CN204145880U

CN204145880U - White covering film

Info

Publication number: CN204145880U
Application number: CN201420677830.3U
Authority: CN
Inventors: 林志铭; 金进兴; 潘莉花; 陈辉
Original assignee: Asia Electronic Material Co Ltd
Current assignee: Asia Electronic Material Co Ltd
Priority date: 2014-11-13
Filing date: 2014-11-13
Publication date: 2015-02-04
Anticipated expiration: 2024-11-13

Abstract

The utility model discloses a kind of white covering film to be made up of successively white core layer, white adhesive layer and release layer, the thickness of white core layer is 6-25 μm, the thickness of white adhesive layer is 6-50 μm, the thickness of release layer is 38-135 μm, the combination of white adhesive layer and sandwich layer is utilized to improve dimensional stability, MD can reach less than 0.1% to size changing rate, and utilize the reflectivity of its white adhesive layer lifting white covering film, reduce its penetrance and reach and cover circuit effect, utilize sandwich layer to be that white polyimide film makes coverlay have high temperature resistant and drug resistance.This white covering film, structure is simple, and for simplifying printing-ink operation in LED industry, improve the reflectivity of LED simultaneously, reduce penetrance, its dimensional stability is splendid, can reach less than 0.1%, and can have screening effect to product circuit.

Description

White covering film

Technical field

The utility model belongs to cover membrane for printed circuit board field, relate generally to one and simplify printing-ink operation for improving in LED industry, realize the feature of its high reflectance simultaneously, improve the brightness of LED and there is the white covering film covering circuit effect, using with the function meeting the electronic product such as mobile phone and dull and stereotyped Light bar.

Background technology

Printed circuit board (PCB) is material indispensable in electronic product, and along with consumption electronic products demand growth, the demand for printed circuit board (PCB) also grows with each passing day.Due to flexible printed wiring board (FPC, Flexible Printed Circuit) there is flexibility and can the characteristic such as three-dimensional space distribution, under technicalization electronic product emphasizes that gesture is driven in development that is compact, flexibility, be widely used in computer and ancillary equipment thereof, communication product and consumption electronic products etc. at present.

Generally speaking, flexible print wiring board is mainly by copper clad laminate (FCCL, Flexible Copper Clad Laminate) and coverlay (CL, Coverlay) formed, general use plastic film as coverlay, or utilizes screen printing technology to form one deck thin insulating ink as coverlay.These known coverlays also exist ink layer be full of cracks or the problem such as to come off.In addition; most coverlay is light polyimide film in the market; and the function of circuit layout is covered in order to make polyimides diaphragm have; then there is the technology forming white composite layer 12 (white ink layer) on polyimide film 11 as shown in Figure 1 and form adhesion coating 13 under polyimide film; but; though this kind of structure reaches the object of covering, the glossiness on polyimide film surface is still excessively bright, cannot meet particular optical application demand.And through high temperature process, easily there is the phenomenon that white composite bed turns yellow.

The demand of optical activity polyimides diaphragm is offseted in order to meet market.Another kind of known features as shown in Figure 2; use the white polyimide film 21 being added with powder; and form following layer 22 at this white polyimide film 21 lower surface; though the polyimides diaphragm manufactured by this way has good extinction effect; but its reflectivity lower (< 80%); penetrance is high, cannot cover circuit layout pattern and be easy to be plagiarized by the same trade.

Current known coverlay, 150 DEG C of bakings 30min, dimensional stability MD are 0.15 ~ 0.20% to (along production mode reform), and white ink coverlay utilizes its symmetry at present, and dimensional stability MD is to reaching less than 0.1%.Then there is the technology forming white composite layer 12 (white ink layer) on polyimide film 11 as shown in Figure 1, but, though this kind of structure reaches the object of covering, but white ink coverlay can by the restriction of temperature in processing procedure at present, Yellowing can be produced for a long time in some high temperature section (fast pressure, Cover Lay slaking, SMT etc.), and the easily contaminated and variable color in surface or with impurity.

Also have a kind of white coverlay for carriers, as shown in Figure 3, there is carrier protective tissue (PI Carrier Film) 34, white composite layer 32, polyimide film 31 and adhesion layer 33 successively from top to bottom.Namely on the basis of Fig. 1; stick on carrier protective tissue (PI Carrier Film) 34; this carrier protective tissue is beneficial in successive process to be avoided described white composite layer contaminated and carries out full processing procedure protection to FPC, is peeled off by described carrier protective tissue in the last processing procedure of FPC.But this white coverlay for carriers, production process is many, and can increase the production process in downstream, disagrees with the object of simplifying operation, also has the worry that carrier comes off.

Utility model content

The demand of optical activity polyimides diaphragm is offseted in order to meet market, simplify printing-ink operation in LED industry, the feature simultaneously realizing its high reflectance improves the brightness of LED and has and cover circuit effect, use with the function meeting the electronic product such as mobile phone and dull and stereotyped Lightbar, the utility model provides a kind of white covering film, this white covering film is used for simplifying printing-ink operation in LED industry, improves the reflectivity of LED simultaneously, reduces penetrance; 150 DEG C of baking 30min, its dimensional stability is splendid, can reach less than 0.1%; And screening effect can be had to product circuit.

The utility model in order to the technical scheme solving its technical problem and adopt is:

A kind of white covering film, be made up of white core layer, white adhesive layer and release layer, described white core layer has relative upper and lower surface, described white adhesive layer is formed at the lower surface of described white core layer, described release layer is attached at the lower surface of described white adhesive layer, the thickness of described white core layer is 6-25 μm, and the thickness of described white adhesive layer is 6-50 μm, and the thickness of described release layer is 38-135 μm.

The utility model in order to the further technical scheme solving its technical problem and adopt is:

Say further, described white core layer is white polyimide film.

It is preferred that the thickness of described white adhesive layer is 6-25 μm.

The beneficial effects of the utility model are: white covering film of the present utility model is by white core layer, white adhesive layer and release layer are formed successively, the thickness of white core layer is 6-25 μm, the thickness of white adhesive layer is 6-50 μm, the thickness of release layer is 38-135 μm, the combination of white adhesive layer and sandwich layer is utilized to improve dimensional stability, MD can reach less than 0.1% to size changing rate, and utilize its white adhesive layer to promote the reflectivity of white covering film, reduce its penetrance and reach and cover circuit effect, sandwich layer is utilized to be that white polyimide film makes coverlay have high temperature resistant and drug resistance.The utility model is stressed that described white covering film, structure is simple, reduce tradition and be coated with the operation of white ink layer on coverlay at FPC, save manpower man-hour, and white covering film also can not produce Yellowing for a long time due to the characteristic of white polyimide film some high temperature section (fast pressure, Cover Lay slaking, SMT etc.) in FPC processing procedure, and surface can not contaminated and variable color or with impurity, also there will not be the anomaly such as etching, electroplating liquid medicine infiltration, thus improve product yield.

Accompanying drawing explanation

Fig. 1 is a kind of known white covering film generalized section;

Fig. 2 is another kind of known white covering film generalized section;

Fig. 3 is another known white covering film generalized section;

Fig. 4 is white covering film generalized section described in the utility model.

Embodiment

Below by way of specific instantiation, embodiment of the present utility model is described, those skilled in the art can understand advantage of the present utility model and effect easily by content disclosed in the present specification.The utility model also can be implemented in further, different ways, that is, under the category do not disclosed departing from the utility model, can give different modifications and change.

Embodiment: a kind of white covering film, as shown in Figure 4, be made up of white core layer 41, white adhesive layer 42 and release layer 43, described white core layer has relative upper and lower surface, described white adhesive layer is formed at the lower surface of described white core layer, and described release layer is attached at the lower surface of described white adhesive layer.

In order to make the white covering film of this example have preferably dimensional stability, MD can reach less than 0.1% to size changing rate, and the thickness of the white covering film of this example meets following condition: the thickness of described white core layer is 6-25 μm; The thickness of described white adhesive layer is 6-50 μm, preferably 6-25 μm.

The thickness of described release layer is 38-135 μm.

In order to make the white covering film of this example have splendid resistance to chemical reagents and heat-resisting quantity, described white core layer is white polyimide film.

The white covering film of this example has following characteristic: 150 DEG C of baking 30min, and its dimensional stability is splendid; There is splendid resistance to chemical reagents and thermal endurance; There is splendid heat-resisting quantity; There is splendid reflectivity, penetrance and splendid circuit shielding.

Prepare the utility model white covering film according to the data in following table 1, another preparation reference examples sample, the white covering film of this reference examples sample does not comprise white adhesive layer, and use general adhesion coating, all the other are the same with embodiment.Penetrance, glossiness, reflectance test are carried out in sampling, and outcome record is in table 1.

Table 1:

As shown in table 1 result, under the condition that gross thickness is identical, compared to the white covering film sample not using white adhesive layer, white covering film penetrance of the present utility model is relatively little, have better glossiness and reflectivity, the function that can meet the electronic product such as mobile phone and dull and stereotyped Light bar uses.

Above-mentioned specification and embodiment are only exemplary illustration principle of the present utility model and effect thereof, are not to restriction of the present utility model.Any creation fallen in the utility model right all belongs to the scope that the utility model is protected.

Claims

1. a white covering film, it is characterized in that: be made up of white core layer (41), white adhesive layer (42) and release layer (43), described white core layer has relative upper and lower surface, described white adhesive layer is formed at the lower surface of described white core layer, described release layer is attached at the lower surface of described white adhesive layer, the thickness of described white core layer is 6-25 μm, the thickness of described white adhesive layer is 6-50 μm, and the thickness of described release layer is 38-135 μm.

2. white covering film as claimed in claim 1, is characterized in that: described white core layer is white polyimide film.

3. white covering film as claimed in claim 1, is characterized in that: the thickness of described white adhesive layer is 6-25 μm.