CN112533383A - 22-layer low-loss PCB manufacturing method - Google Patents

Abstract

The invention provides a 22-layer low-loss PCB manufacturing method which is improved on the basis of original processing, wherein drilling is divided into two production operations, a through hole and a depth control hole which need to be plugged with resin are drilled for the first time, and the resin plugging is performed after production and CAPPING electroplating is performed. And drilling a hole without a resin plug for the second time, and performing subsequent plate electrification and outer layer pattern electrification production. Effectively avoid all through-holes and accuse deep hole to bore the process through 3 coppering, ensure that the qualification rate of coppering quality and product impedance and loss promotes.

Description

22-layer low-loss PCB manufacturing method

Technical Field

The invention relates to the technical field of circuit board production, in particular to a 22-layer low-loss PCB manufacturing method.

Background

The impedance and LOSS (LOSS/insertion LOSS) of the multilayer PCB are critical to the transmission of high-speed signals, and are also important factors for the transmission rate and the degree of undistortion of signals. Therefore, the PCB of the high-end server motherboard type has more and more requirements on impedance and LOSS, and the control level is more and more strict. The impedance and LOSS of the PCB are difficult to increase in manufacturing, and the value of a manufactured product is easy to exceed the standard and cannot meet the requirement of a client.

Disclosure of Invention

Aiming at the problems, the invention aims to provide a 22-layer low-loss PCB manufacturing method, which analyzes main factors influencing PCB impedance and insertion loss and different degrees of impedance influence by researching influencing factors such as different line widths, different medium thicknesses, different dielectric constant changes, circuit layer browning, circuit compensation and the like, and provides an optimal proposal for PCB high-precision impedance design.

Specifically, the method for manufacturing the 22-layer low-loss PCB comprises the following steps:

step 1: performing a first pre-drilling process;

step 2: drilling for the first time, wherein the CPK of the hole precision is more than 1.33; after the first charting, drilling for the second time;

and step 3: and (3) carrying out first-time plate electricity, and continuously and sequentially carrying out: plugging holes with resin, CAPPING electroplating, primary outer layer, copper reduction, grinding and then drilling for the third time;

and 4, step 4: and sequentially carrying out a second plate electrode, a second outer layer, a second patterning electrode and subsequent processes.

Wherein, the first pre-drilling process further comprises:

cutting: cutting a substrate material according to a custom requirement, or selecting a PNL small-size substrate to be manufactured by a next process after baking, wherein the baking condition is set as follows: the temperature is 190 ℃ and the time is 4H;

inner layer: the special LDI ink is adopted during processing, the film thickness control range is 11 +/-2 um, the exposure adopts the major LDI, and the line width control layers are L3, L5, L7, L9, L14, L16, L18 and L20; the line width of a finished product is set to be 3.5mil, and the line distance of the finished product is set to be 4 mil; the upper, middle and lower line widths of the same line are controlled within 0.1 mil; 1/1OZ etch with parameters set to 5.3M/MIN; 2/2OZ was etched with the parameters set to 3.5M/MIN.

Internal inspection: repairing residual copper without repairing wires;

and (3) laminating: punching 7 holes in a PE punching hole before browning, and punching 4 holes on the periphery in a central drilling mode except for 3L-shaped holes, wherein the target distance is X1= 399.397mm, X2=404.397mm, and Y = 583.238 mm; browning is carried out at a linear speed of 5m/min, and drying plates are arranged at a high-speed material browning station at the temperature of 120 ℃ for 60 minutes; after the browning, the fusion and riveting are completed within 12 hours, after the first board inspection layer is qualified, the yield is totally inspected whether the layer is qualified, the number of PP (polypropylene) and the correctness of the Core of the inner layer are 100 percent or not; pressing and using a special M6 process;

laser blind holes; the laser blind holes with L13/L12 layers are produced in a mass production mode after the width and the depth of the measuring hole of the first piece are qualified.

And after the first drilling, whether the hole is blocked by the through hole and the aperture of the crimping hole is detected. And measuring the CPK of the hole precision to be more than 1.33;

and the secondary drilling is mechanical back drilling for the back rotary drilling of the graphic electricity, and different depths are drilled in the first quadrant and the fourth quadrant respectively. The first quadrant is drilled from the first layer to L4/6/8/13/15/17/19, respectively, and not drilled through the corresponding sublayer L5/7/9/14/16/18/20. The depths of the first plate slice analysis back drilling holes are respectively 0.36mm, 0.65mm, 0.94mm, 1.71mm, 1.9mm, 2.29mm and 2.58mm, and the Stub values of the first plate slice analysis back drilling holes are all 7+/-5mil, and the first plate slice analysis back drilling holes are produced in quantity after meeting the requirements; the fourth quadrant is drilled from layer 22 to L19/17/15/10/8/6/4 respectively, not drillable through the corresponding sublayer L18/16/14/7/5/3. The depths of the back drill are respectively 0.36mm, 0.65mm, 0.94mm, 1.71mm, 1.9mm, 2.29mm and 2.58mm, the back drill is subjected to high-pressure water washing, the washing pressure parameter is 2.5kg/cm, and the back drill is inspected after the water washing to ensure that no hole is blocked.

The first sub-board further comprises: removing glue by plasma, baking before production under the condition of 190 ℃ by 2H, keeping the time for no more than 4 hours after baking, transferring copper horizontal line operation, and manufacturing by adopting six pulse electroplating, wherein the hole copper is 0.9-1.0 mil.

The resin plug hole further includes: plugging holes together with the back drilling holes of the small holes, wherein the holes need to be plugged twice, and the front surface and the back surface are plugged once respectively; and (4) performing AOI full inspection after hole plugging grinding.

The first secondary outer layer further comprises: sealing the holes by dry film, covering the holes with dry film width of 24 inch, sealing only the PTH holes of the resin plugs, exposing by using LDI with energy of 90mj and developing at speed of 4 m/min.

Reducing the copper to 0.9 +/-0.1 mil by using a special line; and (4) after copper reduction, removing the film on the surface of the plate, rotating the plate, and producing the plate by using a grinding line, wherein the thickness of copper after plate grinding is controlled to be 0.7-0.9 mil.

Further, the method also comprises the following steps:

the third drilling is produced by a CCD drilling machine, and optical points in a grabbing unit of the CCD drilling machine are processed in a two-drilling mode, wherein drilling parameters are controlled within +/-0.05mm of hole site tolerance, 0.99mm NPTH hole tolerance plus 0.05/-0.025mm, the drilling bit is ground for less than or equal to 2 times, and then the tray rotating plate is mounted after the drilling is finished;

the second secondary plate is electrically plated by adopting six pulse plating, and the electrical parameter range of the copper deposition plate is 0.3-0.5 mil; pre-treating the plate after electrification and turning to the outer layer, and carrying out film pressing operation in a dust-free workshop at the speed of 4m/min, wherein the width of a dry film is 23.875 inch, back drilling holes are drilled on two sides, the type of a negative film is positive, the width of a working draft line is 4.7 mil, and the line distance of the working draft is 2.6 mil;

the second-time graphic electromachining parameters are as follows: electroplating for 0.7mil, copper for the surface of a finished product is 1.9mil, copper for holes is 0.8mil, plugging electroplating is carried out on via holes plugged by resin, the concavity is less than 25um, the quantity is flat and is less than 0.50mm for the finished product, and the copper for the holes is more than or equal to 18 um.

The subsequent process comprises the following steps: back drilling, alkaline etching, external inspection, solder mask, text, impedance test, gold melting, fourth drilling, molding, finished test, FQC and packaging.

The back drilling process also comprises the steps that the fourth quadrant drills to L19/17/15/10/6 from the 22 th layer respectively, does not drill through the corresponding sub-layer L18/16/14/9/5, the depths of the fourth quadrant are 0.36mm, 0.65mm, 0.94mm, 1.71mm and 2.29mm respectively, high-pressure water washing is completed after back drilling, the washing pressure parameter is 2.5kg/cm, and inspection after washing ensures that back drilling is free of hole blocking.

The fourth drilling is produced by adopting a CCD drilling machine, the grinding time of a drill bit is less than or equal to 2 times, the optical point in the CCD grabbing unit is processed in a two-drilling mode, and the drilling parameters are controlled as follows: the position tolerance of the chip BGA PAD and the hole with the size of 1.016mm around the finished product is +/-0.035mm, and the position tolerance of the hole with the size of 3.175mm around the finished product is +/-0.05 mm.

In conclusion, the invention provides a 22-layer low-loss PCB manufacturing method which is improved on the basis of the original processing, the drilling is divided into two production operations, the through hole and the deep control hole which need to be plugged with resin are drilled for the first time, and the resin plug hole is rotated and then CAPPING electroplating is carried out after the production. And drilling a hole without a resin plug for the second time, and performing subsequent plate electrification and outer layer pattern electrification production. Effectively avoid all through-holes and accuse deep hole to bore the process through 3 coppering, ensure that the qualification rate of coppering quality and product impedance and loss promotes.

Drawings

FIG. 1 is a diagram of an anomaly processed by the prior art.

Fig. 2 is a diagram manufactured by the PCB manufacturing method according to the present invention.

Detailed Description

The method for fabricating a 22-layer low-loss PCB according to the present invention will be described in detail with reference to the following embodiments and accompanying drawings.

Example one

As shown in fig. 1, which is an abnormal diagram processed in the prior art, it can be seen that the Via hole copper thickness is abnormal, and the adopted PCB processing flow sequentially comprises: open material → inner layer → inner inspection → press fit → laser blind hole → drill hole 1 → board → electric figure 1 → drill hole 2 → resin plug hole → outer layer 1 → copper reduction → grind → CAPPING electroplate → outer layer 2 → electric figure 2 → back drill → alkaline etch → outer inspection → anti-weld → character → impedance test gold → drill hole 3 → molding → formation test → FQC → package.

Based on the method, LOSS design and manufacture of the server mainboard PCB are firstly carried out, according to 22 layers of server PCB boards, loose low-LOSS R-5775(G) (specified) materials are used, TG is more than or equal to 180 ℃ (specified), customers specify an M6 (G) board, RTF copper foils are used as outer-layer copper foils, namely low-roughness copper foils, commonly called reversal copper foils, so that the minimum CTI of the PCB is finished, and compared with the tracking resistance index, the CTI index is more than or equal to 175. The thickness of the finished board is 2.95 +/-10%, 1/1OZ and 2/2OZ are used as the inner layer, core boards with different thicknesses are used, and the width of the inner/outer layer circuit is required to be manufactured: 3.5 mil. Specification of hole copper: min is 0.6mil, and the specification of surface copper is as follows: 1.9-2.2 mil. High aspect ratio: 14.75:1, SI Coupon (impedance signal integrity standard), backdrilling and POFV (plating via plug filled with resin and then plating copper cap hole to PAD) processes. And (3) performing FA batch manufacturing according to a normal flow of a conventional PCB, and testing and analyzing the abnormal problems of qualified impedance, overproof insertion loss and thicker hole copper.

Table 1: the 22-layer server PCB manufactured by the 22-layer low-loss PCB manufacturing method provided by the invention has the following structural design:

by analyzing and checking factors influencing impedance and insertion loss, a DOE experiment is carried out to determine the optimal process conditions, and proper process parameters are selected. Finding out four important factors (line width, medium thickness, brown coarsening and typesetting angle), compensating the line width: the low level supplements 50um more, the high level supplements 50um more; the content of PP gel is as follows: low level 70%, high level 75%; typesetting angle: the low level is inclined by 3 degrees, and the high level is inclined by 7 degrees; palm chemical liquid medicine, low-level longitude and latitude, high-level ATO. Full factorial testing was performed with 3 trials at the center point for a total of 19 trials. Implementation with Minitab: the non-relevant 3 times were removed to give 16 effective tests.

Table 2: a DOE trial plot of the four factor 2 level of insertion loss;

the test results in the above figures show that the compensation is more than 50um through the normal compensation of the line width ratio, the gel content of the medium thickness PP is 75% (70% before), ATO (Ammet lotion) ultra-low coarsening browning lotion (XJW-Xingjing latitude and longitude lotion), the insertion Loss of the PCB is manufactured by composing and inclining the parameters of 7 degrees (3 degrees before), and the Coppon is tested according to the SI (signal integrity standard) provided by the customer, and the 85 ohm Loss values of the lines of 2, 5 and 10 inch in the weight Loss strip in and out of 4GHz, 8GHz,12.89GHz and 16 GHz. Shown in the figure is 2 inchLO.

The SS bar has a Loss value of 85 ohms for the inner layer at 4 GHz. The detection result is 0.286 db/inch, the minimum value of 16 test values is less than the maximum value of 0.35 db/inch. The results of the other test values were verified one by one, all showed the same standard 11 condition, and the LOSS value was the most desirable. The method presents better result advantages and tests the optimal condition parameters of the process.

Table 3: level 22 server-board sensing load value:

furthermore, based on the experimental data, the thickness of the hole copper of the server mainboard PCB is designed and manufactured, and a 22-layer low-loss PCB manufacturing method is provided.

The method specifically comprises the following steps:

the improvement of PCB, a 22-layer low-loss PCB manufacturing method comprises the following steps: open material → inner layer → inner inspection → press → laser blind hole → drill hole 1 → electric of drawing 1 → drill hole 2 → board electric 1 → resin plug hole → CAPPING electroplating → outer layer 1 → copper reduction → grinding → drill hole 3 → board electric 2 → outer layer 2 → electric of drawing 2 → back drilling → alkaline etching → outer inspection → anti-welding → character → impedance test → gold melting → drill hole 4 → molding → formation test → FQC → packaging.

Comparing the original process with the new process, the PCB is plated with copper for 3 times in the original process, after the through holes and the deep control holes are drilled completely, the PCB is electrified, the resin is filled, the CAPPING is electroplated, and then the PCB is subjected to graphic and electrical operation, wherein the copper thickness of the PCB exceeds the standard and is abnormal, the aperture is small, the uniformity of the copper surface of the PCB is poor, and the PCB is not beneficial to manufacturing of an outer layer circuit (as shown in figure 1). The new process is characterized in that the original drilling is finished by drilling all through holes and depth control holes at one time, and the production operation is divided into two times. And (3) drilling a through hole and a deep control hole which need to be plugged with resin for the first time, and rotating the resin to plug the hole after production and then CAPPING electroplating. And drilling a hole without a resin plug for the second time, and performing subsequent plate electrification and outer layer pattern electrification production. Effectively avoid all through-holes and accuse deep hole to bore through the process of 3 coppering, change management and control hole copper and face copper thickness (as shown in figure 2). Ensure the quality of copper plating and the qualified rate of product impedance and loss to be improved.

The relevant parameters of the processing flow of the server mainboard PCB are as follows:

1) cutting: according to the requirements of customers, the working size of the production plate is designed, and the large-piece base plate material is selected for cutting. Also, according to the required size, the cut PNL small-sized substrate is purchased and baked (190 ℃ 4H) for the next process. The size of the product is as follows: 468mm 620 mm.

2) Inner layer: and (3) typesetting 1PCS/PNL due to larger size according to a PCB design blueprint provided by a customer. The inner layer circuit is fabricated by using the customer-specified matted substrate. The special ink for LDI is used, the film thickness is controlled to be 11 +/-2 mu m, the exposure adopts the large-family LDI, the line width control layers are L3L5L7L9L14L16L18L20, the finished product line width is 3.5mil, the finished product line distance is 4 mil, the line width etching tolerance is +/-20%, and the actual impedance line is controlled to be +8% -7%. And (3) selecting a line body with the etching uniformity of more than 97% for production, and controlling the line width of the upper line, the middle line and the lower line of the same line within 0.1 mil. 1/1OZ etch parameter 5.3M/MIN; 2/2OZ parameter 3.5M/MIN.

3) Internal inspection: depending on the correlation, only the residual copper can be repaired, and no wire repair is allowed. AOI detects the function of superfine wire, works according to the design parameters of the original manuscript, and the yield of the first piece is more than 95 percent.

4) And (3) laminating: PE punches a hole and dashes 7 holes before the brown ization, except 3 holes of L shape, still need to punch out other peripheral 4 hole target distances with the center drilling mode: x1= 399.397mm, X2=404.397mm, Y = 583.238mm brownification is carried out at a linear speed of 5m/min, and a high-speed material brownification station needs to bake plates at 120 ℃ for 60 minutes. The fusion riveting is completed within 12 hours after the browning, the first board inspection layer is qualified, the production and total inspection layer is accurate, the number of PP sheets is large, and the correctness of the Core of the inner layer is 100%. The press was operated using a dedicated M6 pass (increasing vacuum on the bock press by 5 minutes). The tolerance of the thickness (base plate and PP) of the cutting medium layer of the FA first plate is +/-10 percent, the TG value is measured by hot TMA, the DetalTG, the CTE and the thermal stress are qualified and then the mass production is carried out.

5) Laser blind holes: and performing large control such as windowing, laser perforation and the like by using a Conformal Mask operation according to a laser program. L13/L12 layer laser blind hole, the name of the program sub-file is: *. S13/S12. And measuring the width and the depth of the hole in the first production piece, and carrying out mass production after the qualified product is confirmed by IPQC.

6) Drilling 1: the drill bit is produced by using high difficulty parameters, a brand new drill bit is used for the drill bit with the hole diameter smaller than 0.5mm, and the service life of the hole is set to be 500 times for replacement. The first plate is inspected for non-porous deviation, and the mass production is finished by 100 percent inspection by using a hole inspection machine. And detecting whether the apertures of the through hole and the crimping hole are blocked. And the hole accuracy measured CPK > 1.33.

7) FIG. 1: after drilling, carrying out high-pressure water washing, turning to image electricity, and plating tin on the whole plate firstly, wherein the plating tin parameters are as follows: 10ASF 15 Min. It is required to plate tin only and not to plate copper.

8) And (3) drilling 2: and (4) performing mechanical back drilling on the rotary drilling hole after the drilling is finished, and respectively drilling different depths in the first quadrant and the fourth quadrant. The first quadrant is drilled from the first layer to L4/6/8/13/15/17/19, respectively, and not drilled through the corresponding sublayer L5/7/9/14/16/18/20. The depths of the first plate slice analysis back drilling holes are respectively 0.36mm, 0.65mm, 0.94mm, 1.71mm, 1.9mm, 2.29mm and 2.58mm, and the Stub values of the first plate slice analysis back drilling holes are all 7+/-5mil, and the first plate slice analysis back drilling holes are produced in quantity after meeting the requirements; the fourth quadrant is drilled from layer 22 to L19/17/15/10/8/6/4 respectively, not drillable through the corresponding sublayer L18/16/14/7/5/3. The depths of the first plate section analysis back drilling holes are respectively 0.36mm, 0.65mm, 0.94mm, 1.71mm, 1.9mm, 2.29mm and 2.58mm, and the Stub values of the first plate section analysis back drilling holes are all 7+/-5mil, so that the first plate section analysis back drilling holes are produced in quantity after meeting the requirements. High-pressure water washing pressure 2.5kg/cm after back drilling, inspection after water washing, and guarantee that back drilling does not have stifled hole

9) The plate 1 is firstly subjected to plasma degumming and baking before production, and the condition is 190 ℃ by 2H. After baking, the retention time is less than or equal to 4 hours, and copper is transferred to a horizontal line for copper deposition. Six pulse plating is adopted to manufacture the copper-plated hole, and the copper of the hole is ensured to be 0.9-1.0 mil.

10) Resin hole plugging: the ink uses Shanrong 10HF hole plugging ink, and resin hole plugging and a small hole back drilling hole are used for hole plugging together, the hole plugging needs to be performed twice, and the front surface and the back surface of the ink are plugged once respectively. The aluminum sheets for plugging the holes are respectively named as: SZSK 2-1, SZSK 2-2, AOI full inspection after hole plugging grinding, no plugging leakage, no full plugging and 100% plumpness.

11) CAPPING electroplating: six places are subjected to pulse electroplating, and the thickness of the cap electroplated copper is 0.3-0.5 mil.

12) Outer layer 1: and (3) sealing the dry film, namely using a Honghui dry film HD250, wherein the dry film width of a cover hole is 24 inch, sealing the dry film, designing a negative film (positive film) by CAM (only sealing PTH holes of a resin plug), wherein the tool name is L1gk, the L22gk, exposing by using LDI, the energy is 90mj, and the developing speed is 4 m/min.

13) Copper reduction: the copper thickness is reduced to 0.9 + -0.1 mi using a dedicated line. And measuring the copper thickness value by using a copper thickness measuring instrument before and after production to be qualified, and recording data for reference of a post-process.

14) Grinding: and (3) after copper reduction, removing the film on the surface of the plate, rotating the plate, and producing a grinding line, wherein the thickness of the copper on the surface is measured by grinding once, and the thickness of the copper after plate grinding is controlled to be 0.7-0.9mil to meet the requirement.

15) And (3) drilling holes: and drilling holes without resin plug holes, and producing by using a CCD (charge coupled device) drilling machine. The name of the drilling program sub-file is 2nd, 2nd. The drill holes are produced by using high-difficulty parameters. Hole site tolerance +/-0.05mm, 0.99mmNPTH hole tolerance +0.05/-0.025mm, drill bit grinding times = <2 times. And (5) loading a tray and rotating a plate.

16) A plate electrode 2: and (4) performing pulse electroplating at six positions, plating a copper plate for 0.3-0.5mil, and slicing the copper first piece to confirm the thickness requirement of the copper in the crimping hole.

17) Outer layer 2: the plate is electrically treated and then is pre-treated by turning to the outer layer, and the plate is put into a dust-free workshop for film pressing at the speed of 4m/min, and the dry film width is 23.875 inch. And (3) back drilling holes, and double-sided windowing to ensure good tinning, wherein the negative film type is positive, the line width of the working manuscript is 4.7 mil, and the line distance of the working manuscript is 2.6 mil.

18) FIG. 2: electroplating minimum 0.7mil, finished product surface copper minimum 1.9mil, hole copper minimum 0.8mil, via hole plugged by resin needs to be plated with clamping, the depression is less than 25um, the quantity is flat, for finished product hole less than 0.50mm, hole copper must be more than or equal to 18um, and others are according to min20um and avg25 um. The aperture tolerance of the crimping hole is +/-0.05 mm.

19) Back drilling: the fourth quadrant is drilled from layer 22 to L19/17/15/10/6 respectively, not drillable through the corresponding sublayer L18/16/14/9/5. The depths of the first plate section analysis back drilling holes are respectively 0.36mm, 0.65mm, 0.94mm, 1.71mm and 2.29mm, and the Stub values are all 7+/-5mil, so that the first plate section analysis back drilling hole depth values meet the requirements of mass production. After back drilling, the high-pressure water washing pressure is 2.5kg/cm, and after water washing, inspection is carried out to ensure that no hole is blocked during back drilling.

20) Alkaline etching: the line width of the finished product is 3.5mil, the spacing of the finished product is 4 mil, and the etching tolerance of the line width is +/-20%. The tolerance control standard of the SMT welding pad is that the SMT welding pad with the size being more than or equal to 15mil is +/-20% of the original size, and the SMT tolerance with the size being less than or equal to 15mil is controlled according to +2/-0.5 mil. The special control is that the line tolerance of the first part is controlled according to +/-10 percent, and the impedance line is controlled according to +/-8 percent. And (3) selecting a wire body with the etching uniformity of more than 95% for production, and controlling the wire width of the upper, middle and lower wires of the same line within 0.2 mil. The etching is more than 1OZ parameter 5.5M/MIN.

21) External inspection AOI: the width (supporting/crimping) holes of the outer layer of the finished product are larger than or equal to 50um, the non-supporting holes (namely PTH without an insert) are larger than or equal to 20um, the specified area is tested according to the requirements of a drawing, and all the positions of line width/line distance needing to be tested are marked by a measurement engineering department. The residual copper short circuit of the circuit can be repaired, and the open circuit gap can not be repaired. And (4) after AOI, inserting and supporting the baking plate, baking the plate at 150 degrees by 6H, and then turning to solder mask.

22) Solder mask: the solder mask surface is a C + S surface, the color of the solder mask ink is dark green, the viscosity is 100-. The hole is plugged by using an aluminum sheet, then solder mask oil is printed, and the thickness of a printed wet film is controlled to be 35-40 um. The central distance between the pads is less than or equal to 0.4mm, the solder mask thickness on the substrate is not higher than the SMT height by 15um, and the solder mask thickness of the other spaced pads can not be higher than the SMT height. The line angle is more than or equal to 4um, the solder mask on the substrate is less than or equal to 5um than the adjacent welding PAD, and the solder mask on the wiring is less than or equal to 50um than the adjacent welding PAD, and the plug hole can not be higher than the copper surface by 60 um. And (3) exposing by adopting a screen DI machine, automatically expanding and contracting and aligning, controlling +/-20 mu m by using PE, and controlling the exposure energy by 11-12 grids.

23) And (3) writing: the character ink is white, and the character surface is a C + S surface. UL Mark is oblique brother + R SH 2794V-0, and the period format is WWYY.

24) And (3) impedance testing: the customer provides an SI test Coupon that measures the 85 ohm Loss values of the 2, 5, 10 inch lines of the Loss strip at 4GHz, 8GHz,12.89GHz, 16GHz inner and outer body frames, as described in the Loss drawing, which requires the side panel internal impedance and has a test point film.

25) Gold melting: the minimum gold-plating thickness is 2u ', the maximum gold-plating thickness is 10 u ', and the minimum gold-plating nickel thickness is 118 u '. The nickel corrosion is less than 20% according to the control of the factory specification, and the MTO of the nickel groove can not exceed 2. The partition groove inserting frame can be used for mass production after the first gold and nickel piece is qualified. And the rotary plate of the paper separating tray is produced in quantity.

26) And (4) drilling holes: and (3) using a first quadrant, the grade name of a drilling program is 3nd, and 3nd.inn, producing by using a CCD (charge coupled device) drilling machine, wherein the grinding time of a drill bit is not more than 2, the tolerance of the position of a hole with the size of 1.016mm (0.991 mm) of the chip BGA PAD and the surrounding finished product is +/-0.035mm, the tolerance of the position of a hole with the size of 3.175mm of the finished product is +/-0.05mm, and processing by using an optical point (the process feedback BGA PAD cannot be grabbed) in a CCD grabbing unit in a two-drill mode.

27) Molding: CNC, size after molding: width 417 mm, length 400 mm, delivery area: 0.1668 square meters. Before routing, plate edges and LOSS Coupon are numbered, labeled and transferred into the plate.

28) And (3) testing: the bending degree of the plate is less than 0.7 percent (percent) and the thickness of the plate is 4.04 mm. All measurements with flying needles, 100% spot analysis reports were used.

29) FQC: the specification of the product guarantee is IPC-A-6002 level.

30) Packaging: and packaging operation is carried out according to the packaging mode required by the customer, and the packaged product is put into a warehouse for constant-temperature constant-humidity storage.

Example two

As another preferred, the method of the present invention comprises the steps of:

step 1: performing a first pre-drilling process;

step 2: drilling for the first time, wherein the CPK of the hole precision is more than 1.33; after the first charting, drilling for the second time;

and step 3: and (3) carrying out first-time plate electricity, and continuously and sequentially carrying out: plugging holes with resin, CAPPING electroplating, primary outer layer, copper reduction, grinding and then drilling for the third time;

and 4, step 4: and sequentially carrying out a second plate electrode, a second outer layer, a second patterning electrode and subsequent processes.

Wherein, the first pre-drilling process further comprises:

cutting: cutting a substrate material according to a custom requirement, or selecting a PNL small-size substrate to be manufactured by a next process after baking, wherein the baking condition is set as follows: the temperature is 190 ℃ and the time is 4H;

inner layer: the special LDI ink is adopted during processing, the film thickness control range is 11 +/-2 um, the exposure adopts the major LDI, and the line width control layers are L3, L5, L7, L9, L14, L16, L18 and L20; the line width of a finished product is set to be 3.5mil, and the line distance of the finished product is set to be 4 mil; the upper, middle and lower line widths of the same line are controlled within 0.1 mil; 1/1OZ etch with parameters set to 5.3M/MIN; 2/2OZ was etched with the parameters set to 3.5M/MIN.

Internal inspection: repairing residual copper without repairing wires;

and (3) laminating: punching 7 holes in a PE punching hole before browning, and punching 4 holes on the periphery in a central drilling mode except for 3L-shaped holes, wherein the target distance is X1= 399.397mm, X2=404.397mm, and Y = 583.238 mm; browning is carried out at a linear speed of 5m/min, and drying plates are arranged at a high-speed material browning station at the temperature of 120 ℃ for 60 minutes; after the browning, the fusion and riveting are completed within 12 hours, after the first board inspection layer is qualified, the yield is totally inspected whether the layer is qualified, the number of PP (polypropylene) and the correctness of the Core of the inner layer are 100 percent or not; pressing and using a special M6 process;

laser blind holes; the laser blind holes with L13/L12 layers are produced in a mass production mode after the width and the depth of the measuring hole of the first piece are qualified.

Wherein the subsequent process comprises: back drilling, alkaline etching, external inspection, solder mask, text, impedance test, gold melting, third drilling, molding, finished test, FQC and packaging.

The new manufacturing process method is proved by tests to have obvious improvement effect and feasible operation.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1. A22-layer low-loss PCB manufacturing method is characterized by comprising the following steps:

step 1: performing a first pre-drilling process;

step 2: drilling for the first time, wherein the CPK of the hole precision is more than 1.33; after the first charting, drilling for the second time;

and step 3: and (3) carrying out first-time plate electricity, and continuously and sequentially carrying out: plugging holes with resin, CAPPING electroplating, primary outer layer, copper reduction, grinding and then drilling for the third time;

and 4, step 4: and sequentially carrying out a second plate electrode, a second outer layer, a second patterning electrode and subsequent processes.

2. The method of claim 1, wherein the first pre-drilling step further comprises:

cutting: cutting a substrate material according to a custom requirement, or selecting a PNL small-size substrate to be manufactured by a next process after baking, wherein the baking condition is set as follows: the temperature is 190 ℃ and the time is 4H;

inner layer: the special LDI ink is adopted during processing, the film thickness control range is 11 +/-2 um, the exposure adopts the major LDI, and the line width control layers are L3, L5, L7, L9, L14, L16, L18 and L20; the line width of a finished product is set to be 3.5mil, and the line distance of the finished product is set to be 4 mil; the upper, middle and lower line widths of the same line are controlled within 0.1 mil; 1/1OZ etch with parameters set to 5.3M/MIN; 2/2OZ etch with a parameter set to 3.5M/MIN;

internal inspection: repairing residual copper without repairing wires;

and (3) laminating: punching 7 holes in a PE punching hole before browning, and punching 4 holes on the periphery in a central drilling mode except for 3L-shaped holes, wherein the target distance is X1= 399.397mm, X2=404.397mm, and Y = 583.238 mm; browning is carried out at a linear speed of 5m/min, and drying plates are arranged at a high-speed material browning station at the temperature of 120 ℃ for 60 minutes; after the browning, the fusion and riveting are completed within 12 hours, after the first board inspection layer is qualified, the yield is totally inspected whether the layer is qualified, the number of PP (polypropylene) and the correctness of the Core of the inner layer are 100 percent or not; pressing and using a special M6 process;

laser blind holes; the laser blind holes with L13/L12 layers are produced in a mass production mode after the width and the depth of the measuring hole of the first piece are qualified.

3. The method according to claim 1, characterized in that after the first drilling, the method further comprises detecting whether the hole diameters of the through hole and the crimping hole are blocked;

and measuring the CPK of the hole precision to be more than 1.33;

the second drilling is mechanical back drilling for turning the drilling hole after the power is shown, and different depths are drilled in the first quadrant and the fourth quadrant respectively;

the first quadrant is drilled from the first layer to L4/6/8/13/15/17/19 respectively, and cannot be drilled through the corresponding sublayer L5/7/9/14/16/18/20;

the depths of the first plate slice analysis back drilling holes are respectively 0.36mm, 0.65mm, 0.94mm, 1.71mm, 1.9mm, 2.29mm and 2.58mm, and the Stub values of the first plate slice analysis back drilling holes are all 7+/-5mil, and the first plate slice analysis back drilling holes are produced in quantity after meeting the requirements; the fourth quadrant is drilled from the 22 nd layer to L19/17/15/10/8/6/4 respectively, and can not be drilled through the corresponding sublayer L18/16/14/7/5/3;

the depths of the back drill are respectively 0.36mm, 0.65mm, 0.94mm, 1.71mm, 1.9mm, 2.29mm and 2.58mm, the back drill is subjected to high-pressure water washing, the washing pressure parameter is 2.5kg/cm, and the back drill is inspected after the water washing to ensure that no hole is blocked.

4. The method of claim 1, wherein the first subplate circuit further comprises: removing glue by plasma, baking before production under the condition of 190 ℃ by 2H, keeping the time for no more than 4 hours after baking, transferring copper horizontal line operation, and manufacturing by adopting six pulse electroplating, wherein the hole copper is 0.9-1.0 mil.

5. The method of claim 1, wherein the resin plug hole further comprises: plugging holes together with the back drilling holes of the small holes, wherein the holes need to be plugged twice, and the front surface and the back surface are plugged once respectively; and (4) performing AOI full inspection after hole plugging grinding.

6. The method of claim 1, wherein the first minor outer layer further comprises: sealing the holes by dry film, covering the holes with dry film width of 24 inch, sealing only the PTH holes of the resin plugs, exposing by using LDI with energy of 90mj and developing at speed of 4 m/min.

7. The method of claim 1, wherein the copper reduction is to 0.9 ± 0.1mil using a dedicated line; and (4) after copper reduction, removing the film on the surface of the plate, rotating the plate, and producing the plate by using a grinding line, wherein the thickness of copper after plate grinding is controlled to be 0.7-0.9 mil.

8. The method of claim 1, further comprising:

the third drilling is produced by a CCD drilling machine, and optical points in a grabbing unit of the CCD drilling machine are processed in a two-drilling mode, wherein drilling parameters are controlled within +/-0.05mm of hole site tolerance, 0.99mm NPTH hole tolerance plus 0.05/-0.025mm, the drilling bit is ground for less than or equal to 2 times, and then the tray rotating plate is mounted after the drilling is finished;

the second secondary plate is electrically plated by adopting six pulse plating, and the electrical parameter range of the copper deposition plate is 0.3-0.5 mil; the board electricity after changes outer pretreatment, advances dustless workshop with 4m/min speed and carries out the film pressing operation, uses the dry film width: 23.875 inch, back drilling, double-sided windowing, positive negative film type, working draft line width of 4.7 mil, and working draft line distance of 2.6 mil;

the second-time graphic electromachining parameters are as follows: electroplating for 0.7mil, copper for the surface of a finished product is 1.9mil, copper for holes is 0.8mil, plugging electroplating is carried out on via holes plugged by resin, the concavity is less than 25um, the quantity is flat and is less than 0.50mm for the finished product, and the copper for the holes is more than or equal to 18 um.

9. The method of claim 1, wherein the subsequent process comprises: back drilling, alkaline etching, external inspection, solder mask, text, impedance test, gold melting, fourth drilling, molding, finished test, FQC and packaging.

10. The method of claim 9,

the back drilling process further comprises the steps that the fourth quadrant drills to L19/17/15/10/6 from the 22 th layer respectively, does not drill through the corresponding sub-layer L18/16/14/9/5, the depths of the fourth quadrant are 0.36mm, 0.65mm, 0.94mm, 1.71mm and 2.29mm respectively, high-pressure water washing is completed after back drilling, the washing pressure parameter is 2.5kg/cm, and inspection is carried out after washing to ensure that no hole blocking exists after back drilling;

the fourth drilling is produced by adopting a CCD drilling machine, the grinding time of a drill bit is less than or equal to 2 times, the optical point in the CCD grabbing unit is processed in a two-drilling mode, and the drilling parameters are controlled as follows: the position tolerance of the chip BGA PAD and the hole with the size of 1.016mm around the finished product is +/-0.035mm, and the position tolerance of the hole with the size of 3.175mm around the finished product is +/-0.05 mm.

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