WO2018006527A1

WO2018006527A1 - Method for manufacturing a cover film-protected, gold-electroplated and component-inbuilt pcb board

Info

Publication number: WO2018006527A1
Application number: PCT/CN2016/105892
Authority: WO
Inventors: 林启恒; 林映生; 卫雄; 陈春; 刘敏; 李享
Original assignee: 惠州市金百泽电路科技有限公司; 西安金百泽电路科技有限公司; 深圳市金百泽电子科技股份有限公司
Priority date: 2016-07-05
Filing date: 2016-11-15
Publication date: 2018-01-11
Also published as: CN106132113B; CN106132113A

Abstract

Provided is a method for manufacturing a cover film-protected, gold-electroplated and component-inbuilt PCB board, comprising the steps of lamination and stack-up design, inner layer component-mounting surface manufacturing, rapid pressing of a cover film, cover film protection and gold electroplating, inner core board mounting, pressing molding, and post procedures. The method for manufacturing a cover film-protected, gold-electroplated and component-inbuilt PCB board features low costs, excellent quality stability, and high product reliability.

Description

Method for manufacturing cover film protective gold built-in component PCB board

Technical field

The invention relates to the technical field of printed circuit board processing, in particular to a method for manufacturing a cover film protective gold built-in component PCB board.

Background technique

At present, in order to solve the traditional PCB board surface, it is unable to meet more and more component chip requirements, and after the traditional PCB chip, the components are externally placed, and electromagnetic interference is formed between each other, which is easily damaged by external factors. The problem of scrapping, the emergence of built-in device technology, can effectively solve the above problems.

Most of the processing methods of the built-in component PCB are processed according to the following processes: inner layer pattern production→ inner layer pad dry film protection gold→ inner layer pad solder paste printing→ inner layer pad paste component→clean inner layer surface →Lamination→Normal multi-layer board production, among which the problems that are easy to occur in the process are:

First, the internal pad dry film protection gold process is complicated. After the inner core plate pattern is completed, it is necessary to re-adhesive film exposure. It is necessary to use a special resistant gold film to protect the non-gold area, ordinary dry film protection. The gold is easy to fall off, but the cost of the special resistant gold film is 5 times higher than that of the ordinary dry film, and the storage time is 3 months. For the current stage of the built-in component PCB is still in the stage of sample production, the production cost is greatly increased. And the exposure energy is higher than that of the ordinary dry film, the exposure time is long, and the film is removed 2-3 times, otherwise there will be residual dry film, which affects the production efficiency of other products;

Second, after the inner core board is padded, the whole board is browned, and the browning syrup will affect the gold. After the quality of the rear pad SMT, at the same time, after the reflow soldering, the brown film of the non-pad line part is affected by the high temperature, which affects the press quality of the process flow and increases the production risk of the enterprise.

Summary of the invention

The object of the present invention is to provide a method for manufacturing a cover film protective gold built-in component PCB board, which has the characteristics of low cost, good quality stability and high product reliability.

The invention can be implemented by the following technical solutions:

The invention discloses a manufacturing method of a cover film protective gold built-in component PCB board, comprising the following steps:

A. The lamination stack design is designed by laminating the laminated core sheets and adding a cover film to the lamination stack. Adding a cover film, one can protect the inner layer core plate for gold, and the other is to enhance the strength of the thin core plate to ensure that the deformation of the folded plate does not occur during the manufacturing process (SMT, cleaning, transfer, etc.) .

B. The inner layer is attached to the surface of the component: according to the conventional process, the inner core board is opened, the line is made, the AOI is detected, and the browning is performed.

C. Quickly press the cover film, design and prepare through the cover film, and then quickly cover the film on the surface of the rigid plate. If there is a glue on the pad, the laser removes the glue. After the film is quickly pressed, the problem that the non-pad line browning film is discolored by high temperature during reflow is effectively avoided, ensuring the quality of the pressing and avoiding the delamination. After the inner layer of the chip core plate is quickly pressed and covered, the surface is cleaned. Since the other side is a non-patch surface, it is not required to carry out gold, and the whole surface is covered with a thick gold film to protect the material, thereby saving material cost. Carry out gold with other PCBs with large gold area to avoid insufficient effective area of gold The problem of poor gold; at the same time avoiding the browning syrup will affect the quality of the pad SMT after the gold.

D, cover film protection gold: the inner layer of the core plate is quickly pressed to cover the film after cleaning, using the whole surface of the thick gold film to expose the death protection, and then carry out gold;

E, inner core board patch: according to the normal SMT process, solder paste printing, patching, reflow soldering, inspection;

F. Press-compositing type, the circuit board after the inner core board is completed is subjected to plasma cleaning treatment, and the structure of the board is optimized, and then press-combined. Before pressing, it is necessary to optimize the plasma cleaning and pressing structure of the inner core of the component to ensure the quality of the pressing.

G. Post-process: Follow-up production according to the conventional circuit board process.

Further, the step of rapidly pressing the cover film in step C includes:

C1, cover film design and preparation: cover film laser window opening according to the size of the pad and unilateral increase of 6mil, while the core plate cursor point position needs to increase 1mm window. The cover film laser window opening is accurately calculated according to the pad size and compensation (6 mils on one side). Otherwise, too small or too large window compensation will cause the window size to be inconsistent and the window to be offset.

C2, rigid plate quick-pressing cover film: the cover film and the pressure-bonding buffer material are selected to be pressed according to the conventional fast pressing parameters;

C3, laser removal of glue: If there is a problem of the pad on the glue, use laser to remove the glue, make a laser file to carry out laser cleaning to remove the glue and then carry out chemical cleaning, so that the surface of the pad is clean and no glue remains.

Further, the step of synthesizing the F-step includes:

F1, plasma cleaning treatment: In order to ensure the reliability of the lamination, it is necessary to control the cleanliness of the surface after the patch to avoid the rosin residue in the solder paste during the SMT process, and use plasma to clean and cover the surface of the film. Roughening to enhance the quality of the press. In order to ensure the reliability of the lamination, it is necessary to control the cleanliness of the surface after the patch to avoid the rosin residue in the solder paste during the SMT process, and use the plasma to clean and roughen the surface of the cover film to enhance the pressure. Quality.

F2, row plate structure optimization: use "aluminum sheet + epoxy pad + aluminum sheet + PE film + aluminum sheet" to assist the pressing to ensure that the gap between the inner layer component and the patch circuit layer is filled without voids. F3, product pressing: press the product according to the conventional process parameters and process.

Further, in the fast-pressing cover film of the step C, the thickness of the rigid plate copper and the thickness of the cover film are selected in accordance with the requirements of 1:1 or 1:1.5. Taking a 35um copper thick rigid plate as the example, the thickness of the 35um adhesive layer can be used to avoid the small glue layer, the bubble is insufficient, the thermal shock cover film and the rigid plate are easy to stratify; the glue layer is too large, resulting in flow The glue is serious, which seriously affects the gold quality of the pad area.

Further, the cover film has a thickness of 12.5 um, 25 um, 35 um or 50 um. Further, in the rigid plate quick-pressing cover film of the step C2, the release film with the anti-adhesive effect is used to assist the fast pressing, and after the rigid plate is pre-applied to the cover film, two release films are added to the upper and lower sides for rapid pressing and release. The film thickness is controlled at 4 mils or 6 mils and is replaced every 3 times.

Further, in the laser removing fluid in the step C3, the small energy laser is used to remove the glue, and the specific parameters are: pulse width 3 us, energy 3 mj, ablation times 3 times, MASK 3.3 mm.

The invention discloses a method for manufacturing a cover film protective gold built-in component PCB board, which has the following beneficial effects:

First, the cost is low, and the gold core of the patch core plate is replaced by a cover film to replace the special gold dry film, thereby greatly reducing the material cost, and is suitable for the production of the built-in component samples at the current stage;

Second, the quality and stability are good. After the rigid plate is pressed against the film, the browning film of the non-pad line part can be effectively protected, and the browning film discoloration caused by the high temperature reflow furnace is avoided, thereby affecting the subsequent pressing quality and avoiding the premature In the post-gold browning process, the browning syrup attacks the padded gold layer to ensure the quality of the SMT patch;

Third, the product has high reliability. Through the plasma treatment of the inner layer core plate and the optimization of the laminated plate structure, the plate surface cleanliness after the patch is effectively controlled to ensure the reliability of the lamination; the flow is also solved. The problem that the glue cannot fill the gap and easily form a cavity crack.

detailed description

In order to enable those skilled in the art to better understand the technical solutions of the present invention, the products of the present invention will be further described in detail below with reference to the embodiments and the accompanying drawings.

A. The lamination stack design is designed by laminating the laminated core sheets and adding a cover film to the lamination stack;

C. Quick-pressing cover film, through the cover film design and preparation, selecting a cover film with a thickness of 12.5um, 25um, 35um or 50um, and then quickly pressing the cover film on the surface of the rigid plate, if there is a glue on the surface The disc is laser-removed. The specific steps include:

C1, cover film design and preparation: the cover film laser window opening is obtained according to the pad size and the unilateral increase of 6mil, and the position of the core plate cursor point needs to be increased by 1mm to open the window;

C2, rigid plate quick-pressing cover film: the cover film and the press-fit cushioning material are pressed according to the conventional fast-pressing parameters, and the thickness of the rigid plate copper and the thickness of the cover film are required to be 1:1 or 1:1.5; The release film with the anti-adhesive effect is used to assist the fast pressure. After the rigid plate is pre-applied to the cover film, two release films are added to the upper and lower sides for rapid pressing. The thickness of the release film is controlled at 4 mil or 6 mil, and is replaced every 3 times;

C3, laser removal of glue: If there is a problem of the pad on the glue, use laser to remove the glue, make a laser file to carry out laser cleaning to remove the glue and then carry out chemical cleaning, so that the surface of the pad is clean and no glue remains. In the process of removing glue, the small energy laser is used to remove glue. The specific parameters are: pulse width 3us, energy 3mj, ablation times 3 times, MASK3.3mm.

F. Press-compositing type, the circuit board after the inner core board is completed is subjected to plasma cleaning treatment, and the structure of the board is optimized, and then press-combined. The specific steps include:

F1, plasma cleaning treatment: In order to ensure the reliability of the lamination, it is necessary to control the cleanliness of the surface after the patch to avoid the rosin residue in the solder paste during the SMT process, and use the plasma to enter. Clean the line and roughen the surface of the cover film to enhance the quality of the press;

F2, row plate structure optimization: use "aluminum sheet + epoxy pad + aluminum sheet + PE film + aluminum sheet" to assist the pressing to ensure that the gap between the inner layer component and the patch circuit layer is filled without voids.

F3, product pressing: press the product according to the conventional process parameters and process.

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention in any way; and those skilled in the art can smoothly implement the present invention as shown in the drawings and described above. However, those skilled in the art can make equivalent changes to the changes, modifications and evolutions made by the above-disclosed technical contents without departing from the technical scope of the present invention. At the same time, any changes, modifications and evolutions of any equivalent changes made to the above embodiments in accordance with the essential techniques of the present invention are still within the scope of the technical solutions of the present invention.

Claims

A manufacturing method of a cover film protective gold built-in component PCB board, characterized in that the method comprises the following steps:

A. The lamination stack design is designed by laminating the laminated core sheets and adding a cover film to the lamination stack;

B. The inner layer is attached to the surface of the component: according to the conventional process, the inner core board is opened, the line is made, the AOI is detected, and the browning is performed.

C. Quick-pressing the cover film, designing and preparing through the cover film, and then quickly pressing the cover film on the surface of the rigid plate. If there is a glue on the pad, the laser removes the glue:

D, cover film protection gold: the inner layer of the core plate is quickly pressed to cover the film after cleaning, using the whole surface of the thick gold film to expose the death protection, and then carry out gold;

E, inner core board patch: according to the normal SMT process, solder paste printing, patching, reflow soldering, inspection;

F, press-compositing type, the circuit board after the inner core board is completed is subjected to plasma cleaning treatment, and the structure of the board is optimized, and then press-combined;

G. Post-process: Follow-up production according to the conventional circuit board process.
The method for fabricating a cover film protective gold built-in component PCB according to claim 1, wherein the step of rapidly pressing the cover film in step C comprises:

C1, cover film design and preparation: the cover film laser window opening is obtained according to the pad size and the unilateral increase of 6mil, and the position of the core plate cursor point needs to be increased by 1mm to open the window;

C2, rigid plate quick-pressing cover film: select the cover film and press-fit cushioning material according to the conventional fast-pressing parameters Pressing;

C3, laser removal of glue: If there is a problem of the pad on the glue, use laser to remove the glue, make a laser file to carry out laser cleaning to remove the glue and then carry out chemical cleaning, so that the surface of the pad is clean and no glue remains.
The method for fabricating a cover film protective gold built-in component PCB according to claim 2, wherein the step of the press-forming type in the F step comprises:

F1, plasma cleaning treatment: In order to ensure the reliability of the lamination, it is necessary to control the cleanliness of the surface after the patch to avoid the rosin residue in the solder paste during the SMT process, and use plasma to clean and cover the surface of the film. Roughening to enhance the quality of the press;

F2, row plate structure optimization: use "aluminum sheet + epoxy pad + aluminum sheet + PE film + aluminum sheet" to assist the pressing to ensure that the gap between the inner layer component and the patch circuit layer is filled without voids.

F3, product pressing: press the product according to the conventional process parameters and process.
The method for manufacturing a cover film protective gold built-in component PCB according to claim 3, wherein: in the fast pressing cover film of step C, the thickness of the rigid plate copper and the thickness of the cover film are selected according to 1:1 or 1:1.5 requirements.
The method for fabricating a cover film protective gold built-in component PCB according to claim 4, wherein the cover film has a thickness of 12.5 um, 25 um, 35 um or 50 um.
The method for fabricating a cover film protective gold built-in component PCB according to claim 5, wherein in the rigid plate quick-pressing cover film of step C2, a release film having a resisting action is used to assist the fast pressing. After the rigid board is pre-applied to the film, two release films are applied up and down for quick pressing. The release film thickness is controlled at 4 mils or 6 mils and is replaced every 3 times.
The method for manufacturing a cover film protective gold built-in component PCB according to claim 6, wherein: in the step C3, the laser is used to remove the glue, and the small energy laser is used to remove the glue, and the specific parameters are: pulse width 3us, energy 3mj, 3 times of ablation, MASK3.3mm.