阅读说明：本技术 一种淋涂外镀手机背板生产工艺 (Production process of mobile phone backboard plated outside by curtain coating ) 是由 吴建晓 张伦玉 于 2021-09-28 设计创作，主要内容包括：本发明公开了一种淋涂外镀手机背板生产工艺,工艺包括基材层,所述基材层的制成原料包括透明层、保护光挡层、金属保护层、光阻层、制丝层及油墨层；溢流下拉制备基材层,根据推压方式对基材层进行多个阶段的加热拉伸处理,达到薄化效果；薄化后的基材层进行冷却处理,获取透明聚酰亚胺的原料并涂抹覆在基材层的表面层上；对整个基材层进行烘干处理,以获得透明聚酰亚胺的基材层。实现了机械性能得到提高而且其压缩应力和莫氏硬度达到都非常强悍,大大提高了手机背板的强度,跌落时玻璃不易摔烂。本发明的手机背板的质量和理化性能与传统现有的手机背板相比较为强悍。(The invention discloses a production process of a mobile phone backboard plated outside by a curtain coating method, which comprises a substrate layer, wherein the raw materials for manufacturing the substrate layer comprise a transparent layer, a protective light blocking layer, a metal protective layer, a light resistance layer, a silk manufacturing layer and an ink layer; the overflow pull-down is used for preparing a base material layer, and the base material layer is subjected to heating stretching treatment in multiple stages according to a pushing and pressing mode, so that the thinning effect is achieved; cooling the thinned base material layer to obtain a raw material of transparent polyimide, and coating the raw material on the surface layer of the base material layer; and drying the whole substrate layer to obtain the substrate layer of the transparent polyimide. The mechanical property is improved, the compression stress and the Mohs hardness of the mobile phone backboard are very strong, the strength of the mobile phone backboard is greatly improved, and the glass is not easy to break when falling. Compared with the traditional mobile phone back plate, the mobile phone back plate has stronger quality and physical and chemical properties.)

1. A production process for a mobile phone backboard plated outside by curtain coating is characterized by comprising the following steps:

the manufacturing raw materials of the substrate layer comprise a transparent layer, a protective light blocking layer, a metal protective layer, a light resistance layer, a silk manufacturing layer and an ink layer;

the overflow pull-down is used for preparing a base material layer, and the base material layer is subjected to heating stretching treatment in multiple stages according to a pushing and pressing mode, so that the thinning effect is achieved;

cooling the thinned base material layer to obtain a raw material of transparent polyimide, and coating the raw material on the surface layer of the base material layer;

and drying the whole substrate layer to obtain the substrate layer of the transparent polyimide.

2. The production process according to claim 1, wherein the step of the substrate layer comprises:

coating a photoresist layer on the surface layer of the transparent layer, and curing the photoresist layer to obtain a first protective layer;

covering a metal protection layer on the surface layer of the first protection layer;

forming a silk-making layer on the surface layer of the first protective layer in a brushing texture processing mode;

and printing ink layers on the surface layers of the first protective layer and the silk making layer in a full-face mode, and solidifying the ink layers.

3. The process of claim 2 wherein the coating of the light-blocking layer over the transparent layer comprises:

carrying out primary heating treatment on the transparent layer in advance, wherein the heating temperature is 80-90 ℃, and the heating time is 15 minutes;

and carrying out second heating treatment on the transparent layer, wherein the heating temperature is 300 ℃, and the heating time is 30 minutes.

4. The production process according to claim 2, wherein the surface layer of the first protective layer is formed with a filament-making layer in a brush-texturing manner, comprising:

the texture silk appearance layers formed by different densities, line widths and intervals are realized by adjusting the pressure of 1 Pa-1000 Pa and the speed of 1 m/min-20 m/min.

5. The production process according to claim 1, wherein the pressing means performs the heat stretching treatment of the base material layer in a plurality of stages including:

heating the substrate layer through a first high-temperature tension roller in a first stage; performing first stretching thinning on the substrate layer through a second high-temperature tension roller; heating the substrate layer in the second stage through a third high-temperature tension roller; performing second stretching thinning on the base material layer through a fourth high-temperature tension roller; heating the substrate layer through a fifth high-temperature tension roller in a third stage; and performing third stretching thinning on the base material layer through a sixth high-temperature tension roller.

6. The process according to claim 1, wherein the step of cooling the thinned substrate layer comprises:

cooling the base material layer to 300-310 ℃ through a first tension roller; and cooling the base material layer to 60-80 ℃ through a second tension roller.

7. The production process according to claim 1, wherein the step of obtaining a raw material of transparent polyimide and coating the raw material on the surface layer of the substrate layer comprises:

the substrate layer is passed through a coating tank of a raw material of transparent polyimide to the thickness of the polyimide coated on the substrate layer is 30-100 um.

8. The production process according to claim 1, wherein the drying treatment is performed on the entire substrate layer, and comprises:

drying treatment is carried out on the substrate layer through a drying device at 200-350 ℃, and a polyimide layer with the thickness of 6-20 um is obtained, so that the substrate layer with transparent polyimide is formed.

Technical Field

The invention relates to the technical field of production of mobile phone back plates, in particular to a production process of a mobile phone back plate coated with an outer plating layer by spraying.

Background

The mobile phone back plate is a mobile phone peripheral accessory arranged on the back of a mobile phone, mainly plays the functions of protection, decoration and the like, can be used for improving the user experience due to the fact that the mobile phone back plate is arranged on the outermost layer, meets the pursuit of people on fashion and personality, and improves the product competitiveness of the display device. The rear cover or the back plate of the current mobile terminal has weak mechanical strength, has the defects of weak falling resistance and the like, and is not suitable for large-scale production and application.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a production process of a mobile phone backboard plated outside by spraying.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a production process of a mobile phone backboard plated outside by curtain coating comprises the following steps:

the manufacturing raw materials of the substrate layer comprise a transparent layer, a protective light blocking layer, a metal protective layer, a light resistance layer, a silk manufacturing layer and an ink layer;

the overflow pull-down is used for preparing a base material layer, and the base material layer is subjected to heating stretching treatment in multiple stages according to a pushing and pressing mode, so that the thinning effect is achieved;

cooling the thinned base material layer to obtain a raw material of transparent polyimide, and coating the raw material on the surface layer of the base material layer;

and drying the whole substrate layer to obtain the substrate layer of the transparent polyimide.

As a preferable aspect of the present invention, the step of the substrate layer includes:

coating a photoresist layer on the surface layer of the transparent layer, and curing the photoresist layer to obtain a first protective layer;

covering a metal protection layer on the surface layer of the first protection layer;

forming a silk-making layer on the surface layer of the first protective layer in a brushing texture processing mode;

and printing ink layers on the surface layers of the first protective layer and the silk making layer in a full-face mode, and solidifying the ink layers.

As a preferred technical scheme of the invention, the photoresist layer is coated and covered on the transparent layer, and the photoresist layer comprises:

carrying out primary heating treatment on the transparent layer in advance, wherein the heating temperature is 80-90 ℃, and the heating time is 15 minutes;

and carrying out second heating treatment on the transparent layer, wherein the heating temperature is 300 ℃, and the heating time is 30 minutes.

As a preferable aspect of the present invention, a yarn-making layer is formed on a surface layer of the first protective layer by a brush texturing process, and the yarn-making layer includes:

the texture silk appearance layers formed by different densities, line widths and intervals are realized by adjusting the pressure of 1 Pa-1000 Pa and the speed of 1 m/min-20 m/min.

In a preferred aspect of the present invention, the press method for performing a multi-stage heat stretching process on the base material layer includes:

heating the substrate layer through a first high-temperature tension roller in a first stage; performing first stretching thinning on the substrate layer through a second high-temperature tension roller; heating the substrate layer in the second stage through a third high-temperature tension roller; performing second stretching thinning on the base material layer through a fourth high-temperature tension roller; heating the substrate layer through a fifth high-temperature tension roller in a third stage; and performing third stretching thinning on the base material layer through a sixth high-temperature tension roller.

As a preferable aspect of the present invention, the step of cooling the thinned substrate layer includes:

cooling the base material layer to 300-310 ℃ through a first tension roller; and cooling the base material layer to 60-80 ℃ through a second tension roller.

As a preferred technical solution of the present invention, the steps of obtaining a raw material of transparent polyimide and coating the raw material on a surface layer of a substrate layer include:

the substrate layer is passed through a coating tank of a raw material of transparent polyimide to the thickness of the polyimide coated on the substrate layer is 30-100 um.

As a preferred technical solution of the present invention, the drying process of the entire substrate layer includes:

drying treatment is carried out on the substrate layer through a drying device at 200-350 ℃, and a polyimide layer with the thickness of 6-20 um is obtained, so that the substrate layer with transparent polyimide is formed.

Compared with the prior art, the invention has the beneficial effects that:

the mechanical property is improved, the compression stress and the Mohs hardness of the mobile phone backboard are very strong, the strength of the mobile phone backboard is greatly improved, and the glass is not easy to break when falling. Compared with the traditional mobile phone back plate, the mobile phone back plate has stronger quality and physical and chemical properties.

Drawings

Fig. 1 is a flow chart of the steps for forming a substrate layer according to an embodiment of the present invention.

Detailed Description

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

The invention provides a production process of a mobile phone back plate coated with an outer plating layer by a curtain coating process, which improves the mechanical property and has very strong compressive stress and Mohs hardness. According to the illustration in fig. 1, the specific process of the mobile phone back plate comprises the following steps:

the substrate layer, the raw materials of making of the substrate layer of this embodiment include stratum lucidum, protection light blocking layer, metal protection layer, light resistance layer, system silk layer and printing ink layer.

Coating a photoresist layer on the surface layer of the transparent layer, and curing the photoresist layer to obtain a first protective layer; covering a metal protection layer on the surface layer of the first protection layer; forming a silk-making layer on the surface layer of the first protective layer in a brushing texture processing mode; and printing ink layers on the surface layers of the first protective layer and the silk making layer in a full-face mode, and solidifying the ink layers.

In the embodiment, the photoresist layer is coated and covered on the transparent layer, and the first heating treatment is carried out on the transparent layer in advance, the heating temperature is 80-90 ℃, and the heating time is 15 minutes; and carrying out second heating treatment on the transparent layer, wherein the heating temperature is 300 ℃, and the heating time is 30 minutes. The production efficiency is improved, and simultaneously, the good mechanical property of the photoresist layer is ensured, and the self flaw of the photoresist layer is avoided.

In the embodiment, the surface layer of the first protective layer is provided with the silk making layer in a brushing texture processing mode, and the silk making layer comprises a texture silk appearance layer formed by different densities, line widths and intervals through the adjustment of 1 Pa-1000 Pa pressure and 1 m/min-20 m/min speed.

Before the sputtering of the transparent layer, a photoresist layer is cured on the transparent layer to obtain a first protective layer, on one hand, the transparent layer is reinforced through the first protective layer, on the other hand, atoms running at a high speed during the vacuum sputtering strike the first protective layer, so that the impact on the transparent layer is buffered, and the influence of pits formed on the surface of the transparent layer on the overall strength is avoided. Part of metal atoms are embedded into the first protective layer, so that the strength of the mobile phone backboard is greatly improved. The metal protective layer is firmly attached to the surface layer of the first protective layer, and interlayer separation is avoided.

In addition, the transition light resistance layer can be used for assisting in etching the metal protection layer sputtered in vacuum, and the appearance of any shape can be designed, such as a LOGO layer and a glare texture coating; the strength of the rear cover of the film-coated mobile phone glass is greatly improved by using a simple process, and the glass is not easy to break when falling.

The ink layer of the embodiment is firstly subjected to a first sintering treatment to obtain a brightening layer; and carrying out secondary sintering treatment on the surface layer of the brightening layer to obtain the metal color protective layer. The printing brightening layer is specifically prepared by printing opaque ink or metal particle flashing ink with powder and color by using a 100-mesh screen plate, and drying and curing at a high temperature to obtain the brightening layer; the metal color protective layer is printed by scraping twice with a 100-mesh screen plate, and then dried and cured at 160 ℃ to obtain the metal color protective layer.

In the step 1, a substrate layer is prepared by overflow and pull-down, and the substrate layer is subjected to heating and stretching treatment in multiple stages according to a pushing and pressing mode, so that the thinning effect is achieved.

In step 2, the thinned substrate layer is cooled to obtain a raw material of transparent polyimide, and the raw material is coated on the surface layer of the substrate layer.

In step 3, the entire substrate layer is subjected to a drying process to obtain a substrate layer of transparent polyimide.

In the step, the substrate layer is heated in a first stage through a first high-temperature tension roller; performing first stretching thinning on the substrate layer through a second high-temperature tension roller; heating the substrate layer in the second stage through a third high-temperature tension roller; performing second stretching thinning on the base material layer through a fourth high-temperature tension roller; heating the substrate layer through a fifth high-temperature tension roller in a third stage; and performing third stretching thinning on the base material layer through a sixth high-temperature tension roller.

Cooling the thinned base material layer, namely cooling the base material layer to 300-310 ℃ through a first tension roller; and cooling the base material layer to 60-80 ℃ through a second tension roller.

The method comprises the steps of obtaining a raw material of the transparent polyimide and coating the raw material on a surface layer of a base material layer, wherein the coating groove of the raw material of the transparent polyimide is formed in the base material layer, so that the thickness of the polyimide coated on the base material layer is 30-100 microns.

Carry out drying process to whole substrate layer, include and carry out drying process with the substrate layer through 200 ~ 350 ℃ drying device, obtain the polyimide layer that thickness is 6 ~ 20um to form the substrate layer that has transparent polyimide.

The substrate layer of this embodiment has the advantage of high rigidity, high flexibility. Therefore, the technical problem that the minimum bending radius of the base material layer in the prior art cannot meet the requirement of a curled screen of a rear cover of a mobile phone is solved, the technical effects that the process operation is convenient and fast, the flow is simple, and the bending requirement of a flexible screen is met are achieved.

For example, the first embodiment is heated by passing through a first high-temperature tension roller, and the temperature is controlled to be more than 110 ℃; and (5) stretching and thinning the substrate layer by adopting a second high-temperature tension roller, and reducing the thickness of the substrate layer to 42 um. And the substrate layer passes through a third high-temperature tension roller to be heated again, and the temperature is controlled to be 28 ℃ above. And (5) stretching and thinning the substrate layer by adopting a fourth high-temperature tension roller, and reducing the thickness of the substrate layer to 21 um. And the substrate layer passes through a fifth high-temperature tension roller to be heated again, and the temperature is controlled to be 28 ℃ higher than that of the substrate layer. And stretching and thinning the substrate layer by adopting a sixth high-temperature tension roller, and reducing the thickness of the substrate layer to 6 um.

Cooling the base material layer to 300 ℃ through a first tension roller; and cooling the substrate layer to 65 ℃ through a second tension roller.

The substrate layer was passed through a coating bath of a slurry of transparent polyimide to make the thickness of the polyimide wet film on the glass film 35 um.

And drying the glass film through a drying tunnel at 260 ℃ to obtain a polyimide layer with the thickness of 8um, thereby forming a substrate layer with a transparent polyimide layer.

In the second embodiment, the heating is carried out by passing through a first high-temperature tension roller, and the temperature is controlled to be more than 130 ℃; and (5) stretching and thinning the substrate layer by adopting a second high-temperature tension roller, and reducing the thickness of the substrate layer to 44 um. And the substrate layer passes through a third high-temperature tension roller to be heated again, and the temperature is controlled to be above 30 ℃. And (5) stretching and thinning the substrate layer by adopting a fourth high-temperature tension roller, and reducing the thickness of the substrate layer to 23 um.

And the substrate layer passes through a fifth high-temperature tension roller to be heated again, and the temperature is controlled to be 30 ℃ higher than that of the substrate layer. And stretching and thinning the substrate layer by adopting a sixth high-temperature tension roller, and reducing the thickness of the substrate layer to 7 um.

Cooling the base material layer to 300 ℃ through a first tension roller; and cooling the substrate layer to 68 ℃ through a second tension roller.

The substrate layer was passed through a coating bath of a slurry of transparent polyimide to make the thickness of the polyimide wet film on the glass film 50 um.

And drying the glass film through a drying tunnel at 280 ℃ to obtain a polyimide layer with the thickness of 10um, thereby forming a substrate layer with a transparent polyimide layer.

In the third embodiment, the heating is carried out by passing through a first high-temperature tension roller, and the temperature is controlled to be more than 180 ℃; and (5) stretching and thinning the substrate layer by adopting a second high-temperature tension roller, and reducing the thickness of the substrate layer to 48 um. And the substrate layer passes through a third high-temperature tension roller to be heated again, and the temperature is controlled to be 45 ℃ above. And (5) stretching and thinning the substrate layer by adopting a fourth high-temperature tension roller, and reducing the thickness of the substrate layer to 28 um.

And the substrate layer passes through a fifth high-temperature tension roller to be heated again, and the temperature is controlled to be 45 ℃ higher than that of the substrate layer. And stretching and thinning the substrate layer by adopting a sixth high-temperature tension roller, and reducing the thickness of the substrate layer to 10 um.

Cooling the base material layer to 300 ℃ through a first tension roller; and cooling the substrate layer to 70 ℃ through a second tension roller.

The substrate layer was passed through a coating bath of a slurry of transparent polyimide to make the thickness of the polyimide wet film on the glass film 70 um.

And drying the glass film through a drying tunnel at 330 ℃ to obtain a polyimide layer with the thickness of 12um, thereby forming a substrate layer with a transparent polyimide layer.

Finally, the applicant prepares the substrate layer with the transparent polyimide layer with different parameters by the preparation method, and after the detection, the result can be obtained that the thinner the substrate layer is, the smaller the minimum bending radius is, for example, when the substrate layer is only 6um thick, the minimum bending radius is only 2mm, and when the thickness of the substrate layer is in the range of 6-15um, the minimum bending radius is 2-3mm, which can meet the bending requirement of the flexible screen.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.