Method for the bonding and debonding of substrates

Abstract

This invention relates to a method for bonding a product substrate (2) to a carrier substrate (5) via a connecting layer (4), wherein a soluble layer (3) is applied between the connecting layer (4) and the product substrate (2), and wherein a) the soluble layer (3) is soluble by interaction with electromagnetic radiation from a radiation source, and b) the connecting layer (4) and the carrier substrate (5) are at least substantially transparent to the electromagnetic radiation system. Furthermore, this invention relates to a method for bonding a product substrate (2) from a carrier substrate (5) bonded to the product substrate (2) via a connecting layer (4), wherein a soluble layer (3) is applied between the connecting layer (4) and the product substrate (2), and wherein a) the soluble layer (3) is soluble by interaction with electromagnetic radiation from a radiation source, and b) the connecting layer (4) and the carrier substrate (5) are at least substantially transparent to the electromagnetic radiation system. Additionally, this invention relates to the bonding of a corresponding product substrate to a carrier substrate.

Description

Technical Field

[0001] The present invention relates to a method for bonding a product substrate to a carrier substrate via a connecting layer according to technical solution 1, a method for bonding a product substrate from a carrier substrate bonded to the product substrate via a connecting layer according to technical solution 2, and a bonding of a product substrate to a carrier substrate according to technical solution 9. Prior Technology

[0002] Currently, there are many known methods for debonding / separating two substrates (product substrate and carrier substrate). Most methods use so-called bonding adhesives to achieve a temporary bond between the two substrates, which can be easily released. These bonding adhesives are typically polymers, specifically thermoplastics.

[0003] The first method for temporary bonding involves coating the entire surface of a substrate. A second substrate is attached to the first substrate by a bonding operation. Separation of the two substrates (i.e., debonding) is achieved by a shearing process at a high temperature. This temperature is preferably higher than the glass transition temperature of the bonding adhesive. Due to the applied shear force, the two substrates can be moved relative to each other in a very slow process and thus separated from each other.

[0004] A second method for temporary bonding involves treating specific surface areas of the carrier substrate to minimize (or completely eliminate) the adhesion between these surface areas and the bonding adhesive. Besides these specifically treated surface areas, a very small untreated surface area remains. This highly adhesive surface area is typically a circumference a few millimeters thick. After this specific treatment, the carrier substrate is coated with the bonding adhesive over its entire surface. Then, the normal bonding operation is performed. The debonding operation is typically carried out chemically, where the edges of the bonding adhesive are debonded, thereby reducing the adhesive force between the bonding adhesive and the carrier substrate. Thereafter, the carrier substrate can be detached from the product substrate very easily.

[0005] Another method for separating two substrates involves applying a special soluble layer to a transparent carrier substrate before applying the bonding adhesive. Because the carrier substrate is transparent to a specific electromagnetic radiation system, photons are allowed to enter the soluble layer unimpeded. These photons cause a change in the soluble layer, reducing the adhesive force on the bonding adhesive. This method is described in WO2014058601A1, in which a UV laser is emitted onto the soluble layer inside the carrier substrate to induce a reaction there, causing the bonding adhesive to separate from the carrier substrate and thus the carrier substrate to separate from the product substrate. Summary of the Invention

[0006] The present invention relates to a method for bonding a product substrate to a carrier substrate via a connecting layer according to technical solution 1, a method for bonding a product substrate from a carrier substrate bonded to the product substrate via a connecting layer according to technical solution 2, and a bonding of a product substrate to a carrier substrate according to technical solution 9. Simple Explanation of the Diagram

[0007] Other advantages, features, and details of the present invention are disclosed in the following description of preferred embodiments and drawings, wherein: Figure 1a shows a schematic diagram (not to scale) of a first embodiment of the bonding between the product substrate and the carrier substrate. Figure 1b shows a schematic diagram (not to scale) of one embodiment of an inventive method for separating the bonding of the product substrate to the carrier substrate according to Figure 1a. Figure 2a shows a schematic diagram (not to scale) of a second embodiment of the bonding between the product substrate and the carrier substrate. Figure 2b shows a schematic diagram (not to scale) of one embodiment of the inventive method for separating the bonding of the product substrate to the carrier substrate according to Figure 2a. Figure 3 shows a schematic diagram (not to scale) of a third embodiment of the bonding between the product substrate and the carrier substrate. Figure 4 shows a schematic diagram of the first absorption graph (absorbance = absorption) (not to scale) and Figure 5 shows a schematic diagram of the second absorption graph (absorbance = absorption) (not at scale). In the diagram, components that are identical or have the same function are marked with the same reference symbol. Implementation

[0008] The present invention aims to provide a method and an apparatus for optimizing the joining and unjoining / separating process and thereby simplifying subsequent method steps.

[0009] This requirement is achieved by the features of technical solutions 1, 2, and 9. Other advantageous developments of the invention are referenced in the sub-technical solutions. The scope of the invention also covers all combinations of at least two features indicated in the specification, claims, and / or drawings. In the case of indicated value ranges, values ​​falling within the referenced limits should be considered as disclosed as threshold values ​​and can be claimed in any random combination.

[0010] The basic concept of this invention is to propose a method and an apparatus by which a product substrate to a carrier substrate can be bonded, wherein the two can be connected via a bonding layer that is at least primarily transparent to electromagnetic radiation, wherein a soluble layer is disposed between the bonding layer and the product substrate, the soluble layer being designed to dissolve due to interaction with electromagnetic radiation from a radiation source.

[0011] Regarding the method, the present invention can be implemented during the joining process by applying the following features / steps: a) The soluble layer can dissolve due to its interaction with the electromagnetic radiation from the radiation source, and b) Both the connecting layer and the carrier substrate are at least primarily transparent to the electromagnetic radiation.

[0012] Regarding the method, the present invention can be implemented during debonding by (specifically) applying the following features / steps: a) The soluble layer (3) dissolves due to its interaction with the electromagnetic radiation from the radiation source, and b) Both the connecting layer (4) and the carrier substrate (5) are at least primarily transparent to the electromagnetic radiation.

[0013] Regarding the device, the present invention can be implemented (specifically) by means of the following features: a) The soluble layer can dissolve due to its interaction with the electromagnetic radiation from the radiation source, and b) Both the connecting layer (4) and the carrier substrate (5) are at least primarily transparent to the electromagnetic radiation.

[0014] One particularly independent core aspect of this invention lies in the use of a bonding adhesive (connecting layer) that has a low absorption coefficient in the wavelength range of electromagnetic radiation (specifically, laser). This absorption coefficient (here, specifically, a linear absorption coefficient) is preferably normalized to mass density. Mass absorption coefficients thus obtained can then be compared with each other. For elements used in Roentgen radiation and some organic compounds, data can be obtained from the NIST X-ray attenuation database (…). [http: / / www.nist.gov / pml / data / xraycoef]) Obtain the mass absorption coefficient. Since the mass absorption coefficient is highly wavelength-dependent, the following indicates wavelength and mass absorption coefficient ranges for some pure elements and some organic compounds (specifically, polymers). Material Energy range wavelength range Mass absorption coefficient range 1 MeV Nm cm2 / g lead 10-6-102 1240 - 1.2 * 10⁻⁵ 10-2-105 polystyrene 10-6-102 1240 - 1.2 * 10⁻⁵ 10-2-105 PMMA 10-6-102 1240 - 1.2 * 10⁻⁵ 10-2-105 Polytetrafluoroethylene (Teflon) 10-6-102 1240 - 1.2 * 10⁻⁵ 10-2-105 MyLAR 10-6-102 1240 - 1.2 * 10⁻⁵ 10-2-105 polyethylene 10-6-102 1240 - 1.2 * 10⁻⁵ 10-2-105

[0015] The range of mass absorption coefficient values ​​in the NIST X-ray attenuation database refers to a MeV definition range between 10⁻³ MeV and 10² MeV. This definition range does not allow for any direct reading of the mass absorption coefficient in the UV range, as this UV range falls within the 10⁻⁵ MeV definition range. However, the range of mass absorption coefficient values ​​for carbon, nitrogen, and oxygen in the desired UV range is known from US5965065A. Carbon is a major component, especially in organic polymers. Although the mass absorption coefficient of a compound cannot be automatically deduced from the mass absorption coefficient of a pure component, at least the range of values ​​for the compound's mass absorption coefficient can be estimated. From all this information, it is known that the mass absorption coefficient of the compound according to the present invention varies between approximately 10⁻² and 10⁵ cm² / g within the energy definition range of 10⁻⁶ to 10² MeV. This is a range of values ​​to the power of 10. US5965065A also shows that the mass absorption coefficient of carbon varies from 1000 cm² / g to 10⁻⁶ cm² / g within a power of 10 from 1000 eV to 100 eV. Furthermore, an absorption edge for carbon can be identified at approximately 300 eV. All this data reveals that small variations in energy or wavelength range can cause large changes in the absorption properties of a material. Therefore, assigning a single value to the mass absorption coefficient for a single material (specifically, for all possible materials according to the invention) is impossible and ineffective.

[0016] Therefore, according to the present invention, a soluble layer can be applied to a product substrate rather than a carrier substrate. Due to the low absorption of electromagnetic radiation by the bonding adhesive, sufficient photons reach the soluble layer to initiate a separation or debonding operation thereon.

[0017] This invention also relates to an apparatus and method for joining or separating two substrates using an electromagnetic photon source (specifically, a laser). Specifically, the basic concept of this invention is to direct (or specifically focus) electromagnetic radiation onto a soluble layer to reduce adhesion between the product substrate and the carrier substrate. The electromagnetic radiation passes through the adhesive that connects the two substrates without heating them.

[0018] Therefore, the concept of the present invention (specifically) lies in the use of a specially matched combination of bonding adhesives, electromagnetic radiation and soluble layers.

[0019] One particular advantage of this invention is that the soluble layer can be applied to the product substrate. Therefore, the soluble layer is located between the product substrate and the bonding layer. If the adhesion of the soluble layer weakens due to irradiation with electromagnetic radiation (specifically, laser), the product substrate can be directly (specifically, automatically) separated from the bonding adhesive. Therefore, the product substrate is preferably released from the bonding adhesive immediately after separation without any chemical cleaning.

[0020] The soluble layer is preferably designed in a way that it is completely destroyed (specifically, sublimated during the period of negative impact of the invention).

[0021] Electromagnetic radiation interacts with the electrons of materials. This interaction is attributed to the fact that alternating electromagnetic magnetic fields can induce vibrations in charged electrons. Positively charged nuclei have much larger masses and are therefore more inert relative to the electron system. Consequently, the movement of the nucleus is negligible most of the time.

[0022] An alternating electromagnetic magnetic field can produce different physical effects in solid objects (specifically, in molecules) independently of its frequency. Since the inventive concept in the patent specification mainly involves polymers, from now on, the physical effects will be described using molecules (specifically, polymers).

[0023] A molecule, or a part of a molecule, under certain conditions, can absorb photons and convert the photon energy into vibrational and / or rotational and / or positional energy. For this energy conversion to occur, the photons must have a specific frequency. The resulting new energy state is subsequently degraded again by emitting photons of the corresponding wavelength. This constant absorption and release of photons, the associated energy conversion, and the energy distribution among the individual degrees of freedom of the molecule are governed by statistical methods not discussed in detail herein.

[0024] Electromagnetic radiation in the microwave and infrared range primarily stimulates molecular rotation. Electromagnetic radiation in the infrared range better stimulates molecular vibration. There are two different types of vibration: valence (stretching?) vibrations and deformation vibrations. The former ensures that two atoms in the molecule vibrate along their isobond axes, while the second type of vibration occurs between at least three atoms in the molecule, resulting in changes in bond angles.

[0025] Photons from electromagnetic radiation in the UV wavelength range possess enough energy to elevate individual electrons in a molecular structure to higher molecular orbitals or even to detach electrons from their molecular bonds, thus ionizing the molecule. The excited electrons are (specifically) valence electrons, and therefore electrons located in the outermost molecular orbitals. The removal of nuclear electrons obviously requires much higher photon energy, specifically in the roentgen wavelength range. Transmission is highest in that wavelength range, where it is possible for no electron to be excited from the highest occupied molecular orbital (HOMO) to the lowest occupied molecular orbital (LUMO). Since electrons cannot be elevated from the HOMO to the LUMO, photons cannot interact with electrons, and therefore these photons pass unimpeded through solid objects, specifically polymers, and preferably adhesives.

[0026] Therefore, molecular orbital theory has suggested permissible chemical structures for the bonding adhesives according to the present invention. [Radiation source] [,] [Special Message by Photon] [source] [ ]

[0027] According to the present invention, (specifically) a photon source is used as a radiation source.

[0028] Therefore, this source is primarily (preferably only) a photon source. Specifically, this photon source radiates at least primarily, and preferably entirely, within one or more of the following wavelength ranges: — Microwave, 300 mm to 1 mm, — Infrared, specifically Near-infrared, 0.78 μm to 3.0 μm o Mid-infrared, 3.0 μm to 50 μm, o Far-infrared rays, 50 μm to 1000 μm, — Visible light 380 nm to 780 nm, — UV light, specifically o Near-UV light, 360 nm to 315 nm, o Mid-UV light, 315 nm to 280 nm, o Far UV light, 280 nm to 200 nm, o Vacuum UV, 200 nm to 100 nm, o Extreme UV light, 121 nm to 10 nm, — X-ray light, 0.25 nm to 0.001 nm.

[0029] The following wavelength ranges are preferred: 1000 μm to 10 nm, more preferably 780 nm to 100 nm, and most preferably 370 nm to 200 nm.

[0030] It is also possible to use a source that can generate two different wavelength ranges. In this case, all the inventive conditions apply to the individual wavelengths. A combination of UV and IR light would be particularly preferred. IR light is primarily used to heat the soluble layer, while UV light is primarily used to decompose covalent compounds. In this combination, the inventive adhesive must contain low absorption in both wavelength ranges.

[0031] According to the present invention, the coherent photon source is preferably, at least primarily (preferably, only), specifically, a microwave source, preferably a laser, or a laser configured as a coherent photon source for visible light, UV light, and X-ray light.

[0032] The photon source can operate in continuous mode or (preferably) pulsed mode. The pulse duration is specifically less than 1 s, preferably less than 1 ms, more preferably less than 1 μs, and most preferably less than 1 ns. The time between two consecutive pulses is preferably greater than 1 ms, more preferably greater than 100 ms, and most preferably greater than 1 s.

[0033] The wavelength of the photon source is specifically selected such that the photon stream can radiate through the bonding layer (specifically, through the bonding adhesive) at least primarily, preferably completely, without any visible loss due to absorption.

[0034] The absorption of photons through the bonding layer is specifically less than 50%, preferably less than 25%, more preferably less than 10%, most preferably less than 1%, and most preferably less than 0.1%. Therefore, the transmission of photons through the bonding layer will specifically be greater than 50%, preferably greater than 75%, more preferably greater than 90%, most preferably greater than 99%, and most preferably greater than 99.9%. The absorption value is relative to the layer thickness and is selected based on material properties and the requirements of the product wafer.

[0035] Specifically, the properties of the bonding layer and the photon source / electromagnetic radiation are selected (specifically, by selecting the materials themselves) and / or adjusted so that the bonding layer is not significantly heated. Specifically, heating is less than 50°C, preferably less than 25°C, more preferably less than 10°C, most preferably less than 1°C, and very preferably less than 0.1°C. Specifically, heating can be substantially eliminated by using a photon source with an electromagnetic wavelength range that does not excite the vibrational or rotational degrees of freedom of the molecules in the bonding layer. To prevent heating, it is preferable to combine electromagnetic radiation in the UV-VIS wavelength range with a bonding layer that is transparent to UV-VIS.

[0036] The radiation source (specifically, an electromagnetic photon source) according to the present invention will now be described as a preferred embodiment, in which case it is a laser. Alternatively, the radiation source mentioned above can be used instead of a laser.

[0037] Quantitative analysis of the transparency of solid objects (specifically polymers, preferably the bonding layer according to the present invention) is performed using a UV-VIS spectrometer. A UV-VIS spectrometer describes the transmission of photons at a specific wavelength as a function of wavelength. [Carrier Substrate] [ ]

[0038] Regarding a preferred embodiment of the carrier substrate, the most important factor is its transparency to the wavelength of the laser used (electromagnetic radiation according to the invention). According to the invention, the carrier substrate is responsible for coupling the laser beam to the substrate stack (the junction of the product substrate and the carrier substrate) such that the product substrate (specifically, if functional (metallic) units and / or protrusions are present) is at least primarily opaque to the wavelength of the laser. The carrier substrate is preferably selected from materials that will not reduce the intensity of the laser beam to any visible level. The carrier substrate (specifically, primarily, preferably entirely) consists of one or more of the following materials: o glass o Mineral, specifically sapphire o Semiconductor materials, specifically polysiloxane o polymer o Composite materials

[0039] According to the present invention, glass is a preferred material for carrier substrates.

[0040] The thickness of the carrier substrate is selected to be sufficiently large to ensure that the product substrate is sufficiently stable (specifically, bonded to the bonding layer).

[0041] The thickness of the carrier substrate is specifically greater than 100 μm, preferably greater than 500 μm, more preferably greater than 1000 μm, most preferably greater than 1500 μm, and most preferably greater than 2000 μm.

[0042] At the same time, the thickness should be chosen to be as small as possible so that the intensity of the laser beam is reduced as little as possible. The thickness of the carrier substrate is specifically less than 2000 μm, preferably less than 1750 μm, more preferably less than 1500 μm, most preferably less than 1250 μm, and most preferably less than 900 μm. [Connection Layer] [,] [Specifically, a bonding adhesive] [ ]

[0043] The bonding adhesive is selected from one or more of the following materials: — Polymers, specifically Inorganic polymers are preferred. ▪ Polyphosphazene, ▪ Polysiloxane, Polysiloxane ▪ Polysilane, o Organic polymers, specifically ▪ Acrylic esters, styrene, acrylonitrile Acrylonitrile / methyl methacrylate, ▪ Acrylonitrile / butadiene / acrylate ▪ Acrylonitrile / chlorinated polyethylene / styrene Acrylonitrile-butadiene-styrene, ▪ Acrylic polymers, ▪ Alkyd resin, ▪ Butadiene rubber, ▪ Butyl rubber, Casein plastic, artificial horns ▪ Cellulose acetate ▪ Cellulose esters and their derivatives ▪ Hydrated cellulose, ▪ Nitrocellulose, ▪ Chitin, chitosan ▪ Chlorpine rubber, ▪ Cyclic olefin copolymers, ▪ Standardized polyvinyl chloride, ▪ Epoxy resin, ▪ Ethylene acrylate copolymer, ▪ Ethylene polyvinyl acetate ▪ Ethylene-propylene copolymer, ▪ Ethylenepropylene diene rubber, ▪ Vinyl acetate, Expandable polystyrene, ▪ Fluorinated rubber, ▪ Urea-formaldehyde resin, ▪ Urea resin, ▪ Isoprene rubber, ▪ Lignin, ▪ Melamine-formaldehyde resin, ▪ Melamine resin, ▪ Methyl acrylate / butadiene / styrene ▪ Natural rubber, ▪ Perfluoroalkoxyalkanes, ▪ Phenolic formaldehyde resin, ▪ Polyacetal, ▪ Polyacrylonitrile, ▪ Polyamide, ▪ Polybutylene succinate, ▪ Polybutylene terephthalate (PET) ▪ Polycaprolactone, ▪ Polycarbonate, ▪ Polychlorotrifluoroethylene ▪ Polyester ▪ Polyesteramide, ▪ Polyester alcohol, ▪ Polyester block amide, ▪ Polyesterimide, ▪ Polyester, ▪ Polyester styrene, ▪ Polyester, ▪ Polyester terephthalate, ▪ Polyhydroxyalkanoates, ▪ Polyhydroxybutyrate, ▪ Polyimide, ▪ Polyisobutylene, ▪ Polylactic acid, ▪ Polymethacrylamide methyl methamide ▪ Polymethyl methacrylate, ▪ Polymethylpentene, ▪ Polyoxymethylene or polyacetal ▪ Polyphenylene ether, ▪ Polyphenylenesulfide ▪ Poly(phthalamide) ▪ Polypropylene ▪ Polypropylene copolymer, ▪ Polypyrrole, ▪ Polystyrene, ▪ Gathering stones, ▪ Polytetrafluoroethylene (PTFE) ▪ Polypropylene terephthalate (PPT) ▪ Polyurethane, ▪ Polyvinyl acetate, ▪ Polyvinyl butyral, ▪ Polyvinyl chloride (rigid PVC) ▪ Polyvinyl chloride (flexible PVC) ▪ Polyvinylidene fluoride, ▪ Polyvinylpyrrolidone ▪ Styrene-acrylonitrile copolymer, ▪ Styrene-butadiene rubber, ▪ Styrene-butadiene-styrene Synthetic rubber, ▪ Thermoplastic polyurethane, ▪ Unsaturated polyester, ▪ Vinyl acetate copolymer, ▪ Vinyl chloride / ethylene / methacrylate ▪ Vinyl chloride / ethylene ▪ Vinyl chloride-vinyl acetate copolymer, ▪ Softened polyvinyl chloride.

[0044] In particular, inorganic polymers (such as polysiloxane) have relatively high transparency to a wide range of wavelengths of lasers used as radiation sources (preferably lasers according to the invention), and are therefore preferred as bonding adhesives according to the invention.

[0045] The bonding adhesive is preferably applied using the following methods and steps: In the first step, a bonding adhesive is applied by means of a spin coating process. In the second step, a heat treatment is performed to remove any solvent. The heat treatment temperature is specifically above 50°C, preferably above 75°C, more preferably above 100°C, most preferably above 100°C, and very preferably above 150°C. Preferably, the heat treatment temperature is below 500°C. [Soluble layer] [ ]

[0046] The soluble layer may be composed of any random material, which, at least on one side of the soluble layer, preferably facing the product substrate, causes reduced adhesion under the influence of the described electromagnetic radiation. Specifically, the soluble layer according to the invention completely sublimates under the influence of electromagnetic radiation.

[0047] According to a particular embodiment of the present invention, the soluble layer can be configured as a laminated foil.

[0048] The soluble layer according to the present invention is preferably configured or applied as a molecular layer, specifically, a monolayer. Specifically, the thickness of the soluble layer according to the present invention is less than 100 μm, preferably less than 50 μm, more preferably less than 10 μm, most preferably less than 500 nm, and very preferably less than 1 nm.

[0049] The physical and / or chemical properties of the soluble layer relative to electromagnetic radiation are selected, specifically at least partially, more preferably primarily, and more preferably completely, to complement (specifically by means of material selection) and / or set (specifically by setting parameters such as pressure, humidity, and temperature) the corresponding physical and / or chemical properties of the connecting layer and / or carrier substrate. Impact electromagnetic radiation is, specifically at least primarily, and more preferably completely, absorbed by the soluble layer according to the invention.

[0050] Electromagnetic radiation (specifically, photons) is absorbed by the soluble layer according to the present invention by a factor (specifically) greater than 50%, preferably greater than 75%, more preferably greater than 90%, most preferably greater than 99%, and very preferably greater than 99.9%. Therefore, the transmission will be less than 50%, preferably less than 25%, more preferably less than 10%, most preferably less than 1%, and very preferably less than 0.1%. The absorption values ​​here are also set relative to the layer thickness and are selected based on material properties and the requirements of the product wafer.

[0051] Preferably, the material of the soluble layer and the electromagnetic radiation system are selected such that the interaction between the electromagnetic radiation and the soluble layer excites the highest possible number of rotational and / or vibrational degrees of freedom and / or moves the highest possible number of electrons from the highest occupied molecular orbitals to the lowest occupied molecular orbitals. Preferably, the interaction (specifically, only) occurs in the UV-VIS spectrum. Therefore, it has a direct effect on the electronic structure, and preferably, it does not excite rotational and / or vibrational degrees of freedom. Exciting rotational and / or vibrational degrees of freedom would result in heating of the soluble layer according to the invention and thus heating of the adjacent product substrate.

[0052] The material of the soluble layer and the electromagnetic radiation system are selected such that the temperature increase of the soluble layer due to interaction with the electromagnetic radiation is less than 50°C, preferably less than 25°C, more preferably less than 10°C, most preferably less than 1°C, and most preferably less than 0.1°C. Because a photon source with an electromagnetic wavelength range that neither excites vibrations nor rotational degrees of freedom is used, heating can be substantially eliminated. Therefore, to prevent heating, according to the present invention, electromagnetic rays in the UV-VIS wavelength range are utilized in particular.

[0053] Since the decomposition of the soluble layer according to the present invention can be promoted by increased thermal motion, moderate heating of the soluble layer may be necessary according to the present invention. The heating system is preferably at least 0.1°C, more preferably at least 1°C, more preferably at least 5°C, and more preferably at least 10°C.

[0054] The materials considered suitable as soluble layers are specifically as follows: — Polymers, specifically o Organic polymers, specifically ▪ Acrylic esters, styrene, acrylonitrile Acrylonitrile / methyl methacrylate, ▪ Acrylonitrile / butadiene / acrylate ▪ Acrylonitrile / chlorinated polyethylene / styrene Acrylonitrile-butadiene-styrene, ▪ Acrylic polymers, ▪ Alkyd resin, ▪ Butadiene rubber, ▪ Butyl rubber, Casein plastic, artificial horns ▪ Cellulose acetate ▪ Cellulose esters and their derivatives ▪ Hydrated cellulose, ▪ Nitrocellulose, ▪ Chitin, chitosan ▪ Chlorpine rubber, ▪ Cyclic olefin copolymers, ▪ Standardized polyvinyl chloride, ▪ Epoxy resin, ▪ Ethylene acrylate copolymer, ▪ Ethylene polyvinyl acetate ▪ Ethylene-propylene copolymer, ▪ Ethylenepropylene diene rubber, ▪ Vinyl acetate, Expandable polystyrene, ▪ Fluorinated rubber, ▪ Urea-formaldehyde resin, ▪ Urea resin, ▪ Isoprene rubber, ▪ Lignin, ▪ Melamine-formaldehyde resin, ▪ Melamine resin, ▪ Methyl acrylate / butadiene / styrene ▪ Natural rubber, ▪ Perfluoroalkoxyalkanes, ▪ Phenolic formaldehyde resin, ▪ Polyacetal, ▪ Polyacrylonitrile, ▪ Polyamide, ▪ Polybutylene succinate, ▪ Polybutylene terephthalate (PET) ▪ Polycaprolactone, ▪ Polycarbonate, ▪ Polycarbonate, ▪ Polychlorotrifluoroethylene ▪ Polyester ▪ Polyesteramide, ▪ Polyester alcohol, ▪ Polyester block amide, ▪ Polyesterimide, ▪ Polyester, ▪ Polyester styrene, ▪ Polyethylene ▪ Polyester terephthalate, ▪ Polyhydroxyalkanoates, ▪ Polyhydroxybutyrate, ▪ Polyimide, ▪ Polyisobutylene, ▪ Polylactic acid, ▪ Polymethacrylic acid methyl methamide, ▪ Polymethyl methacrylate, ▪ Polymethylpentene, ▪ Polyoxymethylene or polyacetal ▪ Polyphenylene ether, ▪ Polyphenylenesulfide ▪ Poly(phthalamide) ▪ Polypropylene ▪ Polypropylene copolymer, ▪ Polypyrrole, ▪ Polystyrene, ▪ Gathering stones, ▪ Polytetrafluoroethylene (PTFE) ▪ Polypropylene terephthalate (PPT) ▪ Polyurethane, ▪ Polyvinyl acetate, ▪ Polyvinyl butyral, ▪ Polyvinyl chloride (rigid PVC) ▪ Polyvinyl chloride (flexible PVC) ▪ Polyvinylidene fluoride, ▪ Polyvinylpyrrolidone ▪ Styrene-acrylonitrile copolymer, ▪ Styrene-butadiene rubber, ▪ Styrene-butadiene-styrene Synthetic rubber, ▪ Thermoplastic polyurethane, ▪ Unsaturated polyester, ▪ Vinyl acetate copolymer, ▪ Vinyl chloride / ethylene / methacrylate ▪ Vinyl chloride / ethylene ▪ Vinyl chloride-vinyl acetate copolymer, ▪ Softened polyvinyl chloride. o Inorganic polymers ▪ Polyphosphazene ▪ Polysiloxane, Polysiloxane ▪ Polysilane — Metals, specifically Cu, Ag, Au, Al, Fe, Ni, Co, Pt, W, Cr, Pb, Ti, Ta, Zn, Sn — metal alloys — Non-metals o ceramics o glass ▪ Metallic glass ▪ Non-metallic glass, specifically — Organic non-metallic glass — Inorganic non-metallic glass, specifically o Non-oxidized glass, specifically ▪ Halogenated glass ▪ Sulfide glass o Oxide glass, specifically ▪ Phosphate glass ▪ Silicate glass, specifically — Aluminosilicate glass — Lead silicate glass — Alkali metal silicate glass, specifically o Alkali metal and alkaline earth metal silicate glasses — Borosilicate glass — Borate glass, specifically alkali metal borate glass

[0055] According to the present invention, a soluble layer derived from a polymer is preferably used.

[0056] Polymers are suitable for use as soluble layers, specifically due to their numerous bond types, including σ bonds, π bonds, and resonantly stable aromatic compounds (benzene rings). These bonds result in a fairly complex UV-VIS spectrum, appearing in the wavelength range where resonant interactions begin between incident photons and electrons.

[0057] Metals and metal alloys possess the absorption spectrum of crystalline solids. Specifically, metals and metal alloys can be heated by photon excitation, thus making them suitable for use as soluble layers.

[0058] Ceramics and glasses contain minimal interaction effects. Most of them are amorphous or at least partially amorphous.

[0059] The soluble layer is preferably applied using the following methods and steps: In the first method step, a soluble layer is applied by a spin coating process.

[0060] In the second step, heat treatment is performed to remove any solvent. Specifically, the heat treatment temperature is above 50°C, preferably above 75°C, more preferably above 100°C, most preferably above 100°C, and very preferably above 150°C. Preferably, the heat treatment temperature is below 500°C.

[0061] In the third step, a second heat treatment is performed at a higher temperature to harden the soluble layer. Specifically, the heat treatment temperature is above 100°C, preferably above 150°C, more preferably above 200°C, most preferably above 250°C, and very preferably above 300°C. Hardening can also be carried out using electromagnetic radiation (specifically, using UV light). Chemical hardening can also be performed using process gases. Specifically, hardening can be performed using ambient humidity.

[0062] According to a first embodiment of the present invention, the substrate stack (bonding of product substrate to carrier substrate) consists of a product substrate, specifically an inventive soluble layer applied to the entire surface of the product substrate, a bonding adhesive (connecting layer) and a carrier substrate.

[0063] The surface of the product substrate does not need to be flat. There may be coated functional units with raised structures on the top side of the product substrate.

[0064] According to the present invention, this type of substrate stack is specifically manufactured by one or more method steps described below: In the first method step according to the invention, the product substrate, specifically the entire surface, is coated with the inventive soluble layer. The coating of the inventive soluble layer can be achieved by spin coating (preferably), spray coating, or blanket coating. If the inventive soluble layer is a foil, it is preferably laminated.

[0065] In the second method step according to the invention, a bonding adhesive (connecting layer) is applied. The bonding adhesive may be applied to the soluble layer of the invention, and thus to the product substrate and / or carrier substrate.

[0066] In the third method step according to the invention, the two substrates are joined together (in contact with each other, specifically under pressure). A calibration process may be performed prior to joining.

[0067] According to a second embodiment of the present invention, the substrate stack (bonding of the product substrate to the carrier substrate) consists of the product substrate, a non-adhesive coating applied to the center of the product substrate and an inventive soluble layer applied to the periphery, a bonding adhesive (connecting layer) and a carrier substrate.

[0068] According to the present invention, this type of substrate stack is specifically manufactured by one or more method steps described below: In the first method step according to the invention, a non-stick coating is concentrically applied to the product substrate. The non-stick coating can be applied by spin coating or spray coating. The non-stick coating is not applied to the entire surface. Specifically, the outer circumference remains uncoated, and the width of this circumference is less than 10 mm, preferably less than 5 mm, more preferably less than 3 mm, most preferably less than 2 mm, and very preferably less than 1 mm. To obtain this central coating with the uncoated outer circumference, the area of ​​the outer circumference of the product substrate is masked.

[0069] In the second method step according to the invention, the inventive soluble layer is coated around the periphery of the product substrate. The coating of the inventive soluble layer can be achieved by spin coating, spray coating, or blade coating. If the inventive soluble layer is a foil, it is preferably laminated in the peripheral region. Alternatively, the entire surface can be laminated and the central portion of the foil removed.

[0070] In the third method step according to the invention, a bonding adhesive is applied. This bonding adhesive can be applied to the inventive soluble layer, and thus to the product substrate and / or carrier substrate.

[0071] In the fourth method step according to the invention, the two substrates are bonded together (in contact with each other, specifically under pressure). A calibration process may be performed before bonding.

[0072] The impact-induced soluble layer (specifically, by means of electromagnetic radiation) is achieved by a carrier concentrated on the periphery or entirely from the side. Alternatively, the impact-induced soluble layer of the substrate stack can be specifically implemented using the equipment mentioned in PCT / EP2015 / 050607.

[0073] According to a third embodiment of the present invention, the substrate stack comprises a product substrate, a bonding adhesive, a non-adhesive layer applied centrally to a carrier substrate, and an inventive soluble layer applied peripherally. This embodiment is an extension of patent specification US20090218560A1. [De-joining] [operate] [ ]

[0074] Prior to the unbonding operation according to the present invention, the product substrate is preferably fixed to the membrane clamped by the membrane frame. The membrane frame and the membrane stabilize the relatively thin product substrate after the carrier substrate is removed. The carrier substrate is preferably not removed until the product substrate has been applied to the membrane attached to the membrane frame.

[0075] The debonding operation is preferably performed by laser. The laser acts on the soluble layer and thereby reduces the adhesion strength / bonding force between the product substrate and the bonding layer according to the first two embodiments of the invention, and between the carrier substrate and the bonding adhesive according to the third embodiment of the invention. Specifically, the adhesion strength / bonding force is reduced by more than 50%, more preferably more than 75%, and more preferably more than 90%.

[0076] The debonding of the substrate stack according to the second and third embodiments of the invention can be specifically performed in the apparatus described in publication PCT / EP2015 / 050607.

[0077] After the debonding operation, it is preferable to clean the surface of the product substrate. Another important aspect of the present invention is that, according to the first embodiment of the invention, complete removal of the soluble layer results in a product substrate with a relatively clean surface, which makes cleaning faster and more cost-effective.

[0078] Where features of the method have been disclosed, such features are also considered to apply to the apparatus as disclosed, and vice versa.

[0079] All product substrates 2 shown may include functional units 6. However, it is also permissible to have product substrates that do not include any corresponding functional units 6. Functional units 6 may be, for example, microchips, storage modules, MEM components, etc. It is also permissible for functional units 6 to include protrusions 7 (such as solder balls). These protrusions 7 may have different shapes, making it difficult and / or incomplete to coat them with the soluble layer 3. When referring to coating product substrate 2, this includes coating functional units 6 and / or protrusions 7.

[0080] Figure 1a shows a schematic first embodiment of the inventive substrate stack 1 (not to scale) consisting of at least one product substrate 2, a soluble layer 3, a bonding adhesive as a connecting layer 4, and a carrier substrate 5. The inventive soluble layer 3 is, specifically, applied to the top of the provided product substrate 2, which has its (possibly) functional units 6 and protrusion structures 7, specifically its entire surface. The bonding adhesive is adjacent to the surface 3o of the soluble layer and is sequentially connected to the carrier substrate 5.

[0081] Figure 1b shows a schematic diagram (not to scale) of the debonding operation according to the present invention. Laser 9 generates a laser beam 10, which penetrates through the carrier substrate 5 into the bonding adhesive. According to the present invention, the absorption of the bonding adhesive is minimized due to the inventional synchronization of the wavelength of the laser beam 10. Therefore, the laser beam 10, specifically, advances to the soluble layer 3 with minimal, and more preferably negligible, energy loss.

[0082] According to the present invention, the interaction between the photons of the laser beam 10 and the soluble layer 3 is much greater than the interaction with the bonding adhesive, preferably maximally. The soluble layer 3 is at least partially, preferably primarily, and more preferably completely dissolved or destroyed. At least, the adhesive strength between the product substrate 2 and the bonding adhesive is weakened.

[0083] Laser 9 scans the entire surface 3o of the soluble layer, specifically by moving it in the x and / or y directions. Moving the laser beam 10 in the z direction to ensure better focusing is also possible if it is not possible to optimize the parallel laser beam 10.

[0084] Figure 2a shows a second illustrative embodiment of the invention (not to scale) of a substrate 1' consisting of at least one product substrate 2, a soluble layer 3 applied only to the periphery of the product substrate 2, a non-adhesive layer 8 applied to the center of the product substrate 2, a connecting layer 4 configured as a bonding adhesive, and a carrier substrate 5. The adhesion between the non-adhesive layer 8 and the bonding adhesive is minimal according to the invention, while the adhesive strength between the soluble layer 3 and the bonding adhesive is relatively high (at least twice as high).

[0085] Figure 2b shows an analysis of the soluble layer 3 of the second embodiment of the invention shown in Figure 2a. The laser beam 10 is preferably concentrated on the outer periphery of the substrate stack 1'. Preferably, the device is designed such that the laser 9 is fixed while the substrate stack 1' rotates about the rotation axis R.

[0086] Figure 3 shows a schematic third embodiment of the substrate stack 1'' according to the present invention, consisting of at least one product substrate 2, a bonding layer 4 configured as a bonding adhesive, a soluble layer 3 applied only to the periphery of a carrier substrate 5, a non-adhesive layer 8 applied to the center of the carrier substrate 5, and the carrier substrate 5.

[0087] The soluble layer 3 is applied to the outer periphery of the carrier substrate 5, wherein the soluble layer 3 is sensitive to the wavelength of the laser beam 10 used. The debonding operation is performed by the construction of the embodiment of the invention shown in FIG2b or by means of the device disclosed in PCT / EP2015 / 050607.

[0088] Figure 4 shows the absorption spectrum profile of the adhesive, specifically UV-VIS absorption spectrum 11. The absorption spectrum 11 has at least one, specifically more than two, more preferably more than three, most preferably more than four, and very preferably more than five local absorption minima 12.

[0089] For clarity, only a local absorption minimum 12 is shown at the center in the absorption diagram 11. The local absorption minimum 12 is part of the optimal absorption region 13, in which the wavelength of the laser beam 10 of the laser 9 to be used according to the invention is adjusted to match its wavelength range.

[0090] According to the present invention, the bonding adhesive used is selected such that the wavelength of the laser beam 10 is within the optimal absorption region 13, and more precisely matches the absorption minimum 12. This ensures that the bonding adhesive has maximum transparency to the laser beam 10 according to the present invention.

[0091] Figure 5 shows the absorption spectrum profile of the soluble layer 3, specifically absorption spectroscopy 11'. This absorption spectrum is, in particular, a UV-VIS absorption spectrum. Absorption spectroscopy 11' preferably includes at least one, specifically more than two, more preferably more than three, most preferably more than four, and very preferably more than five absorption maxima 14. For clarity, only two local absorption maxima 14 are shown in absorption spectroscopy 11'.

[0092] The local absorption maxima 14 is a portion of the optimal absorption region 13', in which the wavelength of the laser beam 10 of the laser 9 to be used should be adjusted to match its wavelength range. According to the invention, the soluble layer 3 is selected such that the wavelength of the laser beam 10 used is within the optimal absorption region 13', more precisely matching the absorption maxima 14. In this way, it is ensured that the absorption of the soluble layer to the laser beam 10 is at its maximum according to the invention.

[0093] According to the invention, and most importantly, the laser beam 10 reaches the soluble layer 3 completely at any visibility level. Where the wavelengths of the laser beam 10, the bonding adhesive 4, and the soluble layer 3 cannot be optimally adjusted relative to each other, it is preferable to at least adjust the wavelength of the laser beam 10 to match at least one or more absorption minima of the bonding adhesive, so as to allow the photons of the laser beam 10 to reach the soluble layer 3 with the greatest possible unimpeded reach.

[0094] 1, 1', 1'': Substrate stacking (bonding of product substrate to carrier substrate) 2: Product base material 3: Soluble layer 3o: Surface of the soluble layer 4: Connection Layer 5: Carrier substrate 6: Functional Units 7: Protruding structure 8: Non-adhesive layer 9: Laser 10: Laser Beam 11: Absorption diagram 11': Absorption diagram 12: Absorption Minimum 13: Optimal absorption area 13': Optimal absorption region 14: Absorption Maximum 15: Soluble layer after dissolution R: Rotation axis

Claims

1. A method for bonding a product substrate (2) to a carrier substrate (5) via a connecting layer (4), wherein a soluble layer (3) is applied to the entire surface of the product substrate (2) between the connecting layer (4) and the product substrate (2), wherein the product substrate (2) includes a plurality of functional units (6) and protrusions (7) on the surface of the product substrate (2), and wherein a) the soluble layer (3) is soluble by interaction with electromagnetic radiation from a laser, the interaction occurring only in the UV-VIS spectrum, and b) the connecting layer (4) and the carrier substrate (5) are each at least primarily transparent to the electromagnetic radiation system.

2. A method for bonding a product substrate (2) to a carrier substrate (5) bonded to a product substrate (2) via a connecting layer (4), wherein a soluble layer (3) is applied to the entire surface of the product substrate (2) between the connecting layer (4) and the product substrate (2), wherein the product substrate (2) includes a plurality of functional units (6) and protrusions (7) on the surface of the product substrate (2), and wherein a) the soluble layer (3) dissolves due to interaction with electromagnetic radiation from a laser, the interaction occurring only in the UV-VIS spectrum, and b) the connecting layer (4) and the carrier substrate (5) are each at least primarily transparent to the electromagnetic radiation system.

3. The method of claim 1 or 2, wherein the soluble layer (3) is sublimated by the electromagnetic radiation.

4. The method of claim 1 or 2, wherein the soluble layer (3) is formed or applied with a layer thickness of less than 10 μm.

5. A composite of a product substrate to a carrier substrate having a product substrate (2) bonded to a carrier substrate (5) via a connecting layer (4), wherein a soluble layer (3) is applied to the entire surface of the product substrate (2) between the connecting layer (4) and the product substrate (2), wherein the product substrate (2) includes a plurality of functional units (6) and protrusions (7) on the surface of the product substrate (2), and wherein a) the soluble layer (3) is soluble by interaction with electromagnetic radiation from a laser, the interaction occurring only in the UV-VIS spectrum, and b) the connecting layer (4) and the carrier substrate (5) are each at least primarily transparent to the electromagnetic radiation transmitted through the connecting layer (4).

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