CN117038826A - Fluorescent film and coating method thereof - Google Patents

Abstract

The invention belongs to the technical field of fluorescent films, and in particular relates to a fluorescent film and a coating method thereof, wherein the fluorescent film comprises a base film and a fluorescent layer, the fluorescent layer is arranged on the base film, and the tensile modulus of the fluorescent layer is more than 100Mpa and less than 500Mpa in the temperature range of 0-25 ℃; the tensile modulus of the fluorescent layer is more than 0.5Mpa and less than 3Mpa in the temperature range of 60-80 ℃; the tensile modulus of the fluorescent layer is less than 0.5Mpa in the temperature range of more than 80 ℃. The fluorescent layer adopted by the fluorescent film has the characteristics that the fluorescent layer is in a semi-cured state at room temperature and can flow when the temperature is increased, and when the fluorescent film is coated, the fluorescent layer can flow by increasing the temperature, so that the fluorescent film is uniformly coated on the light-emitting element; the production efficiency is effectively improved, and the cost is reduced; the luminous efficiency and the light distribution concentration of the product are greatly improved.

Description

Fluorescent film and coating method thereof

Technical Field

The invention relates to a fluorescent film and a coating method thereof, belonging to the technical field of fluorescent films.

Background

The light emitting diode (Light Emitting Diode; LED) is a semiconductor element capable of realizing a plurality of colors of light by forming a light emitting source by a PN structure of the compound semiconductor (Compound semiconductor material). In recent years, blue LEDs and ultraviolet LEDs have been realized using nitrides having excellent physical and chemical properties, and white light or other monochromatic light can be manufactured using blue LEDs or ultraviolet LEDs and fluorescent materials, thereby expanding the application range of light emitting diodes.

In general, a reflective layer is formed at a lower portion of an LED chip and light is emitted through an upper portion of the chip and four sides of front and rear, left and right, and thus, when a luminescent color is converted using a fluorescent material, the fluorescent material needs to be coated to the upper portion of the chip and the four sides of the chip, and a thickness needs to be uniform, which is very important for ensuring uniform light quality. Accordingly, various conformal coating (Conformal coating) techniques are proposed in the prior art, but most techniques need to be performed before a wire bonding (wirebonding) process, and thus can be applied only to a limited amount to flip chip (flip chip) type packages, or during fluorescent coating, separate wire bonding pad portions are opened to be coated, which has the inconvenience of requiring additional processes. In addition, this method employs a pre-mold lead frame type for the packaging process, and is difficult to apply when fluorescence is applied in units of individual chips.

After the wire bonding process is completed, there is a dispensing process (dispersing) in which phosphor particles are dispersed on a highly heat-resistant and light-transmitting resin to form a paste, and then droplets are ejected through a nozzle having a certain diameter to apply the phosphor to the entire chip. In this process, it is important to maintain good viscosity of the fluorescent particles and the resin for better ejection of micro droplets. In order to smoothly eject micro-droplets with fluorescent particles, it is necessary to reduce the viscosity of the resin in the dispensing process, and due to the reduced viscosity, the inorganic fluorescent particles in the solid phase are liable to partially settle during the process, which may occur in the tube of the apparatus storing the micro-droplets or after the dispensing and before the process of curing the fluorescent paste, thereby reducing the dispersibility of the fluorescent particles in the resin and thus affecting the concentration of light distribution.

Disclosure of Invention

The present invention addresses the above-described shortcomings of the prior art by providing a fluorescent film and a method of coating the same.

The technical scheme for solving the technical problems is as follows:

a fluorescent film, comprising a base film and a fluorescent layer, wherein the fluorescent layer is arranged on the base film, and the tensile modulus of the fluorescent layer is more than 100Mpa and less than 500Mpa in the temperature range of 0-25 ℃; the tensile modulus of the fluorescent layer is more than 0.5Mpa and less than 3Mpa in the temperature range of 60-80 ℃; the tensile modulus of the fluorescent layer is less than 0.5Mpa in the temperature range of more than 80 ℃.

Based on the technical scheme, the invention can also make the following improvements:

further, the fluorescent layer comprises fluorescent particles and matrix resin, wherein the matrix resin is single-layer, double-layer or multi-layer, and the fluorescent particles are uniformly distributed in at least one layer of matrix resin.

The fluorescent particles may be either a Garnet-type phosphor (YAG, TAG, luAG), a silicate-type phosphor, a nitride-type phosphor, a sulfide-type phosphor, an oxide-type phosphor, or the like, or may be mixed singly or in a prescribed ratio. The base resin is a resin type that satisfies high adhesion, high light transmittance, high heat resistance, high light refractive index, moisture resistance, and the like.

Further, when the number of layers of the matrix resin is greater than 1, the matrix resins of adjacent layers have different viscosities and/or mechanical strengths.

Further, the shape of the fluorescent layer is adapted to the shape of the base film, or the fluorescent layer is formed by uniformly arranging a plurality of fluorescent sheets on the base film.

Further, the matrix resin has a structure represented by the following general formula I:

wherein n is 1-20;

r1 is selected from any one of amino, c=c, epoxy, hydrazine, diazo, azido, c=c with aromatic amine, c=c with aromatic group, glycidyl ether with aromatic group, glycidyl ester with aromatic group;

r2 is selected from any one of hydrogen atom, alkyl with 1-6 carbon atoms, alkyl with 6-15 carbon atoms and aryl, and the same group as R1.

According to the invention, the acrylic resin is subjected to surface modification by adopting the substances such as the siloxane with reactivity, so that the acrylic resin surface is grafted with the structure with the end siloxane groups, on one hand, the transparency of the fluorescent film can be effectively improved, and on the other hand, the structure can form stronger hydrogen bonds with oxygen in fluorescent particles, so that the binding capacity is enhanced, the dispersion performance of the fluorescent particles in the acrylic resin is promoted, and the problem that the inorganic fluorescent particles of a solid phase are partially settled when the fluorescent film is placed for a long time is effectively solved.

Further, the base film is made of a stretchable polymer material, for example, the base film is made of any one of PVC, polyamide fluoride, PET and PI.

Further, a temporary adhesive layer may be further formed between the fluorescent layer and the cover film.

The temporary adhesive layer maintains the adhesive force of the fluorescent layer and adheres closely to the base film, and in the packaging process, the adhesive force is easily weakened when the fluorescent layer is peeled off from the base film in order to coat the fluorescent layer on the LED chip. The temporary adhesive layer may be selectively applied according to the process requirements, and is not necessary. As the temporary adhesive layer, a material based on a mixture of a polymer resin and an ultraviolet curable polymer may be used, which has a characteristic of weakening adhesion due to ultraviolet irradiation. The thickness of the temporary bonding layer may be in the range of several to several tens of micrometers.

Further, a cover film is further arranged on the fluorescent layer, and the shape of the cover film is matched with the shape of the base film, or the shape of the cover film is matched with the shape of the fluorescent layer.

When the fluorescent layer is formed by uniformly arranging a plurality of fluorescent sheets on the base film, the cover film can be a continuous sheet shape matched with the shape of the base film, and can also be composed of a plurality of cover films matched with the size of the fluorescent sheets.

Further, the cover film is made of any one of PVC, polyamide fluoride, PET and PI.

Further, the fluorescent layer is provided with a containing hole, and the base film is provided with a through hole corresponding to the containing hole.

The invention also discloses a coating method adopting the fluorescent film, which specifically comprises the following steps:

outputting the fluorescent film through a supply scroll, and respectively placing a pickup head and a push rod on the upper side and the lower side of the fluorescent film;

step two, the pushing rod presses the base film from bottom to top, and the pickup head picks up the fluorescent layer;

step three, placing the luminous element to be coated on a heating platform, and placing a fluorescent layer above the luminous element by a pickup head;

heating by a heating platform, wherein the fluorescent layer is close to the light-emitting element, the temperature of the fluorescent layer is increased to generate fluidity, the fluorescent layer flows to the upper surface of the light-emitting element, and the periphery of the light-emitting element is coated;

and fifthly, recovering the residual base film through a recovery reel.

The invention also discloses another coating method adopting the fluorescent film, which specifically comprises the following steps:

step one, placing a light-emitting element to be coated on a heating platform, and placing a fluorescent film above the light-emitting element;

step two, uncovering a cover film on the fluorescent layer, and placing the fluorescent layer towards the light-emitting element;

a press roller is arranged above the fluorescent film, and pressure is sequentially applied to the back surface of the base film through the press roller;

and step four, heating by a heating platform, increasing the temperature to generate fluidity of the fluorescent layer, enabling the fluorescent layer to flow to the upper surface of the light-emitting element, and coating the periphery of the light-emitting element.

The invention has the beneficial effects that:

the fluorescent layer adopted by the fluorescent film has the characteristics that the fluorescent layer is in a semi-cured state at room temperature and can flow when the temperature is increased, and when the fluorescent film is coated, the fluorescent layer can flow by increasing the temperature, so that the fluorescent film is uniformly coated on the light-emitting element; compared with the traditional dispensing and spraying process, the invention has simple structure, effectively improves the production efficiency and reduces the cost; the luminous efficiency and the light distribution concentration of the product are greatly improved.

Drawings

FIG. 1 is an internal structure of a fluorescent film according to an embodiment of the present invention;

FIG. 2 (a) is an example of a phosphor layer bilayer structure of a phosphor film according to an embodiment of the present invention;

FIG. 2 (b) is another embodiment of a phosphor layer bilayer structure of a phosphor film according to an embodiment of the present invention;

FIG. 2 (c) is another embodiment of a phosphor layer bilayer structure of a phosphor film according to an embodiment of the present invention;

fig. 3 (a) is a structure of a receiving hole of a fluorescent film according to an embodiment of the present invention;

FIG. 3 (b) is a cross-sectional view of section A-A of FIG. 3 (a);

fig. 3 (c) is a schematic structural diagram of a light emitting element according to an embodiment of the present invention;

FIG. 4 shows a structure of a second fluorescent film according to another embodiment of the present invention;

FIG. 5 is a schematic diagram of a supply spool storing phosphor film II;

FIG. 6 is a schematic diagram of a third fluorescent film according to another embodiment of the present invention;

FIG. 7 is a structure of a fourth fluorescent film according to another embodiment of the present invention;

FIG. 8 (a) is a structure of a phosphor film five according to another embodiment of the present invention;

fig. 8 (b) is a schematic structural view showing a receiving hole of a fluorescent film five according to another embodiment of the present invention corresponding to an electrode of a light emitting element;

FIG. 9 (a) is a schematic diagram illustrating a process of forming a base film and a fluorescent layer of a fluorescent film II according to an embodiment of the present invention;

FIG. 9 (b) is a schematic diagram illustrating a cutting process of a first cutting line of a second fluorescent film according to an embodiment of the present invention;

FIG. 9 (c) is a schematic diagram illustrating a cutting process of a second cutting line of a fluorescent film II according to an embodiment of the present invention;

FIG. 9 (d) is a schematic drawing showing the stretching process of the second base film of the fluorescent film according to the embodiment of the present invention;

FIG. 9 (e) is a schematic diagram of a second fluorescent film according to an embodiment of the present invention;

fig. 10 (b) is a schematic diagram illustrating a cutting process of a first cutting line of a fluorescent film III according to an embodiment of the present invention;

FIG. 10 (c) is a schematic drawing showing the stretching process of the base film of the third fluorescent film according to the embodiment of the present invention;

FIG. 10 (d) is a schematic view of the stretched base film of the third fluorescent film according to the embodiment of the present invention;

FIG. 10 (e) is a schematic diagram showing the formation process of a cap film of a fluorescent film III according to an embodiment of the present invention;

FIG. 10 (f) is a schematic diagram showing a cutting process of a second cutting line of a third fluorescent film according to an embodiment of the present invention;

FIG. 11 (a) is a schematic diagram showing the formation process of a base film and a mask of a fluorescent film III according to an embodiment of the present invention;

FIG. 11 (b) is a schematic diagram illustrating a process of forming a phosphor layer of a phosphor film III according to an embodiment of the present invention;

FIG. 11 (c) is a schematic structural diagram of a phosphor layer of a phosphor film III according to an embodiment of the present invention;

FIG. 11 (d) is a schematic diagram showing a cutting process of the base film of the third fluorescent film according to the embodiment of the present invention;

FIG. 11 (e) is a schematic diagram showing the formation process of a cap film of a fluorescent film III according to an embodiment of the present invention;

FIG. 12 is a schematic view of another embodiment of a cover film forming process of a fluorescent film III according to an embodiment of the present invention;

FIG. 13 (a) is a schematic illustration of the coating process of the fluorescent film II according to the embodiment 1 of the present invention;

FIG. 13 (b) is a pick-up process of the phosphor layer of embodiment 1 of the present invention;

FIG. 13 (c) shows the joining process of example 1 of the present invention;

fig. 13 (d) is a schematic structural view of the light emitting element of embodiment 1 of the present invention after coating;

fig. 14 (a) is a schematic structural view of a pickup head according to embodiment 1 of the present invention;

fig. 14 (b) is another structural schematic diagram of the pickup head of embodiment 1 of the present invention;

FIG. 15 is a schematic view showing the coating process of the third fluorescent film of example 2 of the present invention;

FIG. 16 (a) is a schematic view showing another coating process of the third fluorescent film of example 2 of the present invention;

fig. 16 (b) is a schematic structural view of a light-emitting element of embodiment 2 of the present invention after coating;

FIG. 17 is a schematic view showing a pressing manner using a pressing roller according to embodiment 2 of the present invention;

FIG. 18 is a schematic view showing a coating process of a fourth fluorescent film according to example 3 of the present invention;

FIG. 19 (a) is a schematic view showing the heating mode in example 1 of the present invention;

fig. 19 (b) is another structural schematic diagram of the light-emitting element of embodiment 1 of the present invention after coating;

fig. 20 (c) is a schematic view showing a process of coating the fluorescent film five on the light emitting element according to the embodiment of the present invention;

fig. 20 (d) is a schematic view of a heating process in the coating process of the fluorescent film five according to the embodiment of the present invention;

fig. 20 (e) is a schematic diagram showing a cutting process of a light emitting element after coating of a fluorescent film five according to an embodiment of the present invention;

fig. 21 is a schematic diagram of a structure of a light-emitting element device in which a light-emitting element is mounted.

The reference numerals are recorded as follows: 100. a fluorescent film; 100', fluorescent film a; 110. a base film; 111. a through hole; 120. a temporary adhesive layer; 130. a fluorescent layer; 130a, a first fluorescent layer; 130b, a second fluorescent layer; 130' a matrix resin paste; 131. a fluorescent sheet; 132. fluorescent particles; 135. a matrix resin; 135a, layer-one matrix resin; 135b, layer two matrix resin; 136. a receiving hole; 150. covering a film; 151. a cover membrane; 1', a light emitting element device; 2. a main body portion; 3. a lead frame; 4. a lead wire; 5. a sealing part; 10. a substrate; 20. a light emitting element; 21. an electrode; 200. a second fluorescent film; 300. a fluorescent film III; 400. a fluorescent film IV; 500. a fifth fluorescent film; 600. a fluorescent film six; RE, supply spool; RE1, supply spool one; w, a wafer; l1, a first cutting line; l2, a second cutting line; m, masking; H. a pick-up head; PP, push pin; RE2, a recovery reel; s, heating a platform; PR, pressing head; C. a clip; RL, press roll.

Detailed Description

The principles and features of the present invention are described below with reference to the drawings, the examples are illustrated for the purpose of illustrating the invention and are not to be construed as limiting the scope of the invention.

1. Preparation of fluorescent layer

Preparation example 1

1.79g of 3-propylamino-trimethoxysiloxane (Mr= 179.29) is added into 100g of acrylate resin (Mr is about 4000), heated to 40 ℃ and reacted for 5 hours to obtain siloxane modified acrylate, 10g of LED fluorescent powder is added, heated to 50 ℃ and reacted for 10 hours, and then fully stirred for standby.

Preparation example 2

To 3.58g of 3-propylamino-trimethoxysiloxane (mr= 179.29), 10g of LED phosphor was added, heated to 60 ℃, reacted for 3 hours, then added to 100g of acrylate resin (Mr about 6000), heated to 40 ℃ and stirred for 5 hours for further use.

2. Preparation of fluorescent film

Fig. 1 shows a structure of a fluorescent film 100 according to an embodiment of the present invention, the fluorescent film 100 including a base film 110, a fluorescent layer 130 formed on the base film 110, and a cap film 150 protecting the fluorescent layer. A temporary adhesive layer 120 may be further provided between the base film 110 and the fluorescent layer 130. The base film 110 is made of any one of PVC, polyamide fluoride, PET, and PI.

The fluorescent layer 130 includes fluorescent particles 132 and a matrix resin 135, the matrix resin is single-layer, double-layer or multi-layer (not shown in the figure), fig. 2 (a) -2 (c) show the structure of the fluorescent layer 130 as double-layer, wherein the fluorescent layer 130 includes a first fluorescent layer 130a and a second fluorescent layer 130b, a layer one matrix resin 135a and a layer two matrix resin 135b are disposed in the first fluorescent layer 130a, and the fluorescent particles 132 are uniformly distributed in at least one layer of matrix resin. The matrix resin material of each layer may have different characteristics. For example, the layer-matrix resin 135a constituting the first phosphor layer 130a has a higher strength than the layer-matrix resin 135b constituting the second phosphor layer 130b, so that the phosphor layer 130 can stably maintain its shape. In addition, the layer-two matrix resin 135b constituting the second fluorescent layer 130b is formed to have a higher adhesive force than the layer-one matrix resin 135a of the first fluorescent layer 130a, thereby being easily adhered to the light emitting element 20. Either one of the first phosphor layer 130a or the second phosphor layer 130b may be composed of a transparent layer. Specifically, as shown in fig. 2 (b), the first fluorescent layer 130a forms a transparent layer that does not contain fluorescent particles 132, and only the second fluorescent layer 130b may contain fluorescent particles 132. In addition, as shown in fig. 2 (c), only the first fluorescent layer 130a contains fluorescent particles 132, and the second fluorescent layer 130b may not contain fluorescent particles 132.

The shape of the cover film 150 is matched with the shape of the base film 110, or the shape of the cover film 150 is matched with the shape of the fluorescent layer 130, and the cover film 150 is made of any one of PVC, polyamide, PET, and PI.

Referring to fig. 3 (a) -3 (c), the fluorescent layer 130 is provided with a receiving hole 136, and the base film 110 is provided with a through hole 111 corresponding to the receiving hole 136. The receiving hole 136 may be formed to penetrate the phosphor layer 130 corresponding to the position and structure of the electrode 21 of the light emitting element 20. Thereby, even if the fluorescent layer 130 is placed on the light emitting element 20 during the encapsulation process, the electrode 21 of the light emitting element 20 is accommodated in the accommodation hole 136 and is not covered by the fluorescent layer 130 to be exposed to the outside. Thereafter, the electric wire can be stably combined with the electric wire, and thus, the possibility of deformation of the electric wire during the packaging process can be avoided. As shown in fig. 3, when the accommodation hole 136 is provided in the fluorescent layer 130, the through hole 111 corresponding to the accommodation hole 136 is provided in the base film 110, so that a structure penetrating the fluorescent film a100' as a whole can be formed. In fig. 3, one electrode 21 is illustrated as being formed on the light emitting element 20, but the electrode structure is not limited thereto, and a plurality of electrodes 21 may be provided, in which case the receiving hole 136 may be formed corresponding to the plurality of electrodes 21. The receiving hole 136 and the through hole 111 may be formed by punching or laser irradiation, or may be formed by etching. Here, the light emitting element 20 includes an LED chip including a semiconductor layer and an active layer, and at least one electrode 21 may be provided on the upper surface of the light emitting element 20.

The phosphor layer 130 may also be added with further spacers (not shown). When the phosphor layer 130 is coated onto the target material, the spacer may help maintain the coating thickness, and the thickness of the spacer may be the same size as the thickness to be coated. The spacer content in the phosphor layer 130 is preferably not more than 1% by mass based on the total mass of the phosphor layer. In order to prevent the deterioration of the light characteristics, the spacer may be made of an inorganic or organic material having excellent light transmittance. Alternatively, when light is to be reflected on the surface of the spacer, an inorganic or organic material whose surface is coated with a reflective layer having a high light reflectance may be used.

Fig. 4 shows a structure of a fluorescent film 200 according to another embodiment of the present invention. The second fluorescent film 200 of the present embodiment has a structure in which the fluorescent layer 130 is cut in advance with a predetermined specification. That is, the fluorescent layer 130 is composed of a plurality of fluorescent sheets 131 having a predetermined size and spaced apart at predetermined intervals. Also, each of the fluorescent sheets 131 constituting the fluorescent layer 130 may be composed of a single layer, or may be stacked in a plurality of layers as shown in fig. 2. The cover film 150 is composed of a plurality of cover films 151 having a size corresponding to the fluorescent sheet 131. The size of the fluorescent sheets 131 or the interval between them is determined according to the object to which the fluorescent sheets 131 are required to be coated, for example, when a plurality of light emitting elements are applied to the arranged substrate, it may be determined according to the size of the light emitting elements and the interval of the arrangement. The plurality of fluorescent sheets 131 may be arranged in one direction or two dimensions. Although not shown, the plurality of fluorescent sheets 131 may be formed with receiving holes 136 as shown in fig. 3 (a) corresponding to positions of electrodes provided in the light emitting element, respectively.

Fig. 5 shows an example of how the second phosphor film 200 shown in fig. 4 is stored. In this embodiment, the second fluorescent film 200 is in a strip shape, and is easy to store in a roll (reel) form, and referring to fig. 5, the second fluorescent film 200 of this embodiment is stored and stored by the supply reel RE. At room temperature, the fluorescent sheets 131 are stored in this form, and when in use, a desired number of fluorescent sheets 131 are heated and coated with a target substance. Although the fluorescent sheets 131 are shown to be one-dimensionally arranged on the fluorescent film two 200, this is exemplary and not limited thereto.

Fig. 6 shows the structure of a phosphor film III 300 according to another embodiment of the present invention. The fluorescent layer 130 of the fluorescent film three 300 of the present embodiment is composed of a plurality of fluorescent sheets 131 having a predetermined size and spaced apart at predetermined intervals, and the cover film 150 is composed of one integral film covering the plurality of fluorescent sheets 131, which is different from the embodiment shown in fig. 4. The phosphor sheets 131 may be arranged in one dimension or in two dimensions in this embodiment. The fluorescent film 300 of the present embodiment may be stored in a roll form as shown in fig. 5, and the cover film 150 may be separated from the fluorescent layer 130 when in use. Also, although not illustrated, the plurality of fluorescent sheets 131 may be composed of a plurality of layers as illustrated in fig. 2, and each of the fluorescent sheets 131 may be formed with receiving holes 136 as illustrated in fig. 3 corresponding to positions of electrodes provided in the light emitting element, respectively.

Fig. 7 shows a structure of a fluorescent film 400 according to another embodiment of the present invention. In the present embodiment, the base film 110, the fluorescent layer 130, and the cover film 150 are each composed of one integral film. The fluorescent film 400 may have a band shape, and may have a shape that is easy to store around a reel, as shown in fig. 5. Also, the phosphor layer 130 may be composed of a plurality of layers as shown in fig. 2, and the receiving holes 136 as shown in fig. 3 may be formed on the phosphor layer 130 corresponding to the positions of the electrodes provided in the respective light emitting elements according to the positions of the LED chips and the arrangement intervals. In addition, in use, the cover film 150 is separated from the fluorescent layer 130.

Fig. 8 (a) schematically shows the structure of a fluorescent film five 500 according to another embodiment of the present invention. In the present embodiment, the fluorescent film five 500 has a shape corresponding to the wafer W as a whole so as to be uniformly covered in a state of the wafer W before the plurality of light emitting elements 20 grown on the wafer W by the CVD apparatus or the like are each cut. In addition, a plurality of accommodating holes 136 may be provided in accordance with the arrangement intervals of the plurality of light emitting elements 20 arranged on the wafer W, respectively, corresponding to the positions of the electrodes 21 on the respective light emitting elements 20. Also, the phosphor layer 130 may be composed of a plurality of layers as shown in fig. 2, and through holes 111 corresponding to the receiving holes 136 formed in the phosphor layer 130 may be formed in the base film 110, respectively, and if a cover film 150 is provided, the cover film 150 may be used separately from the phosphor layer 130.

Preparation example 3

Referring to fig. 9 (a) -9 (e), a method for preparing a fluorescent film 200 according to an embodiment of the present invention shown in fig. 4 is described, which specifically includes the following steps:

first, a base film 110 is prepared, a fluorescent layer 130 is formed on the base film 110, and a cap film 150 is formed on the fluorescent layer 130, see fig. 9 (a) -9 (b).

Cutting the fluorescent layer 130 and the cover film 150 into blocks of a predetermined size; specifically, the fluorescent layer 130 is cut along a plurality of first cutting lines L1, which are unidirectionally arranged on the fluorescent layer 130 and the cover film 150, and then cut along a second cutting line L2, which is perpendicular to the first cutting lines L1 and cuts the base film 110, the fluorescent layer 130, and the cover film 150 in a stripe shape, see fig. 9 (b) -9 (c).

Step three, referring to fig. 9 (d), the strip-shaped base film 110 is stretched in the length direction to obtain a fluorescent film, and as shown in fig. 9 (e), the fluorescent layer 130 of the fluorescent film two 200 is divided into a plurality of fluorescent sheets 131, and the cover film 150 is also divided into a plurality of cover films 151. As shown in fig. 5, the prepared fluorescent film two 200 can be easily stored in a roll form.

Preparation example 4

Referring to fig. 9 (a), 10 (b) -10 (f), a method for preparing a fluorescent film III 300 according to an embodiment of the present invention shown in fig. 6 is described, which specifically includes the following steps:

step one, first, a base film 110 is prepared, and a fluorescent layer 130 is formed on the base film 110, see fig. 9 (a).

Step two, referring to fig. 10 (b), the fluorescent layer 130 is cut along a plurality of first cutting lines L1 which are unidirectionally arranged on the fluorescent layer 130.

Step three, as shown in fig. 10 (c), the base film 110 is stretched in the left-right direction, and as shown in fig. 10 (d), the fluorescent layer 130 of the fluorescent film two 200 is divided into a plurality of areas by the first cutting line L1.

In the fourth step, as shown in fig. 10 e, a cap film 150 is formed on the fluorescent layer 130, and a temporary adhesive layer (not shown) may be further formed on the surface where the cap film 150 is bonded to the fluorescent layer 130.

Step five, as shown in fig. 10 (f), the second dicing line L2 perpendicular to the first dicing line L1 is further cut, and the second dicing line cuts the base film 110, the fluorescent layer 130, and the cover film 150 in a stripe shape, so as to prepare a fluorescent film three 300 shown in fig. 6. As shown in fig. 5, the prepared phosphor film three 300 can be easily stored in a roll form.

Preparation example 5

Referring to fig. 11 (a) -11 (e), another preparation method of the fluorescent film three 300 according to the embodiment of the present invention shown in fig. 6 is described, which specifically includes the following steps:

step one, see 11 (a), preparing a base film 110, and providing a mask M with a plurality of holes on the base film 110, wherein the size and the interval of the plurality of holes of the mask M are determined according to the size and the interval of fluorescent sheets to be manufactured;

step two, as shown in fig. 11 (b), by printing the matrix resin paste 130' mixed with fluorescent particles in a plurality of holes of the mask M, a fluorescent layer 130 having a plurality of fluorescent sheets 131 is formed in the plurality of holes of the mask M, and as shown in fig. 11 (c), the formation of a single-layer fluorescent layer 130 by printing is shown in fig. 11 (c), but not limited thereto, and a fluorescent layer 130 of a multi-layer structure may be formed as shown in fig. 2;

step three, as shown in fig. 11 (d), cutting the structure shown in fig. 11 (c) into strips;

step four, as shown in fig. 11 (e), a cap film 150 is formed on the fluorescent layer 130. As shown in fig. 5, the prepared phosphor film three 300 may be stored in a roll type.

In the preparation process of the third fluorescent film 300, the sequence of the third step and the fourth step may be adjusted, for example, the sixth fluorescent film 600 shown in fig. 12 may be formed by forming the cover film 150 on the fluorescent layer 130 with the structure shown in fig. 11 (c), and then cutting the cover film into strips.

3. Method for coating fluorescent film

Example 1

Taking the second fluorescent film 200 as shown in fig. 9 (e) as an example, wherein the second fluorescent film 200 is prepared by adopting the fluorescent layer of preparation example 1 and the fluorescent film preparation method of preparation example 3, the invention provides a coating method of a fluorescent film, which specifically comprises the following steps:

step one, outputting a fluorescent film II 200 through a supply reel I RE1, uncovering a cover film 150 on a fluorescent layer 130, and respectively placing a pick-up head H and a push pin PP on the upper side and the lower side of the fluorescent film;

referring to fig. 13 (a), a schematic diagram of a coating process of a fluorescent film 200 of the present embodiment is provided, in which a supply reel RE1 for supplying the fluorescent film 200, a base film 110, a pick-up head H for picking up a fluorescent sheet 131 and a cover film 151, a push pin PP, and a recovery reel RE2 of the base film 110 are arranged. In addition, if a temporary adhesive layer is formed between the base film 110 and the fluorescent sheet 131, ultraviolet light irradiation may be used to weaken the adhesion before proceeding to the subsequent step.

Step two, referring to fig. 13 (b), the push pins PP press the base film 110 from the bottom up, and the pick-up head H picks up the fluorescent layer 130 and the cover film 150;

a gripper C contacting the object is mounted on the pickup head H, a plurality of vacuum micro tubes (not shown) may be formed on the surface of the gripper C, and the object may be picked up by the vacuum micro tubes formed on the pickup head H, and the gripper C may be made of rubber, metal, heat-resistant engineering plastic, or the like.

Step three, referring to fig. 13 (c), placing the substrate 10 to be coated with the light emitting element 20 wire-bonded on the heating stage S, and placing the fluorescent layer 130 above the light emitting element 20 by the pick-up head H;

step four, the heating platform S heats, the fluorescent layer 130 and the cover film 150 on the fluorescent layer 130 approach the light emitting element, the temperature is raised by the heating platform S, the fluorescent layer 130 generates fluidity, as shown in fig. 13 (d), the fluorescent layer 130 flows to the upper surface of the light emitting element 20, and the periphery of the light emitting element 20 is coated;

and fifthly, recovering the residual base film through a recovery reel.

Fig. 14 (a) and 14 (b) show example structures of different embodiments of a clip C mounted on a pickup H, which clip C can be used in embodiment 1 described above. In embodiment 1, the clip C may be a flat type, or a cavity type similar to that of fig. 14 (a) and 14 (b) may be used. Such a cavity functions as a frame to maintain a constant shape when picking up the cover membrane 151 and the phosphor sheet 131. The depth of the cavity is greater than the thickness of the cover membrane 151, and may be less than the sum of the thicknesses of the cover membrane 151 and the phosphor sheet 131. The inner wall of the cavity may be inclined at a right angle as shown in fig. 14 (a) or at an obtuse angle as shown in fig. 14 (b).

Referring to fig. 19 (a), the fluorescent sheet 131 of the present embodiment may also be directly heated by the pickup head H or indirectly heated by the heating stage S of the main body part 2 to which the light emitting element 20 is mounted, thereby generating fluidity, and falls off from the cover film 151 by its own weight to flow onto the light emitting element 20, coating the light emitting element 20 including an electric wire.

Referring to fig. 19 (b), the fluorescent layer 130 formed on the light emitting element 20 by the fluorescent sheet 131 is coated along the shape of the wire, having a shape corresponding to the shape of the wire. In the light emitting element package shown in fig. 19 (b), two electrodes are provided on the upper surface of the light emitting element 20, so that a structure connected to two wires is shown, but the number of electrodes and wires may be changed in various ways. A sealing portion (not shown) may be formed on the main body 2 to cover and protect the light emitting element 20 including the fluorescent layer 130.

Example 2

Taking the third fluorescent film 300 shown in fig. 6 as an example, referring to fig. 15, wherein the third fluorescent film 300 is prepared by adopting the fluorescent layer of preparation example 2 and the fluorescent film preparation method of preparation example 4, the invention provides a method for coating a fluorescent film, which adopts a mode of directly applying pressure, and specifically comprises the following steps:

in step one, the fluorescent film three 300 is supplied from the supply spool one RE1, and the cover film 150 is first detached, and the fluorescent film three 300 is arranged such that the fluorescent sheet 131 faces the light emitting element 20.

Step two, the substrate 10 to which the light emitting element 20 is wire-bonded is set on the heating stage S, and pressure is applied to the back surface of the base film 110 on which the fluorescent sheet 131 is placed by the pressing head PR.

In the fourth step, as the fluorescent sheet 131 approaches the light emitting element 20, the heat causes fluidity of the fluorescent sheet 131, the fluorescent sheet 131 flows to the upper surface of the light emitting element 20, the periphery of the light emitting element 20 is coated, and the base film 110 after the fluorescent sheet 131 is recovered by the recovery reel RE2.

Referring to fig. 16 (a) and 16 (b), in the present embodiment, a plurality of fluorescent sheets 131 may be simultaneously coated on a plurality of light emitting elements 20 by using a pressing head PR of a larger size, and a fluorescent film three 300 may be provided and recovered in the same manner as in fig. 15. Alternatively, the third fluorescent film 300 may be arranged in accordance with the shape of the light emitting element 20, and the cover film 150 may be peeled off from the third fluorescent film 300 and used.

Referring to fig. 17, in the present embodiment, a pressing roller RL may be used instead of the pressing head PR as shown in fig. 15 and 16 (a), and a manner of applying pressure to the back surface of the base film 110 is sequentially performed by the pressing roller RL, thereby sequentially coating a plurality of fluorescent sheets 131 on a plurality of light emitting elements 20 at the same time, and a fluorescent film three 300 may be provided and recovered in the same manner as in fig. 15. Alternatively, the third fluorescent film 300 may be arranged in accordance with the shape of the light emitting element 20, and the cover film 150 may be peeled off from the third fluorescent film 300 and used.

Example 3

Taking the fluorescent film four 400 shown in fig. 7 as an example, referring to fig. 18, unlike embodiment 2, coating of the plurality of light emitting elements 20 may be performed by using a pressing roller RL and pressing, and in this embodiment, the fluorescent layer 130 uses the fluorescent film four 400 shown in fig. 7, and the cover film 150 of the fluorescent film four 400 is removed before coating. The fluorescent layer 130 is applied so as to surround the entire plurality of light emitting elements 20, and then cut for each light emitting element 20. In this embodiment, the light-emitting elements 20 may be coated around the light-emitting elements at one time by directly applying pressure, and the other steps are the same as those in embodiment 2, and will not be described again.

In the above description of the fluorescent layer coating method, the light emitting element wire-bonded to the substrate is described as an example, but the present invention is not limited thereto, and the technical solution of the present invention is applicable to all types of light emitting elements of array type and flip chip type for PCB or COB application.

A light emitting element package was coated with a commercially available fluorescent film (conventional dispensing process) as comparative example 1, and the comparative example 1 was compared with the performance data of the light emitting element coated in example 1, and the results are shown in the following tables 1-2.

TABLE 1 production efficiency and cost comparison

Table 2 optical performance test data for example 1 and comparative example 1

Sample of	Test conditions: identical to	IF(mA)	VF(V)	P(mW)	Φ(lm)	Light effect (lm/W)
							Example 1	0	120	3.03	363.6	71.39	196.3
Comparative example 1	0	120	3.03	363.6	66.16	182

Because the whole process flow of the embodiment 1 is in seamless connection, the automation is high, the structure is simple, and the steps of dispensing, bonding wires and baking in the traditional process of the comparative example 1 are omitted, so that the production time is shortened to half of the previous time. On the premise of not changing the number of production equipment at present, the production efficiency can be doubled, and the improvement of the production efficiency and the BIN entering rate can indirectly reduce the production cost by 30 percent.

Fig. 20 (c) to 20 (e) and 21 schematically illustrate structural diagrams of the light emitting element after coating according to other embodiments of the present invention.

Fig. 20 (c) shows a stage of coating the fluorescent film five 500 on the light emitting element 20. The phosphor film five 500 is coated on the light emitting elements 20 so that each of the accommodation holes 136 and the electrodes 21 of each of the light emitting elements 20 coincide with each other. Then, as shown in fig. 20 (d), the base film 110 is removed, the fluorescent layer 130 is made flowable by heating, and the fluorescent layer 130 that generates fluidity flows around the light emitting element 20 except for the electrode 21, so that at least a part of the upper surface and the side surface of the light emitting element 20 is covered with the fluorescent layer 130.

As described above, the fluorescent layers 130 are coated together on the plurality of light emitting elements 20, and then cut into individual light emitting elements 20 coated with the fluorescent layers 130 by a dicing process, as shown in fig. 20 (e).

Fig. 21 shows a light-emitting element device 1' on which the light-emitting element 20 is mounted. Each of the light emitting elements 20 separated in fig. 20 (e) is mounted on the lead frame 3 of the main body part 2, and the electrode 21 of the non-coated fluorescent layer 130 is electrically connected to the lead frame 3 through the lead 4. In addition, the light emitting element 20 and the lead 4 are manufactured into a light emitting element device 1' by a packaging process sealed by the sealing portion 5.

The technical proposal of the invention is adopted to coat the fluorescent layer of the light-emitting element, and the lead-bonded light-emitting element is not required to be physically pressed, thus the possibility of deformation in the lead can be fundamentally eliminated, and the invention has the advantage of improving the reliability of the light-emitting element. Since the fluorescent layer is formed to cover the upper surface and the side surface of the light emitting element, the occurrence of the light leakage phenomenon can be effectively prevented, thereby improving the light extraction efficiency. Since the fluorescent layer is manufactured and coated in the form of a film of a certain thickness, there is an advantage in that thickness deviation is reduced and dispersion distribution between products is reduced as a whole.

The foregoing description of the preferred embodiments of the invention is not intended to limit the invention to the precise form disclosed, and any such modifications, equivalents, and alternatives falling within the spirit and scope of the invention are intended to be included within the scope of the invention.

Claims (10)

1. The fluorescent film is characterized by comprising a base film and a fluorescent layer, wherein the fluorescent layer is arranged on the base film, and the tensile modulus of the fluorescent layer is more than 100Mpa and less than 500Mpa in the temperature range of 0-25 ℃; the tensile modulus of the fluorescent layer is more than 0.5Mpa and less than 3Mpa in the temperature range of 60-80 ℃; the tensile modulus of the fluorescent layer is less than 0.5Mpa in the temperature range of more than 80 ℃.

2. The phosphor film of claim 1, wherein said phosphor layer comprises phosphor particles and a matrix resin, said matrix resin being a single layer, a double layer or a plurality of layers, said phosphor particles being uniformly distributed within at least one layer of said matrix resin.

3. The phosphor film according to claim 2, wherein when the number of layers of the matrix resin is greater than 1, the matrix resins of adjacent layers have different viscosities and/or mechanical strengths.

4. The phosphor film according to claim 2, wherein the phosphor layer has a shape matching the shape of the base film, or the phosphor layer is formed by uniformly arranging a plurality of phosphor plates on the base film.

5. The phosphor film according to claim 2, wherein the matrix resin has a structure represented by the following general formula I:

wherein n is 1-20;

r1 is selected from any one of amino, c=c, epoxy, hydrazine, diazo, azido, c=c with aromatic amine, c=c with aromatic group, glycidyl ether with aromatic group, glycidyl ester with aromatic group;

r2 is selected from any one of hydrogen atom, alkyl with 1-6 carbon atoms, alkyl with 6-15 carbon atoms and aryl, and the same group as R1.

6. The fluorescent film according to claim 4, wherein the base film is made of any one of PVC, polyamide fluoride, PET, and PI.

7. The fluorescent film according to claim 4, wherein a cover film is further provided on the fluorescent layer, the shape of the cover film is matched with the shape of the base film, or the shape of the cover film is matched with the shape of the fluorescent layer, and the cover film is made of any one of PVC, polyamide, PET and PI.

8. The fluorescent film of claim 4, wherein the fluorescent layer is provided with a receiving hole, and the base film is provided with a through hole corresponding to the receiving hole.

9. A method of coating a fluorescent film according to any one of claims 1 to 8, comprising the steps of:

outputting the fluorescent film through a supply scroll, and respectively placing a pickup head and a push rod on the upper side and the lower side of the fluorescent film;

step two, the pushing rod presses the base film from bottom to top, and the pickup head picks up the fluorescent layer;

step three, placing the luminous element to be coated on a heating platform, and placing a fluorescent layer above the luminous element by a pickup head;

heating by a heating platform, wherein the fluorescent layer is close to the light-emitting element, the temperature of the fluorescent layer is increased to generate fluidity, the fluorescent layer flows to the upper surface of the light-emitting element, and the periphery of the light-emitting element is coated;

and fifthly, recovering the residual base film through a recovery reel.

10. A method of coating a fluorescent film according to any one of claims 1 to 8, comprising the steps of:

step one, placing a light-emitting element to be coated on a heating platform, and placing a fluorescent film above the light-emitting element;

step two, placing the fluorescent layer towards the light-emitting element;

a press roller is arranged above the fluorescent film, and pressure is sequentially applied to the back surface of the base film through the press roller;

and step four, heating by a heating platform, increasing the temperature to generate fluidity of the fluorescent layer, enabling the fluorescent layer to flow to the upper surface of the light-emitting element, and coating the periphery of the light-emitting element.