CN112533378B

CN112533378B - Manufacturing method of resin plug hole of thin PCB

Info

Publication number: CN112533378B
Application number: CN202011264104.5A
Authority: CN
Inventors: 彭腾; 陈彦青; 崔良端; 陶善磊; 许童; 朱忠翰; 朱正大; 李燚
Original assignee: Sun Create Electronics Co ltd
Current assignee: Sun Create Electronics Co ltd
Priority date: 2020-11-12
Filing date: 2020-11-12
Publication date: 2021-11-30
Anticipated expiration: 2040-11-12
Also published as: CN112533378A

Abstract

The invention discloses a method for manufacturing resin plug holes of a thin PCB (printed circuit board). the method comprises the steps of firstly, using a double-sided jig and an air guide base plate to plug holes of the PCB with resin; after the hole plugging is finished, the PCB and the double-sided jig are baked together; after baking, polishing the double-sided jig; after polishing, using laser to ablate the resin in the hole; the invention discloses a method for manufacturing a laminated plate, which comprises the steps of removing double-sided jigs, entering a subsequent production flow, creatively providing a concept of the laminated plate, firstly adding rigid jigs on two sides of a PCB to form the laminated plate, removing resin on the surface of the laminated plate through mechanical polishing because the rigidity of the laminated plate is higher, so that the resin on the surface of the laminated plate is positioned on the same plane, and removing resin in holes of upper and lower layers of jigs through laser ablation to obtain an ideal PCB resin plugged plate.

Description

Manufacturing method of resin plug hole of thin PCB

Technical Field

The invention belongs to the technical field of circuit boards, and particularly relates to a manufacturing method of a resin plug hole of a thin PCB.

Background

Due to the strong trend of miniaturization and multi-functionalization of electronic products, the PCB, which is the parent of the electronic product, is also changed accordingly. Specifically, the thickness of the used substrate is continuously reduced, so that the size of the PCB is reduced, and the requirement of multiple functions is met, thereby providing a challenge for subsequent component soldering. Specifically, the size of the PCB is reduced, the PCB is more compact in wiring, the original abundant welding space is insufficient, a plurality of disc mesoporous structures are formed, the disc mesoporous structures can cause insufficient welding area of a welding pad, the welding flux can easily flow into the back through holes during welding and short circuit can occur, and therefore poor welding and insufficient false welding can occur due to the fact that the welding flux is lost.

The traditional plug hole process is as follows: plugging holes, baking, mechanically/manually polishing resin, and transferring to a next procedure. The polishing mode is to remove resin protruding from the surface of the plate by the action of mechanical force. This mechanical/manual grinding is acceptable when the PCB board thickness is above 0.5mm and the material is a thermosetting epoxy but when the board thickness is low by values below 0.5mm, even 0.1 mm; or when the plate material is a PTFE soft plate with low Young modulus, the plate is easy to deform, the plate surface has pits, orifice depressions, plate bending and the like in the traditional mechanical polishing, and the plate is easy to scrap.

Disclosure of Invention

The invention aims to provide a resin hole plugging processing method of a thin PCB (the thickness is less than or equal to 0.5mm, and the thinnest can be 0.1mm) so as to solve various quality problems such as plate size deformation, orifice depression and the like easily caused in the traditional grinding method.

The purpose of the invention can be realized by the following technical scheme:

a method for manufacturing resin plug holes of a thin PCB comprises the following steps:

A. forming a multilayer structure of the air guide backing plate, the double-sided jig lower-layer jig, the PCB and the double-sided jig upper-layer jig by using the double-sided jig and the air guide backing plate, and baking after resin hole plugging;

B. after baking, polishing resin on the PCB together with the double-sided jig to polish the resin on the two sides of the double-sided jig;

C. carrying out laser ablation on the resin in the hole;

D. and removing the double-sided jig to finish the manufacture of the resin plug hole of the thin PCB.

Preferably, in the step A, the double-sided jig is two FR-4 dielectric plates with the same hole position and hole diameter, and the air guide base plate is the FR-4 dielectric plate.

Preferably, the hole position and the hole diameter on the double-sided jig are the same as those of the PCB, the hole position on the air guide base plate is the same as that of the PCB, and the hole diameter of the air guide base plate is 2.0mm larger than that of the PCB.

Preferably, the thickness of the double-sided jig is 0.5mm, and the thickness of the air guide cushion plate is 1.6 mm.

Preferably, the concrete steps of resin hole plugging in the step A are as follows:

the air guide backing plate is placed on the working table to be fixed, the lower layer jig of the double-layer jig, the PCB and the upper layer jig of the double-layer jig are sequentially stacked, hole sites of all layers are aligned, the double-face pin is inserted into the jig fixing hole, the double-layer jig is fixed to form a laminated plate of the jig PCB, the laminated plate is placed on the air guide backing plate and aligned to the hole sites to be plugged, resin is guaranteed to penetrate through the lower layer jig of the double-layer jig during plugging, and baking is carried out after plugging is finished.

Preferably, in the step C, the specific step of performing laser ablation on the resin in the hole of the laminated plate includes the steps of firstly performing laser ablation on the test hole of the laminated plate to obtain laser parameters, then performing laser ablation on the inner hole of the plate until the resin in the hole of the upper layer jig of the double-layer jig is completely ablated, and then performing ablation on the resin in the hole of the lower layer jig of the double-layer jig by the same method until the resin in the hole of the lower layer jig of the double-layer jig is completely ablated.

Preferably, in the step D, after laser ablation is finished, splitting the laminated plate, removing the upper jig and the lower jig of the double-layer jig to obtain the PCB, and polishing the protruding positions of individual resins on the surface of the PCB by using abrasive paper.

The invention has the beneficial effects that:

the invention creatively provides a laminated plate concept, firstly, rigid jigs are added on two sides of a PCB to form the laminated plate, because the rigidity of the laminated plate is higher, resin on the surface of the laminated plate can be removed through mechanical polishing, so that the resin on the surface of the laminated plate is positioned on the same plane, and then the resin in holes of the upper jig and the lower jig is removed through laser ablation, so that an ideal PCB resin jack plate is obtained.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all 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.

A method for manufacturing resin plug holes of a thin PCB comprises the following specific production flow:

s1, drilling the PCB, wherein the drilling comprises the following steps: the device comprises an original data hole, a graph positioning hole, a laminated slab fixing hole outside a graph area and a laser ablation testing hole, wherein the first two items are required by a conventional production process, and the laminated slab fixing hole and the laser ablation testing hole are specially designed in the invention;

s2, preferably selecting two FR-4 dielectric boards with the thickness of 0.5mm as an upper layer jig and a lower layer jig of the double-layer jig, and drilling the same holes on the upper layer jig and the lower layer jig, wherein the hole diameter and the hole position are consistent with those of the PCB;

s3, preferably selecting an FR-4 dielectric plate with the thickness of 2.0mm as an air guide backing plate, drilling holes, wherein the hole positions are consistent with those of the PCB, and the aperture is enlarged by 2.0 mm;

s4, carrying out hole metallization and whole board electro-coppering treatment on the PCB;

s5, plugging the PCB with resin, the method comprises the following steps: fixing an air guide base plate on a worktable of a plughole machine, aligning and fixing a lower jig of a double-layer jig, a PCB and an upper jig of the double-layer jig to form a laminated plate, placing and fixing the laminated plate on the air guide base plate, and then carrying out resin plughole on the laminated plate, wherein resin needs to be ensured to penetrate through the lower jig during plughole;

s6, standing for 15min after hole plugging is finished, and baking;

and S7, after baking, polishing the laminated board by a grinding machine or manual polishing treatment.

S8, after the laminated plate is polished, carrying out laser ablation treatment, specifically as follows: firstly, carrying out ablation treatment on the laser ablation hole, and adjusting laser ablation parameters until resin in the hole of the single-layer jig is completely ablated and the resin of the PCB is still intact, namely the residual height of the resin in the hole of the single-layer jig is less than or equal to 0.05 mm;

performing the same operation on the other single-layer jig;

and after the laser ablation is finished, removing the upper and lower layer jigs, and transferring to the next procedure for production.

The invention is not to be considered as limited to the specific embodiments shown and described, but is to be understood to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

For resin via holes of PCB boards, mechanical grinding is commonly used in the industry. However, in the process of plugging the holes of the thin PCB, mechanical grinding causes problems such as deformation of the board, surface pits, etc., which are difficult to overcome, so that mechanical grinding cannot achieve resin plugging of the thin PCB.

Furthermore, with the single use laser ablation technique, the resin assumes a circular arc shape at the orifice due to the conventional way of plugging the orifice. Thus, if laser ablation is used directly, it cannot be achieved because the orifice resin is not in the same horizontal plane.

Aiming at the two problems, the invention creatively adds rigid jigs to two sides of the PCB to form the laminated plate by proposing the concept of the laminated plate creatively, because the rigidity of the laminated plate is higher, the resin on the surface of the laminated plate can be removed by mechanical polishing, so that the resin on the surface of the laminated plate is positioned on the same plane, and then the resin in the holes of the upper and lower layers of jigs is removed by laser ablation, thus obtaining the ideal PCB resin plugging plate.

The foregoing is merely exemplary and illustrative of the present invention and various modifications, additions and substitutions may be made by those skilled in the art to the specific embodiments described without departing from the scope of the invention as defined in the following claims.

Claims

1. A method for manufacturing resin plug holes of a thin PCB is characterized by comprising the following steps:

C. performing laser ablation on the resin in the hole until the resin in the hole of the upper jig of the double-layer jig and the resin in the hole of the lower jig of the double-layer jig are completely ablated;

2. The method for manufacturing the resin plug hole of the thin PCB as claimed in claim 1, wherein in the step A, the double-sided jig is two FR-4 dielectric plates with the same hole position and hole diameter, and the air guide pad plate is the FR-4 dielectric plate.

3. The method of claim 2, wherein the holes on the double-sided jig are the same as the holes on the PCB, the holes on the air guide plate are the same as the holes on the PCB, and the holes on the air guide plate are 2.0mm larger than the holes on the PCB.

4. The method as claimed in claim 3, wherein the double-sided jig has a thickness of 0.5mm and the air guide plate has a thickness of 1.6 mm.

5. The method as claimed in claim 1, wherein the step A of resin plugging comprises the following steps:

6. The method as claimed in claim 5, wherein in step C, the step of laser ablating the resin in the holes of the laminated board comprises laser ablating the test holes of the laminated board to obtain laser parameters, laser ablating the inner holes of the board until the resin in the holes of the upper layer of the double-layer jig is completely ablated, and then ablating the resin in the holes of the lower layer of the double-layer jig by the same method until the resin in the holes of the lower layer of the double-layer jig is completely ablated.

7. The method as claimed in claim 6, wherein in step D, after laser ablation, the laminated board is separated, the upper jig and the lower jig of the double-layer jig are removed to obtain the PCB, and the individual resin protruding positions on the surface of the PCB are sanded.