CN115247038A

CN115247038A - Adhesive composites and methods of use thereof

Info

Publication number: CN115247038A
Application number: CN202110453040.1A
Authority: CN
Inventors: 骆名华; 林宏文; 翁志豪
Original assignee: Yiztech Co ltd
Current assignee: Dongguan Debang Yihua Materials Co ltd
Priority date: 2021-04-26
Filing date: 2021-04-26
Publication date: 2022-10-28

Abstract

An adhesive composite applied to a die, comprising: acrylic resin and solid resin particles. Wherein the acrylic resin comprises an acrylic monomer and a curing agent. The solid resin particles are disposed in the acrylic resin and support the crystal grains. The weight of the acrylic monomer in the acrylic resin is 80-100, and the weight of the solid resin particles relative to the acrylic resin is 0-30. The invention further includes a method of using the adhesive composite.

Description

Adhesive composites and methods of use thereof

Technical Field

The present invention relates to an adhesive composite and a method for using the same, and more particularly, to an adhesive composite and a method for using the same applied to a die packaging process.

Background

The semiconductor package generally refers to a wafer (wafer) processed from a front stage of a semiconductor, and after performing processes such as cutting (sawing), pick-up (pick-up), die bonding (die bonding), and wire bonding (wire bonding), a packaging material is coated on the cut die (die) to protect the durability and the service life of a finished Integrated Circuit (IC) device (e.g., a chip), and facilitate wide circuit board assembly applications. Although the die bonding process in the foregoing steps is only one of many processes for back-end packaging of semiconductors, as revolutionary materials such as gallium nitride (GaN) and silicon carbide (SiC) become more popular in the 5G era, terminal electronic products are increasingly being developed for light, thin, short and small applications, and related packaging technologies are gradually developing toward miniaturization. The most difficult point of the die bonding process is how to accurately fix the die on the substrate or stack the die to the thinnest thickness with the least amount of media, and the electrical characteristics can be achieved without distortion and pass various reliability tests, and it is critical to avoid the die from shifting or falling off.

In the prior art, adhesives suitable for electronic packaging applications generally have good mechanical strength characteristics, and with the trend toward miniaturization of chips, extend to various package types such as quad flat no-lead (QFN), dual flat no-lead (DFN), dual in-line package (DIP), small plastic Quad Flat Package (QFP), small Outline Transistor (SOT), small Outline Integrated Circuit (SOIC), and the like. Particularly, for precise control of the thickness of the Bonding Line (BLT), if the thickness of the bonding line is too thin, the die may be easily detached from the substrate due to poor adhesion of the die surface and/or the substrate or excessive stress in the resin of the adhesive. If the bond line thickness is too thick or non-uniform, the adhesive may easily form large fillets that overflow onto the top of the die, thereby contaminating the top of the die and causing trouble and inconvenience in the subsequent wire bonding process.

However, as semiconductor dies become thinner and thinner, the pressure applied to the die may be too great due to the slight difference in the thickness of the bonding line during the bonding or stacking process between the die and the substrate, so that the die may be damaged, fall off, tilted or warped, which may result in die bonding failure and difficulty in increasing the overall process yield of the integrated circuit device.

Therefore, how to design an adhesive compound and a method for using the same, especially to solve the technical problems that the die bonding process in the prior art is prone to fail and the overall process yield of the integrated circuit device is difficult to increase, is an important issue studied by the inventors of the present invention.

Disclosure of Invention

One of the objectives of the present invention is to provide an adhesive composite, which can solve the technical problems of the prior art that die bonding is prone to fail and the overall process yield of the integrated circuit device is difficult to increase, so as to achieve the purposes of increasing the process yield and reducing the production cost.

In order to achieve the above object, the adhesive composite of the present invention is applied to a die, and the adhesive composite includes: acrylic resin and solid resin particles. Wherein the acrylic resin comprises an acrylic monomer and a curing agent. The solid resin particles are disposed in the acrylic resin and support the crystal grains. Wherein the weight part of the acrylic monomer in the acrylic resin is greater than or equal to 80 and less than 100, and the weight part of the solid resin particles relative to the acrylic resin is greater than or equal to 0 and less than or equal to 30. Wherein, after being uniformly mixed with the melted solid resin particles, the acrylic resin is heated to the solidification temperature, so that the peeling strength between the crystal grains and the substrate is between 10 kilograms and 25 kilograms.

Further, in the adhesive composite, the solid resin particles include bismaleimide resin, and the particle size of the solid resin particles is between 10 micrometers and 30 micrometers.

Further, in the adhesive composite, the melting temperature of the solid resin particles is between 130 ℃ and 160 ℃.

Further, in the adhesive composite, the curing temperature is between 150 ℃ and 175 ℃.

In addition, in the adhesive compound, the curing agent is peroxide, and the weight part of the curing agent in the acrylic resin is 2.

Further, in the adhesive composite, the grain size is 2*2 mm square, and the substrate is composed of copper or its alloy.

Another objective of the present invention is to provide a method for using an adhesive compound, which can solve the technical problems of the prior art that die bonding is prone to fail and the overall process yield of an integrated circuit device is difficult to increase, thereby achieving the purpose of increasing the process yield and reducing the production cost.

In order to achieve the above object, the adhesive composite of the present invention is applied to a die, and the method of using the adhesive composite comprises the following steps: the solid resin particles are disposed in an acrylic resin to form an adhesive composite, and the acrylic resin includes an acrylic monomer and a curing agent. The crystal grains are covered on the adhesive compound, and the solid resin particles are clamped between the crystal grains and the substrate. The adhesive composite is heated to the melting temperature of the solid resin particles to uniformly mix the acrylic resin with the melted solid resin particles. Heating the adhesive composite to a curing temperature to perform a curing reaction, so that the die and the substrate have a peel strength of 10 kg to 25 kg. Wherein the acrylic monomer accounts for 80-100 parts by weight of the acrylic resin, and the solid resin particles account for 0-30 parts by weight of the acrylic resin.

Further, in the method for using the adhesive composite, the solid resin particles comprise bismaleimide resin, and the particle size of the solid resin particles is between 10 microns and 30 microns.

In a method for using the adhesive composite, the melting temperature of the solid resin particles is between 130 ℃ and 160 ℃, and the curing temperature is between 150 ℃ and 175 ℃.

In the method for using the adhesive composite, the curing agent is peroxide, and the weight part of the curing agent in the acrylic resin is 2.

Further, in the method for using the adhesive composite, the grain size is 2*2 mm square, and the substrate is composed of copper metal or its alloy.

In using the adhesive composite of the present invention and the method of using the adhesive composite, it is critical that the solid resin particles be disposed in an acrylic resin to form the adhesive composite. The acrylic resin (e.g., PMMA, commonly known as acryl gel, etc.) may include an acrylic monomer (e.g., methyl Methacrylate (MMA)) and a curing agent (e.g., peroxide). The solid resin particles may be Bismaleimide (BMI) resin, and particularly, the bismaleimide resin may share the curing agent suitable for the acrylic monomer, so that the acrylic resin and the melted solid resin particles may be uniformly mixed and heated to a curing temperature, so that the peeling strength between the die and the substrate is 10 kg to 25 kg. The physical properties of the peel strength are matched with the following proportion relationship: the weight ratio of the acrylic monomer to the acrylic resin is 80-100, and the weight ratio of the solid resin particles to the acrylic resin is 0-30. Therefore, after the crystal grains are coated on the adhesive compound, the solid resin particles clamped between the crystal grains and the substrate are in a molten state by heating, and after the acrylic resin and the molten solid resin particles are uniformly mixed, the adhesive compound is heated to a curing temperature to carry out curing reaction, and finally, an integrally formed bonding structure is formed between the crystal grains and the substrate. Furthermore, after the adhesive compound is cured, no contact point without adhesive property exists between the die and the substrate (i.e. the particles of the solid resin particles disappear), so that not only can the internal stress between the die and the substrate be effectively adjusted and balanced, but also the die is not easy to crack or damage, and the molten solid resin particles can further enhance the peeling strength between the die and the substrate after being cured, thereby reducing the probability of the die falling off, inclining or warping from the substrate, well controlling the thickness of a Bonding Line (BLT), and effectively improving the yield of the die bonding process.

Therefore, the adhesive compound and the use method thereof can solve the technical problems that the die bonding process in the prior art is easy to fail and the overall process yield of the integrated circuit element is difficult to improve, so that the die and the substrate can be bonded more tightly, and the purposes of improving the process yield and reducing the production cost are achieved.

The invention is described in detail below with reference to the drawings and specific examples, but the invention is not limited thereto.

Drawings

FIG. 1 is a schematic structural view of an adhesive composite of the present invention prior to the curing reaction;

FIG. 2 is a schematic structural view of the adhesive composite of the present invention after the curing reaction; and

FIG. 3 is a flow chart of a method of using the adhesive composite of the present invention.

Wherein, the reference numbers:

1 acrylic resin

2 solid resin particles

3: bonding structure

11 contact point

100 crystal grain

200 base plate

S1-S4 step

Detailed Description

The following description of the embodiments of the present invention is provided by way of specific embodiments, and other advantages and effects of the present invention will be readily apparent to those skilled in the art from the description provided herein. The invention is capable of other and different embodiments and its several details are capable of modification and various changes in form and detail are capable of being made without departing from the spirit and scope of the invention.

It should be understood that the structures, ratios, sizes, and numbers of elements shown in the drawings and described in the specification are only used for understanding and reading the content provided by the specification, and are not used to limit the conditions and conditions of the present invention, so the present invention has no technical significance.

The technical contents and detailed description of the present invention are described below with reference to the accompanying drawings.

Referring to fig. 1 and fig. 2, fig. 1 is a schematic structural view of the adhesive composite of the invention before a curing reaction. FIG. 2 is a schematic structural diagram of the adhesive composite of the present invention after the curing reaction.

In an embodiment of the present invention, the adhesive composite provided by the present invention is applied to a die (die) 100, and the adhesive composite includes: acrylic resin 1 and solid resin particles 2. The acrylic resin 1 may include acrylic monomers (not shown, such as methyl acrylate, ethyl acrylate, n-butyl acrylate, methyl Methacrylate (MMA), n-butyl methacrylate, etc.) and a curing agent (not shown). Wherein the weight ratio of the acrylic monomer to the acrylic resin 1 is ≧ 80 and < 100. As the acrylic resin 1, a thermosetting acrylic resin or a thermoplastic acrylic resin may be included. The thermosetting acrylic resin is an infusible acrylic polymer which takes an acrylic monomer as a basic component and is crosslinked into a network structure, has more excellent heat resistance, water resistance, solvent resistance, wear resistance and scratch resistance (scratch resistance) besides the general performance of the acrylic resin, and has various forms such as a body casting material, a solution type, an emulsion type and a water-based type. The crosslinking modes are divided into two categories: (1) The functional group in the reactive crosslinking type polymer has no crosslinking reactivity; or (2) the self-crosslinking polymer chain itself contains more than two functional groups with reaction capability. The thermoplastic acrylic resin can be a thermoplastic resin prepared by polymerizing acrylic acid, methacrylic acid and derivatives (such as esters, nitriles and amides) thereof. The softening by heating and the solidification by cooling can be repeated. The general linear high molecular compound can be a homopolymer or a copolymer, and has good physical and mechanical properties, excellent weather resistance, chemical resistance and water resistance, and high gloss retention and color retention. The molecular weight of the thermoplastic acrylic resin used in the paint industry is 75000-120000, and nitrocellulose, cellulose acetate butyrate, perchloroethylene resin and the like are commonly used in combination to improve the performance of the coating film. The thermoplastic acrylic resin is one of solvent type acrylic resins, can be melted and dissolved in a proper solvent, and the paint prepared by the thermoplastic acrylic resin is a macromolecular integrated film after the solvent is volatilized, does not have a crosslinking reaction during film forming, and belongs to a non-reactive paint. In order to realize better physical and chemical properties, the molecular weight of the resin should be large, but in order to ensure that the total amount of nonvolatile substances is not too low and the molecular weight is not too large, the physical and chemical properties and the workability are balanced when the molecular weight is generally tens of thousands. In the embodiment of the present invention, the acrylic resin 1 may be polymethyl methacrylate (PMMA), also called acrylic (acrylic) or organic glass, and the corresponding acrylic monomer is Methyl Methacrylate (MMA).

Further, the adhesive composite may further include a dispersant (dispersant), the dispersant may be simultaneously or sequentially and uniformly mixed with the acrylic monomer in the acrylic resin 1, the addition of the dispersant may prevent the agglomeration or sedimentation of the material molecules, may make the physical properties of the material more uniform throughout, and may obtain the acrylic resin 1 with uniform physical properties during the subsequent degradation (e.g., roll-milling dispersion, etc., which may cause the bond between the material molecules to be broken). Dispersants are generally classified into two major classes, inorganic dispersants and organic dispersants. Inorganic dispersants commonly used are silicates (e.g., water glass) and alkali metal phosphates (e.g., sodium tripolyphosphate, sodium hexametaphosphate, sodium pyrophosphate, and the like). The organic dispersant includes triethylhexyl phosphoric acid, sodium dodecyl sulfate, methyl amyl alcohol, cellulose derivatives, polyacrylamide, guar gum, fatty acid polyglycol ester, etc. In addition, the curing temperature of the acrylic resin 1 may be between 150 degrees celsius and 200 degrees celsius. And further, the curing condition of the acrylic resin 1 may be 175 degrees celsius and continuously heated for 60 minutes. In the embodiment of the present invention, the proportion of the dispersant (dispersant) to the acrylic resin 1 may be < 1wt% or less.

The solid resin particles 2 are disposed in the acrylic resin 1 and are used to support the die 100 on the substrate 200. In the embodiment of the present invention, the solid resin particle 2 may be made of Bismaleimide (BMI) resin, and the particle size of the solid resin particle 2 is between 10 micrometers and 30 micrometers, the melting temperature of the solid resin particle 2 is between 130 degrees celsius and 160 degrees celsius, and the curing temperature may preferably be between 150 degrees celsius and 175 degrees celsius. The Bismaleimide (BMI) is a bifunctional compound, the double-active end group of the Bismaleimide (BMI) is maleimide (maleimide and imide), the BMI has the characteristics of heat resistance, weather resistance and humidity resistance of polyimide resin, radiation resistance and good dielectric property, and has the physical property and the molding processing mode which are equivalent to those of epoxy resin. In particular, the bismaleimide resin may share the curing agent suitable for the acrylic monomer, and the acrylic resin 1 and the melted solid resin particles 2 may be uniformly mixed and then subjected to a curing reaction to form the integrally formed bonding structure 3, thereby enhancing the bonding strength between the crystal grain 100 and the substrate 200. Wherein the weight part of the solid resin particles 2 relative to the acrylic resin 1 is more than 0 and less than or equal to 30. In the embodiment of the present invention, the curing agent is a peroxide (peroxide) having a strong oxidizing property, and the curing agent accounts for 2 parts by weight of the acrylic resin 1. Wherein, after the acrylic resin 1 and the melted solid resin particles 2 are uniformly mixed, and heated to the solidification temperature, the peeling strength between the crystal grain 100 and the substrate 200 can be between 10 kg and 25 kg. The aforementioned effects are achieved by providing a crystal grain 100 of 2*2 mm square, and a substrate 200 made of copper or its alloy.

FIG. 3 is a flow chart of a method of using the adhesive composite of the present invention. When the adhesive composite of the present invention is used and the method of using the adhesive composite is operated, it is essential that the solid resin particles 2 are disposed in the acrylic resin 1 to form the adhesive composite (step S1). Then, the die 100 is placed on the adhesive composite, and the solid resin particles 2 are sandwiched between the die 100 and the substrate 200 (step S2), and there is a contact point 11 without adhesive property between the die 100 and the substrate 200. The acrylic resin 1 (e.g., PMMA, commonly known as acryl gel, etc.) may include an acrylic monomer (e.g., methyl Methacrylate (MMA)) and a curing agent (e.g., peroxide). The solid resin particles 2 may be Bismaleimide (BMI) resin, and particularly, the bismaleimide resin may share the curing agent suitable for the acrylic monomer, so that the acrylic resin 1 and the melted solid resin particles 2 may be uniformly mixed and heated to the curing temperature to have a peel strength between 10 kg and 25 kg between the die 100 and the substrate 200. The physical properties of the peel strength are matched with the following proportion relationship: the weight of the acrylic monomer in the acrylic resin 1 is 80-100, and the weight of the solid resin particles 2 relative to the acrylic resin 1 is 0-30. After the die 100 is coated on the adhesive composite, the solid resin particles 2 sandwiched between the die 100 and the substrate 200 are melted by heating, and the acrylic resin 1 and the melted solid resin particles 2 are uniformly mixed (step S3), the adhesive composite is heated to the curing temperature to perform a curing reaction (step S4), and finally the integrally formed bonding structure 3 is formed between the die 100 and the substrate 200. Furthermore, since the adhesive compound does not have the contact point 11 without adhesive property between the die 100 and the substrate 200 after the curing reaction (i.e. the particles of the solid resin particle 2 have disappeared), not only the internal stress between the die 100 and the substrate 200 can be effectively adjusted and balanced, so that the die 100 is not easily cracked or damaged, but also the peel strength between the die 100 and the substrate 200 can be enhanced by the melted solid resin particle 2 after the curing, thereby reducing the probability of the die 100 falling off, tilting or warping from the substrate 200, well controlling the thickness of the Bonding Line (BLT), and effectively increasing the yield of the die bonding process.

Therefore, the adhesive compound and the using method thereof can solve the technical problems that the die bonding process in the prior art is easy to fail and the overall process yield of the integrated circuit element is difficult to improve, so that the die 100 and the substrate 200 can be bonded more tightly, and the purposes of improving the process yield and reducing the production cost are achieved.

Finally, the following table shows four formulations in the described examples of the invention versus a control:

	control group	Formulation I	Formulation II	Formulation III	Formulation IV
						Acrylic acid monomer	100	95	90	85	80
Solid resin particles	0	5	10	15	20
						Curing agent	2	2	2	2	2
Peel Strength (Kg)	6	12	15	20	22
						BLT(μm)	1～5	15～30	15～30	15～30	15～30

As can be seen from the above table, the bonding structure 3 solidified after the solid resin particles 2 are melted in the four formulations can significantly enhance the peel strength between the die 100 and the substrate 200, so that the peel strength between the die 100 and the substrate 200 is better than that of the control group.

While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. An adhesive composite applied to a die, comprising:

an acrylic resin including an acrylic monomer and a curing agent; and

a solid resin particle disposed in the acrylic resin and supporting the crystal grain;

wherein the acrylic monomer accounts for 80 parts by weight or more and less than 100 parts by weight of the acrylic resin, and the solid resin particles account for 0 part by weight or more and less than 30 parts by weight of the acrylic resin;

wherein, the acrylic resin is uniformly mixed with the melted solid resin particles, and then heated to a curing temperature, so that the peeling strength between the crystal grains and a substrate is between 10 kg and 25 kg.

2. The adhesive composite of claim 1, wherein the solid resin particles comprise bismaleimide resin and have a particle size of 10-30 microns.

3. The adhesive composite of claim 1, wherein the solid resin particles have a melting temperature of 130 ℃ to 160 ℃.

4. The adhesive composite of claim 1, wherein the curing temperature is between 150 degrees Celsius and 175 degrees Celsius.

5. The adhesive composite of claim 1, wherein the curing agent is a peroxide and the curing agent is 2 parts by weight of the acrylic resin.

6. The adhesive composite of claim 1, wherein the grain size is 2*2 mm square and the substrate is comprised of copper metal or its alloy.

7. A method of using an adhesive composite applied to a die, the method comprising:

disposing a solid resin particle in an acrylic resin to form the adhesive composite, wherein the acrylic resin comprises an acrylic monomer and a curing agent;

covering the crystal grain on the adhesive compound, and enabling the solid resin particles to be clamped between the crystal grain and a substrate;

heating the adhesive composite to a melting temperature of the solid resin particles to uniformly mix the acrylic resin and the melted solid resin particles; and

heating the adhesive composite to a curing temperature to perform a curing reaction, so that the peeling strength between the crystal grains and the substrate is 10-25 kg;

wherein the acrylic monomer accounts for 80 parts by weight or more and less than 100 parts by weight of the acrylic resin, and the solid resin particles account for 0 parts by weight or more and less than 30 parts by weight of the acrylic resin.

8. The method of claim 7, wherein the solid resin particles comprise bismaleimide resin, and the solid resin particles have a particle size of 10-30 μm.

9. The method of claim 7, wherein the melting temperature of the solid resin particles is between 130 degrees Celsius and 160 degrees Celsius, and the curing temperature is between 150 degrees Celsius and 175 degrees Celsius.

10. The method of claim 7, wherein the curing agent is peroxide and the curing agent is 2 parts by weight of the acrylic resin.

11. The method of claim 7, wherein the grain size is 2*2 mm square, and the substrate is made of copper or its alloy.