CN112492747A

CN112492747A - Packaging substrate with three-layer plate structure and manufacturing method thereof

Info

Publication number: CN112492747A
Application number: CN202110000648.9A
Authority: CN
Inventors: 岳长来
Original assignee: Shenzhen Hemei Jingyi Semiconductor Technology Co ltd
Current assignee: Shenzhen Hemei Jingyi Semiconductor Technology Co ltd
Priority date: 2021-01-04
Filing date: 2021-01-04
Publication date: 2021-03-12
Anticipated expiration: 2041-01-04
Also published as: CN112492747B

Abstract

The invention discloses a packaging substrate with a three-layer plate structure and a manufacturing method thereof, and relates to the technical field of packaging substrates. Including inlayer circuit layer and outer pressfitting layer, the top and the bottom on inlayer circuit layer all are provided with outer circuit layer, inlayer circuit layer includes the core, the top and the bottom of core all set gradually inlayer thick copper foil, inlayer thin copper foil, inlayer prepreg and inlayer medium thickness copper foil, outer pressfitting layer includes outer prepreg and outer thin copper foil. Through setting up inlayer circuit layer and outer pressfitting layer, the design of laying copper of packaging substrate plate edge hexagon increases incomplete copper rate, has effectually solved when follow-up pressfitting because of the not enough interior bubble scheduling problem that leads to packaging substrate of exhaust, has avoided three-layer board process board warpage phenomenon, has prevented effectively that the copper foil from taking place in the pressfitting in-process and corrugating, bubbling, overflow and glue bad phenomenon, has improved the yield of product, has wide application prospect.

Description

Packaging substrate with three-layer plate structure and manufacturing method thereof

Technical Field

The invention relates to the technical field of packaging substrates, in particular to a packaging substrate with a three-layer structure and a manufacturing method thereof.

Background

As a basic industry of the electronic information industry, the industrial scale of the packaging substrate industry is getting larger, along with the high-speed development of the electronic circuit industry technology, the electronic packaging substrate technology is developing towards the directions of high speed, ultra-thinness and high reliability, the integration function of components is becoming wider day by day, the requirement of electronic products on the high density of the packaging substrate is more prominent, the electronic packaging substrate technology is developing from the PCB industry to the packaging substrate industry and is widely applied to communication, aviation, medical treatment, automotive electronics, tablet computers, smart phones and the like, at present, the packaging substrate industry mostly uses an even number of multilayer packaging substrates and an odd number of multilayer boards, and the three-layer packaging substrate is a packaging substrate which can be used in the chip packaging process.

The existing three-layer packaging substrate manufacturing method is to find the two sides of a core plate to be coated with temporary bonding materials and then to be laminated with prepregs, form a circuit by using a layer adding method, form two three-layer packaging substrates on the two sides of the core plate after 2 times of laminating processing, divide the two three-layer packaging substrates from the core plate to form a three-layer plate.

Disclosure of Invention

In view of the deficiencies of the prior art, the present invention provides a package substrate with a three-layer structure and a method for manufacturing the same, so as to solve the problems mentioned in the background art.

In order to achieve the purpose, the invention provides the following technical scheme: the packaging substrate comprises an inner layer circuit layer and an outer layer laminated layer, wherein the top and the bottom of the inner layer circuit layer are provided with the outer layer circuit layer respectively, the inner layer circuit layer comprises a core plate, and the top and the bottom of the core plate are sequentially provided with an inner layer thick copper foil, an inner layer thin copper foil, an inner layer prepreg and an inner layer medium-thick copper foil;

the outer laminated layer comprises an outer prepreg and an outer thin copper foil, and the outer prepreg and the outer thin copper foil are sequentially arranged on the back surfaces of the two inner medium-thickness copper foils.

As a preferred technical scheme of the invention, the core board is an epoxy resin glass fiber base material.

As a preferred technical scheme of the invention, the thickness of the inner-layer thick copper foil is 18um, and the thickness of the inner-layer thin copper foil is 3 um.

As a preferred technical scheme of the invention, the thickness of the inner-layer prepreg is 25um, and the thickness of the inner-layer medium-thickness copper foil is 12 um.

As a preferred technical scheme of the invention, the thickness of the outer-layer prepreg is 25um, and the thickness of the outer-layer thin copper foil is 3 um.

A method for manufacturing a packaging substrate with a three-layer plate structure comprises the following steps:

s1, manufacturing a bearing plate: the method comprises the following steps of (1) forming an inner-layer thick copper foil and an inner-layer thin copper foil on two sides of a core plate by adopting an epoxy resin glass fiber base material as the core plate, hot-pressing the inner-layer thick copper foil which cannot be recrystallized on the two sides of the core plate by using a hydraulic vacuum machine, and laminating the two inner-layer thin copper foils to form a bearing plate;

s2, manufacturing a packaging substrate: sequentially carrying out high-temperature pressing operation on the inner-layer prepreg and the inner-layer medium-thickness copper foil on the two sides of the bearing plate, melting the inner-layer prepreg through high temperature and high pressure to be tightly combined with the inner-layer thin copper foil, and combining the inner-layer prepreg and the inner-layer thin copper foil on the two sides of the bearing plate to form a six-layer structure packaging substrate;

s3, manufacturing an inner layer circuit layer: respectively manufacturing the same inner layer circuit layer on the inner layer medium-thickness copper foil of the packaging substrate, and developing and etching to form a circuit pattern;

s4, browning treatment before pressing: the packaging substrate is treated by acid washing liquid and browning liquid, so that the binding force between the inner thin copper foil and the inner prepreg of the packaging substrate is improved, and a double-sided browning layer is formed on the copper surface of the circuit of the packaging substrate;

s5, outer layer pressing: sequentially carrying out high-temperature pressing operation on an outer-layer prepreg and an outer-layer thin copper foil on two sides of the packaging substrate, and melting the outer-layer prepreg through high temperature and high pressure and tightly combining the outer-layer prepreg with the outer-layer thin copper foil and a browning layer of the packaging substrate to form the packaging substrate with an eight-layer structure;

s6, board splitting operation: the eight-layer structure packaging substrate is separated by manufacturing and processing, the inner-layer thick copper foil and the inner-layer thin copper foil are separated, two three-layer board structure consistent packaging substrates and bearing board structures are formed, and the bearing board structures are composed of core boards and double-sided inner-layer thick copper foils.

As a preferred technical solution of the present invention, the manufacturing steps of the bearing plate in S1 are as follows: 1 piece of glass epoxy base material with the thickness of 100um is taken as a core plate, inner thick copper foils which cannot be recrystallized are hot-pressed on two sides of the core plate by a hydraulic vacuum machine, a layer of inner thin copper foil is respectively superposed on each inner thick copper foil, and the hot-pressing pressure is 30Kg/cm²The hot pressing temperature is 180 ℃, the main hot pressing time is 1 hour, the hot pressing is finished and then the bearing plate is cooled, and when the temperature reaches about 50 ℃, the bearing plate with the double-sided thickness of 18um +3um is taken out.

As a preferred technical scheme of the invention, the packaging substrate in S2 does not need to be subjected to browning treatment before being pressed, the inner-layer prepreg is taken out from the freezing bin and then is heated for 8-12 hours, the size of the inner-layer prepreg is 2.5mm longer than the single side of the size of the packaging substrate, and the type of the inner-layer prepreg corresponding to the glue content is selected according to the product requirement.

As a preferred technical scheme of the present invention, after the package substrate is laminated in S2, a layer of photosensitive dry film is attached to the copper foil surface of the laminated package substrate, in the process of film attachment, the laminated package substrate is subjected to acid cleaning, the surface of the package substrate is roughened by a roughening solution, so as to improve the bonding force between the dry film and the copper foil surface of the package substrate, then the residual roughening solution is washed with water, then the surface of the package substrate is oxidized by acid cleaning, the surface of the package substrate is dried by strong wind, and then the photosensitive dry film with thickness is vacuumized and pressed on the copper foil of the package substrate to form a pressed film, so as to obtain the package substrate with a six-layer structure and double-sided dry film.

As a preferred technical solution of the present invention, when the package substrate is separated in S6, the position of the package substrate is fixed first, the package substrate is placed on the table top in the longitudinal direction, the outer thin copper foil surface after the outer layer is pressed faces upward, and the two ends of the package substrate are fixed, so that the package substrate is not moved during the separation process to avoid scratching.

Compared with the prior art, the invention provides the packaging substrate with the three-layer plate structure and the manufacturing method thereof, and the packaging substrate has the following beneficial effects:

according to the packaging substrate with the three-layer board structure and the manufacturing method thereof, the inner layer circuit layer and the outer layer pressing layer are arranged, the residual copper rate is increased through the hexagonal copper laying design of the edges of the packaging substrate, the problems that bubbles exist in the packaging substrate due to insufficient exhaust during subsequent pressing are effectively solved, the board warping phenomenon in the three-layer board dividing process is avoided, the phenomena that copper foil wrinkles, bubbles and glue overflow are bad in the pressing process are effectively prevented, the yield of products is improved, and the packaging substrate has a wide application prospect.

Drawings

Fig. 1 is a schematic structural diagram of a package substrate with a three-layer structure and a method for manufacturing the same according to the present invention;

FIG. 2 is a front view of a carrier plate structure of a three-layer package substrate and a method for fabricating the same according to the present invention;

FIG. 3 is a front view of a package substrate with a three-layer structure and a method for fabricating the same according to the present invention;

FIG. 4 is a schematic illustration showing the exposure of the inner circuit layer of a three-layer package substrate and a method for fabricating the same according to the present invention;

FIG. 5 is a schematic diagram of an inner circuit layer development of a package substrate with a three-layer structure and a method for fabricating the same according to the present invention;

FIG. 6 is a schematic diagram of an etching process of an inner circuit layer of a package substrate with a three-layer structure and a method for fabricating the same according to the present invention;

FIG. 7 is a schematic diagram of a dry film stripping of a package substrate with a three-layer structure and a method for fabricating the same according to the present invention;

FIG. 8 is a schematic diagram of a three-layer package substrate and a method for fabricating the same according to the present invention;

fig. 9 is a schematic view illustrating a manufacturing process of a package substrate with a three-layer structure and a method for manufacturing the same according to the present invention.

In the figure: 1. an inner layer circuit layer; 11. a core board; 12. an inner thick copper foil; 13. an inner thin copper foil; 14. an inner prepreg; 15. an inner medium-thickness copper foil; 2. an outer lamination layer; 21. an outer prepreg; 22. and an outer layer of thin copper foil.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The first embodiment is as follows:

referring to fig. 1 to 8, a package substrate with a three-layer board structure includes an inner circuit layer 1 and an outer laminated layer 2, the top and the bottom of the inner circuit layer 1 are provided with outer circuit layers, the inner circuit layer 1 includes a core board 11, and the top and the bottom of the core board 11 are sequentially provided with an inner thick copper foil 12, an inner thin copper foil 13, an inner prepreg 14, and an inner medium-thick copper foil 15.

Outer pressfitting layer 2 includes outer prepreg 21 and outer thin copper foil 22, two the back of the body of inner layer medium thickness copper foil 15 has all set gradually outer prepreg 21 and outer thin copper foil 22, core 11 is the glass fiber substrate of epoxy, the thickness of inner layer thick copper foil 12 is 18um, the thickness of inner layer thin copper foil 13 is 3um, the thickness of inner layer prepreg 14 is 25um, the thickness of inner layer medium thickness copper foil 15 is 12um, the thickness of outer prepreg 21 is 25um, the thickness of outer thin copper foil 22 is 3 um.

Referring to fig. 9, a method for manufacturing a package substrate with a three-layer structure includes the following steps:

s1, manufacturing a bearing plate: the method comprises the steps of adopting an epoxy resin glass fiber base material as a core plate 11, forming inner-layer thick copper foils 12 and inner-layer thin copper foils 13 on two sides of the core plate 11, hot-pressing the inner-layer thick copper foils 12 which cannot be recrystallized on the two sides of the core plate 11 by using a hydraulic vacuum machine, and laminating the two inner-layer thin copper foils 13 on the two inner-layer thick copper foils 12 respectively to form the bearing plate.

S2, manufacturing a packaging substrate: the high-temperature laminating operation of the inner-layer prepreg 14 and the inner-layer medium-thickness copper foil 15 is sequentially carried out on the two sides of the bearing plate, the inner-layer prepreg 14 is melted through high temperature and high pressure and is tightly combined with the inner-layer thin copper foil 13, and the inner-layer thin copper foil 13 on the two sides of the bearing plate is combined to form a six-layer structure packaging substrate, which specifically comprises the following three steps:

the method comprises the following steps of firstly, stacking packaging substrates, directly washing and drying a bearing plate, putting the bearing plate into a dust-free workshop, pre-stacking and typesetting before vacuum hot pressing, wherein in the stacking process, the bottommost part is a bearing bottom plate, kraft paper is put on the bottom plate, mirror steel plates are sequentially arranged above the kraft paper, cut inner-layer medium-thickness copper foils 15 with the thickness of 12um are arranged above the mirror steel plates, corresponding inner-layer prepregs 14 after temperature return are put above the inner-layer medium-thickness copper foils 15, then the bearing plate is put at the central position, the prepregs are put above the bearing plate, then the inner-layer medium-thickness copper foils 15 are put at the center, the mirror steel plates are put above the inner-layer medium-thickness copper foils 15, the kraft paper is put on the mirror steel plates, then the mirror steel plates are sequentially and repeatedly stacked, the number of stacked plates is determined according to the capacity of a hot press.

And secondly, pushing a box of stacked plates into a vacuum hot press by a skip car, melting resin in the inner-layer prepreg 14 by using heat energy provided by machinery according to the number of each time segment so as to bond the substrates and fill gaps, melting the inner-layer prepreg 14 through high temperature and high pressure, tightly combining the inner-layer prepreg with the inner-layer thin copper foil 13 to form a six-layer structure packaging substrate, sealing the plate edges by the copper foils, pulling out the pressed plates by the skip car for disassembly, separating the mirror steel plate, the laminated packaging substrate, kraft paper and the like, and separating the packaging substrate from the packaging substrate by using a rubber sheet.

Setting the temperature of the vacuum hot press to 1-2 sections at 140 ℃ respectively, and pressing for 5 minutes, wherein the pressure is controlled at 7Kg/cm²3-4 stages of prepressing at 160 ℃ for 5 minutes, and controlling the pressure at 16Kg/cm²The temperature of the 5 th, 6 th and 7 th sections is 220 ℃, and the pressure is 35Kg/cm²The time is respectively 5 minutes, 40 minutes and 30 minutes, and the temperature of the last 8 th stage is 140 ℃ and 20Kg/cm²Pressure of (3), low temperature pressing for 10 minutes;

thirdly, referring to fig. 4, a layer of photosensitive dry film is attached to the copper foil surface of the laminated packaging substrate, in the process of film attachment, the laminated packaging substrate is firstly subjected to acid cleaning of the board surface, the board surface of the packaging substrate is subjected to roughening treatment through roughening liquid medicine, the binding force between the dry film and the copper foil surface of the packaging substrate is improved, then the residual roughening liquid medicine on the board surface is washed with water, then the board surface is subjected to acid cleaning and oxidation, strong wind blows and drying are performed on the board surface of the packaging substrate, and then the photosensitive dry film with thickness is vacuumized and attached to the copper foil of the packaging substrate to form a pressed film to manufacture the packaging substrate with the double-sided dry film and the six-layer.

And (3) parameter control during medium coarsening and film pressing operation: coarsening liquid medicine Cu²⁺The concentration is 35g/L, H₂SO₄The concentration is 65g/L, H₂O₂The concentration is 20g/L, the concentration of CB-5564 is 1%, the temperature of the liquid medicine in the tank is controlled at 24 ℃, and the spraying pressure is controlled at 1.2/cm²The coarsening and galling amount is controlled within the range of 0.9 +/-0.3 um, and the pickling H is carried out₂SO₄The concentration is 3.5-4.5%, the temperature is controlled within 105-125 deg.C, the film pressing time is controlled at 1.5 s, the speed of the package substrate and the substrate feeding speed is controlled at 2.5m/min, and the pressure is controlled at 0.45Kg/cm²。

S3, manufacturing an inner layer circuit layer 1: the same inner layer circuit layer 1 is respectively manufactured on the inner layer medium-thickness copper foil 15 of the packaging substrate, and the inner layer circuit layer is developed and etched into a circuit pattern, which is specifically divided into the following two steps:

first, referring to fig. 4, the laser direct imaging is used to scan the inner layer circuit data onto the surface of the package substrate in the form of image data by light, so as to realize the circuit exposure operation, and attach the circuit pattern on the dry film of the package substrate.

Exposing the pattern file, vacuumizing the packaging substrate by an exposure machine, controlling the exposure energy at 60MJ, adjusting 5-6 grids of an exposure ruler, automatically aligning, drilling holes on the packaging substrate before the inner layer circuit, therefore, the two sides are centrally exposed, the inner layer circuit exposure film needs to be exposed by adjusting the proportion of lengthening the long side by 0.65mm and lengthening the short side by 0.45mm, the exposure data process edge is designed to be hexagonal, the diameter is 1.12mm, the distance between the hexagon and the hexagon is 0.2mm, cutting a hexagonal technological edge exhaust channel at the edges of the Strip plate at a distance of 0.5mm, paving copper on the Panel technological edge to form the same hexagon, and the distance of 8.5mm apart from increasing 0.5mm interval, the hexagon of hexagon cancellation that is less than one-third remains the hexagon, and the design of copper is spread to the hexagon of board edge increases incomplete copper rate, and effectual when having solved follow-up pressfitting has the bubble scheduling problem in the board because of exhausting inadequately.

And secondly, performing inner layer development etching operation, wherein the front surface of the packaging substrate faces upwards, when developing solution in a nozzle is sprayed on the surface of the packaging substrate, the developing solution reacts, part of dry film which is not exposed out is removed to form a developed circuit pattern on the packaging substrate, the etching speed is adjusted to be 2-4m/min, the requirements of line width and space are confirmed, redundant copper in line width and space is etched in a biting manner, the etched circuit pattern is reserved on the copper foil surface, parameter setting is up to be capable of batch etching after the requirement is met, the surface of the packaging substrate is cleaned through hydrochloric acid pickling, water washing, blow drying and drying are performed on the surface of the packaging substrate, the cured dry film of the exposed part of the surface of the packaging substrate is removed through a film removing liquid, the complete circuit pattern can be exposed, the film can be completely removed, and the inner layer circuit layer 1 is obtained after washing, pickling.

Passing through Na with the concentration of 0.9 +/-0.1 percent₂CO₃The developing solution is at 31 deg.C, at a speed of 4.5 m/min, and under a pressure of 0.5Kg/cm²And a down pressure of 0.8Kg/cm²Etching the inner layer plate with its front side facing upwards, regulating etching speed, regulating etching amount according to different circuit requirements, wherein the etching requirement is 36.5% hydrochloric acid solution, the ratio of etching solution to hydrochloric acid is 1:3, the temperature of etching solution is controlled at 50 +/-2 ℃, and the spraying pressure is 2.4Kg/cm²The single-side etching amount of the circuit is controlled to be 16 mu m, the film stripping solution temperature is controlled to be 45 ℃, the film stripping solution concentration is 10.5 percent, the film stripping speed is controlled according to 2.6 +/-0.8 m/min, and the spraying upper and lower pressures are 1.9Kg/cm during film stripping²And (4) the following steps.

S4, browning treatment before pressing: the packaging substrate is treated by acid washing liquid and browning liquid, the binding force of the inner thin copper foil 13 and the inner prepreg 14 of the packaging substrate is improved, a double-faced browning layer is formed on the copper surface of the circuit of the packaging substrate, and the packaging substrate is specifically divided into the following ten steps:

firstly, soaking a six-layer structure packaging substrate in pickling solution for 1 minute, wherein the pickling concentration is 98%, and the temperature is controlled to be 30 +/-2 ℃.

And secondly, washing the pickled packaging substrate by deionized water at normal temperature.

And thirdly, soaking the washed packaging substrate in alkaline degreasing agent liquid medicine for 2 minutes, wherein the concentration of the liquid medicine is 80-120ml/L, and the temperature of the alkaline liquid is 50 +/-2 ℃.

And fourthly, washing the packaging substrate subjected to alkali washing by deionized water at normal temperature.

And fifthly, immersing the washed packaging substrate into the browning pre-immersion liquid for 1-2 minutes, wherein the concentration of the browning pre-immersion liquid is 15-25ml/L, and the temperature is 35 +/-3 ℃.

And sixthly, soaking the presoaked packaging substrate in browning liquid for 1-2 minutes, wherein the concentration of the browning liquid is 45-55ml/L, the temperature is 35 +/-3 ℃, the browning speed is 1.2-1.5m/min, and the biting amount can be controlled to be 1.2 +/-0.3 um.

And seventhly, cleaning the browned packaging substrate with deionized water at normal temperature.

And eighth step, cleaning the browned packaging substrate with pure water at normal temperature.

And step nine, absorbing the excessive moisture on the surface of the packaging substrate by using a water-absorbing sponge.

And tenth, drying the packaging substrate with the six-layer structure by strong wind and hot wind.

The pickling has the main functions of removing copper surface oxides, neutralizing residual stripping liquid, coarsening a copper surface, ensuring stable microetching, film forming and coloring, and the browning has the function of forming a uniform brown organic metal film on the copper surface, so that the binding force between the copper surface and the prepreg can be enhanced, and simultaneously, the copper is prevented from reacting with amino groups of the inner-layer prepreg 14 in the high-temperature pressing process.

S5, outer layer pressing: the high-temperature pressing operation of the outer-layer prepreg 21 and the outer-layer thin copper foil 22 is sequentially carried out on two sides of the packaging substrate, the outer-layer prepreg 21 is melted through high temperature and high pressure and is tightly combined with the outer-layer thin copper foil 22 and a browning layer of the packaging substrate to form the packaging substrate with an eight-layer structure, and the method specifically comprises the following eleven steps:

firstly, a heating plate is started to heat up, and the temperature is pre-raised to about 80 ℃.

Secondly, overlapping the packaging substrate, wherein the bottom is a bearing bottom plate, kraft paper is put on the bearing bottom plate, a mirror steel plate is put above the kraft paper, an outer layer thin copper foil 22 with the thickness of 3um is cut above the mirror steel plate, putting the corresponding outer-layer prepreg 21 after being warmed up above the outer-layer thin copper foil 22, putting the browned packaging substrate with the six-layer structure on the outer-layer prepreg 21 at the central position, then an outer layer prepreg 21 is placed above the surface of the packaging substrate, an outer layer thin copper foil 22 with the thickness of 3um is placed at the center, a mirror steel plate is placed above the surface of the outer layer thin copper foil 22, kraft paper is placed on the mirror steel plate, the mirror steel plate is placed and overlapped in sequence, the six-layer structure of the packaging substrate is pressed into a furnace with 60 pieces, 20 pieces of kraft paper are needed to be used for buffering on the outermost (upper and lower) steel plates, and finally, a cover plate is loaded on the kraft paper.

When the 3um outer layer thin copper foil 22 is cut, the cutting size of the copper foil must be larger than the packaging substrate to be pressed, at least 3cm is reserved on each side, the function is to prevent glue flowing, the thickness of the outer layer prepreg 21 is 25um, the glue content is 72%, the outer layer prepreg 21 is taken out from a freezing bin and then is heated for 12 hours, the size of the outer layer prepreg 21 is 2.5mm larger than each side of the packaging substrate, the size of the mirror surface steel plate is 660 x 560mm, and the thickness is 1.3 +/-0.3 mm.

And thirdly, pushing a box of the plates stacked in the previous step into a hot press from a loading trolley, and closing a bin door of the vacuum hot press.

And fourthly, vacuumizing after the bin gate is closed, wherein the vacuumizing time is controlled within 5min, and the vacuum degree is less than or equal to-0.095 MPa and more than 680 mmHg.

Fifthly, the oil cylinder rises, the oil amount is not lower than 2/3 of the oil level height, and the temperature range of the oil liquid must be controlled within 15-60 ℃.

Sixthly, starting hot pressing, setting temperature and pressure time, and pressing at high temperature according to each temperatureThe number of sections is respectively set to 1-2 sections, the temperature of 140 ℃ is set for pressing for 10 minutes, and the pressure is controlled to be 7Kg/cm²3-4 sections of prepressing at 160 ℃ for 10 minutes, and controlling the pressure at 16Kg/cm²The temperature of the 5 th, 6 th and 7 th sections is 220 ℃, and the pressure is 35Kg/cm²The time is 10 minutes, 80 minutes and 60 minutes respectively, and the temperature of the last 8 th stage is 140 ℃ and 20Kg/cm²The outer layer prepreg 21 is pressurized at high temperature to melt the outer layer prepreg 21 and flow the glue, the uneven gaps are filled with the glue of the outer layer prepreg 21, the current values of the temperature and the pressure are automatically heated and pressurized to the set values, and the time is calculated.

Seventhly, starting to discharge vacuum, wherein the vacuum discharge pressure is 6kg/cm²—7kg/cm²When the front door needs to be opened, the oil cylinder descends, the oil amount is not lower than 2/3 of the oil level height, and the temperature range of the oil liquid needs to be controlled within 15-60 ℃.

Eighthly, starting cold pressing, wherein the cold pressing temperature is 140 +/-1.5 ℃, and 60Kg/cm²And (3) cold pressing for 60 minutes under pressure, converting the outer-layer prepreg 21 into a cured state through cold pressing, and tightly combining the copper foil surface of the packaging substrate with the six-layer structure and the outer-layer thin copper foil 22 together under the action of the cold pressing to form the packaging substrate with the eight-layer structure.

And ninthly, cooling after cold pressing is finished, and pulling out the pressed eight-layer structure packaging substrate by a skip car to disassemble and discharge.

And tenth, performing target shooting operation, namely placing the packaging substrate with the eight-layer structure on an automatic target shooting machine, penetrating through X-Ray to generate a CCD (charge coupled device) visual image, displaying a target to be subjected to target shooting, calculating the target by a visual system, calculating coordinates, accurately moving a drill spindle on a pumping control to the central position of the target, drilling through the target hole, milling away copper foil at the target position of the three-layer plate, exposing a target ring, and facilitating subsequent drilling positioning and identification.

And step ten, edge milling operation, namely milling the copper foil and the gummosis outside the size of the packaging substrate with the eight-layer structure to ensure that the edge structure of the packaging substrate is smooth and flat.

S6, board splitting operation: the eight-layer structure packaging substrate is separated by manufacturing and processing, the inner-layer thick copper foil 12 and the inner-layer thin copper foil 13 are separated to form two packaging substrates and bearing plate structures with three-layer plate structures consistent, the bearing plate structure is composed of a core plate 11 and a double-sided inner-layer thick copper foil 12, and the eight-layer structure packaging substrate is specifically divided into the following four steps:

firstly, cleaning a workbench, and cleaning the surface of the workbench by using alcohol dust-free cloth.

And secondly, preparing a silk thread in advance, wherein the silk thread must have the characteristic of soft and strong tensile force.

And thirdly, fixing the position of the packaging substrate, placing the packaging substrate on the table board in the longitudinal direction, enabling the outer layer thin copper foil 22 after outer layer pressing to face upwards, fixing the positions of two ends of the packaging substrate, and ensuring that the packaging substrate cannot move in the board splitting process so as to avoid scraping.

Fourthly, starting to divide the board, dividing the board into two packaging substrates with a three-layer board structure, firstly determining the layering position of a torn corner, identifying a silk thread between an inner thin copper foil 13 and an inner thick copper foil 12 in the middle of the packaging substrates, starting to divide the board from the left side of the packaging substrates, setting the tension of the left side and the right side as 110N, dividing the board from the top end of the left side to the tail end at a constant speed according to the speed of one thirty second board, wearing disposable gloves to put three layers of boards above the inner thin copper foil 13 separated from the boards into a tray, putting a piece of clean white paper per three layers, turning the surface of the divided inner thick copper foil 12 downwards, automatically adsorbing and turning the inner thin copper foil 13 upwards, fixing the two ends of the packaging substrates, identifying the silk thread between the inner thin copper foil 13 and the inner thick copper foil 12 in the middle of the substrates, starting to divide the board from the left side of the substrates, setting the tension of the left side and, and (3) dividing the board from the top end of the left side to the tail end at a constant speed according to the speed of one thirty second board, namely completing the three-layer board dividing process, wherein the thickness of the three-layer board after board dividing is 56um +/-1 um, and obtaining the packaging substrate with the ultrathin three-layer structure.

The structure of the bearing plate and the structure of the ultrathin three-layer plate are separated, so that the operability in plate separation is improved, the subsequent process is easy to control, the manufacturing yield of the packaging substrate with the three-layer structure is improved, and the plate bending phenomenon of the ultrathin three-layer plate caused by plate separation is avoided.

As a specific technical solution of the embodimentThe specific steps for manufacturing the bearing plate in the step S1 are as follows: 1 piece of glass epoxy base material with the thickness of 100um is taken as a core plate 11, inner thick copper foils 12 which cannot be recrystallized are hot-pressed on two sides of the core plate by a hydraulic vacuum machine, a layer of inner thin copper foil 13 is respectively superposed on each inner thick copper foil 12, and the hot-pressing pressure is 30Kg/cm²The hot pressing temperature is 180 ℃, the main hot pressing time is 1 hour, the hot pressing is finished and then the bearing plate is cooled, and when the temperature reaches about 50 ℃, the bearing plate with the double-sided thickness of 18um +3um is taken out.

As a specific technical solution of this embodiment, in S2, the package substrate does not need to be subjected to browning treatment before being pressed, the inner prepreg 14 is taken out from the freezing bin and then heated for 8-12 hours, the size of the inner prepreg 14 is 2.5mm longer than the single side of the size of the package substrate, and the type of the inner prepreg 14 corresponding to the gel content (including the thickness, gel content, size requirements, and the like of the inner prepreg 14) is selected according to the product requirements.

As a specific technical scheme of this embodiment, after the package substrate is laminated in S2, a photosensitive dry film is attached to a copper foil surface of the laminated package substrate, in the process of laminating the photosensitive dry film, the laminated package substrate is subjected to acid cleaning first, the surface of the package substrate is roughened by a roughening solution, the bonding force between the dry film and the copper foil surface of the package substrate is improved, then the residual roughening solution is washed by water, then the acid cleaning solution is oxidized, the strong wind blows the dry package substrate surface to dry, and then the photosensitive dry film with thickness is vacuumized and pressed on the copper foil of the package substrate to form a pressed film to obtain the package substrate with a six-layer structure having a double-sided dry film.

As a specific technical solution of this embodiment, when the package substrate is separated in S6, the package substrate is first fixed in position, the package substrate is placed on the table top in the longitudinal direction, the outer thin copper foil 22 after outer lamination faces upward, and the two ends of the package substrate are fixed in position, so that the package substrate is not moved during the separation process to avoid scratching.

Example two:

Setting the temperature of the vacuum hot press to 1-2 sections at 140 ℃ respectively, and pressing for 5 minutes, wherein the pressure is controlled at 7Kg/cm²3-4 stages of prepressing at 160 ℃ for 5 minutes, and controlling the pressure at 16Kg/cm²The temperature of the 5 th, 6 th and 7 th sections is 220 ℃, and the pressure is 35Kg/cm²The time is respectively 5 minutes, 40 minutes and 30 minutes, and the temperature of the last 8 th stage is 140 ℃ and 20Kg/cm²Low temperature for 10 minutes.

And (3) parameter control during medium coarsening and film pressing operation: coarsening liquid medicine Cu²⁺The concentration is 45g/L, H₂SO₄Concentration of 75g/L, H₂O₂The concentration is 30g/L, the concentration of CB-5564 is 1%, the temperature of the liquid medicine in the tank is controlled at 26 ℃, and the spraying pressure is controlled at 1.4/cm²The coarsening and galling amount is controlled within the range of 0.9 +/-0.3 um, and the pickling H is carried out₂SO₄The concentration is 3.5-4.5%, the temperature is controlled within 105-125 deg.C, the film pressing time is controlled at 1.5 s, the speed of the package substrate and the substrate feeding speed is controlled at 2.5m/min, and the pressure is controlled at 0.45Kg/cm²。

Passing through Na with the concentration of 0.9 +/-0.1 percent₂CO₃Developing solution with a temperature of 32 deg.C, a speed of 4.5 m/min, and a pressure of 0.5Kg/cm²And a down pressure of 0.8Kg/cm²Etching the inner layer plate with its front side facing upwards, regulating etching speed, regulating etching amount according to different circuit requirements, wherein the etching requirement is 36.5% hydrochloric acid solution, the ratio of etching solution to hydrochloric acid is 1:3, the temperature of etching solution is controlled at 50 +/-2 ℃, and the spraying pressure is 2.6Kg/cm²The single-side etching amount of the circuit is controlled to be 16 mu m, the film stripping solution temperature is controlled to be 45 ℃, the film stripping solution concentration is 10.5 percent, the film stripping speed is controlled according to 2.6 +/-0.8 m/min, and the spraying upper and lower pressures are 1.5Kg/cm during film stripping²And (4) the following steps.

Sixthly, starting hot pressing, setting the temperature and the pressure time, setting the high-temperature pressing temperature for 1-2 sections at 140 ℃ for 10 minutes according to the number of each section, and controlling the pressure at 7Kg/cm²3-4 sections of prepressing at 160 ℃ for 10 minutes, and controlling the pressure at 16Kg/cm²The temperature of the 5 th, 6 th and 7 th sections is 220 ℃, and the pressure is 35Kg/cm²The time is 10 minutes, 80 minutes and 60 minutes respectively, and the temperature of the last 8 th stage is 140 ℃ and 20Kg/cm²The outer layer prepreg 21 is pressurized at high temperature to melt the outer layer prepreg 21 and flow the glue, the uneven gaps are filled with the glue of the outer layer prepreg 21, the current values of the temperature and the pressure are automatically heated and pressurized to the set values, and the time is calculated.

Seventhly, starting to discharge vacuum, wherein the vacuum discharge pressure is 6kg/cm²—7kg/cm²When the front door needs to be opened, the oil cylinder descends, and the oil quantity is not lower than the oil level2/3 degree, the temperature range of the oil liquid must be controlled within 15-60 ℃.

As a specific technical solution of this embodiment, the specific steps of manufacturing the bearing plate in S1 are as follows: 1 piece of glass epoxy base material with the thickness of 100um is taken as a core plate 11, inner thick copper foils 12 which cannot be recrystallized are hot-pressed on two sides of the core plate by a hydraulic vacuum machine, a layer of inner thin copper foil 13 is respectively superposed on each inner thick copper foil 12, and the hot-pressing pressure is 30Kg/cm²The hot pressing temperature is 180 ℃, the main hot pressing time is 1 hour, the hot pressing is finished and then the bearing plate is cooled, and when the temperature reaches about 50 ℃, the bearing plate with the double-sided thickness of 18um +3um is taken out.

In conclusion, according to the packaging substrate with the three-layer board structure and the manufacturing method thereof, the inner-layer circuit layer 1 and the outer-layer pressing layer 2 are arranged, the residual copper rate is increased through the hexagonal copper laying design of the edges of the packaging substrate, the problems that air bubbles exist in the packaging substrate due to insufficient exhaust during subsequent pressing are effectively solved, the board warping phenomenon in the three-layer board dividing process is avoided, the phenomena that copper foil wrinkles, bubbles and glue overflows in the pressing process are effectively prevented, the yield of products is improved, and the packaging substrate has a wide application prospect.

It should be noted that, in this document, terms such as "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The utility model provides a three-layer plate structure's packaging substrate, includes inlayer circuit layer (1) and outer pressfitting layer (2), its characterized in that: the circuit board comprises an inner layer circuit layer (1), an outer layer circuit layer (1) and a core board (11), wherein the top and the bottom of the inner layer circuit layer (1) are both provided with an inner thick copper foil (12), an inner thin copper foil (13), an inner prepreg (14) and an inner medium thick copper foil (15) in sequence;

outer pressfitting layer (2) are including outer prepreg (21) and outer thin copper foil (22), two the back of the body of inlayer medium thickness copper foil (15) all sets gradually outer prepreg (21) and outer thin copper foil (22).

2. The package substrate of a three-layer board structure as claimed in claim 1, wherein: the core board (11) is an epoxy resin glass fiber base material.

3. The package substrate of a three-layer board structure as claimed in claim 1, wherein: the thickness of inlayer thick copper foil (12) is 18um, the thickness of inlayer thin copper foil (13) is 3 um.

4. The package substrate of a three-layer board structure as claimed in claim 1, wherein: the thickness of inlayer prepreg (14) is 25um, the thickness of inlayer medium thickness copper foil (15) is 12 um.

5. The package substrate of a three-layer board structure as claimed in claim 1, wherein: the thickness of outer prepreg (21) is 25um, the thickness of outer thin copper foil (22) is 3 um.

6. A method for manufacturing a package substrate based on a three-layer structure as claimed in any one of claims 1 to 5, comprising the steps of:

s1, manufacturing a bearing plate: adopting an epoxy resin glass fiber base material as a core plate (11), forming an inner-layer thick copper foil (12) and an inner-layer thin copper foil (13) on two sides of the core plate (11), hot-pressing the inner-layer thick copper foil (12) which cannot be recrystallized on the two sides of the core plate (11) by using a hydraulic vacuum machine, and respectively superposing one inner-layer thin copper foil (13) on the two inner-layer thick copper foils (12) for pressing to form a bearing plate;

s2, manufacturing a packaging substrate: sequentially carrying out high-temperature pressing operation on an inner-layer prepreg (14) and an inner-layer medium-thickness copper foil (15) on two sides of the bearing plate, melting the inner-layer prepreg (14) through high temperature and high pressure to be tightly combined with the inner-layer thin copper foil (13), and combining the inner-layer prepreg with the inner-layer thin copper foils (13) on the two sides of the bearing plate to form a six-layer structure packaging substrate;

s3, manufacturing an inner layer circuit layer (1): respectively manufacturing the same inner layer circuit layer (1) on the inner layer medium-thickness copper foil (15) of the packaging substrate, and developing and etching to form a circuit pattern;

s4, browning treatment before pressing: the packaging substrate is treated by acid washing liquid and browning liquid, so that the binding force between the inner thin copper foil (13) and the inner prepreg (14) of the packaging substrate is improved, and a double-sided browning layer is formed on the copper surface of the circuit of the packaging substrate;

s5, outer layer pressing: sequentially carrying out high-temperature pressing operation on an outer-layer prepreg (21) and an outer-layer thin copper foil (22) on two sides of the packaging substrate, and melting the outer-layer prepreg (21) through high temperature and high pressure and tightly combining the outer-layer prepreg, the outer-layer thin copper foil (22) and a browning layer of the packaging substrate to form the packaging substrate with an eight-layer structure;

s6, board splitting operation: the eight-layer structure packaging substrate is separated by manufacturing and processing, the inner layer thick copper foil (12) and the inner layer thin copper foil (13) are separated, two packaging substrates with three-layer structures consistent and a bearing plate structure are formed, and the bearing plate structure is composed of a core plate (11) and double-sided inner layer thick copper foils (12).

7. The method as claimed in claim 6, wherein the step of fabricating the carrier board in S1 comprises: 1 piece of glass epoxy base material with the thickness of 100um is taken as a core board (11), inner thick copper foils (12) which can not be recrystallized are hot-pressed on two sides of the core board by a hydraulic vacuum machine, a layer of inner thin copper foil (13) is respectively superposed on the inner thick copper foils (12), and the hot-pressing pressure is 30Kg/cm²The hot pressing temperature is 180 ℃, the main hot pressing time is 1 hour, the hot pressing is finished and then the bearing plate is cooled, and when the temperature reaches about 50 ℃, the bearing plate with the double-sided thickness of 18um +3um is taken out.

8. The method for manufacturing the packaging substrate with the three-layer plate structure according to claim 6, wherein no browning treatment is needed before the packaging substrate is laminated in S2, the inner-layer prepreg (14) is taken out from the freezing bin and then is heated for 8-12 hours, the size of the inner-layer prepreg (14) is 2.5mm longer than the single side of the size of the packaging substrate, and the type of the inner-layer prepreg (14) is selected according to the product requirement, wherein the type of the inner-layer prepreg (14) corresponds to the glue content.

9. The method of claim 6, wherein after the packaging substrate is laminated in step S2, a dry film layer is applied on the copper foil surface of the laminated packaging substrate, during the lamination process, the laminated packaging substrate is first subjected to acid cleaning to roughen the packaging substrate surface, thereby improving the bonding force between the dry film and the copper foil surface of the packaging substrate, then the residual roughening solution is washed with water, then the acid cleaning is performed to oxidize the packaging substrate surface, and the packaging substrate surface is dried by strong wind blowing, and then the thick dry film layer is vacuumized and pressed on the copper foil of the packaging substrate to form a film pressing process, thereby obtaining the packaging substrate with six-layer structure having double-sided dry films.

10. The method as claimed in claim 6, wherein in step S6, when the package substrate is separated, the package substrate is fixed, the package substrate is placed on the table top along the longitudinal direction, the outer thin copper foil (22) faces upward after the outer layer is laminated, and the two ends of the package substrate are fixed to prevent the package substrate from moving and scratching.