CN111818721A

CN111818721A - Multilayer PCB laminating cover plate and preparation method thereof

Info

Publication number: CN111818721A
Application number: CN202010599264.9A
Authority: CN
Inventors: 阙勋; 吴艺; 林翠翠; 蒙志林
Original assignee: Zhaoqing Changlong Electronics Co ltd
Current assignee: Zhaoqing Changlong Electronics Co ltd
Priority date: 2020-06-28
Filing date: 2020-06-28
Publication date: 2020-10-23

Abstract

The invention discloses a multilayer PCB laminated cover plate, which comprises a multilayer PCB, pure glue, a cover plate and a release film; the multilayer PCB comprises two copper foils serving as a bottom layer and a surface layer, and a first prepreg, a first inner core board, a second prepreg, a second inner core board, a third prepreg, a third inner core board and a fourth prepreg which are arranged between the two copper foils and are sequentially stacked; through the harmomegathus coefficient adjustment cover plate size according to multilayer PCB size data and apron, drill out the hole on the apron, use pure glue with multilayer PCB board and apron bonding together, can shorten the pressfitting consuming time, make the harmomegathus of multilayer PCB board and apron change for a short time in the pressfitting, can the position of accurate control multilayer PCB board and apron after the pressfitting, and to multilayer PCB board in manufacturing procedure, the structure of apron and pure glue corresponds the preparation, make multilayer PCB board and pure glue, the cover plate size keeps unanimous, avoid drilling error, influence product quality.

Description

Multilayer PCB laminating cover plate and preparation method thereof

Technical Field

The invention particularly relates to a multilayer PCB laminating cover plate and a preparation method thereof.

Background

After the PCB is manufactured, the cover plate is pressed on the surface of the attachment piece, holes are drilled in the cover plate, and the bonding pads on the PCB are exposed from the holes of the cover plate for assembling parts after pressing, so that the position precision between the cover plate and the PCB after pressing is required to be high, the position precision is generally required to be +/-0.05 mm, and the position precision of a high-precision product is required to be +/-0.025 mm.

However, the existing PCB manufacturing technology has the following disadvantages:

when the PCB is pressed with the cover plate, the bonding pad on the PCB and the hole on the cover plate are displaced after pressing due to different expansion and contraction coefficients of the PCB and the cover plate;

2. the prepreg is used for laminating, the heating time is long (2-3 hours are needed), the expansion and shrinkage size fluctuation is caused by different heating rates, and the difficulty of precision control of laminating the PCB and the cover plate is increased.

Disclosure of Invention

In view of the above, the present invention is to provide a multi-layer PCB stacked cover plate with consistent size, small error and high product quality, and a method for manufacturing the multi-layer PCB stacked cover plate.

In order to solve the technical problems, the technical scheme of the invention is as follows:

a multi-layer PCB laminating cover plate comprises a plurality of layers of PCBs, pure glue laid on the multi-layer PCBs, a cover plate attached to the multi-layer PCBs through the pure glue, and release films attached to the bottom surfaces of the multi-layer PCBs and the surfaces of the cover plate respectively; the multilayer PCB comprises two copper foils serving as a bottom layer and a surface layer, and a first prepreg, a first inner core plate, a second prepreg, a second inner core plate, a third prepreg, a third inner core plate and a fourth prepreg which are arranged between the two copper foils and are sequentially stacked.

Further, the first inner core board is arranged between the first prepreg and the second prepreg, the second inner core board is arranged between the second prepreg and the third prepreg, and the third inner core board is arranged between the third prepreg and the fourth prepreg.

A preparation method of a multilayer PCB laminated cover plate comprises the following steps:

step 1, the specific process of the multilayer PCB board is as follows:

a. respectively carrying out preset inner layer circuit manufacturing on the plates of which the first inner layer core plate, the second inner layer core plate and the third inner layer core plate are manufactured, then carrying out electrical detection on the preset circuits of the plates through a circuit board detector, and removing fault plates to obtain qualified plates for later use;

b. dividing the corresponding area of the board prepared in the concrete step a into a first inner core board, a second inner core board and a third inner core board, then embedding the first inner core board between a first prepreg and a second prepreg, embedding the second inner core board between the second prepreg and a third prepreg, embedding the third inner core board between the third prepreg and a fourth prepreg, then covering and veneering by using a copper foil, and then matching the board body through pressing to prepare a multilayer PCB (printed circuit board) blank for standby;

c. b, drilling a round hole at a preset position of a hole to be formed on the board surface or board edge of the multilayer PCB board blank prepared in the step b, then carrying out copper plating etching, pouring prepared chemical copper on the multilayer PCB board blank after drilling is finished, filling the hole groove with the chemical copper, then electroplating the multilayer PCB board blank, thickening the multilayer PCB board blank by electroplating the chemical copper, then etching and removing the copper foils which are not needed on the upper surface and the lower surface of the multilayer PCB board blank by adopting an acid etching method, reserving a covering part, forming a final needed outer layer circuit, and finally carrying out electric detection by a circuit board detector to remove the failed multilayer PCB board blank for later use;

D. c, screen printing of solder mask ink is carried out on the surface of the multilayer PCB plate blank prepared in the step c, then the solder mask ink is completely cured through baking to complete solder mask treatment, finally, the multilayer circuit board blank is subjected to plate grinding to remove burrs, and finally, open circuit or short circuit testing is carried out to remove unqualified multilayer circuit board blanks for later use;

step 2, pure glue processing: cutting the pure glue according to the condition of the multilayer PCB prepared in the step 1, and mechanically drilling the pure glue according to the size expansion and contraction of the multilayer PCB 1 for later use;

step 3, cover plate preparation: cutting according to the size of the multilayer PCB, etching the surface of the cover plate by adopting an acid etching method, removing an unnecessary copper layer, covering the etched cover plate by adopting a wet film, performing intense light irradiation on a part needing to be kept for welding prevention to harden the part, firmly adhering the part on the surface of the cover plate to finish welding prevention treatment, performing expansion and contraction adjustment according to the size expansion and contraction of the multilayer circuit board prepared in the step 1 and the size expansion and contraction of the pure glue prepared in the step 2, and correspondingly performing mechanical drilling to finish the cover plate processing for later use;

step 4, the specific process of preparing the multilayer PCB laminated cover plate comprises the following steps:

a. tearing off release paper on one side surface of the pure glue processed in the step (2), bonding the release paper with the multilayer PCB prepared in the step (1), tearing off the release paper on the other side surface of the pure glue, and bonding the release paper with the cover plate prepared in the step (3) to prepare a blank for later use;

b. b, baking the blank prepared in the step a for 1 hour at the temperature of 120 +/-5 ℃ to eliminate the stress of the blank and improve the warping degree of the board surface for later use;

c. drilling and milling edges: drilling a circular hole at a preset position of a hole to be formed on the plate surface or the plate edge of the blank; after drilling is completed, when the edge of the prepared blank needs to be milled out of the frame, the single side is milled to be 1mm large for later use;

d. surface treatment and packaging ex-warehouse: and c, grinding the blank with the edge finished in the step c to remove burrs, finishing surface treatment, then performing electric detection on the blank through a circuit board detector, removing the failed product to obtain a qualified product, and finally packaging and delivering out of the warehouse.

The technical effects of the invention are mainly reflected in the following aspects: through the harmomegathus coefficient adjustment cover plate size according to multilayer PCB size data and apron, drill out the hole on the apron, use pure glue with multilayer PCB board and apron bonding together, can shorten the pressfitting consuming time, make the harmomegathus of multilayer PCB board and apron change for a short time in the pressfitting, can the position of accurate control multilayer PCB board and apron after the pressfitting, and to multilayer PCB board in manufacturing procedure, the structure of apron and pure glue corresponds the preparation, make multilayer PCB board and pure glue, the cover plate size keeps unanimous, avoid drilling error, influence product quality.

Drawings

FIG. 1 is a schematic diagram of a multi-layer PCB stack cover plate according to the present invention;

fig. 2 is a structural view of the multi-layer PCB of fig. 1.

Detailed Description

The embodiments of the present invention are described in further detail to make the technical solutions of the present invention easier to understand and master.

Examples

A multi-layer PCB laminated cover plate comprises a multi-layer PCB 1, pure glue 2 laid on the multi-layer PCB 1, a cover plate 3 attached to the multi-layer PCB 1 through the pure glue 2, and release films 4 attached to the bottom surface of the multi-layer PCB 1 and the surface of the cover plate 3 respectively; the multilayer PCB board 1 comprises two copper foils 11 as a bottom layer and a surface layer, and a first prepreg 12, a first inner core board 13, a second prepreg 14, a second inner core board 15, a third prepreg 16, a third inner core board 17 and a fourth prepreg 18 which are arranged between the two copper foils 11 and are sequentially stacked.

step 1, the specific process of the multilayer PCB board 1 is as follows:

a. respectively carrying out preset inner layer circuit manufacturing on the plates which are manufactured into the first inner layer core plate 13, the second inner layer core plate 15 and the third inner layer core plate 17, then carrying out electric detection on the preset circuits of the plates through a circuit board detector, and removing fault plates to obtain qualified plates for later use;

b. dividing the corresponding area of the board prepared in the specific step a into a first inner core board 13, a second inner core board 15 and a third inner core board 17, then embedding the first inner core board 13 between a first prepreg 12 and a second prepreg 14, embedding the second inner core board 15 between the second prepreg 14 and a third prepreg 16, embedding the third inner core board 17 between the third prepreg 16 and a fourth prepreg 18, then covering and veneering by using a copper foil 11, and then matching the board by pressing to prepare a multilayer PCB (printed circuit board) blank for standby;

step 2, pure glue processing: cutting pure glue according to the condition of the multilayer PCB (printed circuit board) 1 prepared in the step (1), and mechanically drilling the pure glue according to the size expansion and contraction of the multilayer PCB 1 for later use;

step 3, cover plate preparation: cutting according to the size of the multilayer PCB (printed circuit board) 1, etching the surface of the cover plate by adopting an acid etching method, removing an unnecessary copper layer, covering the etched cover plate by adopting a wet film, performing intense light irradiation on a part needing to be kept for welding prevention to harden the part, firmly adhering the part on the surface of the cover plate to finish welding prevention treatment, performing expansion and contraction adjustment according to the size expansion and contraction of the multilayer circuit board prepared in the step 1 and the size expansion and contraction of the pure glue prepared in the step 2, and correspondingly performing mechanical drilling to finish the cover plate for later use;

a. tearing off release paper on one side surface of the pure glue processed in the step (2), adhering the torn release paper with the multilayer PCB (printed circuit board) 1 prepared in the step (1), tearing off the release paper on the other side surface of the pure glue, and adhering the torn release paper with the cover plate prepared in the step (3) to prepare a blank for later use;

In the present embodiment, the first core board 13 is disposed between the first prepreg 12 and the second prepreg 14, the second core board 15 is disposed between the second prepreg 14 and the third prepreg 16, and the third core board 17 is disposed between the third prepreg 16 and the fourth prepreg 18.

The above are only typical examples of the present invention, and besides, the present invention may have other embodiments, and all the technical solutions formed by equivalent substitutions or equivalent changes are within the scope of the present invention as claimed.

Claims

1. The utility model provides a multilayer PCB board pressfitting apron which characterized in that: the PCB comprises a plurality of layers of PCBs, pure glue laid on the plurality of layers of PCBs, a cover plate attached to the plurality of layers of PCBs through the pure glue, and release films respectively attached to the bottom surfaces of the plurality of layers of PCBs and the surface of the cover plate; the multilayer PCB comprises two copper foils serving as a bottom layer and a surface layer, and a first prepreg, a first inner core plate, a second prepreg, a second inner core plate, a third prepreg, a third inner core plate and a fourth prepreg which are arranged between the two copper foils and are sequentially stacked.

2. The multi-layer PCB board laminate cover of claim 1, wherein: the first inner core board is arranged between the first prepreg and the second prepreg, the second inner core board is arranged between the second prepreg and the third prepreg, and the third inner core board is arranged between the third prepreg and the fourth prepreg.

3. A method for preparing a multi-layer PCB laminated cover plate according to claim 1, comprising the steps of:

step 1, the specific process of the multilayer PCB board is as follows: