrafluoroethylene copolymer comprises units based on tetrafluoroethylene, units based on ethylene and units based on a third monomer other than tetrafluoroethylene and ethylene, and in all units in the ethylene/tetrafluoroethylene copolymer, the units based on tetrafluoroethylene are from 40 to 69.7 mol %, the units based on ethylene are from 30 to 59.7 mol %, and the units based on the third monomer are from 0.3 to 1.7 mol %.

8 . The mold release film according to claim 6 , wherein the third monomer is hexafluoropropylene, perfluoro(propyl vinyl ether), (perfluoroethyl) ethylene or (perfluorobutyl) ethylene.

9 . The mold release film according to claim 6 , wherein the third monomer is (perfluorobutyl) ethylene.

10 . The mold release film according to claim 5 , wherein the melt flow rate (MFR) of the ethylene/tetrafluoroethylene copolymer is from 2 to 40 g/10 min.

11 . The mold release film according to claim 4 , wherein the fluoroolefin type polymer is a perfluoro(alkyl vinyl ether)/tetrafluoroethylene copolymer.

12 . The mold release film according to claim 1 , wherein the mold release film is made of a fluororesin film obtained by contacting a fluororesin film with a solvent to reduce components extractable by the solvent.

13 . A process for producing a semiconductor package formed of a semiconductor element and a curable resin and having a resin-encapsulation portion for encapsulating the semiconductor element, which comprises
a step of disposing the mold release film as defined in claim 1 on a cavity surface of a mold to be in contact with the curable resin, so that the first surface faces the space in the cavity, a step of disposing a substrate having a semiconductor element mounted thereon, in the cavity, encapsulating the semiconductor element with the curable resin, and curing the curable resin in such a state that it is in contact with the mold release film, to form a resin-encapsulation portion, thereby to obtain an encapsulated product comprising the substrate, the semiconductor element mounted on the substrate and the resin-encapsulation portion for encapsulating the semiconductor element, and a step of releasing the encapsulated product from the mold.

14 . A process for producing a semiconductor package formed of a semiconductor element and a curable resin and having a resin-encapsulation portion for encapsulating the semiconductor element, and an ink layer formed on the surface of the resin-encapsulation portion, which comprises
of disposing the mold release film as defined in claim 1 on a cavity surface of a mold to be in contact with the curable resin, so that the first surface faces the space in the cavity, a step of disposing a substrate having a semiconductor element mounted thereon, in the cavity, encapsulating the semiconductor element with the curable resin, and curing the curable resin in such a state that it is in contact with the mold release film, to form a resin-encapsulation portion, thereby to obtain an encapsulated product comprising the substrate, the semiconductor element mounted on the substrate and the resin-encapsulation portion for encapsulating the semiconductor element, a step of releasing the encapsulated product from the mold, and a step of forming an ink layer by using an ink, on the surface of the resin-encapsulation portion of the encapsulated product, which was in contact with the mold release film.

Assignees

• Asahi Glass Co Ltd

Inventors

• Kasai Wataru
• Suzuki Masami

Classifications

• H10W90/754

  between a chip and a stacked insulating package substrate, interposer or RDL · CPC title

• H10W74/114

  by a substrate and the encapsulations · CPC title

• H10W74/00

  Encapsulations, e.g. protective coatings · CPC title

• H10W72/0198

  batch processes · CPC title

• H10W74/017 Primary

  Auxiliary layers for moulds, e.g. release layers or layers preventing residue · CPC title