Polyimide materials for glass substrate modification

Abstract

This invention provides a polyimide material for modifying glass substrates. Specifically, this invention relates to a polyimide precursor composition comprising an amide ester oligomer having the structure of formula (I): (I), wherein G, R x and n as defined herein, and each P is an independent divalent organic group, wherein, based on the total molar number of all divalent organic groups P in the composition, about 1 mol% to about 20 mol% of the divalent organic groups P are diamine residues selected from nitrogen-containing heteroaromatic rings having at least two nitrogen atoms, aromatic rings or heterocycles having at least two -COOH groups, and about 0.5 mol% to about 40 mol% of the divalent organic groups P are, wherein R 1 R 2 R 3 R 4 R 5 R 6 And m is as defined in this article.

Description

Technical Field

[0001] This invention relates to a polyimide material for modifying glass substrates. Background Technology

[0002] Glass possesses properties such as low dielectric constant, high resistivity, and bending resistance. Therefore, in semiconductor packaging applications, glass substrates offer advantages such as high bandwidth density, high interconnect density, and high data transmission rate, while significantly reducing energy loss during data transmission, facilitating the packaging of more electronic components on a single substrate. Furthermore, glass substrates also hold promise for applications in optical communications. Consequently, the semiconductor industry has placed high hopes on glass substrates in recent years and invested considerable research and development efforts.

[0003] To achieve electrical communication with electronic components and / or external power sources, through-glass vias (TGVs) can be formed in the glass substrate. For example, multiple vias penetrating the upper and lower surfaces of the glass substrate can be formed by etching or laser processing. Conductive material (usually copper) is then filled into these vias, creating through-glass vias that electrically connect the upper and lower surfaces of the glass substrate. Furthermore, various metal wiring designs can be applied to the glass substrate to obtain patterned conductive materials.

[0004] Glass metallization technology is one of the key processes in this field. One of the main research directions in glass metallization technology is the wet metal deposition process. The wet metal deposition process uses metal oxides as adhesives. First, the adhesive is applied to the main surface of the glass and the walls of the vias using a sol-gel method, followed by sintering to solidify the adhesive. Then, a metal seed layer is deposited using electroless plating, and finally, glass vias and metal wiring are formed through electroplating and patterning processes. The sintering temperature required is approximately at least 300°C to 500°C, and the heat treatment time is approximately at least 30 minutes. The thermal stress generated by this high temperature can easily cause microcracks in the glass. Furthermore, the metal oxides currently used as adhesives are usually zinc oxide, tin oxide, or manganese oxide. These cannot be applied to different types of glass in one go, and there are concerns about their stability. In particular, in the subsequent metal patterning process, when acidic etching solutions are used to etch metal to form the desired circuit pattern, the metal oxides are easily eroded, and the adhesion between the exposed metal oxides and the subsequently applied additives (such as resins) may deteriorate.

[0005] In response to the aforementioned technical challenges, the industry hopes to develop better glass metallization technologies and materials that facilitate glass metallization. Summary of the Invention

[0006] This invention provides a polyimide material for modifying glass substrates. Specifically, this invention relates to a polyimide precursor composition comprising an oligomer having the structure of formula (I): (I), where G and R x and n as defined herein, and each P is an independent divalent organic group, wherein, based on the total molar number of all divalent organic groups P in the composition, about 1 mol% to about 20 mol% of the divalent organic groups P are diamine residues selected from nitrogen-containing heteroaromatic rings having at least two nitrogen atoms, aromatic rings or heterocycles having at least two -COOH groups, and combinations thereof, and about 0.5 mol% to about 40 mol% of the divalent organic groups P are , where R 1 R 2 R 3 R 4 R 5 R 6 And m is as defined in this article.

[0007] To make the above-mentioned objectives, technical features and advantages of the present invention more apparent and understandable, the following detailed description is provided with reference to some specific embodiments. Attached Figure Description

[0008] Figure 1 This illustrates a glass-modified structure according to an embodiment of the present invention;

[0009] Figure 2 This invention illustrates a glass modification method and metallization process according to an embodiment of the present invention.

[0010] Figure 3 This diagram shows a peel strength test sample according to an embodiment of the present invention.

[0011] Explanation of icon numbers

[0012] 11: Glass substrate

[0013] 11h: Through hole

[0014] 12: Polyimide layer

[0015] 21: Glass substrate

[0016] 21h: Through hole

[0017] 22: Polyimide layer

[0018] 23: Conductive layer

[0019] 24: Organic insulating layer

[0020] 31: Glass substrate

[0021] 32: PI tape

[0022] 33: Cutting line

[0023] R: Rewiring layer Detailed Implementation

[0024] To facilitate understanding of the disclosures presented herein, several terms are defined below.

[0025] The term “about” means the acceptable error of a particular value as determined by a person skilled in the art, which depends in part on how the value is measured or determined.

[0026] The term "alkyl" refers to a saturated straight-chain or branched hydrocarbon group, preferably having 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms; examples include (but are not limited to): methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tributyl, n-pentyl, neopentyl, n-hexyl, etc.

[0027] The term "alkenyl" refers to an unsaturated straight-chain or branched hydrocarbon group having at least one carbon-carbon double bond, preferably having 2 to 10 carbon atoms, more preferably having 3 to 8 carbon atoms; examples include (but are not limited to) vinyl, propenyl, methacryl, isopropenyl, pentenyl, hexenyl, heptenyl, 1-propenyl, 2-butenyl, 2-methyl-2-butenyl and similar groups.

[0028] The term "aryl" refers to an aromatic ring system having 6 to 14 carbon atoms, such as a 6-carbon monocyclic, 10-carbon bicyclic, or 14-carbon tricyclic aromatic ring system. Examples of aryl groups include (but are not limited to) phenyl, tolyl, naphthyl, fluorenyl, anthracene, phenanthryl, and similar groups.

[0029] The term "heterocyclic group" refers to a 3- to 14-membered cyclic group, preferably a 4- to 10-membered cyclic group, more preferably a 5- or 6-membered cyclic group, consisting of a carbon atom and at least one heteroatom selected from N, O, or S; preferably having 1 to 4 heteroatoms, more preferably having 1 to 3 heteroatoms; for example, it may be a 5- or 6-membered heterocyclic group having 1 to 3 heteroatoms selected from N, O, or S. The heterocyclic group of the present invention may be a monocyclic, bicyclic, or tricyclic ring system, comprising a fused ring (e.g., a fused ring formed together with another heterocycle or another aromatic carbide ring).

[0030] Each aspect and embodiment of the invention disclosed in this specification can be individually combined with all other aspects and embodiments of the invention, covering all possible combinations.

[0031] The following sections will explain the glass substrate, polyimide material, metallization process, and applications.

[0032] glass substrate

[0033] The main component of glass is silicon dioxide, and other components, such as metals or metal oxides, may be included as needed, with the proportions of each component adjusted according to requirements (e.g., color or heat resistance). This invention does not limit the type of glass. In some embodiments, the polyimide material of this invention is applicable to any type or most types of glass without particular limitation.

[0034] Glass has the following advantages: low dielectric constant, high resistivity, bending resistance and low cost. It can also play a role in heat dissipation to a certain extent. In addition, the high light transmittance of glass makes it suitable for optical electronic components and has the prospect of being used in optical communication.

[0035] Typically, glass substrates are sheet-like and have two main surfaces. According to some embodiments, the glass substrate of the present invention has two main surfaces and a plurality of glass vias (TGVs). Each via is generally cylindrical (straight or oblique). According to some embodiments, the glass substrate of the present invention generally has a thickness of about 0.1 mm to 2 mm, for example, 0.1, 0.2, 0.3, 0.5, 0.8, 1.0, 1.2, 1.5, or 2 mm, but is not limited thereto. The size of the vias in the glass substrate can be adjusted depending on its application. In some embodiments, when used as a glass interposer, the vias in the glass substrate have a diameter of about 5 micrometers to 500 micrometers, such as 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 300, 400, or 500 micrometers, and generally have an aspect ratio of about 30:1 to about 1:1, such as 30:1, 25:1, 20:1, 15:1, 10:1, 5:1, 3:1, 2:1, or 1:1, but are not limited thereto. In some embodiments, when used for connection to an external power source (e.g., as a replacement or auxiliary IC carrier), the vias in the glass substrate may have a larger size, for example, a diameter of 100 to 500 micrometers (e.g., 100, 200, 300, 400, or 500 micrometers), but are not limited thereto.

[0036] When glass substrates are used in semiconductor packaging, their surfaces are often provided with metal wiring and add-on materials (organic materials or dielectric materials, such as Ajinomoto Build-up Film (ABF) or polyimide). However, generally speaking, the adhesion between glass and metal is not good, and methods to improve the adhesion between glass and metal include surface treatment of the glass, for example, using an adhesive. In some embodiments, in addition to having good adhesion to the metal, a preferred adhesive should have good adhesion to both the glass and the add-on material. This invention provides a polyimide material that can be used as an adhesive, which will be described in detail below.

[0037] Polyimide materials

[0038] This invention provides a polyimide precursor composition that can be applied to the surface of a glass substrate and cured by heating to form a polyimide layer. The polyimide material of this invention can be used as an adhesion agent. In some embodiments, the adhesion agent is also referred to as a glass modifier or adhesion promoting agent.

[0039] According to some embodiments of the present invention, the aforementioned polyimide precursor composition comprises an amide acid or amide ester oligomer having the structure of formula (I): (I), where:

[0040] G is an independent tetravalent organic group;

[0041] R x Each is independent of H, C1-C 14 Alkyl groups, or groups containing ethylene unsaturated groups;

[0042] n is an integer from 1 to 200; and

[0043] Each of P is an independent divalent organic group, wherein, based on the total molar number of all divalent organic groups P in the composition, approximately 1 mol% to approximately 20 mol% of the divalent organic groups P are diamine residues selected from nitrogen-containing heteroaromatic rings having at least two nitrogen atoms, aromatic rings or heterocycles having at least two -COOH groups, and combinations thereof, and approximately 0.5 mol% to approximately 40 mol% of the divalent organic groups P are... (Linear polysiloxane), the remaining P groups can each independently be other divalent aromatic groups or divalent heterocyclic groups.

[0044] in:

[0045] R 1 and R 2 Each is an independent C1-C4 alkylene group.

[0046] R 3 R 4 R 5 and R 6 Each is independently H, C1-C4 alkyl, or phenyl, and

[0047] m is an integer greater than 0.

[0048] According to some embodiments of the present invention, the divalent organic group P is approximately 1 mol% to approximately 20 mol% of the organic group P. , , , , or .

[0049] According to some embodiments of the present invention, G is selected from the group consisting of:

[0050] and ;

[0051] Where X is independently H, halogen, C1-C4 perfluoroalkyl, or C1-C4 alkyl, and A and B each appear independently as covalently bonded, unsubstituted, or substituted with one or more groups selected from hydroxyl and C1-C4 alkyl groups, namely C1-C4 alkylene, C1-C4 perfluoroalkylene, C1-C4 alkoxide, silane, -O-, -S-, -C(O)-, -OC(O)-, -S(O)2-, -C(=O)O-(C1-C4 alkylene)-OC(=O)-, -CONH-, phenylene, biphenylene, or , where K is -O-, -S(O)2-, C1-C4 alkylene or C1-C4 perfluoroalkylene.

[0052] According to a preferred embodiment of the present invention, G is selected from the group consisting of:

[0053] ;

[0054] Z can be H, methyl, trifluoromethyl, or halogen.

[0055] To achieve better adhesion with glass and metal, according to a preferred embodiment of the present invention, G is selected from the group consisting of:

[0056] , , , , , , , and .

[0057] According to some embodiments of the present invention, R x Each of these can be independently H, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tributyl, 2-hydroxypropyl methacrylate, ethyl methacrylate, ethyl acrylate, propenyl, methacryl, n-butylenyl, isobutylenyl, or a group selected from the following:

[0058] , , , and .

[0059] According to some embodiments of the present invention, R x Each can be H, isopropyl, or n-butyl.

[0060] According to some embodiments of the present invention, n is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 40, 50, 60, 70, 80, 90, 100, 120, 150, 180 or 200, preferably an integer from 5 to 150, and more preferably an integer from 9 to 100.

[0061] According to some embodiments of the present invention, the divalent organic groups P in the composition are approximately 1 mol% to approximately 20 mol% (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 16, 18 or 20 mol%, preferably 2 to 16 mol%, more preferably 5 to 12 mol%) of divalent organic groups P. , , , , or The divalent organic group P is present in an amount of approximately 0.5 mol% to approximately 40 mol% (e.g., 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 18, 20, 25, 30, 35 or 40 mol%, preferably 5 to 35 mol%, more preferably 10 to 30 mol%). .

[0062] According to some embodiments of the present invention, the remaining P groups may each be independently other divalent aromatic groups or divalent heterocyclic groups, preferably selected from the following group:

[0063] , , and their combinations,

[0064] Where R9 is independently H, C1-C4 alkyl, C1-C4 perfluoroalkyl, C1-C4 alkoxy, halogen, -OH, -COOH, -NH2, or -SH; a is independently an integer from 0 to 4; b is independently an integer from 0 to 4; R 10 It is a covalent bond or a group selected from the group consisting of: -O-, -S-, -CH2-, -S(O)2-, , , -C(CF3)2-, -C(O)-, -C(CH3)2-, -CONH-, , , and Where c and d are each independent integers from 0 to 20, R9 and a are as described above, and R 12 It is -S(O)2-, covalently bonded, C1-C-4 alkylene or C1-C4 perfluoroalkylene;

[0065] The other divalent aromatic groups or divalent heterocyclic groups mentioned above are preferably selected from the following group:

[0066]

[0067] and its combinations,

[0068] Where each of a is an independent integer from 0 to 4, and each of Z is an independent hydrogen, methyl, trifluoromethyl, or halogen.

[0069] The other divalent aromatic groups or divalent heterocyclic groups mentioned above are preferably selected from the following group:

[0070] and their combinations.

[0071] Regarding the aforementioned formula According to some embodiments of the present invention, R 1 and R 2 Each of these components is independently methylene, ethylene, n-propylene, isopropylene, n-butylene, isobutylene, or tributylene. According to a preferred embodiment of the present invention, R 1 and R 2 All are methylene, ethylene, or n-propylene. According to a preferred embodiment of the present invention, R... 1 and R 2 All are n-propyltrimethylamine.

[0072] According to some embodiments of the present invention, R 3 R 4 R 5 and R 6 Each can be independently H, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tributyl, or phenyl. 3 R 4 R 5 and R 6 All are methyl groups.

[0073] According to some embodiments of the present invention, m is an integer greater than 0, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 18, 20, 30, 40, 50, or 100. According to a preferred embodiment of the present invention, m is 1 or 2. According to a more preferred embodiment of the present invention, m is 1.

[0074] According to some embodiments of the present invention, the aforementioned polyimide layer has repeating units of formula (II): (II), where G, P and n are defined as described above.

[0075] The polyimide of the present invention is not a block copolymer, but a random copolymer, that is, the divalent organic groups P are randomly distributed in the polyimide, thus the polymerization steps are simple.

[0076] Generally, polyimides do not exhibit good adhesion to both glass and metal, and adhesion to only one of them is insufficient for glass metallization. However, the inventors of this invention have experimentally developed a polyimide material with excellent adhesion to both glass and metal. This polyimide material is suitable as an adhesive for glass metallization and is applicable to various glass substrates. Furthermore, the inventors have also discovered that the polyimide material of this invention exhibits excellent adhesion to glass-ceramic substrates, silicon substrates, and metals, and is therefore also suitable for the metallization of glass-ceramic substrates and silicon substrates. While not wishing to be bound by theory, it is believed that this may be due to the presence of a specific divalent organic group P in the polyimide material of this invention. For example, the divalent organic group P contains a nitrogen-containing heteroaromatic ring or carboxyl group (-COOH) with at least two nitrogen atoms, which has an affinity for metal ions. This affinity is achieved through the nitrogen atom and the carboxyl group (-COOH). - The lone pair of electrons on the P group can act as an electron donor, attracting electron-deficient metal ions; in addition, the linear polysiloxane contained in the divalent organic group P has an affinity for glass, because the structure of polysiloxane has a certain degree of structural similarity with glass, and polysiloxane can form hydrogen bonds with glass or form chemical bonds through heating.

[0077] The polyimide precursor composition of the present invention further comprises a solvent that can increase the leveling properties of the composition. The aforementioned solvent can be any suitable solvent well known to those skilled in the art, and its content is not particularly limited, as long as it facilitates coating of the composition.

[0078] According to some embodiments of the present invention, the content of the oligomer having the structure of formula (I) is from about 0.1 wt% to about 20 wt%, preferably from about 1 wt% to about 5 wt%, based on the total weight of the overall polyimide precursor composition.

[0079] The polyimide precursor compositions of the present invention may include other optional materials well known in formulation techniques, such as antioxidants, hindered amine light stabilizers, UV light absorbers and stabilizers, surfactants, initiators, catalysts, flow control agents, thixotropic agents, fillers, fungicides, and other conventional additives. The polyimide precursor compositions of the present invention do not require the addition of adhesion promoters to exhibit good adhesion to glass, metals, and dielectric materials.

[0080] The polyimide precursor composition of the present invention may be supplemented with a catalyst as needed to cure the polyimide at a lower curing temperature, achieving the effect of low-temperature curing. According to some embodiments of the present invention, the catalyst is an amine, such as a tertiary amine, a nitrogen-containing heterocyclic compound, or a nitrogen-containing heteroaryl compound; specific examples include triethylamine, etc. , and .

[0081] This invention also provides a polyimide prepared from the aforementioned polyimide precursor composition. The polyimide of this invention can be obtained by wet coating the aforementioned polyimide precursor composition onto a glass substrate, followed by heating and cyclization. The aforementioned wet coating can be achieved by any method known in the art, such as dip coating, spraying, spin coating, flow coating, and similar methods. The polyimide of this invention is a thermosetting polyimide.

[0082] The polyimide precursor of the present invention (an oligomer having the structure of formula (I)) has low molecular weight, resulting in low viscosity and good workability. The polyimide precursor composition of the present invention can have a viscosity as low as only 1 to 10 cp (e.g., 5 cp), which can penetrate into glass vias through-holes via capillary action to form a thin layer, which is then cured to form a polyimide layer. That is, the polyimide layer can be disposed on the walls of a plurality of vias.

[0083] According to some embodiments of the present invention, the curing temperature of the polyimide precursor is from 150°C to 350°C, for example, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 300, or 350°C; in some preferred embodiments, curing can be carried out at 150°C to 250°C to achieve low-temperature curing. According to some embodiments of the present invention, the curing time of the polyimide precursor is from 15 minutes to 200 minutes, for example, 15, 30, 60, 90, 120, 150, 180, or 200 minutes. The heating step of the present invention can be carried out in a single stage, two stages, or multiple stages. For example, the solvent can be removed by heating in a first stage at a lower temperature (e.g., 80°C or 90°C) and a shorter duration (e.g., 5 minutes or 10 minutes), followed by curing in a second stage at a higher temperature (e.g., 150°C) and a longer duration (e.g., 1 hour). If necessary, a third stage can be performed at an even higher temperature (e.g., 250°C or 350°C) and a longer duration (e.g., 2 hours).

[0084] According to some embodiments of the present invention, the polyimide film formed after curing the polyimide precursor has a thickness of about 0.05 to about 20 micrometers, preferably about 0.1 to about 10 micrometers, for example 0.1, 0.2, 0.3, 0.5, 1, 1.5, 2, 5 or 10 micrometers.

[0085] According to some embodiments of the present invention, the polyimide of the present invention has a glass transition temperature (Tg) of about 150°C to 300°C. g For example, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, or 300°C. Generally, polyimides have a temperature range above 300°C. g The polyimide of this invention has a lower Tg compared to conventional polyimides. g Therefore, if a heating step is involved in a subsequent process and the temperature exceeds the T value of the polyimide of this invention, g This can improve the flowability of polyimide, helping to ensure that polyimide is closely aligned / in contact with its adjacent layers.

[0086] According to a preferred embodiment of the glass modification structure of the present invention, the glass substrate has two main surfaces and a plurality of through holes, and the polyimide layer is disposed on at least one main surface of the glass substrate and on the walls of each through hole. Figure 1 This illustrates a glass-modified structure according to an embodiment of the present invention. For example... Figure 1 As shown, the glass substrate 11 has two main surfaces and a plurality of through holes 11h, and a polyimide layer 12 is disposed on each of the main surfaces of the glass substrate 11 and on each of the through hole walls.

[0087] Metallization process

[0088] Because polyimide is an insulator, it is impossible to directly fabricate metal layers or metal circuits on its surface. It is known in the industry that sputtering or electroless plating methods are used to first make its surface a conductor (this can also be described as forming a tie coating or seed layer on the surface, typically only a few nanometers to tens of nanometers thick), followed by electroplating to metallize the polyimide. Specifically, the method of making the polyimide surface a conductor through electroless plating involves: first cleaning and roughening the polyimide layer surface with a cleaning agent; then activating the polyimide layer surface with a surfactant containing metal ions, or using a composition containing both a cleaning agent and a surfactant to simultaneously clean and activate the polyimide layer surface; next, a reducing agent is used to reduce the metal ions attached to the polyimide substrate surface into a metal catalyst; after this, electroless plating and / or electroplating can be performed on the polyimide surface to prepare a metal layer.

[0089] The cleaning agent described above may be an alkaline compound, such as, but not limited to, potassium hydroxide, sodium hydroxide, calcium hydroxide, or lithium hydroxide, preferably containing at least one of potassium hydroxide, sodium hydroxide, calcium hydroxide, and lithium hydroxide. The surfactant containing metal ions described above may be, for example, but not limited to, sulfates, nitrites, diamine nitrites, chlorides, or dichlorodiamine salts of metal ions, and the metal ions may be, for example, but not limited to, palladium ions, nickel ions, chromium ions, titanium ions, or copper ions, preferably containing at least one of palladium ions, nickel ions, chromium ions, titanium ions, and copper ions. The reducing agent described above may be, for example, but not limited to, borohydrides (e.g., sodium borohydride, potassium borohydride), aminoboranes (e.g., diaminoborane, trimethylamineborane, or triethylamineborane), hydrazine hydrate, hypophosphite, or their salts (e.g., sodium hypophosphite or potassium hypophosphite).

[0090] This invention can fabricate metal circuits using any known suitable metallization process. According to some embodiments of the invention, a layer of nickel is first chemically plated onto the surface of the polyimide as a seed layer, and then a layer of copper is electroplated onto the surface of the nickel. The polyimide of this invention does not require the addition of adhesion promoters, nor does it require heating / baking after plating the metal onto the polyimide surface; it already exhibits good adhesion to the metal. According to some embodiments of the invention, the peel strength between the polyimide and the metal layer can reach 400 gf / cm or more, for example, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, or 1500 gf / cm, preferably 600 gf / cm or more.

[0091] According to some embodiments of the present invention, the aforementioned plated metal layer fills the through holes of the TGV glass substrate to form glass vias, and the diameter of the glass vias varies mainly with the diameter of the through holes of the TGV glass substrate and the thickness of the polyimide layer disposed on the wall of the through holes.

[0092] The aforementioned plated metal layer needs to be patterned to form the desired circuit pattern, and the patterning process generally uses an acidic etching solution. The polyimide of the present invention is acid-resistant, so only the metal layer (and the seed layer) will be etched by the acidic etching solution. In contrast, the prior art wet metal deposition process uses metal oxides as adhesives, so in addition to the metal layer, the metal oxides are also easily eroded by the acidic etching solution, resulting in poor stability.

[0093] application

[0094] In some embodiments, the modified glass substrate of the present invention can be applied to industries such as Micro LED, semiconductor packaging (e.g., 2.5D and 3D packaging), IC substrates, microelectromechanical systems (MEMS), biotechnology chips, and 5G chips. Taking semiconductor packaging as an example, the glass substrate can serve as a glass interlayer.

[0095] In some embodiments, a redistribution layer (RDL) may be formed on the upper and lower surfaces, or both, of the glass substrate to increase the flexibility of IC design and enable electrical connections between the chip, IC carrier, and / or printed circuit board (PCB). The RDL comprises a patterned metal layer (circuit layer) and an organic insulating layer (dielectric layer). In some embodiments, the organic insulating layer may be an additive layer, which is an organic dielectric material used to protect the metal conductors, provide insulation, reduce dielectric loss, and regulate thermal stress warpage. Currently, the organic insulating layer materials used in the industry are Ajinomoto Build-up Film (ABF) or polyimide. The technical feature of the polyimide in this invention is at least that the polyimide exposed after the metal layer is patterned exhibits good adhesion when in direct contact with the subsequently formed organic insulating layer, because polyimide and the aforementioned organic insulating layer materials are both organic resins and have high compatibility. In contrast, the previous wet metal deposition process used metal oxides as adhesives, which had poor adhesion to the organic insulating layer material and were prone to separation.

[0096] Figure 2 This illustrates a glass modification method and metallization process according to an embodiment of the present invention. For example... Figure 2As shown, a glass substrate 21 is taken, and a plurality of through holes 21h penetrating the upper and lower surfaces of the glass substrate 21 are formed by etching, laser, or a combination thereof. Then, a polyimide precursor composition is applied to the upper and lower surfaces of the glass substrate 21 and the walls of the through holes, and heated to cure to form a polyimide layer 22. Next, a seed layer (not shown in the figure) is formed on the surface of the polyimide layer 22 by sputtering or chemical plating. Then, a conductive material (usually copper) is applied to form a conductive layer 23, which fills the through holes 21h to form glass vias. Next, the conductive layer 23 is patterned to form metal lines, exposing part of the polyimide layer 22. Then, an organic insulating layer 24 is applied and patterned (or planarized) to form a redistribution layer R. The aforementioned steps can be repeated multiple times to make the redistribution layer contain more patterned conductive layers 23 and organic insulating layers 24.

[0097] Furthermore, in some embodiments of the present invention, the polyimide of the present invention has a relatively low Ti. g When subsequent processes involve heating steps and the heating temperature exceeds the T value of the polyimide of this invention... g This can improve the flowability of polyimide, helping to ensure that the polyimide is tightly aligned / in contact with the organic insulating layer.

[0098] The modified glass substrate of this invention is suitable not only for applications with fine metal lines, such as glass interposers, but also for applications with lower requirements for metal line precision, such as IC substrates. IC substrates typically consist of bismaleimide triazine resin (BT) as the core layer, Ajinomoto Build-up Film (ABF) as the build-up material, and metal conductors, which are electrically connected to larger external metal balls. The modified glass substrate of this invention can replace bismaleimide triazine resin (BT) as the core layer of an IC substrate, offering a more advanced option and exhibiting comprehensive benefits such as stability and low transmission loss.

[0099] The beneficial effects of this invention are:

[0100] This invention provides a polyimide material with excellent adhesion to both glass and metal. The polyimide material of this invention is suitable as an adhesive for glass metallization and is applicable to a variety of glass substrates. It achieves good adhesion to glass, metal, and dielectric materials without the need for adhesion promoters. Furthermore, the polyimide of this invention has a relatively low Tg. g When subsequent processes involve heating steps and the heating temperature exceeds the T value of the polyimide of this invention... gThis process can improve the flowability of polyimide, helping to ensure close alignment / contact between the polyimide and the organic insulating layer, further increasing adhesion. The peel strength between the polyimide layer and the substrate of this invention can reach 550 gf / cm or more, and the peel strength between the polyimide layer and the metal can reach 400 gf / cm or more.

[0101] Example

[0102] The following embodiments are provided to further illustrate the present invention, but are not intended to limit the scope of the invention. Any modifications and alterations that can be easily made by those skilled in the art are included within the scope of the disclosure in this specification and the appended claims.

[0103] The abbreviations mentioned in the following embodiments are defined as follows:

[0104] <Diacid anhydride>

[0105] A-1: 3,3',4,4'-biphenyltetracarboxylic dianhydride;

[0106] A-2: 1,2,4,5-Benzenetetracarboxylic anhydride;

[0107] A-3: 4,4'-(hexafluoroisopropylidene)diphthalic anhydride;

[0108] A-4: 4,4'-oxydiphthalic anhydride;

[0109] A-5: 3,3',4,4'-benzophenonetetracarboxylic dianhydride;

[0110] <Diamine>

[0111] <Diamines with other aromatic or heterocyclic groups>

[0112] D-1: p-phenylenediamine;

[0113] D-2: 4,4'-diamino-2,2'-dimethylbiphenyl;

[0114] D-3: 4,4'-diaminodiphenyl ether;

[0115] D-4: 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl;

[0116] D-5: 1,3-bis(4-aminophenoxy)benzene;

[0117] D-6: 1,4-bis(4-aminophenoxy)benzene;

[0118] D-7: 1,3-bis(3-aminophenoxy)benzene;

[0119] D-8: 2,2-bis[4-(4-aminophenoxy)phenyl]propane;

[0120] <Diamines with linear polysiloxanes and contrasting diamines with similar linear structures>

[0121] D-9: 1,3-bis(3-aminopropyl)tetramethyldisiloxane;

[0122] D-10: Bis(3-aminopropyl) terminated poly(dimethylsiloxane), Mn~2500;

[0123] D-11: Bis(3-aminopropyl) terminated poly(dimethylsiloxane), Mn~27000;

[0124] D-12: Bis(3-aminopropyl) terminated polyethylene glycol, Mn~1500;

[0125] D-13: 4,7,10-trioxa-1,13-tridecanediamine;

[0126] <Diamine having a nitrogen-containing heteroaromatic ring or at least two -COOH groups>

[0127] D-14: 5,5'-methylenebis(2-aminobenzoic acid);

[0128] D-15: [2,2'-bipyridine]-5,5'-diamine;

[0129] D-16: [2,2'-bipyrimidine]-5,5'-diamine;

[0130] D-17: 3,5-diamino-1,2,4-triazole;

[0131] <Catalyst>

[0132] C-1: Triethylamine;

[0133] C-2: Pyridine;

[0134] C-3: Imidazole;

[0135] C-4: Piperidine;

[0136] C-5: Monoethanolamine.

[0137] Preparation of Amino Acid / Amino Ester Oligomers

[0138] Examples 1 to 44 and Comparative Examples 1 to 28: Following the amounts specified in Tables 1 to 3, the dianhydrides were weighed, poured into reaction flasks, and 2000 g of NMP solvent was added and stirred. Each diamine monomer was added at room temperature and stirred for 1 hour, then heated to 50°C for 8 hours, and finally cooled to room temperature for collection. Solvent was added as needed to adjust the solid content to obtain an amic acid / amic ester oligomer solution with a solid content of 20 wt%.

[0139] Examples 45 to 57: The synthesis of amic acid / amic acid ester oligomers was the same as described above. However, after cooling to room temperature, a specified weight percentage (relative to the weight of the amic acid / amic acid ester oligomer) of catalyst was added, and the mixture was stirred for another 2 hours before collection. Due to the addition of the catalyst, the subsequent curing temperature (see the hard bake temperature in Table 4) was reduced.

[0140] Examples 58 to 66: Compared to Examples 45 to 57, no catalyst was added, but the same low subsequent curing temperature was maintained as in Examples 45 to 57.

[0141] Peel strength (adhesion) test between polyimide and glass

[0142] like Figure 3 As shown in the schematic diagram, a 20 cm × 20 cm Corning EXG (0.7 mm thick) glass substrate 31 was taken. A 20 cm × 1.5 cm PI tape 32 was attached to the right side of the upper surface of the glass substrate 31. The amyl acid / amyl ester oligomer adhesive of the examples and comparative examples was spin-coated onto the glass substrate 31 and the PI tape 32. Then, soft baking (90°C / 10 min) and hard baking (two stages: 150°C / 1hr + 350°C / 2hr or 150°C / 1hr + 250°C / 2hr) were performed (depending on the different examples) to prepare a polyimide film with a thickness of 10 μm. After hard baking, the sample was cut into 20 cm × 1 cm test strips along the cutting line 33 with a blade. The PI tape side of the test strip was separated from the glass, and the polyimide film on the PI tape side was pulled up. The tensile strength of the pulled-up polyimide film was tested and recorded using an Instron 3342 tensile testing machine. A peel strength greater than 550 gf / cm is considered passing; otherwise, the subsequent peel strength (adhesion) test between polyimide and metal will not be conducted.

[0143] Peel strength (adhesion) test between polyimide and metal

[0144] The amyl acid / amyl ester oligomer solutions of the examples and comparative examples were spin-coated onto a 20 cm x 20 cm Corning EXG (0.7 mm thick) glass substrate. The PI coating thickness was 1 μm. After soft baking at 80°C for 5 min, a hard baking was performed at temperatures of 150°C / 1 hr + 350°C / 2 hr or 150°C / 1 hr + 250°C / 2 hr (depending on the specific example). After hard baking, the treated samples were immersed in an aqueous solution containing 1.5 g / L sodium hydroxide and 0.5 g / L palladium sulfate at 50°C for 10 minutes, rinsed with pure water, and then immersed in a 1M diaminoborane aqueous solution at 25°C. (aq)The plating process (NH2-BH-NH2) lasted for 10 minutes, followed by rinsing and drying with pure water. Electroless nickel plating (NPR-18 (manufactured by Uemura Kogyo Co., Ltd.), 45°C, 3 minutes) was then performed, followed by copper plating to a thickness of 18 μm (electroplating solution composition: copper sulfate: 70 g / L, sulfuric acid: 200 g / L, chloride ions: 50 mg / L, electroplating additive (LUCINA SF-M, Okuno Pharmaceutical Co., Ltd.): 5 mL / L. Electroplating temperature: 25°C, cathode current density: 3 A / dm³). 2 ).

[0145] The sample was cut into 20 cm × 1 cm test strips. The polyimide layer at the end of the test strip was slightly separated from the copper plating layer, and the peel strength was measured using an Instron 3342 tensile testing machine. A peel strength greater than 400 gf / cm was considered passing.

[0146] The second-stage hard-bake temperature and test results of each embodiment and comparative example are recorded in Tables 1 to 4.

[0147] Table 1

[0148]

[0149]

[0150] Table 2

[0151]

[0152] Table 3

[0153]

[0154]

[0155] Table 4

[0156]

[0157] Tables 1 to 4 show that the polyimide of the present invention comprises a diamine residue selected from nitrogen-containing heteroaromatic rings having at least two nitrogen atoms, aromatic rings or heterocycles having at least two -COOH groups, and combinations thereof, and The polyimide has a group that allows it to form a peel strength of over 550 gf / cm between the polyimide and glass, and over 400 gf / cm between the polyimide and metal.

[0158] The effects of different glasses on tensile strength were tested using polyimide from Examples 58 and 61, as shown in Table 5.

[0159] Table 5

[0160]

[0161] The results show that the polyimide of the present invention is applicable to a variety of glass substrates, and its peel strength with glass is greater than 1600 gf / cm, so it cannot be separated. Its peel strength with metal is greater than the requirement of 400 gf / cm.

Claims

1. A polyimide precursor composition comprising an oligomer having the structure of formula (I): (I)， in: G can be an independent tetravalent organic group. R x Each is independent of H, C1-C 14 Alkyl groups, or groups containing ethylene unsaturated groups, n is an integer from 1 to 200, and Each P is an independent divalent organic group, wherein, based on the total molar number of all divalent organic groups P in the oligomer, approximately 1 mol% to approximately 20 mol% of the divalent organic groups P are diamine residues selected from nitrogen-containing heteroaromatic rings having at least two nitrogen atoms, aromatic rings or heterocycles having at least two -COOH groups, and combinations thereof, and approximately 0.5 mol% to approximately 40 mol% of the divalent organic groups P are... , in: R 1 and R 2 Each is independently a C1-C4 alkyl group. R 3 R 4 R 5 and R 6 Each is independently H, C1-C4 alkyl, or phenyl, and m is an integer greater than 0.

2. The polyimide precursor composition according to claim 1, wherein: R 1 and R 2 All are methylene, ethylene, or n-propylene, and R 3 R 4 R 5 and R 6 Each can be methyl or phenyl independently.

3. The polyimide precursor composition according to claim 2, wherein: R 1 and R 2 All are n-propyltrimethylamine. R 3 R 4 R 5 and R 6 Each is independently a methyl group, and m is 1.

4. The polyimide precursor composition according to claim 1, wherein the diamine residue is selected from... , , , , , and their combinations.

5. The polyimide precursor composition according to claim 1, wherein P further comprises a separate divalent aromatic group or a divalent heterocyclic group selected from the group consisting of: , , and their combinations, in: R9 can be independently H, C1-C4 alkyl, C1-C4 perfluoroalkyl, C1-C4 alkoxy, halogen, -OH, -COOH, -NH2, or -SH. each 'a' is an independent integer from 0 to 4. b are each an independent integer from 0 to 4, and R 10 It is a covalent bond or a group selected from the group consisting of: -O-, -S-, -CH2-, -S(O)2-, , , -C(CF3)2-, -C(O)-, -C(CH3)2-, -CONH-, , , and , in: c and d are each independent integers from 0 to 20. R9 and a are as described above; and R 12 It is -S(O)2-, covalent, C1-C-4 alkylene or C1-C4 perfluoroalkylene.

6. The polyimide precursor composition according to claim 1, wherein G is selected from the group consisting of: and ; in: X can be hydrogen, halogen, C1-C4 perfluoroalkyl, or C1-C4 alkyl. A and B each appear independently as covalent bonds, unsubstituted or substituted with one or more groups selected from hydroxyl and C1-C4 alkyl groups, including C1-C4 perfluoroalkylene, C1-C4 alkoxide, silane, -O-, -S-, -C(O)-, -OC(O)-, -S(O)2-, -C(=O)O-(C1-C4 alkylene)-OC(=O)-, -CONH-, phenylene, biphenylene, or... , in: K is -O-, -S(O)2-, C1-C4 alkylene or C1-C4 perfluoroalkylene.

7. The polyimide precursor composition according to claim 5, wherein: G is a group composed of the following: Z can be H, methyl, trifluoromethyl, or halogen. Each divalent aromatic group or divalent heterocyclic group in P is selected from the group consisting of the following: and its combinations, Where each 'a' is an independent integer from 0 to 4, and each 'Z' is an independent hydrogen, methyl, trifluoromethyl, or halogen. R x Each of these can be independently H, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tributyl, 2-hydroxypropyl methacrylate, ethyl methacrylate, ethyl acrylate, propenyl, methacryl, n-butenyl, or isobutylenyl. n is an integer from 5 to 150.

8. The polyimide precursor composition according to claim 5, wherein G is selected from the group consisting of: , , , , , , , and .

9. The polyimide precursor composition of claim 5, wherein the divalent aromatic group or divalent heterocyclic group is selected from the group consisting of: , , and their combinations.

10. A polyimide film obtained from a polyimide precursor composition as claimed in any one of claims 1 to 9.

11. Use of a polyimide precursor composition according to any one of claims 1 to 9 or a polyimide film according to claim 10, wherein the composition is used for modifying a glass substrate, or as an adhesion agent coated on the surface of a glass substrate to improve the adhesion of a metal layer to the glass.

Images