Manufacturing method of an embedded chip substrate and temporary bonding structure

Abstract

The application discloses a manufacturing method of an embedded chip substrate and a temporary bonding structure, and relates to the technical field of semiconductor packaging, so as to solve the problem of excessive warping of the substrate in the manufacturing process. The manufacturing method of the embedded chip substrate comprises the following steps: substrate windowing, first temporary bonding, chip pasting, first compression and resin embedding, second temporary bonding, first debonding, second compression and resin embedding, second debonding, circuit manufacturing, resin insulation layer processing, intermediate circuit manufacturing and solidification. In the method, the resin in the structure is in an incomplete solidification state before the symmetric structure is formed, pre-solidification is performed after each resin layer is processed, and complete solidification is not performed. After all the resin layers are processed, solidification is performed once again, so that the symmetric structure can be formed after the low warping state is maintained, and the solidification rate is above 90%, and the resin cracking can be effectively avoided. The temporary bonding structure is a temporary structure generated in the manufacturing method of the embedded chip substrate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor packaging, and in particular to a manufacturing method of an embedded chip substrate and a temporary bonding structure. BACKGROUND

[0002] Embedding a chip in a substrate is an advanced packaging form. By embedding a bare chip in a substrate, the packaging size can be reduced, the signal transmission distance between chips and the surface packaging elements of the substrate can be greatly reduced, the signal transmission loss can be reduced, and the signal transmission quality can be improved.

[0003] At present, the main manufacturing method of the embedded chip substrate is to embed a bare chip in a printed circuit board core plate by digging a cavity, fill the cavity with resin, and then form a substrate by multi-layer wiring on both sides of the core plate.

[0004] In the existing manufacturing method of the embedded chip substrate, the substrate is prone to severe warping during the single-sided pressing process after filling the resin on one side of the substrate. During the insulation lamination and curing and baking process of the other side of the substrate, the substrate is flattened again. The repeated bending of the substrate from warping to flattening can cause the rigid resin to crack due to the high modulus of the cured embedded resin. The weak interfacial bonding force between the rigid embedded resin and the chip can also cause the interface to crack. Resin cracking and chip interface separation can cause the embedded substrate to fail, and even in a humid environment, water vapor can accumulate at the cracked interface, causing the embedded substrate to burn and other serious reliability problems. Therefore, how to reduce the warping of the substrate during substrate processing and manufacturing is a technical problem in the processing and manufacturing of embedded substrates, and is an important problem in improving the reliability of embedded substrates. SUMMARY

[0005] The present application provides a manufacturing method of an embedded chip substrate and a temporary bonding structure.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0007] A manufacturing method of an embedded chip substrate, comprising the steps of:

[0008] Windowing the substrate to form a receiving cavity for accommodating the chip, the two sides of the substrate being a first bonding surface and a resin filling surface, respectively;

[0009] First temporary bonding, bonding a first bonding material layer to the first bonding surface, the first bonding material layer comprising a foamed film, a support film and a pressure-sensitive adhesive film stacked in sequence, and the foamed film of the first bonding material layer being bonded to the substrate, and a first support plate being fixed to the side of the first bonding material layer away from the substrate;

[0010] Chip pasting, pasting a chip in the accommodating cavity;

[0011] First compression of embedding resin, compressing embedding resin on the embedding resin surface of the substrate to form a first resin layer, and the second bonding surface is on the side of the first resin layer away from the substrate;

[0012] Second temporary bonding, bonding a second bonding material layer on the second bonding surface, the second bonding material layer includes a foaming film, a supporting film and a pressure sensitive adhesive film which are stacked in sequence, the foaming film of the second bonding material layer is bonded with the first resin layer, and a second supporting plate is fixed on the side of the second bonding material layer away from the first resin layer, and the first pre-curing is performed;

[0013] First debonding, debonding the foaming film of the first bonding material layer and the first bonding surface to remove the first bonding material layer and the first supporting plate;

[0014] Second compression of embedding resin, compressing embedding resin on the first bonding surface of the substrate to form a second resin layer, and the second pre-curing is performed;

[0015] Second debonding, debonding the foaming film of the second bonding material layer and the first resin layer to remove the second bonding material layer and the second supporting plate;

[0016] Blind hole processing, blind holes are formed on the upper surface and the lower surface of the structure formed in the previous step;

[0017] Circuit manufacturing, circuits are processed on the upper surface and the lower surface of the structure formed in the previous step;

[0018] Resin insulation layer processing, resin insulation layers are arranged on the upper surface and the lower surface of the structure formed in the previous step, and the pre-curing is performed;

[0019] Intermediate circuit manufacturing, the blind hole processing, the circuit manufacturing and the resin insulation layer processing steps are repeated N times, N≥0, to form N layers of intermediate circuits, and the pre-curing is not performed in the Nth resin insulation layer processing step, and the copper foil is compressed on the surface of the resin insulation layer formed in the Nth resin insulation layer processing step, and then the pre-curing is performed, so that the resin insulation layer in the formed structure is cured to more than 50%;

[0020] Curing, the structure formed in the previous step is cured to more than 90% in a laminator under the clamping of a mirror surface steel plate, a preset vacuum degree and a preset pressure;

[0021] Outer circuit manufacturing, the blind hole processing and the circuit manufacturing steps are performed on the cured structure to form an outer circuit;

[0022] Resist layer manufacturing, a resist layer is manufactured on the surface of the outer circuit;

[0023] a coating layer, the structure surface formed after the manufacturing of the solder resist layer is coated with the coating layer.

[0024] In an implementation, the first debonding is followed by a first cleaning of the first bonding surface; and / or,

[0025] The second debonding is followed by a second cleaning of the second bonding surface.

[0026] In an implementation, the first pre-curing is specifically to cure the resin in the structure formed in this step to more than 50%; or, the first pre-curing is specifically to place the structure formed in this step in a constant temperature environment of 130-150℃ for 30-60min to pre-cure the resin in the structure.

[0027] In an implementation, the second pre-curing is specifically to cure the resin in the structure formed in this step to more than 80%; or, the second pre-curing is specifically to place the structure formed in this step in a constant temperature environment of 170-185℃ for 25-35min to pre-cure the resin in the structure.

[0028] In an implementation, the pre-curing in the resin insulation layer processing step is specifically to cure the resin insulation layer in the structure to 70-80%; or, the pre-curing in the resin insulation layer processing step is specifically to place the structure formed in a constant temperature environment of 95-105℃ for 25-35min, and then place it in a constant temperature environment of 170-185℃ for 25-35min.

[0029] In an implementation, the raw material used in the first pressing and burying resin step, the second pressing and burying resin step, and the insulation layer processing step is all ABF resin sheet, which includes an ABF layer, an OPP film attached to the first side of the ABF layer, and a PET film attached to the second side of the ABF layer.

[0030] In an implementation, the first pressing and burying resin step is specifically to remove the OPP film of the ABF resin sheet, and press the first side of the ABF resin sheet against the burying resin surface of the substrate to form a first resin layer, and perform a first pre-curing to cure the resin in the structure formed in this step to more than 50%, the side of the first resin layer away from the substrate being the second bonding surface and retaining the PET film; and / or,

[0031] The second pressing and filling resin step specifically involves removing the OPP film of the ABF resin sheet and pressing the first side of the ABF resin sheet onto the first bonding surface of the substrate to form a second resin layer, and performing a second pre-curing to cure the resin in the structure formed in this step to more than 70%, with the second resin layer retaining the PET film.

[0032] In one implementation, the curing temperature of the first pre-curing is lower than the debonding temperature of the first bonded material layer; or,

[0033] The debonding temperature of the first bonding material layer is lower than that of the second bonding material layer.

[0034] A temporary bonding structure, comprising:

[0035] A substrate having an accommodating cavity for accommodating a chip, and the two sides of the substrate being a first bonding surface and an embedded resin surface, respectively;

[0036] The chip is disposed within the accommodating cavity;

[0037] A first bonding material layer and a first support plate, wherein the first bonding material layer is bonded to the first bonding surface, the first bonding material layer includes a foamed film, a support film and a pressure-sensitive adhesive film stacked in sequence, and the foamed film of the first bonding material layer is bonded to the substrate, and the first support plate is bonded to the pressure-sensitive adhesive film of the first bonding material layer;

[0038] A first resin layer is located on the buried resin surface of the substrate, and the side of the first resin layer facing away from the substrate is the second bonding surface.

[0039] The second bonding material layer and the second support plate are bonded to the second bonding surface. The second bonding material layer includes a foamed film, a support film and a pressure-sensitive adhesive film stacked in sequence. The foamed film of the second bonding material layer is bonded to the first resin layer, and the second support plate is bonded to the pressure-sensitive adhesive film of the first bonding material layer.

[0040] In one implementation, the back side of the chip is bonded to the foam film of the first bonding material layer.

[0041] In one implementation, the first support plate and / or the second support plate are double-sided copper-clad laminates, metal plates, glass plates, or ceramic plates; and / or, the thickness of the first support plate and / or the second support plate is greater than 0.2 mm.

[0042] In the manufacturing method of the embedded chip substrate provided in the above embodiment, the foamed film of the first bonding material layer is bonded to the first bonding surface of the substrate, and the foamed film of the second bonding material layer is bonded to the first resin layer, so that contamination caused by the pressure-sensitive adhesive can be avoided. In the debonding process, the first debonding step only needs to heat to the debonding temperature of the foamed film of the first bonding material layer, and the second debonding step only needs to heat to the debonding temperature of the foamed film of the second bonding material layer, so that the foamed film is separated from the substrate or the first resin layer. Compared with the pressure-sensitive adhesive film and the substrate or the first resin layer, contamination caused by the pressure-sensitive adhesive can be avoided, and debonding is easier.

[0043] In the above embodiment, the chip is placed in the accommodating cavity, and the back surface of the chip is bonded to the foamed film of the first bonding material layer. The back surface of the chip is the side of the chip away from the bonding pad, and the front surface of the chip is the side of the chip with the bonding pad. That is, the side of the chip away from the bonding pad is bonded to the foamed film of the first bonding material layer. After the first debonding is completed, cleaning is performed to remove the temporary bonding adhesive residues generated in the debonding process of the foamed film. The cleaning includes water washing, ultrasonic water washing, and adhesive removal treatment in an adhesive removal tank, so that the temporary bonding adhesive residues on the surface of the substrate and the temporary bonding adhesive residues on the back surface of the chip are effectively removed. If the side of the chip with the bonding pad is bonded to the foamed film of the first bonding material layer, the adhesive removal tank cannot be used for adhesive removal treatment, and more strict cleaning is required, and the cleaning process is more complex. Therefore, the back surface of the chip is preferably bonded to the foamed film of the first bonding material layer.

[0044] In addition, in the manufacturing method of the embedded chip substrate provided in the above embodiment, the first filling and embedding resin is pre-cured after the first pressing, and the second filling and embedding resin is pre-cured after the second pressing. Pre-curing is performed after each resin insulation layer processing, but complete curing is not performed. The curing degree of the resin in the structure is below 80% after the intermediate circuit is completed. After all the resin layers are processed, one-time curing is performed. In the curing step, the resin layers in the formed structure are cured to above 90%. In other words, in this application, pre-curing is performed after each resin layer processing, but complete curing is not performed. After all the resin layers are processed, one-time curing is performed to achieve a curing degree of above 90%. In the manufacturing method of the embedded chip substrate, the resin in the structure is in an incomplete curing state before the symmetrical structure is formed. In this way, the symmetrical structure is formed after the curing degree is above 90% in a low warping state, and resin cracking can be effectively avoided.

[0045] The application also provides a temporary bonding structure. The temporary bonding structure provided in the application has the same beneficial effects as the manufacturing method of the embedded chip substrate provided in the above technical solution, and details are not repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0046] The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings:

[0047] Figure 1 A flow chart of a method for manufacturing an embedded chip substrate according to an embodiment of the present application;

[0048] Figure 2 A structure formed after a substrate opening step according to an embodiment of the present application;

[0049] Figure 3 A structure formed after a first temporary bonding step according to an embodiment of the present application;

[0050] Figure 4 A structure formed after a chip attaching step according to an embodiment of the present application;

[0051] Figure 5 A structure formed after a first compression filling resin step according to an embodiment of the present application;

[0052] Figure 6 A structure formed after a second temporary bonding step according to an embodiment of the present application;

[0053] Figure 7 A structure formed after a first debonding step according to an embodiment of the present application;

[0054] Figure 8 A structure formed after a second compression filling resin step according to an embodiment of the present application;

[0055] Figure 9 A structure formed after a second debonding step according to an embodiment of the present application;

[0056] Figure 10 A structure formed after a blind via processing step according to an embodiment of the present application;

[0057] Figure 11 A structure formed after a circuit fabrication step according to an embodiment of the present application;

[0058] Figure 12 A structure formed after a first resin insulation layer processing step according to an embodiment of the present application;

[0059] Figure 13 A structure formed after a repeated circuit fabrication step according to an embodiment of the present application;

[0060] Figure 14 A structure formed after a second resin insulation layer processing step according to an embodiment of the present application;

[0061] Figure 15 The structure formed after the step of manufacturing the outer layer circuit provided by the embodiment of the present application;

[0062] Figure 16 The structure formed after the step of manufacturing the solder resist layer provided by the embodiment of the present application;

[0063] Figure 17 The structure schematic diagram of the first bonding material layer or the second bonding material layer provided by the embodiment of the present application.

[0064] The figure mark: 1-substrate, 1a-housing cavity, 1b-substrate circuit, 2-first bonding material layer, 3-first support plate, 4-chip, 5-first resin layer, 6-second bonding material layer, 7-second support plate, 8-second resin layer, 9-blind hole, 10-resin layer outside circuit, 11-first resin insulation layer, 12-first resin insulation layer outside circuit, 13-second resin insulation layer, 14-outer layer circuit, 15-solder resist layer, a-foamed film, b-supporting film, c-pressure sensitive adhesive film. DETAILED DESCRIPTION

[0065] In order to make the technical problems, technical solutions and beneficial effects of the present application more clearly understood, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0066] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0067] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited. The meaning of "several" is one or more, unless otherwise explicitly and specifically limited.

[0068] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0069] In the description of the present application, it should be noted that unless specifically defined and limited otherwise, the terms "mounting", "connected", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0070] Please refer to Figure 1 , Figure 1 The flow chart of the embodiment provided by the present application, the manufacturing method of the embedded chip substrate in the embodiment includes the following steps:

[0071] S1: opening window of the substrate 1, opening the accommodating cavity 1a for accommodating the chip 4 on the substrate 1, and the two surfaces of the substrate 1 are respectively the first bonding surface and the filling resin surface;

[0072] In this step, the surface of the substrate 1 can have a circuit or not, Figure 2 The substrate has a substrate circuit 1b. Specifically, the substrate 1 can be a resin substrate 1 without surface circuit or a double-sided copper clad plate without surface circuit, of course, the copper circuit can also be arranged on the surface of the substrate 1. The accommodating cavity 1a opened on the substrate 1 can be a through hole penetrating through the thickness direction of the substrate 1. The two surfaces of the substrate 1 are respectively the first bonding surface and the filling resin surface. Specifically, the two surfaces of the substrate 1 along the thickness direction of the substrate 1 are respectively the first bonding surface and the filling resin surface, or in other words, when the substrate 1 is placed horizontally, that is, the thickness direction of the substrate 1 is along the vertical direction, the upper surface and the lower surface of the substrate 1 are respectively the filling resin surface and the first bonding surface. The structure formed after the opening window step of the substrate 1 is shown in Figure 2 .

[0073] The substrate 1 can be a BT (Bismaleimide Triazine) resin substrate or a substrate 1 of FR4 material. The BT resin material has a very high glass transition temperature, excellent dielectric properties, low thermal expansion rate, good mechanical characteristics and other properties, which is more suitable for the manufacture of the substrate 1. FR4 is a code of a kind of flame retardant material grade, which means that the resin material must be able to extinguish itself after burning. Of course, the substrate 1 can also be of other materials, which is not limited here.

[0074] S2: first temporary bonding, bonding the first bonding material layer 2 to the first bonding surface, the first bonding material layer 2 includes the foaming film a, the supporting film b and the pressure sensitive adhesive film c which are stacked in sequence, and the foaming film a of the first bonding material layer 2 is bonded with the substrate 1, and the side of the first bonding material layer 2 away from the substrate 1 is fixed with the first supporting plate 3;

[0075] In this embodiment, the first bonding material layer 2 can be 3195N temporary bonding glue produced by Nitto Company and capable of being thermally foamed at 170°C. Of course, other temporary bonding glue can also be selected according to actual conditions, which is not limited herein. Figure 3

[0076] It should be noted that the first bonding material layer 2 can be bonded with the first support plate 3 first and then bonded with the substrate 1. In this way, the first bonding material layer 2 can be bonded with the first support plate 3 in advance before the chip 4 is packaged for standby. Of course, the first bonding material layer 2 can also be bonded with the substrate 1 first and then bonded with the first support plate 3, which is not limited herein.

[0077] The material of the first support plate 3 can be BT resin, and the first support plate 3 can be a double-sided copper-clad plate made of BT resin. Of course, the first support plate 3 can also be made of other materials, which is not limited herein. The thickness of the first support plate 3 can be greater than or equal to 0.2 mm. Specifically, the thickness of the first support plate 3 can be 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, etc. Further, the thickness of the first support plate 3 can be greater than or equal to 0.8 mm, such as 0.8 mm, 0.9 mm, etc. In this way, the strength of the first support plate 3 can be ensured to prevent the substrate 1 from warping during processing.

[0078] In this embodiment, the first bonding material layer 2 can be 3195N temporary bonding glue produced by Nitto Company and capable of being thermally foamed at 170°C. Of course, other temporary bonding glue can also be selected according to actual conditions, which is not limited herein.

[0079] S3: Paste the chip 4, and set the chip 4 in the accommodating cavity 1a;

[0080] The chip 4 is set in the accommodating cavity 1a of the substrate 1. The electrode side of the chip 4 can face away from the side of the first bonding material layer 2, that is, the electrode of the chip 4 is placed upward, or the electrode side of the chip 4 can be placed downward. When the accommodating cavity 1a is a through hole, the chip 4 can be in contact with the foamed film a of the first bonding material layer 2, and when the electrode side of the chip 4 is downward, the electrode thereof is in contact with the foamed film a of the first bonding material layer 2. The structure formed after the step of pasting the chip 4 is shown in Figure 4

[0081] ​​Preferably, when the chip 4 is attached, the electrode side of the chip 4 can be directed to the side away from the first bonding material layer 2, i.e. the electrodes of the chip 4 are directed upward, so that the foamed film of the first bonding material layer 2 does not contact the electrodes of the chip 4, but contacts the back of the chip 4, and can also prevent the chip electrode surface from being contaminated, which can cause the contaminants to be embedded in the substrate and cause serious reliability problems. Alternatively, the surface insulating layer of the chip 4 can also be made of a resin with a protective film to prevent the chip electrode surface from being contaminated.

[0082] S4: First pressing and filling resin, pressing and filling resin on the filling resin surface of the substrate 1 to form a first resin layer 5, and the side of the first resin layer 5 away from the substrate 1 being a second bonding surface;

[0083] That is, pressing and filling resin on the filling resin surface of the substrate 1, and the filled resin forming a first resin layer 5. In this embodiment, the filling resin surface can be the upper surface of the substrate 1. Pressing and filling resin on the filling resin surface of the substrate 1 can be pressing resin on the filling resin surface of the substrate 1, which can be specifically performed by a vacuum film pressing machine to press resin on the filling resin surface of the substrate 1. During the process of pressing and filling resin, the resin fills the gaps between the circuits on the surface of the substrate 1 and the gaps around the chip 4. The structure formed after this first pressing and filling resin step is shown in FIG. 2. Figure 5

[0084] The surface of the first resin layer 5 has a protective film, and in the second temporary bonding step, the foamed film of the second bonding material layer 6 is bonded to the protective film of the first resin layer 5, so that after debonding, the protective film can be peeled off to prevent contamination.

[0085] ABF resin sheet can be selected in this first pressing and filling resin step. The ABF resin sheet includes an ABF layer, an OPP (O-phenylphenol) film attached to the first side of the ABF layer, and a PET (polyethylene glycol terephthalate) film attached to the second side of the ABF layer.

[0086] In this first pressing and filling resin step, the OPP film of the ABF resin sheet is removed, and the first side of the ABF resin sheet is pressed onto the filling resin surface of the substrate to form a first resin layer, and the side of the first resin layer away from the substrate is a second bonding surface and retains the PET film. That is, in this step, the OPP film of the ABF resin sheet is torn off and the PET film is retained. The side of the ABF resin sheet from which the OPP film is removed is pressed onto the filling resin surface of the substrate.

[0087] ​Specifically, low-temperature vacuum pressing can be performed by using a vacuum laminator to press the ABF resin sheet without OPP film on the filling resin surface of the substrate, in which only lamination and flattening of the ABF resin sheet are achieved in the vacuum laminator, which includes a vacuum laminating section and a flattening section. The vacuum laminating section is mainly used to press the ABF resin sheet on the filling resin surface of the substrate, and the surface of the ABF resin sheet is still uneven after pressing by the vacuum laminating section due to the uneven inner layer circuit surface. Then, the flattening section is used to flatten the ABF resin sheet to make the surface of the ABF resin sheet flat.

[0088] The resin can be specifically selected as an ABF resin sheet of model GXT31. Of course, the resin can also be a semi-cured PP (Prepreg) sheet or a resin-coated copper (Resin Coated Copper, RCC) sheet, which is not limited herein.

[0089] S5: Second temporary bonding, bonding the second bonding material layer 6 to the second bonding surface, and fixing the second support plate 7 on the side of the second bonding material layer 6 away from the first resin layer 5; the second bonding material layer 6 includes a foaming film a, a support film b and a pressure-sensitive adhesive film c which are sequentially stacked, and the foaming film a of the second bonding material layer 6 is bonded to the first resin layer 5, specifically, the foaming film a of the second bonding material layer 6 is bonded to the protective film of the first resin layer 5, and the protective film can be a copper foil or a film of other materials. The second support plate 7 is fixed on the side of the second bonding material layer 6 away from the first resin layer 5, and the first pre-curing is performed in this step.

[0090] In this embodiment, the second bonding surface is the upper surface of the first resin layer 5. The second support plate 7 is fixed on the side of the second bonding material layer 6 away from the first resin layer 5, i.e., the second bonding material layer 6 is located between the second support plate 7 and the first resin layer 5, and the second support plate 7 is bonded to the pressure-sensitive adhesive film c of the second bonding material layer 6. The structure formed after the second temporary bonding is shown in Figure 6 .

[0091] It should be noted that the second bonding material layer 6 can be bonded to the second support plate 7 first and then bonded to the first resin layer 5, so that the second bonding material layer 6 can be bonded to the second support plate 7 in advance before the chip 4 is packaged for standby. Of course, the second bonding material layer 6 can also be bonded to the first resin layer 5 first and then bonded to the second support plate 7, which is not limited herein.

[0092] After the second bonding material layer 6 is bonded to the second bonding surface, the first pre-curing is performed. The first pre-curing can be low-temperature thermal curing, which cures the first resin layer 5 to a certain extent but not completely. The structure formed after the first pressing and filling resin step is shown in Figure 5 .

[0093] The first pre-curing can be specifically that the structure formed in this step is placed in a constant temperature environment of 140°C for 30 minutes. The first pre-curing is performed in an oven.

[0094] The material of the second support plate 7 can be BT resin, and the second support plate 7 can be a double-sided copper-clad plate made of BT resin. Of course, the second support plate 7 can also be made of other materials, which are not limited herein. The thickness of the second support plate 7 can be greater than or equal to 0.2 mm, and specifically, the thickness of the second support plate 7 can be 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, etc. Further, the thickness of the second support plate 7 can be greater than or equal to 0.8 mm, such as 0.8 mm, 0.9 mm, etc., so as to ensure the strength of the second support plate 7 and prevent the substrate 1 from warping during processing.

[0095] In this embodiment, the second bonding material layer 6 can be 31950E temporary bonding glue produced by Nitto Company with a foaming debonding temperature of 210°C. Of course, other temporary bonding glue can also be selected according to actual conditions, which are not limited herein.

[0096] Since only the OPP film of the ABF resin sheet is torn off and the PET film is retained in the S4 step, the second bonding material layer 6 is directly bonded with the PET film of the first resin layer 5, so as to avoid the second bonding material layer 6 directly contacting the ABF layer of the first resin layer 5. After subsequent debonding, the PET film is torn off, so as to ensure that the first resin layer 5 is not contaminated and residual by bonding. The PET film can be torn off before the blind hole processing step or after the blind hole processing step.

[0097] S6: First debonding, debonding the foamed film a of the first bonding material layer 2 from the first bonding surface to remove the first bonding material layer 2 and the first support plate 3;

[0098] In this step, only the foamed film a of the first bonding material layer 2 is debonded from the first bonding surface of the substrate 1, that is, the first bonding material layer 2 and the first support plate 3 are removed from the substrate 1, while the foamed film a of the second bonding material layer 6 is not debonded from the first resin layer 5, and the foamed film a of the second bonding material layer 6 is still bonded with the first resin layer 5. The first debonding can be low-temperature debonding, and the debonding temperature of the first bonding material layer 2 is lower than that of the second bonding material layer 6. The structure formed after the first debonding step is shown in Figure 7

[0099] ​The first pre-curing temperature should be lower than the debonding temperature of the first bonding material layer 2. If the debonding temperature of the first bonding material layer 2 is 170°C, the first pre-curing temperature should be lower than 170°C. Preferably, the first pre-curing temperature is lower than the debonding temperature of the first bonding material layer 2 by 10°C or more, or by 25-35°C. Specifically, the first pre-curing temperature is lower than the debonding temperature of the first bonding material layer 2 by 10°C, 15°C, 20°C, 25°C, 30°C, or 35°C. Preferably, the first pre-curing temperature can be lower than the debonding temperature of the first bonding material layer 2 by 20°C or 30°C.

[0100] S7: Second compression of the embedding resin, the embedding resin is compressed on the first bonding surface of the substrate 1 to form the second resin layer 8, and second pre-curing is performed;

[0101] That is, the embedding resin is compressed on the first bonding surface of the substrate 1 to form the second resin layer 8. The compression of the embedding resin on the first bonding surface of the substrate 1 can be the compression of the resin on the first bonding surface of the substrate 1, and specifically, a vacuum film compression machine can be used to compress the resin on the first bonding surface of the substrate 1. During the compression of the embedding resin, the resin fills the gaps between the surface circuits of the substrate 1 and the gaps around the chip 4.

[0102] After the compression of the embedding resin on the first bonding surface of the substrate 1, the second pre-curing is performed. The second pre-curing can be low-temperature thermal curing, which cures the second resin layer 8 to a certain extent but not completely. The structure formed after the second compression of the embedding resin is shown in FIG. 8. Figure 8 It should be noted that during the second pre-curing, the first resin layer 5 and the second resin layer 8 are further cured, and the first resin layer 5 and the second resin layer 8 reach the same curing degree after the second pre-curing, but the first resin layer 5 and the second resin layer 8 are not completely cured. The second pre-curing can specifically be: placing the structure formed in this step in a constant temperature environment of 180°C for 30 min.

[0103] It should be noted that the thickness and / or material of the first resin layer 5 and the second resin layer 8 can be the same, so that the structure of the first resin layer 5 and the second resin layer 8 on the upper and lower surfaces of the substrate 1 is symmetrical, thereby reducing warping.

[0104] ABF resin sheet can also be selected in the second lamination and filling resin step. In the second lamination and filling resin step, the OPP film of the ABF resin sheet is removed, and the first side of the ABF resin sheet is laminated to the first bonding surface of the substrate 1 to form the second resin layer 8, and the second pre-curing is performed, and the PET film is reserved on the side of the second resin layer 8 away from the substrate. That is, in this step, the OPP film of the ABF resin sheet is torn off and the PET film is reserved. The side of the ABF resin sheet from which the OPP film is removed is laminated to the first bonding surface of the substrate 1.

[0105] Thus, the PET film can protect the ABF layer, and the PET film can be torn off before or after the blind hole processing. The lamination of the second resin layer 8 is also performed in the vacuum laminator, and the second pre-curing is performed in the oven, which will not be described in detail here.

[0106] In this step, the ABF resin sheet with the model GXT31 can be selected as the resin. Of course, the resin can also be a semi-cured PP sheet or a resin sheet RCC with copper, which is not limited here.

[0107] S8: second debonding, the foamed film a of the second bonding material layer 6 and the first resin layer 5 are debonded to remove the second bonding material layer 6 and the second support plate 7.

[0108] In this step, the foamed film a of the second bonding material layer 6 is debonded from the second bonding surface of the first resin layer 5, that is, the second bonding material layer 6 and the second support plate 7 are removed from the substrate 1. The structure formed after the second debonding step is shown in Figure 9 .

[0109] The debonding temperature of the second bonding material layer 6 should be higher than the debonding temperature of the first bonding material layer 2, and the debonding temperature of the second bonding material layer 6 can be 210°C. Moreover, the second pre-curing temperature should be lower than the debonding temperature of the second bonding material layer 6, and if the debonding temperature of the second bonding material layer 6 is 210°C, the second pre-curing temperature should be lower than 210°C. Preferably, the second pre-curing temperature is lower than the debonding temperature of the second bonding material layer 6 by more than 10°C or 25-35°C, and specifically, the second pre-curing temperature can be lower than the debonding temperature of the second bonding material layer 6 by 20°C or 30°C.

[0110] S9: blind hole 9 processing, blind hole 9 is opened on the upper surface and the lower surface of the structure formed in the previous step. That is, the blind hole 9 is opened on the upper surface and the lower surface of the structure formed in the previous step before the blind hole 9 processing step, which can be the surface of the first resin layer 5 and the second resin layer 8 in this embodiment, so that the circuit covered by the first resin layer 5 and the second resin layer 8 is electrically connected to the outer circuit 14 through the blind hole 9. Specifically, the laser drilling method can be used to form the blind hole 9 on the surface of the first resin layer 5 and the second resin layer 8. The structure formed after the blind hole 9 processing step is shown in FIG. 9. Figure 10

[0111] S10: circuit processing, the circuit is processed on the upper surface and the lower surface of the structure formed in the previous step;

[0112] Specifically, the circuit is processed on the upper surface and the lower surface of the structure formed in the previous step to form the resin layer outer circuit 10, which can be the circuit processed on the surface of the first resin layer 5 and the second resin layer 8 in this embodiment, and the circuit is electrically connected to the circuit covered by the first resin layer 5 and the second resin layer 8 through the blind hole 9. The structure formed after the circuit processing step is shown in FIG. 10. Figure 11

[0113] S11: resin insulation layer processing, the resin insulation layer is arranged on the upper surface and the lower surface of the structure formed in the previous step, and pre-curing is performed;

[0114] That is, the resin is pressed and filled on the upper surface and the lower surface of the structure formed in the previous step to form the resin insulation layer on the upper surface and the lower surface of the structure formed in the curing step. Specifically, the resin insulation layer formed in this step is the first resin insulation layer 11. The resin fills the gap between the circuits formed in the circuit processing step, and the first resin insulation layer 11 covers the circuits formed in the circuit processing step and partially contacts the first resin layer 5 or the second resin layer 8. Pre-curing is performed, and the pre-curing is the third pre-curing, that is, the first resin insulation layer 11 is cured to a certain degree, but not completely cured. The structure formed after the first resin insulation layer processing step is shown in FIG. 11. Figure 12

[0115] The resin insulation layer can also be an ABF resin sheet. In the insulation layer processing step, the OPP film of the ABF resin sheet is removed, and the first side of the ABF resin sheet is pressed on the upper surface and the lower surface of the structure formed in the previous step, and the third pre-curing is performed to cure the resin in the structure formed in this step to 70%-80%. The PET film is reserved on the side of the insulation layer away from the substrate to protect the insulation layer from being contaminated.

[0116] The resin of the insulation layer in this step can be an ABF resin sheet of model GXT31. Of course, the resin can also be a semi-cured PP sheet or a resin sheet RCC with copper, which is not limited here.​​​

[0117] The third pre-curing can be specifically placing the formed structure in a constant temperature environment of 100°C for 30 min, and then placing it in a constant temperature environment of 180°C for 30 min, so that the curing degree of the resin insulation layer reaches 70%-80%.

[0118] S12: making intermediate circuits, repeating the blind hole processing, circuit making and resin insulation layer processing steps for N times, N≥0, to form N layers of intermediate circuits, and not performing pre-curing in the Nth resin insulation layer processing step, and performing pre-curing after the copper foil is laminated on the surface of the resin insulation layer formed in the Nth resin insulation layer processing step, so that the resin insulation layer in the formed structure is cured to more than 50%.

[0119] Wherein, the blind hole 9 processing, circuit making and resin insulation layer processing steps are repeated for N times, N≥0, and N>0, and N layers of intermediate circuits can be processed in this step. When N=0, the outer circuit is directly processed. That is, one layer of intermediate circuit is processed each time the blind hole 9 processing, circuit making and resin insulation layer processing steps are repeated. In this embodiment, the focus is that, in addition to the Nth resin insulation layer processing step, pre-curing is performed once after the resin insulation layer is arranged on the surface of the circuit in each of the other resin insulation layer processing steps, and the curing is not complete. The structure formed after the repeated circuit making step is shown in Figure 13 .

[0120] The insulation layer formed in the repeated first resin insulation layer processing step is the second resin insulation layer, the insulation layer formed in the repeated second resin insulation layer processing step is the third resin insulation layer, and so on. Similarly, the pre-curing in the repeated first resin insulation layer processing step is the fourth pre-curing, the pre-curing in the repeated second resin insulation layer processing step is the fifth pre-curing, and so on.

[0121] When the blind hole processing, circuit making and resin insulation layer processing steps are repeated once, the upper surface and the lower surface of the structure formed in the previous step are laminated with filling resin to form the second resin insulation layer 13, that is, the upper surface and the lower surface of the structure formed in the repeated circuit making step are laminated with filling resin to form the second resin insulation layer 13. Specifically, the resin fills the gap between the circuits formed in the previous step, the second resin insulation layer 13 covers the circuits formed in the circuit making step and partially contacts the first resin insulation layer 11. And the fourth pre-curing is performed, that is, the resin in the structure is cured to a certain extent, but not completely cured. The structure formed after the second resin insulation layer processing step is shown in Figure 14 . The material of the second resin insulation layer 13 can also be ABF resin, and of course can also be PP (Prepreg semi-cured sheet) or resin-coated copper sheet RCC (Resin Coated Copper).

[0122] The fourth pre-curing can be specifically placing the formed structure in a constant temperature environment of 100°C for 30 minutes, and then placing it in a constant temperature environment of 180°C for 30 minutes, so that the curing degree of the first resin insulation layer 11 reaches 70%-80%.

[0123] Furthermore, the resin insulation layer surface formed in the Nth resin insulation layer processing step is pre-cured after the copper foil is pressed thereon, so that the resin insulation layer in the formed structure is cured to more than 50%.

[0124] Specifically, the copper foil is pressed on the surface of the resin insulation layer which is the outermost layer in the structure formed in the intermediate circuit manufacturing step. In this embodiment, the copper foil can be pressed on the upper surface and the lower surface of the structure formed in the intermediate circuit manufacturing step. It should be noted that if the surface of the resin layer which is the outermost layer in the structure formed in the previous step has a PET film, the PET film is removed before the copper foil is pressed thereon, and then pre-curing is performed.

[0125] Alternatively, the resin insulation layer and the copper foil can be pressed together in the Nth resin insulation layer processing step, that is, when the last layer of resin insulation layer is pressed, the last layer of resin insulation layer and the copper foil are pressed together.

[0126] It should be noted that in the S12 intermediate circuit manufacturing step, pre-curing is not performed after the resin insulation layer is pressed in the last resin insulation layer processing, or pre-curing can not be performed in the Nth resin insulation layer processing, that is, the copper foil is directly pressed after the resin insulation layer pressing is completed, and then pre-curing is performed. In the S12 intermediate circuit manufacturing step, pre-curing is performed after the resin insulation layer is pressed in the N-1 resin insulation layer processing steps except the last resin insulation layer processing.

[0127] S13: curing, the structure formed in the previous step is placed in a laminator with mirror steel plate clamping, and the resin in the structure is cured to more than 90% under the preset vacuum degree and the preset pressure.

[0128] In this step, high temperature curing can be used. After this step, all the resins in the structure are cured to more than 90%, i.e., the first resin layer 5, the second resin layer 8, the first resin insulation layer 11 and the second resin insulation layer 13 are cured to more than 90% or have a curing degree of more than 90%. Specifically, the resins in the structure to be formed are cured to more than 90% in an environment of more than 190°C. Specifically, the structure to be formed can be placed in a constant temperature environment of more than 190°C to cure the resins in the structure to more than 90%. For example, the structure to be formed can be placed in a constant temperature environment of 190°C or 195°C to cure the resins in the structure to more than 90%. Preferably, the structure to be formed is placed in a constant temperature environment of 190°C to cure the resins in the structure to more than 90%. In addition, the structure to be formed can also be placed in a constant temperature environment of 190°C-210°C to cure the resins in the structure to more than 90%.

[0129] Specifically, the structure to be formed can be placed in a laminator, the structure formed in the previous step is clamped by mirror steel plates, and the resins in the structure are cured to more than 90% under a preset vacuum degree and a preset pressure. Since the laminator has mirror steel plates on the top and bottom, the substrate structure is flattened and cured under a low warping at a low pressure of 0.1 MPa-0.7 MPa and a temperature of 190°C-210°C in a vacuum environment. The preset pressure is 0.1 MPa-0.7 MPa.

[0130] S14: manufacturing an outer layer circuit, performing blind hole processing and circuit manufacturing on the structure after curing to form an outer layer circuit;

[0131] Specifically, blind hole processing and circuit manufacturing are performed on the upper surface and the lower surface of the structure after curing, and in this embodiment, the upper surface and the lower surface of the second resin insulation layer 13 are processed to form the outer layer circuit 14. The structure formed after this step is shown in FIG. 4. Figure 15

[0132] S15: manufacturing a solder resist layer, manufacturing a solder resist layer 15 on the surface of the outer layer circuit 14. The structure formed after this step of manufacturing the solder resist layer 15 is shown in FIG. 5. Figure 16

[0133] S16: coating, coating a coating layer on the surface of the structure formed after manufacturing the solder resist layer 15. Specifically, the material of the coating layer can be NiPdAu (nickel palladium gold), NiAu (nickel gold), Sn (tin) or OSP (Organic Solderability Preservatives).

[0134] ​​In the manufacturing method of the embedded chip substrate provided in the above embodiment, the foamed film of the first bonding material layer 2 is bonded to the first bonding surface of the substrate 1, and the foamed film a of the second bonding material layer 6 is bonded to the first resin layer 5, so that the contamination caused by the pressure-sensitive adhesive can be avoided. In the debonding process, the first debonding step only needs to heat to the debonding temperature of the foamed film a of the first bonding material layer 2, and the second debonding step only needs to heat to the debonding temperature of the foamed film a of the second bonding material layer 6, so that the foamed film is separated from the substrate 1 or the first resin layer 5. Compared with the pressure-sensitive adhesive film and the substrate 1 or the first resin layer 5, the contamination caused by the pressure-sensitive adhesive can be avoided, and the debonding is easier.

[0135] In addition, in the manufacturing method of the embedded chip substrate provided in the above embodiment, the first pre-curing is performed after the first compression and filling of the resin, and the second pre-curing is performed after the second compression and filling of the resin. After each resin insulating layer processing, only pre-curing is performed, but no complete curing is performed. After the intermediate circuit is completed, the curing degree of the resin in the structure is below 80%, and after all the resin layer processing is completed, one-time curing is performed. In the curing step, the resin layer in the structure formed is cured to above 90%, that is, the curing degree of the resin in the structure after the curing step is above 90%. In other words, in this application, after each resin layer processing is completed, one-time pre-curing is performed, but not complete curing, and after all the resin layers are processed, one-time curing is performed to achieve a curing degree of above 90%. In the manufacturing method of the embedded chip substrate, before the symmetric structure is formed, the resin in the structure is in an incomplete curing state. In this way, the symmetric structure can be formed after the low warping state is maintained, and the resin can be cured to above 90%. This can effectively avoid the cracking of the resin.

[0136] In addition, in the manufacturing method of the embedded chip substrate provided in the above embodiment, the first support plate 3 and / or the second support plate 7 support the substrate 1 during the steps of pasting the chip 4, embedding the first resin layer, and embedding the second resin layer. The support of the first support plate 3 and / or the second support plate 7 can reduce the overall warping of the substrate 1 caused by the asymmetric structure during the manufacturing process of the embedded chip substrate, so that the substrate 1 is always in a low warping state during the entire manufacturing process of the embedded chip substrate. In addition, the first pre-curing is performed after the first compression and filling of the resin, and the second pre-curing is performed after the second compression and filling of the resin. Finally, the first resin layer 5 and the second resin layer 8 achieve the same curing degree, the entire substrate 1 forms a symmetric structure, the warping level of the substrate 1 is reduced, the excessive warping of the substrate 1 caused by the different curing degrees of the first resin layer 5 and the second resin layer 8 during the manufacturing process of the embedded chip substrate is avoided, and the cracking of the brittle cured resin and the cracking of the interface between the chip 4 and the resin with weak bonding force are avoided.

[0137] In addition, S6 ，The first cleaning step and / or S8 ， The second cleaning step.

[0138] Specifically, the first debonding in this embodiment can further include a step: S6 ， The first cleaning, cleaning the first bonding surface. That is, after the first bonding material layer 2 is debonded from the first bonding surface, in order to prevent material residues, the first bonding surface can be cleaned. Specifically, the first bonding surface can be cleaned by a plasma cleaning machine, of course, other cleaning methods can also be used, such as glue removal cleaning, which is not limited here. Specifically, the glue removal tank can be used at 70-85°C for 2-5 minutes to remove the surface residual foam film residues.

[0139] In addition, the second debonding in this embodiment can further include a step: S8 ， The second cleaning, cleaning the second bonding surface. That is, after the second bonding material layer 6 is debonded from the second bonding surface, in order to prevent material residues, the second bonding surface can be cleaned. Specifically, the second bonding surface can be cleaned by a plasma cleaning machine, of course, other cleaning methods can also be used, which is not limited here.

[0140] In the above embodiments, the first pre-curing can be specifically: curing the resin in the formed structure to 50% or more, that is, the resin curing degree after the first pre-curing is 50% or more, and the resin curing degree after the first pre-curing can be 60%, 70%, 75%, etc., so that the resin is hardened, and the resin rigidity and mechanical impact resistance are improved. Preferably, the resin in the formed structure is cured to 70% or more, but not completely cured.

[0141] Alternatively, the first pre-curing can be specifically: placing the formed structure in a constant temperature environment of 130-150°C for 30-60min to pre-cure the resin in the structure. Specifically, the formed structure can be placed in a constant temperature environment of 130°C, 135°C, 140°C or 150°C, and the holding time can be 30min, 40min or 50min. Preferably, the formed structure is placed in a constant temperature environment of 140°C for 60min.

[0142] In addition, in the above embodiments, the second pre-curing can be specifically: curing the resin in the formed structure to 70% or more, that is, the resin curing degree after the second pre-curing is 70% or more, and the resin curing degree after the first pre-curing can be 70%, 75%, 80%, etc., so that the resin is hardened, and the resin rigidity and mechanical impact resistance are improved. Preferably, the resin in the formed structure is cured to 80% or more, but not completely cured.

[0143] Alternatively, the second pre-curing can be specifically as follows: the formed structure is placed in a constant temperature environment of 170-185°C for 25-35 min to pre-cure the resin in the structure. Specifically, the formed structure can be placed in a constant temperature environment of 170°C, 175°C, 180°C or 185°C, and the holding time can be 25 min, 30 min or 35 min. Preferably, the formed structure is placed in a constant temperature environment of 180°C for 30 min.

[0144] In each of the above embodiments, the pre-curing in the resin insulation layer processing step in the S11 is referred to as third pre-curing hereinafter. The third pre-curing can be specifically as follows: the resin insulation layer in the formed structure is cured to more than 70-80%, i.e., the degree of curing is 70-80%, and the degree of curing of the first resin insulation layer 11 after the third pre-curing can be 70%, 75%, 80%, etc., so as to harden the resin and improve the rigidity and mechanical impact resistance of the resin.

[0145] Alternatively, the third pre-curing can be specifically as follows: the formed structure is placed in a constant temperature environment of 95-105°C for 25-35 min, and then placed in a constant temperature environment of 170-185°C for 25-35 min. Specifically, the formed structure can be placed in a constant temperature environment of 95°C, 100°C or 105°C for 25-35 min, and then placed in a constant temperature environment of 170°C, 180°C or 185°C for 25-35 min. Preferably, the formed structure is placed in a constant temperature environment of 100°C for 30 min, and then placed in a constant temperature environment of 180°C for 30 min.

[0146] In each of the above embodiments, the pre-curing in the resin insulation layer processing step in the S11 is referred to as third pre-curing hereinafter. The third pre-curing can be specifically as follows: the resin insulation layer in the formed structure is cured to more than 70-80%, i.e., the degree of curing is 70-80%, and the degree of curing of the first resin insulation layer 11 after the third pre-curing can be 70%, 75%, 80%, etc., so as to harden the resin and improve the rigidity and mechanical impact resistance of the resin.

[0147] Alternatively, the fourth pre-curing can be specifically as follows: after the formed structure is placed in a constant temperature environment of 95-105°C for 25-35 minutes, it is then placed in a constant temperature environment of 170-185°C for 25-35 minutes. Specifically, the formed structure can be placed in a constant temperature environment of 95°C, 100°C or 105°C, and the holding time can be 25 minutes, 30 minutes or 35 minutes, and then it is placed in a constant temperature environment of 170°C, 180°C or 185°C, and the holding time can be 25 minutes, 30 minutes or 35 minutes. Preferably, the formed structure is placed in a constant temperature environment of 100°C for 30 minutes, and then it is placed in a constant temperature environment of 180°C for 30 minutes.

[0148] In an optional embodiment, the first pre-curing has a curing temperature lower than the debonding temperature of the foamed film a of the first bonding material layer 2. If the debonding temperature of the foamed film a of the first bonding material layer 2 is 165-175°C, the first pre-curing temperature should be lower than 165-175°C. Specifically, the debonding temperature of the foamed film a of the first bonding material layer 2 can be 170°C. Preferably, the first pre-curing temperature is lower than the first debonding temperature by 10°C or more, or the first pre-curing temperature is lower than the first debonding temperature by 15-35°C, and specifically the first pre-curing temperature can be lower than the first debonding temperature by 20°C or 30°C.

[0149] The second pre-curing has a curing temperature lower than the debonding temperature of the foamed film a of the second bonding material layer 6 by 10°C or more, or the second pre-curing temperature is lower than the second debonding temperature by 15-25°C, and preferably the second pre-curing temperature can be lower than the second debonding temperature by 20°C.

[0150] The debonding temperature of the foamed film a of the first bonding material layer 2 is lower than the debonding temperature of the foamed film a of the second bonding material layer 6, so that the foamed film a of the second bonding material layer 6 can still be bonded to the first resin layer 5 when the foamed film a of the first bonding material layer 2 is debonded. The debonding temperature of the foamed film a of the first bonding material layer 2 can be 165-175°C, preferably the debonding temperature of the foamed film a of the first bonding material layer 2 can be 170°C. The debonding temperature of the foamed film a of the second bonding material layer 6 can be 200-220°C, preferably the debonding temperature of the foamed film a of the second bonding material layer 6 can be 210°C. Preferably, the debonding temperature of the foamed film a of the first bonding material layer 2 can be lower than the debonding temperature of the foamed film a of the second bonding material layer 6 by 15°C or more or 15-35°C, specifically the debonding temperature of the foamed film a of the first bonding material layer 2 can be lower than the debonding temperature of the foamed film a of the second bonding material layer 6 by 15°C, 20°C, 25°C, 30°C, 35°C, and preferably the debonding temperature of the foamed film a of the first bonding material layer 2 and the debonding temperature of the foamed film a of the second bonding material layer 6 are different by 30°C.

[0151] In addition, in a preferred embodiment, the surface of the first resin layer 5 is provided with a protective film, and in the second temporary bonding step, the foamed film of the second bonding material layer 6 is bonded to the protective film of the first resin layer 5, so that the protective film can be peeled off after debonding to prevent pollution.

[0152] The embodiment of the present application also provides a temporary bonding structure, as shown in Figure 6 The temporary bonding structure includes a substrate 1, a chip 4, a first bonding material layer 2, a first support plate 3, a first resin layer 5, a second bonding material layer 6, and a second support plate 7. The temporary bonding structure is specifically the structure formed after the S8 step. Specifically, the substrate 1 is provided with a receiving cavity 1a for accommodating the chip 4, and the two surfaces of the substrate 1 are respectively a first bonding surface and a backfill resin surface. When the substrate 1 is horizontally placed, i.e. the thickness direction of the substrate 1 is along the vertical direction, the upper surface and the lower surface of the substrate 1 are respectively the backfill resin surface and the first bonding surface. The chip 4 is arranged in the receiving cavity 1a, and the electrode side of the chip 4 can be placed upward or downward. The first bonding material layer 2 is bonded to the first bonding surface, and the first support plate 3 is fixed to the side of the first bonding material layer 2 away from the substrate 1. As shown in Figure 17 The first bonding material layer 2 can include a foamed film a, a support film b, and a pressure-sensitive adhesive film c which are sequentially stacked, and the foamed film a of the first bonding material layer 2 is bonded to the substrate 1. The side of the first bonding material layer 2 away from the substrate 1 is fixed with the first support plate 3, and the pressure-sensitive adhesive film c of the first bonding material layer 2 is bonded to the first support plate 3, i.e. the first bonding material layer 2 is located between the first support plate 3 and the substrate 1.

[0153] The first resin layer 5 is located on the filling resin surface of the substrate 1, and the second bonding surface is located on the side of the first resin layer 5 away from the substrate 1. The filling resin surface can be the upper surface of the substrate 1, and the resin fills the gaps between the surface circuits of the substrate 1 and the gaps around the chip 4. The second bonding material layer 6 is bonded to the second bonding surface, and the second bonding material layer 6 comprises a foamed film a, a supporting film b and a pressure-sensitive adhesive film c which are sequentially stacked, and the foamed film a of the second bonding material layer 6 is bonded to the first resin layer 5. The second supporting plate 7 is fixed to the side of the second bonding material layer 6 away from the first resin layer 5, and the pressure-sensitive adhesive film c of the second bonding material layer 6 is bonded to the second supporting plate 7. The second bonding surface is the upper surface of the first resin layer 5, the second bonding material layer 6 is located between the second supporting plate 7 and the first resin layer 5, and the second supporting plate 7 is bonded to the side of the second bonding material layer 6 away from the first resin layer 5.

[0154] In the above temporary bonding structure, the foamed film of the first bonding material layer 2 is bonded to the first bonding surface of the substrate 1, and the foamed film a of the second bonding material layer 6 is bonded to the first resin layer 5, so that contamination caused by the pressure-sensitive adhesive can be avoided. During the debonding process, only the foamed film a of the first bonding material layer 2 needs to be heated to the debonding temperature in the first debonding step, and only the foamed film a of the second bonding material layer 6 needs to be heated to the debonding temperature in the second debonding step, so that the foamed film is separated from the substrate 1 or the first resin layer 5. Compared with the pressure-sensitive adhesive film and the substrate 1 or the first resin layer 5, contamination caused by the pressure-sensitive adhesive can be avoided, and debonding is easier.

[0155] In the above temporary bonding structure, the first supporting plate 3 and the second supporting plate 7 are used to provide support on both sides of the substrate 1 at the same time, so that the substrate 1 is supported by the first supporting plate 3 and / or the second supporting plate 7 during the steps of attaching the chip 4, embedding the first resin layer and the second resin layer, etc., thereby reducing the overall warping of the substrate 1 caused by structural asymmetry during the manufacturing process of the embedded chip substrate, and ensuring that the substrate 1 is always in a low-warping state during the entire manufacturing process of the embedded chip substrate.

[0156] In the above embodiment, the chip is placed in the accommodating cavity, and the back surface of the chip 4 is bonded to the foamed film of the first bonding material layer 2. The back surface of the chip 4 is the side of the chip 4 away from the bonding pad, and the front surface of the chip 4 is the side of the chip 4 having the bonding pad. That is, the side of the chip 4 away from the bonding pad is bonded to the foamed film a of the first bonding material layer 2. After the first debonding is completed, the foamed film a is cleaned to remove the temporary bonding adhesive residue generated during the debonding process. The cleaning includes water washing, ultrasonic water washing, and degreasing treatment in a degreasing tank to effectively remove the temporary bonding adhesive residue on the surface of the substrate and the temporary bonding adhesive residue on the back surface of the chip. If the side of the chip 4 having the bonding pad is bonded to the foamed film of the first bonding material layer 2, the degreasing tank cannot be used for degreasing treatment, and more stringent cleaning is required, which makes the cleaning process more complex. Therefore, it is preferred that the back surface of the chip 4 is bonded to the foamed film a of the first bonding material layer 2.

[0157] Further, the first support plate 3 can be a double-sided copper-clad plate, a metal plate, a glass plate or a ceramic plate, each of which has high rigidity. Similarly, the second support plate 7 can also be a double-sided copper-clad plate, a metal plate, a glass plate or a ceramic plate, and other types of plates can also be selected, which are not limited herein.

[0158] The thickness of the first support plate 3 can be greater than or equal to 0.2 mm, and specifically, the thickness of the first support plate 3 can be 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, etc. Further, the thickness of the first support plate 3 can be greater than or equal to 0.5 mm, such as 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, etc., so as to ensure the strength of the first support plate 3 and prevent the substrate 1 from warping during processing.

[0159] The thickness of the second support plate 7 can be greater than or equal to 0.2 mm, and specifically, the thickness of the second support plate 7 can be 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, etc. Further, the thickness of the second support plate 7 can be greater than or equal to 0.5 mm, such as 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, etc., so as to ensure the strength of the second support plate 7 and prevent the substrate 1 from warping during processing.

[0160] In the description of the above embodiments, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0161] The above description is merely specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method of manufacturing an embedded chip substrate, characterized by, The method comprises the steps of: substrate windowing, a substrate is provided with a receiving cavity for receiving a chip, two surfaces of the substrate are a first bonding surface and a filling resin surface respectively; first temporary bonding, a first bonding material layer is bonded to the first bonding surface, the first bonding material layer comprises a foamed film, a support film and a pressure-sensitive adhesive film which are stacked in sequence, the foamed film of the first bonding material layer is bonded to the substrate, and a first support plate is fixed to a side of the first bonding material layer away from the substrate; chip pasting, the chip is arranged in the receiving cavity; first compression filling resin, a first resin layer is formed by compressing filling resin on the filling resin surface of the substrate, a second bonding surface is formed on a side of the first resin layer away from the substrate; second temporary bonding, a second bonding material layer is bonded to the second bonding surface, the second bonding material layer comprises a foamed film, a support film and a pressure-sensitive adhesive film which are stacked in sequence, the foamed film of the second bonding material layer is bonded to the first resin layer, a second support plate is fixed to a side of the second bonding material layer away from the first resin layer, and a first pre-curing is performed; first debonding, the foamed film of the first bonding material layer and the first bonding surface are debonded to remove the first bonding material layer and the first support plate; second compression filling resin, a second resin layer is formed by compressing filling resin on the first bonding surface of the substrate, and a second pre-curing is performed; second debonding, the foamed film of the second bonding material layer and the first resin layer are debonded to remove the second bonding material layer and the second support plate; blind hole processing, blind holes are formed on upper and lower surfaces of a structure formed in the previous step; circuit manufacturing, circuits are processed on the upper and lower surfaces of the structure formed in the previous step; resin insulation layer processing, resin insulation layers are arranged on the upper and lower surfaces of the structure formed in the previous step, and a pre-curing is performed; intermediate circuit manufacturing, the steps of blind hole processing, circuit manufacturing and resin insulation layer processing are repeated N times (N≥0) to form N layers of intermediate circuits, no pre-curing is performed in the Nth resin insulation layer processing step, and a copper foil is compressed on a surface of the resin insulation layer formed in the Nth resin insulation layer processing step, and then a pre-curing is performed to cure the resin insulation layers in the formed structure to more than 50%; curing, the structure formed in the previous step is cured to more than 90% in a laminating machine under mirror steel plate clamping, a preset vacuum degree and a preset pressure; outer circuit manufacturing, blind hole processing and circuit manufacturing steps are performed on the cured structure to form an outer circuit; resist manufacturing, a resist layer is manufactured on a surface of the outer circuit; coating, a coating layer is formed on a surface of the structure formed after the resist manufacturing.

2. The method of manufacturing an embedded chip substrate according to claim 1, wherein After the first debonding, the method further comprises the steps of: first cleaning, cleaning the first bonding surface; and / or After the second debonding, the method further comprises the step of: second cleaning, cleaning the second bonding surface.

3. The method of manufacturing a core-in board as claimed in claim 1, wherein The first pre-curing specifically refers to curing the resin in the structure formed in this step to 50% or more; or the first pre-curing specifically refers to placing the structure formed in this step in a constant temperature environment of 130-150°C for 30-60 min to pre-cure the resin in the structure.

4. The method of manufacturing a core-in board according to claim 1, wherein The second pre-curing specifically refers to curing the resin in the structure formed in this step to 80% or more; or the second pre-curing specifically refers to placing the structure formed in this step in a constant temperature environment of 170-185°C for 25-35 min to pre-cure the resin in the structure.

5. The method of manufacturing a buried chip substrate according to claim 1, wherein The pre-curing in the resin insulation layer processing step specifically refers to curing the resin insulation layer in the structure to 70-80%; or the pre-curing in the resin insulation layer processing step specifically refers to placing the formed structure in a constant temperature environment of 95-105°C for 25-35 min, and then placing it in a constant temperature environment of 170-185°C for 25-35 min.

6. The method of manufacturing an embedded chip-on-substrate according to claim 1, wherein The raw materials used in the first pressing and embedding resin step, the second pressing and embedding resin step, and the insulation layer processing step are all ABF resin sheets, which include an ABF layer, an OPP film attached to the first side of the ABF layer, and a PET film attached to the second side of the ABF layer.

7. The method of manufacturing an embedded chip substrate according to claim 6, wherein The first pressing and embedding resin step specifically refers to removing the OPP film of the ABF resin sheet, pressing the first side of the ABF resin sheet against the embedding resin side of the substrate to form a first resin layer, and pre-curing the resin in the structure formed in this step to 50% or more, the second bonding surface of the first resin layer facing away from the substrate retains the PET film; and / or, The second pressing and embedding resin step specifically refers to removing the OPP film of the ABF resin sheet, pressing the first side of the ABF resin sheet against the first bonding surface of the substrate to form a second resin layer, and pre-curing the resin in the structure formed in this step to 70% or more, the second resin layer retains the PET film.

8. The method of manufacturing a buried chip substrate according to claim 1, wherein The curing temperature of the first pre-curing is lower than the debonding temperature of the first bonding material layer; or The debonding temperature of the first bonding material layer is lower than the debonding temperature of the second bonding material layer.

9. A temporary bonded structure, characterized by, It comprises: a substrate, which is provided with a receiving cavity for accommodating a chip, and the two surfaces of the substrate are respectively a first bonding surface and an embedding resin surface; a chip, which is arranged in the receiving cavity; a first bonding material layer and a first support plate, the first bonding material layer is bonded to the first bonding surface, the first bonding material layer comprises a foaming film, a support film and a pressure sensitive adhesive film which are stacked in turn, and the foaming film of the first bonding material layer is bonded to the substrate, the first support plate is bonded to the pressure sensitive adhesive film of the first bonding material layer; a first resin layer, which is located on the embedding resin surface of the substrate, and the second bonding surface of the first resin layer facing away from the substrate; A second bonding material layer is bonded to the second bonding surface, and the second bonding material layer comprises a foamed film, a support film and a pressure-sensitive adhesive film which are sequentially stacked, and the foamed film of the second bonding material layer is bonded to the first resin layer.

10. The method of manufacturing a chip-on-board substrate according to any one of claims 1 to 8 or the temporary bonding structure according to claim 9, wherein The back surface of the chip is bonded to the foamed film of the first bonding material layer.

11. The method of manufacturing a chip-on-board according to any one of claims 1 to 8 or the temporary bonding structure according to claim 9, wherein The first support plate and / or the second support plate is a double-sided copper-clad plate, a metal plate, a glass plate or a ceramic plate; and / or the thickness of the first support plate and / or the second support plate is greater than 0.2 mm.

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