SILICONE-BASED ADHESIVE SHEET, MULTILAYER STRUCTURE INCLUDING SAME, AND METHOD FOR PRODUCING SEMICONDUCTOR DEVICE

Abstract

Provided is: a layered body wherein a sheet surface has slight adhesiveness, enabling easy temporary securing of a semiconductor chip, or the like, that has been diced, onto a semiconductor substrate, and wherein permanent adhesion to an adhered object is expressed through post-curing; a layered body that includes the same; a semiconductor device that uses the same; and a method for manufacturing the semiconductor device. A silicone-based adhesive sheet is disclosed herein, wherein, prior to heating, the delamination mode of the adhesive surface from a non-adhesive substrate is interfacial delamination, and after heating of the adhesive surface in a range of between 50 and 200 C., the delamination mode of the adhesive surface from another non-adhesive substrate changes to cohesive fracturing, and exhibits permanent adhesion.

Claims

1. A silicone-based adhesive sheet wherein, prior to heating, the delamination mode of an adhesive surface with another non-adhesive substrate is interfacial delamination, and wherein, after heating of the adhesive surface in a range of between 50 and 200 C., the delamination mode of the adhesive surface from another non-adhesive substrate changes to cohesive fracturing, and exhibits permanent adhesion.

2. The silicone-based adhesive sheet as set forth in claim 1, wherein: when a texture analyzer is used to lower a stainless steel probe with a diameter of 8 mm at a rate of 0.01 mm/s in respect to any surface of the sheet, to apply a load of 50 gf, followed by raising the probe at a rate of 0.5 mm/s after holding the load for 0.5 seconds, the adhesive sheet undergoes interfacial delamination from the probe, and the adhesive strength exhibits a maximum value, and, furthermore, when the surface that exhibited the maximum value for the adhesive strength is further heated for three hours in a range of between 100 and 200 C., the delamination mode of the adhesive surface from another non-adhesive substrate changes to cohesive fracturing, and exhibits permanent adhesion.

3. The silicone-based adhesive sheet as set forth in claim 1, wherein: the maximum value for the adhesive strength is a value of no less than 10 gf.

4. The silicone-based adhesive sheet as set forth in claim 1, wherein: the thickness of the sheet is in a range of between 5 and 1000 m.

5. The silicone-based adhesive sheet as set forth in claim 1, wherein: the sheet is held between substrates having releaseability in respect to the sheet, where at least one substrate has an oxygen atom or a sulfur atom on a surface that contacts the sheet.

6. The silicone-based adhesive sheet as set forth in claim 5, wherein: the silicone-based adhesive sheet is a cross-linked material of a cross-linkable silicone composition, where the composition is cross-linked between substrates that have releaseability in respect to the cross-linked material, and wherein at least one of the substrates has an oxygen atom or a sulfur atom on the surface that contacts the composition.

7. The silicone-based adhesive sheet as set forth in claim 5, wherein: the substrate is a sheet-shaped substrate made from an organic resin, wherein the oxygen atom is an atom for structuring a group that is selected from a set comprising carbonyl groups, alkoxy groups, ester groups, and ether groups, and the sulfur atom is an atom for structuring a group that is selected from a set comprising sulfone groups and thioether groups.

8. The silicone-based adhesive sheet as set forth in claim 1, being a cross-linked material of a cross-linkable silicone composition the composition comprising: (A) an organopolysiloxane that includes at least two silicon atom-bonded alkenyl groups in a single molecule; (B) an organopolysiloxane that includes at least two silicon-bonded hydrogen atoms in a single molecule; (C) at least one type of adhesion promoting agent; and (D) a hydrosilylation reaction catalyst.

9. The silicone-based adhesive sheet as set forth in claim 1, wherein: a semiconductor chip or a wafer for semiconductors is bonded to an attaching portion thereof.

10. A layered body that includes the silicone-based adhesive sheet as set forth in claim 1.

11. The layered body as set forth in claim 10, being a die attach film for a semiconductor chip or for a wafer for semiconductors.

12. The layered body as set forth in claim 11, having a structure wherein the semiconductor chip or the wafer for semiconductors is disposed on a substrate with the silicone-based adhesive sheet interposed therebetween.

13. A semiconductor device having a structure wherein a semiconductor chip or a wafer for a semiconductor is secured on the substrate through a cured material of the silicone-based adhesive sheet of claim 1.

14. The semiconductor device as set forth in claim 13, being a micro-electromechanical system (MEMS) device.

15. A method for manufacturing a semiconductor, the method comprising the following steps: 1) layering the silicone-based adhesive sheet set forth in claim 1 on the back face of a wafer for a semiconductor; 2) forming individual pieces through dicing the layered body obtained in Step 1); 3) arranging, on a semiconductor substrate, with the surface of the silicone-based adhesive sheet interposed therebetween, the pieces of the wafer for the semiconductor, obtained in Step 2); and 4) heating, in a range of between 50 and 200 C., the structural unit, produced in Step 3), wherein the individual pieces of the wafer for the semiconductor are disposed on the semiconductor substrate, with the surface of the silicone-based adhesive sheet interposed therebetween, to bond the pieces of the wafer for the semiconductor onto the top of the semiconductor substrate through the silicone-based adhesive sheet.

16. A method for manufacturing a semiconductor device, the method comprising the following steps: 1) dividing the silicone-based adhesive sheet set forth in claim 1 through claim 9, into individual pieces of a size that approximates that of a semiconductor chip; 2) disposing, on a semiconductor substrate, the silicone-based adhesive sheet that has been divided into individual pieces in Step 1); 3) disposing a semiconductor chip onto the silicone-based adhesive sheet that has been divided into individual pieces, disposed on the semiconductor substrate in Step 2); and 4) heating, in a range of between 50 and 200 C., the structural unit, obtained in Step 3), wherein a semiconductor chip is disposed on the semiconductor substrate, with the silicone-based adhesive sheet interposed therebetween, to bond the semiconductor chip onto the top of the semiconductor substrate through the silicone-based adhesive sheet.

17. The method for manufacturing a semiconductor device as set forth in claim 15, wherein: the semiconductor device is a micro electro mechanical system (MEMS) device.

18. The method for manufacturing a semiconductor device as set forth in claim 16, wherein: the semiconductor device is a micro electro mechanical system (MEMS) device.

Description

EMBODIMENTS

[0099] The silicone-based adhesive sheet and manufacturing method thereof, and semiconductor device, according to the present invention, will be explained in detail through embodiments and reference examples, but the present invention is not limited thereto. Note that in the embodiments the viscosity is a value measured at 25 C., and the adhesiveness of the silicone-based adhesive sheet, and the state of the surface of the sheet, are evaluated, as described below, using a texture analyzer (model TAXT plus, manufactured by Eco Instruments Company, Limited).

Embodiments 1 Through 5 and Reference Examples 1 Through 4

[0100] While embodiments will be used below to explain the present invention, the present invention is not limited thereby. The compounds and compositions below are used as raw materials in Embodiments 1 through 5 and in Reference Examples 1 and 2, given below. Note that in Reference Examples 3 and 4, commercially available silicone adhesive agent products are used as-is.

[Components of the Curable Organopolysiloxane Composition]

[0101] (A1) Dimethyl polysiloxane blocked with dimethylvinyl siloxy groups on both ends of the molecular chain, with a viscosity of 2000 mPa.Math.s (inclusion proportion of vinyl groups=0.23% by weight)

[0102] (A2) Dimethyl polysiloxane blocked with dimethylvinyl siloxy groups on both ends of the molecular chain, with a viscosity of 40,000 mPa.Math.s (inclusion proportion of vinyl groups=0.08% by weight)

[0103] (A3) Dimethyl polysiloxane blocked with dimethylvinyl siloxy groups on both ends of the molecular chain, with a viscosity of 400 mPa.Math.s (inclusion proportion of vinyl groups=0.44% by weight)

[0104] (A4) Dimethyl polysiloxane blocked with dimethylvinyl siloxy groups on both ends of the molecular chain, with a viscosity of 80 mPa.Math.s (inclusion proportion of vinyl groups=1.50% by weight)

[0105] (A5) A silicone resin polysiloxane mixture comprising 70% by weight dimethyl polysiloxane blocked with dimethylvinyl siloxy groups on both ends of the molecular chain, with a viscosity of 2000 mPa.Math.s (inclusion proportion of vinyl groups=0.23% by weight) and 30% by weight of an organopolysiloxane resin structured from SiO.sub.4/2 units, (CH.sub.3).sub.3SiO.sub.1/2 units, and (CH.sub.3).sub.2(CH.sub.2CH)SiO.sub.1/2 units (inclusion proportion of vinyl groups=2.5% by weight)

[0106] (A6) A silicone resin polysiloxane mixture comprising 50 parts by weight dimethyl polysiloxane blocked with dimethylvinyl siloxy groups on both ends of the molecular chain, with a viscosity of 20,000 mPa.Math.s (inclusion proportion of vinyl groups=1.75% by weight) and 50% by weight of an organopolysiloxane resin structured from SiO.sub.4/2 units, (CH.sub.3).sub.3SiO.sub.1/2 units, and (CH.sub.3).sub.2(CH.sub.2CH)SiO.sub.1/2 units (inclusion proportion of vinyl groups=4.1% by weight)

[0107] (A7) A silicone resin polysiloxane mixture comprising 20 parts by weight dimethyl polysiloxane blocked with dimethylvinyl siloxy groups on both ends of the molecular chain, with a viscosity of 80 mPa.Math.s (inclusion proportion of vinyl groups=1.50% by weight) and 80% by weight of an organopolysiloxane resin structured from SiO.sub.4/2 units, (CH.sub.3).sub.3SiO.sub.1/2 units, and (CH.sub.3).sub.2(CH.sub.2CH)SiO.sub.1/2 units (inclusion proportion of vinyl groups=3.0% by weight)

[0108] (A8) A mixture of 80 parts by weight dimethyl polysiloxane blocked with dimethylvinyl siloxy groups on both ends of the molecular chain, with a viscosity of 2000 mPa.Math.s (inclusion proportion of vinyl groups=0.23% by weight) and 20 parts by weight of a fumed silica that has a screened surface area of 200 m.sup.2/g, through the BET method

[0109] (B1) A copolymer of methyl hydrogen siloxane and dimethyl siloxane blocked with trimethyl siloxy groups on both ends of the molecular chain, with a viscosity of 60 mPa.Math.s (silicon atom-bonded hydrogen atom inclusion proportion=0.7% by weight)

[0110] (B2) Dimethyl siloxane blocked with dimethyl hydrogen siloxy groups on both ends of the molecular chain, with a viscosity of 15 mPa.Math.s (silicon atom-bonded hydrogen atom inclusion proportion=0.12% by weight)

[0111] (B3) Methyl hydrogen polysiloxane blocked with trimethyl siloxy groups on both ends of the molecular chain, with a viscosity of 23 mPa.Math.s (silicon atom-bonded hydrogen atom inclusion proportion=1.55% by weight)

[0112] (B4) An organo polysiloxane resin with a viscosity of 25 mPa.Math.s made from SiO.sub.4/2 units and H(CH.sub.3).sub.2SiO.sub.1/2 units (silicon atom-bonded hydrogen atom inclusion proportion=0.97% by weight)

[0113] (C1) An adhesion imparting agent that is a condensation reaction product, with a mass ratio of 1:1 of a copolymer of methylvinyl siloxane-dimethyl siloxane blocked with hydroxyl groups at both ends of the molecular chain, with a viscosity of 30 mPa.Math.s, and 3-glycidoxy propyltrimethoxy silane

[0114] (D) A complex of platinum and 1,3-divinyl-1,1,3,3-tetramethyl disiloxane, with a platinum density of 0.6% by weight

[0115] (E) Components as reaction controlling agents: [0116] (E1) Ethynyl cyclohexanol [0117] (E2) 1,3,5,7-tetramethyl-1,3,5,7-tetravinyl cyclotetrasiloxane

[Preparation of the Curable Organopolysiloxane Composition and Silicone-Based Adhesive Sheet]

[0118] Each of the components listed above was mixed uniformly, except for the component (D), with the weight ratios (parts by weight) described in Table 1, below, and finally the component (D) was mixed with the weight ratios (parts by weight) described in Table 1. After vacuum degassing of the composition, it was held between the polyether sulfone resin films with thicknesses of 50 m, the thicknesses of the compositions were adjusted so as to be 80 m, through two stainless steel rollers for which the clearance had been set, and each composition was cross-linked through heating for 30 minutes in a hot air recirculating oven at 100 C. to produce the silicone-based adhesive sheets of Embodiments 1 through 5 and of Reference Examples 1 and 2. Note that the numbers of moles of the silicon atom-bonded atoms (SiH), in respect to one mole of the vinyl groups (Vi) in the composition, are expressed as mole ratios in Table 1.

TABLE-US-00001 TABLE 1 Component Test Example (parts by Embodiments Reference Examples weight) 1 2 3 4 5 1 2 A1 22.4 4.0 7.5 3.0 A2 5.2 31.1 A3 61.8 43.0 A4 5.0 6.6 20.0 A5 50.9 A6 27.7 A7 80.5 A8 75.1 39.1 59.1 25.0 25.0 30.0 B1 1.8 4.2 3.5 6.4 1.3 B2 14.7 B3 12.0 4.4 B4 9.3 C1 0.5 0.5 2.2 1.0 1.0 1.0 1.0 D 0.2 0.2 0.2 0.2 0.2 0.2 0.2 E1 0.01 0.01 0.01 0.14 0.20 0.08 0.10 E2 0.5 0.5 6.0 4.5 H/Vi 1.5 1.5 3 1.8 1.1 1.7 1.1 (Mole Ratio)

Reference Example 3

[0119] A silicon film with a thickness of 80 m was produced through coating silicone adhesive agent SD4580 FC, manufactured by Toray-Dow Corning, to a thickness of 50 m on a PET film, and thermally curing for five minutes at 120 C.

Reference Example 4

[0120] A silicon film with a thickness of 80 m was produced through coating silicone adhesive agent SD4584 FC, manufactured by Toray-Dow Corning, to a thickness of 50 m on a PET film, and thermally curing for five minutes at 120 C.

[0121] The surface characteristics of the silicone-based adhesive sheets according to the embodiments and according to reference examples, the temporary securing properties thereof, and the permanent adhesion (=bonding) thereof, were evaluated through the methods described above, and the results are given in Table 2.

[Surface Tackiness of the Silicone-Based Adhesive Sheets]

[0122] Test bodies were manufactured by adhering the silicone-based adhesive sheets (20 mm20 mm) onto glass (25 mm75 mm) using double-sided tape for silicone (5302A, manufactured by Nitto Denko). A stainless steel probe with a diameter of 8 mm of a texture analyzer was lowered at a rate of 0.01 mm/s in respect to the sheet surface, and after applying a load of 50 gf, the load was held for 0.5 seconds, after which the probe was raised at a rate of 0.5 mm/s. The stress applied to the probe when raising was measured. Those wherein a maximum value was produced during measurement were defined as Has maximum value, and those wherein no maximum value was produced were defined as No maximum value, and the maximum value for those wherein a value is produced during measurement was defined as the tackiness (go. Note that for those siliconic adhesive sheets that had maximum values, all of the adhesive sheets had interfacial delamination from the probe, and did not produce the residual paste that would accompany cohesive fracturing of the adhesive layer.

[Silicon Chip Temporary Securing Performance Test]

[0123] 2 mm-square silicon chips (with a thickness of 625 m) were placed onto the silicone-based adhesive sheets that were affixed to glass and a load of 50 gf was applied for 0.5 seconds at 25 C. using a die attached press. The units were then dropped naturally from a vertical height of 100 mm within five minutes thereafter. Those wherein the silicon chips became detached from the silicone-based adhesive sheets surface were scored as x, and those wherein they remained secured to the sheet were scored as . Moreover, the silicon chips that remained held on the sheet were easily removed through interfacial delamination using stainless steel tweezers.

[Adhesiveness of Silicone-based Adhesive Sheet]

[0124] After adhering a silicone-based adhesive sheet (5 mm20 mm) onto a silicon wafer (30 mm30 mm), heating was carried out for five minutes at 130 C. in a die press at 3 kgf, to manufacture test bodies by bonding the film to the substrate. Through peeling the silicone-based adhesive sheets in these test bodies using stainless steel tweezers, the adhesive of the films, in respect to the substrate, were evaluated using the following standards:

[0125] : Paste residual accompanying cohesive fracturing of the adhesive layer was produced on more than half of the adhered surface when peeling the adhered surface after heating.

[0126] X: Delamination was at the interface with the adhered object, without cohesive fracturing of the adhesive layer, with the exception of a trivial transferred component, on the adhesive surface when the adhesive surface was peeled after heating.

TABLE-US-00002 TABLE 2 Reference Embodiments Examples 1 2 3 4 5 1 2 3 4 Silicone Film Surface Tackiness Had maximum Yes Yes Yes Yes Yes No No Yes Yes value? Tackiness (gf) 199 172 211 125 346 0.2 0.2 794 480 Silicon Chip Temporary Securing Performance Test Temporary x x securing performance Silicone Film Adhesiveness Adhesion after x x x x heating for five minutes at 130 C.

CONCLUSION

[0127] As can be appreciated from the test results for Embodiments 1 through 5 and Reference Examples 1 through 2, the silicone-based adhesive sheets that exhibited behavior wherein the delamination mode in the surface tackiness performance testing was interfacial delamination, and had a maximum value, also had superior temporary securing performance for silicon chips and had the property of expressing permanent bonding, after heating at heating conditions of no more than three hours in a range of between 100 and 200 C. On their hand, while, as in Reference Examples 3 and 4, the silicone adhesive agents exhibited good temporary securing performance, they did not exhibit permanent adhesion after heating, as in the silicone-based adhesive sheet according to the present application, so they cannot improve the manufacturing efficiency for small high-precision semiconductor devices such as MEMS devices. Moreover, in Reference Examples 1 and 2, the surface tackiness was inadequate, and thus would be difficult to use for temporarily securing or temporary placement of silicon chips.