CN116056322B

CN116056322B - A stacked laser hole structure and manufacturing method thereof

Info

Publication number: CN116056322B
Application number: CN202310055900.5A
Authority: CN
Inventors: 余丞博; 黄建; 卞和平
Original assignee: KUNSHAN HULI MICROELECTRONICS CO Ltd
Current assignee: KUNSHAN HULI MICROELECTRONICS CO Ltd
Priority date: 2023-01-16
Filing date: 2023-01-16
Publication date: 2025-02-18
Anticipated expiration: 2043-01-16
Also published as: CN116056322A

Abstract

The present invention discloses a stacked laser hole structure and a manufacturing method thereof. The present invention adopts a mechanical through hole stacked first laser hole structure. Compared with a traditional HDI board, the structure is more compact. Compared with a traditional anylayer board, the laser hole is easier to align. In addition, a metal boss is arranged between the first laser hole and the mechanical through hole to ensure the reliability of the through hole joint surface, and can withstand extreme environments or long-term impacts encountered in industries such as aerospace, military industry, and automobiles.

Description

Stacked laser hole structure and manufacturing method thereof

Technical Field

The invention relates to a stacked laser hole structure and a manufacturing method thereof, and belongs to the field of PCB preparation.

Background

In recent years, circuit boards are being developed in a small and dense direction, and the corresponding through holes on the circuit boards are also becoming smaller, so that a high-density interconnection circuit board, i.e., an HDI board, is developed. The conventional through hole and laser hole on the HDI board are designed in a staggered manner or anylayer (called as 'anylayer board') by using full laser hole superposition, but the problems are that 1, the staggered design has the problem of complex circuit and large volume, 2, the full laser superposition extremely tests the laser hole alignment capability and the sheet production capability, and the alignment is difficult to control when the full laser superposition is generally superposed on 4 layers.

Disclosure of Invention

The invention provides a stacked laser hole structure and a manufacturing method thereof, which solve the problems disclosed in the background art.

In order to solve the technical problems, the invention adopts the following technical scheme:

The utility model provides a fold laser pore structure, including the base plate, the last mechanical through-hole that has beaten of base plate, the top surface of base plate, the bottom surface of base plate and mechanical through-hole inner wall all have plated the metal level, the packing has been filled in the mechanical through-hole that has plated the metal level, the top and the bottom of packing have all been plated the metal boss, the pressfitting has the dielectric layer on base plate top surface metal level and the metal boss, beat first radium perforation on the dielectric layer, first radium perforation and mechanical through-hole are on same straight line, first radium perforation bottom is leaned on with the metal boss, the aperture of first radium perforation bottom opening and mechanical through-hole all is less than the diameter of metal boss, the metal level has been plated to the dielectric layer top surface's metal level fills up first radium perforation.

The filler is resin or metal.

The metal layers on the top and bottom surfaces of the substrate are etched with circuits, the etching depth extends to the metal base layer of the substrate, the metal layer on the top surface of the dielectric layer is etched with circuits, and the etching depth extends to the metal base layer of the dielectric layer.

And a second laser perforation is also made on the dielectric layer, no mechanical through hole is arranged below the second laser perforation, the bottom end of the second laser perforation is attached to the metal layer on the top surface of the substrate, and the metal layer on the top surface of the dielectric layer is also filled with the second laser perforation.

A manufacturing method of a stacked laser hole structure comprises the following steps:

Step 1, manufacturing a substrate, and drilling a mechanical through hole on the substrate;

Step 2, metallizing the substrate with the mechanical through holes, and plating a metal layer on the top surface, the bottom surface and the inner wall of the mechanical through holes;

step 3, filling the mechanical through holes plated with the metal layers with fillers;

step 4, re-metallizing the substrate filled with the filler, and plating a metal layer covering the filler on the top surface and the bottom surface of the substrate;

Step 5, pressing a dry film on the top surface and the bottom surface of the re-metallized substrate, and perforating the part of the dry film, which is opposite to the mechanical through hole, wherein the aperture of the perforated hole is larger than that of the mechanical through hole;

step 6, plating metal bosses in the openings, and removing the dry film;

Step 7, laminating a dielectric layer on the metal layer and the metal boss on the top surface of the substrate;

Step 8, a first laser perforation is made on the dielectric layer, wherein the first laser perforation and the mechanical through hole are on the same straight line, the bottom end of the first laser perforation is abutted against the metal boss, and the diameter of the metal boss is larger than the aperture of the bottom end opening of the first laser perforation and the aperture of the mechanical through hole;

And 9, plating a metal layer on the top surface of the dielectric layer, and filling the metal layer on the top surface of the dielectric layer with the first laser holes.

And grinding off the uneven part of the surface of the filler before the substrate is metallized again, and roughening the surface of the filler.

Etching lines on the metal layers on the top surface and the bottom surface of the substrate before pressing the film, wherein the etching depth extends to the metal base layer of the substrate;

Or alternatively

And etching circuits on the metal layers on the top surface and the bottom surface of the substrate with the dry film removed before laminating the dielectric layers, wherein the etching depth extends to the metal base layer of the substrate.

After the top surface of the dielectric layer is plated with a metal layer, a circuit is etched on the metal layer on the top surface of the dielectric layer, and the etching depth extends to the metal base layer of the dielectric layer.

When the first laser perforation is made, a second laser perforation is made on the dielectric layer, wherein a mechanical through hole is not formed below the second laser perforation, the bottom end of the second laser perforation is attached to the metal layer on the top surface of the substrate, and the metal layer on the top surface of the dielectric layer is also filled with the second laser perforation.

The invention has the beneficial effects that the mechanical through hole is adopted to stack the first laser hole structure, compared with the traditional HDI board, the structure is more compact, compared with the traditional anylay board laser hole, the alignment is easier, and the metal boss is arranged between the first laser hole and the mechanical through hole, so that the reliability of the joint surface of the through hole can be ensured, and extreme environments or long-term impacts in the industries of aerospace, military industry, automobiles and the like can be borne.

Drawings

FIG. 1 is a schematic diagram of a stacked laser aperture structure;

FIG. 2 is a flow chart of stacked laser via structure fabrication;

FIG. 3 is a schematic view of a structure of a substrate;

FIG. 4 is a schematic view of the structure of the substrate after drilling the mechanical through holes;

FIG. 5 is a schematic structural diagram of a metallized substrate;

FIG. 6 is a schematic structural view of a post-plug-filler substrate;

FIG. 7 is a schematic diagram of a structure of a substrate after re-metallization;

FIG. 8 is a schematic diagram of a structure of a substrate after pressing a dry film and punching;

FIG. 9 is a schematic view of the structure of a substrate after plating a metal boss;

FIG. 10 is a schematic diagram of the structure of the substrate after etching the circuit;

FIG. 11 is a schematic view of the structure after lamination of the prepregs;

FIG. 12 is a schematic diagram of the structure after laser drilling;

Fig. 13 is a schematic diagram of a structure of a dielectric layer after top surface metallization.

Detailed Description

The invention is further described below with reference to the accompanying drawings. The following examples are only for more clearly illustrating the technical aspects of the present invention, and are not intended to limit the scope of the present invention.

As shown in FIG. 1, a stacked laser hole structure comprises a substrate 1, wherein the substrate 1 is formed by laminating double-sided boards or multi-layer boards, a mechanical through hole 2 is formed in the substrate 1, a metal layer 8 is plated on the top surface of the substrate 1, the bottom surface of the substrate 1 and the inner wall of the mechanical through hole 2, metal is specifically copper, a filler 3 is plugged in the mechanical through hole 2 plated with the metal layer 8, resin or metal is adopted as the filler 3, resin is adopted here, metal bosses 7 are plated on the top end and the bottom end of the filler 3, circuits are etched on the metal layer 8 on the top surface and the bottom surface of the substrate 1, and the etching depth extends to the metal base layer of the substrate 1 all the time.

The metal layer 8 on the top surface of the substrate 1 and the metal boss 7 are pressed with the medium layer 4, the medium layer 4 is provided with the first laser perforation 5 and the second laser perforation 6, the first laser perforation 5 and the mechanical through hole 2 are on the same straight line, the bottom end of the first laser perforation 5 is abutted against the metal boss 7, the aperture of the bottom end opening of the first laser perforation 5 and the aperture of the mechanical through hole 2 are smaller than the diameter of the metal boss 7, the mechanical through hole 2 is not arranged below the second laser perforation 6, the bottom end of the second laser perforation 6 is abutted against the metal layer 8 on the top surface of the substrate 1, the metal layer 8 on the top surface of the medium layer 4 is plated with the metal layer 8, the metal layer 8 on the top surface of the medium layer 4 is filled with the first laser perforation 5 and the second laser perforation 6, the etched depth is extended to the metal base layer of the medium layer 4, and all the etched lines are not right against the mechanical through holes 2 and the laser through hole 6.

The invention adopts a structure that the mechanical through holes 2 are stacked with the first laser holes 5, the structure is more compact, the traditional anylay plates need to be repeatedly aligned, each step-up is performed on the basis of the last time, each step-up Kong Leishe holes need to be punched on the laser holes of the previous layer, the higher the order is, the higher the alignment difficulty is, the lower the product yield is, for example, the 4 layers of laser holes are, the 3 times of alignment is required, the invention adopts the structure that the mechanical through holes 2 are stacked with the first laser holes 5, the mechanical holes are adopted to replace the laser holes of the previous 3 layers, and the alignment is easier.

If the metal boss 7 is not arranged between the first laser perforation 5 and the mechanical through hole 2, the joint surface of the mechanical through hole 2 and the laser hole is easy to break under the action of transverse shearing stress and longitudinal expansion stress when the mechanical through hole 2 is subjected to cold thermal shock or extreme environment because the expansion coefficient of the resin in the mechanical through hole 2 is inconsistent with that of the plate body curing sheet material and the mechanical through hole 2 is the whole copper plating structure penetrating through the whole substrate 1.

In fig. 1, F1 is the longitudinal expansion and contraction stress of the material, F2 is the transverse expansion and contraction stress of the material, F3 is the weakened transverse expansion and contraction stress, h1 is the thickness of the laser hole dielectric layer 4 with the metal boss 7, h2 is the thickness of the laser hole dielectric layer 4 without the metal boss 7, h1 is less than h2, and the tearing effect F3 is less than F2 through the metal boss 7, so that the metal boss 7 is arranged between the first laser hole 5 and the mechanical through hole 2, the reliability of the through hole joint surface can be ensured, and extreme environments or long-term impacts encountered by industries such as aerospace, military industry, automobile and the like can be borne.

Based on the structure, the invention also discloses a corresponding manufacturing method, which is shown in fig. 2 and comprises the following steps:

step 1, a substrate 1 is manufactured, and a mechanical through hole 2 is drilled on the substrate 1, see fig. 3 and 4.

And 2, metallizing the substrate 1 with the mechanical through holes 2, and plating a metal layer 8 on the top surface of the substrate 1, the bottom surface of the substrate 1 and the inner wall of the mechanical through holes 2, as shown in fig. 5.

And 3, filling the mechanical through hole 2 plated with the metal layer 8 with the filler 3, grinding off the uneven part of the surface of the filler 3, and roughening the surface of the filler 3, as shown in fig. 6.

Step 4, the substrate 1 after filling the filler 3 is metallized again, and a metal layer 8 covering the filler 3 is plated on the top and bottom surfaces of the substrate 1, see fig. 7.

And 5, pressing dry films on the top surface and the bottom surface of the re-metallized substrate 1, wherein the dry films are photosensitive dry films for common PCBs, and the parts of the dry films, which are opposite to the mechanical through holes 2, are provided with holes, and the hole diameters of the holes are larger than those of the mechanical through holes 2, as shown in fig. 8.

Step 6, plating a metal boss 7, namely a copper boss, in the opening hole, and removing the dry film, see fig. 9.

And 5 and 6, namely carrying out pattern electroplating on the whole surface pressed film, and manufacturing a metal boss 7 on the mechanical through hole 2 through pattern electroplating.

And 7, etching circuits on the metal layers 8 on the top surface and the bottom surface of the substrate 1 with the dry film removed, wherein the etching depth extends to the metal base layer of the substrate 1, as shown in fig. 10.

The etching circuit of the substrate 1 can also be selected before the film is pressed and dried, and the specific situation can be determined according to the actual situation.

After the pattern electroplating is completed to manufacture the metal boss 7, the plate surface is uneven, and when the photosensitive film is pressed again for etching, a special photosensitive film is needed, and the photosensitive wet film is generally used for coating or the photosensitive dry film with high glue content is generally used for preventing gaps from penetrating etching liquid medicine after film pressing.

Step 7, laminating a dielectric layer 4 on the metal layer 8 and the metal boss 7 on the top surface of the substrate 1, see fig. 11.

Step 8, a first laser perforation 5 and a second laser perforation 6 are made on the dielectric layer 4, wherein the first laser perforation 5 and the mechanical through hole 2 are on the same straight line, the bottom end of the first laser perforation 5 is abutted against the metal boss 7, the diameter of the metal boss 7 is larger than the aperture of the bottom end opening of the first laser perforation 5 and the aperture of the mechanical through hole 2, the mechanical through hole 2 is not arranged below the second laser perforation 6, and the bottom end of the second laser perforation 6 is abutted against the metal layer 8 on the top surface of the substrate 1, as shown in fig. 12.

Step 9, plating a metal layer 8 on the top surface of the dielectric layer 4, and filling the first laser holes 5 and the second laser holes 6 with the metal layer 8 on the top surface of the dielectric layer 4, see fig. 13.

Further, a circuit can be etched on the metal layer 8 on the top surface of the dielectric layer 4 obtained in the step 9, and the etching depth extends to the metal base layer of the dielectric layer 4, see fig. 1.

The foregoing is merely a preferred embodiment of the present invention, and it should be noted that modifications and variations could be made by those skilled in the art without departing from the technical principles of the present invention, and such modifications and variations should also be regarded as being within the scope of the invention.

Claims

1. The utility model provides a fold laser pore structure, a serial communication port, which comprises a substrate, the last mechanical through-hole that has beaten of base plate, the top surface of base plate, the bottom surface of base plate and mechanical through-hole inner wall all have plated the metal layer, the mechanical through-hole intussuseption that has plated the metal layer has the filler, the top and the bottom of filler all have plated the metal boss, the metal boss on filler top upwards protrudes in the metal layer of base plate top surface, and the metal boss on filler top and the metal layer of base plate top surface form step structure in the longitudinal direction, the metal boss on filler bottom and the metal layer of base plate bottom surface form step structure, the pressfitting has the dielectric layer on base plate top surface metal layer and the metal boss, beat first radium perforation on the dielectric layer, first radium perforation and mechanical through-hole are on same straight line, first radium perforation bottom and metal boss are pasted, first radium perforation bottom opening and mechanical through-hole's aperture all are less than the diameter of metal boss, the metal layer has been plated to the dielectric layer top surface, and the metal layer on the metal layer top surface fills up first radium.

2. The stacked laser pore structure of claim 1, wherein the filler is a resin or a metal.

3. The laminated laser hole structure of claim 1, wherein the metal layers on the top and bottom surfaces of the substrate are etched with lines, the etching depth extends to the metal base layer of the substrate, the metal layer on the top surface of the dielectric layer is etched with lines, and the etching depth extends to the metal base layer of the dielectric layer.

4. The laminated laser hole structure of claim 1, wherein a second laser hole is further formed in the dielectric layer, no mechanical through hole is formed below the second laser hole, the bottom end of the second laser hole is abutted to the metal layer on the top surface of the substrate, and the metal layer on the top surface of the dielectric layer is also filled with the second laser hole.

5. The manufacturing method of the stacked laser hole structure is characterized by comprising the following steps of:

Step 6, plating metal bosses in the holes, and removing the dry film, wherein the metal bosses at the top end of the filler protrude upwards from the metal layer on the top surface of the substrate, the metal bosses at the top end of the filler and the metal layer on the top surface of the substrate form a step structure in the longitudinal direction, the metal bosses at the bottom end of the filler protrude downwards from the metal layer on the bottom surface of the substrate, and the metal bosses at the bottom end of the filler and the metal layer on the bottom surface of the substrate form a step structure in the longitudinal direction;

6. The method of claim 5, wherein the roughened filler surface is polished to remove uneven filler surface portions before the substrate is re-metallized.

7. The method of claim 5, wherein the etching is performed to a depth extending to the metal base layer of the substrate before the film is pressed to dry;

Or alternatively

8. The method of claim 5, further etching a circuit on the metal layer on the top surface of the dielectric layer after the metal layer is plated on the top surface of the dielectric layer, wherein the etching depth extends to the metal base layer of the dielectric layer.

9. The method of claim 5, wherein a second laser perforation is made on the dielectric layer when the first laser perforation is made, wherein no mechanical through hole is formed below the second laser perforation, the bottom end of the second laser perforation is abutted against the metal layer on the top surface of the substrate, and the metal layer on the top surface of the dielectric layer is also filled with the second laser perforation.