CN210959013U

CN210959013U - Flexible printed circuit board

Info

Publication number: CN210959013U
Application number: CN201920413475.1U
Authority: CN
Inventors: 马承义; 慎华兵; 顾志明; 刘彩平
Original assignee: Shenzhen BYD Electronic Components Co Ltd
Current assignee: Shenzhen Holitech Optoelectronics Co Ltd
Priority date: 2019-03-29
Filing date: 2019-03-29
Publication date: 2020-07-07
Anticipated expiration: 2029-03-29

Abstract

The utility model provides a flexible printed circuit board, include by the substrate layer, the wire layer, the solder mask triplex, the substrate layer is the attachment of wire layer, the wire layer is for keeping copper line and the pad at the substrate layer, the solder mask is for the solder mask oil or set up the solder mask in the position outside windowing area, the solder mask is made by solder mask printing, solder mask printing includes solder mask oil printing and solder mask covering, solder mask covering is for the solder mask film through die-cut of mould, laminating, pressfitting preparation; the solder mask is printed by solder mask ink, exposed, developed and cured, a windowing position is punched on the solder mask by a die, the windowing position is larger than the solder mask windowing position, meanwhile, a counterpoint hole and a counterpoint PAD windowing position are punched on the solder mask, the counterpoint PAD is a counterpoint PAD arranged on a lead layer, and the solder mask is positioned through the counterpoint hole and the counterpoint PAD and is cured on a printed circuit board through illumination; the liquid solder mask printing is laser jet printing with a tolerance of +/-0.035 mm.

Description

Flexible printed circuit board

Technical Field

The utility model relates to a production and the practicality that flexible line way board hinders welding, especially a flexible printed wiring board.

Background

Along with the development of economy and the high-speed development of electronic industry, the use amount of printed circuit boards is continuously rising, meanwhile, the printed circuit boards also enter equipment of various industries, in addition, in order to meet the requirements of small space, high density and bending, the development of flexible circuit boards also enters a rapid development time, and particularly, compared with a hard board, the flexible circuit board is used as a connecting part of an electronic product, such as a mobile phone flat cable, a liquid crystal module and the like, the flexible circuit board has the advantages of smaller volume, lighter weight, bending deflection, three-dimensional assembly and the like. The other characteristic is that most of the soft boards are pasted with components. Therefore, the solder mask window problem of the flexible circuit board becomes very important, the solder mask window is too large, the quantity of the tin paste is large, short circuit or displacement is easy to cause, and if the solder mask window is too small, tin deficiency or false soldering can be formed; in addition, in the existing use and production, the miniaturization of the device and the lightness of the structure become mainstream, so that the miniaturization of the welding position is also the mainstream of the market, and the manufacture of the resistance welding windowing window is more and more important.

The prior flexible printed circuit board is generally composed of a substrate layer, a lead layer and a solder mask layer. The solder mask layer is formed by using a solder mask material, a window is formed in a region needing to be welded, a local lead layer is exposed, and the region not needing to be welded is covered.

The existing technical proposal

Using a film-shaped solder resist material, punching out a window by using a grinding tool, and manually attaching the window to the lead layer. The disadvantage of this solution is mainly the first limited grinding tool processing capacity, the maximum processing capacity of the grinding tool is 0.5mm, the opening is less than 0.5mm, and the die cutting process cannot be performed. Secondly, the material after the grinding apparatus die-cut needs the manual work to paste in the circuit layer, and the manual work position precision of laminating 0.15mm, and the laminating precision is low, can't satisfy the demand of current high accuracy production.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is to provide a flexible line way board has improved the production precision of hindering and welds, and then realizes the high efficiency and the high-quality of welding and production, satisfies current production and demand of using.

In order to solve the technical problem, the utility model adopts the following technical scheme: the flexible printed circuit board comprises a substrate layer, a wire layer and a solder mask layer, wherein the substrate layer is an attachment of the wire layer, the wire layer is a copper wire and a bonding pad which are reserved on the substrate layer, the solder mask layer is a protective layer which is arranged outside a windowing area and used for solder mask, the solder mask layer comprises a solder mask oil printing layer and a solder mask covering layer, and the solder mask covering layer is manufactured by punching, laminating and pressing a solder mask through a die; the solder mask oil printing layer is manufactured by the processes of solder mask oil printing, exposure, development and curing, a windowing position punched on the solder mask by a die is arranged on the solder mask covering layer, the windowing position is larger than the solder mask windowing, meanwhile, a counterpoint hole and a counterpoint PAD are also arranged on the solder mask covering layer, the counterpoint PAD is a counterpoint PAD arranged on the lead layer, and the solder mask covering layer is positioned through the counterpoint hole and the counterpoint PAD and is cured on the printed circuit board through illumination; the solder mask oil printing layer is formed by adopting liquid solder mask oil in a laser jet printing mode, and the laser jet printing tolerance is +/-0.035 mm. According to the utility model discloses a design concept, the position of windowing of stamping is regional position of windowing, regional position of windowing is pad windowing, counterpoint precision and the superimposed counterpoint maximum value of harmomegathus tolerance parameter value.

According to the design of the utility model, flexible printed wiring board's counterpoint PAD divide into flange edge counterpoint PAD and inboard counterpoint PAD, the flange edge counterpoint PAD is butterfly copper dish or is endocentric multilayer torus, inboard counterpoint PAD sets up and is counterpointing the precision height and hinder and weld the little region of windowing.

Compared with the prior art, the utility model discloses following beneficial effect has:

1) the accurate resistance welding windowing requirement is realized, and the problem in the welding process is solved.

2) The wiring density of the flexible printed circuit board is improved, and the density of the bonding pads is increased.

3) The problem of small-size resistance welding windowing is solved.

4) And laser jet printing is used, so that the windowing position precision and the size precision are improved.

Drawings

Fig. 1 is a structural diagram of the present invention.

Detailed Description

Referring to fig. 1, the utility model relates to a flexible printed circuit board, include by substrate layer 1, wire layer 2, solder mask 3 triplex, substrate layer 1 is the attachment of wire layer 2, wire layer 2 is for keeping copper line and the pad 4 of substrate layer 1, solder mask 3 is the protective layer that is used for resistance welding that sets up outside the windowing area, the solder mask includes solder mask oil printing layer and solder mask overburden, the solder mask overburden is by the solder mask through die-cut of mould, laminating, pressfitting preparation; the solder mask oil printing layer is manufactured by the solder mask oil printing, exposing, developing and curing processes, a windowing position 5 punched on the solder mask by a die is arranged on the solder mask covering layer, the windowing position 5 is larger than the solder mask windowing, meanwhile, a counterpoint hole and a counterpoint PAD6 are also arranged on the solder mask covering layer, the counterpoint PAD6 is a counterpoint PAD arranged on the lead layer 2, and the solder mask covering layer is positioned through the counterpoint hole and the counterpoint PAD and is cured on the printed circuit board through illumination; the solder mask oil printing layer is formed by adopting liquid solder mask oil in a laser jet printing mode, and the laser jet printing tolerance is +/-0.035 mm.

According to the design of the utility model, the position of windowing 5 is the position of windowing regionally, the position of windowing is the pad window, counterpoint precision and the superimposed counterpoint maximum value of harmomegathus tolerance parameter value regionally.

According to the design concept of the utility model, flexible printed wiring board's counterpoint PAD6 divide into flange edge counterpoint PAD6 and inboard counterpoint PAD6, flange edge counterpoint PAD6 is butterfly copper dish or is endocentric multilayer torus, inboard counterpoint PAD6 sets up at the counterpoint precision height and hinders and weld the small region of windowing.

Example 1:

cutting a solder mask, punching and processing a windowing position 5 with relatively large size and relatively poor position accuracy according to the self processing capacity of equipment, the requirement of solder mask windowing and the alignment accuracy, curing the solder mask, and then printing solder mask oil through laser jet printing, wherein the jet printing is performed from inside to outside, the solder mask oil printing and the solder mask film covering part are overlapped in the jet printing process, and the maximum value of the overlapped part is the tolerance value of alignment tolerance; in the printing process, the solder mask film and the liquid solder mask oil used for solder mask film covering and solder mask oil printing are the solder mask oil composed of the same component, the 'synergistic' laser spray printing equipment is preferably used, the 'sun' ink is matched, the local spray printing is carried out on the part needing windowing, and finally, the high-precision and small-size windowing window is obtained. The position precision can meet +/-35 um, and the size precision can meet 0.075 mm.

Example 2:

cutting a corresponding solder mask according to the typesetting size, simultaneously punching a windowing position 5, a corresponding positioning hole and a windowing position 5 of an alignment PAD6 according to the design of the solder mask windowing position 5, wherein the windowing position 5 of the alignment PAD6 is the same as the windowing position 5 on the circuit or slightly larger than 0.05mm and is within the allowed strictest tolerance range; counterpoint the setting according to locating hole and counterpoint PAD6, solder mask and base plate are the circuit combination on the base plate, form the protective layer, and laser spouts seal according to counterpoint PAD 6's setting, counterpoints, carries out simultaneously and spouts the seal by inside to outside, sets up corresponding overlap area as required simultaneously, realizes the design of windowing of most accurate.

Claims

1. A flexible printed circuit board comprises a substrate layer, a wire layer and a solder mask layer, wherein the substrate layer is an attachment of the wire layer, the wire layer is a copper wire and a solder pad which are reserved on the substrate layer, and the solder mask layer is a protective layer which is arranged outside a windowing area and used for solder mask, and is characterized in that the solder mask layer comprises a solder mask oil printing layer and a solder mask covering layer which is manufactured by the solder mask through die cutting, laminating and pressing; the solder mask oil printing layer is manufactured by the processes of solder mask oil printing, exposure, development and curing, a windowing position punched on the solder mask by a die is arranged on the solder mask covering layer, the windowing position is larger than the solder mask windowing, meanwhile, a counterpoint hole and a counterpoint PAD are also arranged on the solder mask covering layer, the counterpoint PAD is a counterpoint PAD arranged on the lead layer, and the solder mask covering layer is positioned through the counterpoint hole and the counterpoint PAD and is cured on the printed circuit board through illumination; the solder mask oil printing layer is formed by adopting liquid solder mask oil in a laser jet printing mode, and the laser jet printing tolerance is +/-0.035 mm.

2. The flexible printed wiring board of claim 1, wherein the windowing level is an area windowing level, and the area windowing level is an alignment maximum value of pad windowing, alignment precision and superposition of shrinkage and expansion tolerance parameter values.

3. The flexible printed wiring board of claim 1 or 2, wherein the alignment PAD of the flexible printed wiring board is divided into a board edge alignment PAD and an in-board alignment PAD, the board edge alignment PAD is a butterfly copper disc or a concentric multi-layer ring body, and the in-board alignment PAD is arranged in an area with high alignment precision and small solder mask window.