TWI669207B - Method for bonding heterogeneous materials of semiconductor element - Google Patents

Abstract

The invention provides a method for bonding heterogeneous materials of a semiconductor element. First, a patterned bonding paste is formed on a first substrate, and then the semiconductor element to be bonded with the bonding paste is bonded with the bonding paste to cure the bonding paste. It is easier to form a functional layer obtained by curing the adhesive on the surface of the semiconductor element, and the thickness uniformity of the functional layer can be improved.

Description

Method for bonding heterogeneous materials of semiconductor element

The present invention relates to a bonding method, and more particularly, to a bonding method for heterogeneous materials for semiconductor devices.

It is known that when a functional layer is formed on the top surface of a semiconductor element that is different from the material of the top surface of the semiconductor element, it can generally be formed by means of adhesion, spray coating, dispensing, and the like. However, the adhesive method needs to consider the reliability of the adhesive and it is not easy to produce in batches; the spray method is likely to cause the semiconductor element to contaminate the functional layer material on the surrounding surface in addition to the top surface; and it is formed by dispensing. In the case of a functional layer, since the functional layer needs to have a certain thickness, it may cause the disadvantage of uneven film thickness due to the influence of the cohesion and surface tension of the material. In addition, the problem of material overflow may easily occur. Taking the semiconductor element as a light emitting element and the functional layer containing a wavelength conversion material that can be used to change the light emitting wavelength of the light emitting element as an example, if the film thickness of the functional layer formed on the top surface of the light emitting element is uneven, the light emitting color will be different The problem.

Therefore, an object of the present invention is to provide a method for bonding heterogeneous materials of a semiconductor device.

Then, the method for bonding heterogeneous materials of a semiconductor device according to the present invention includes the following steps.

In step A, a first substrate is prepared.

In step B, a patterned adhesive is formed on the first substrate.

In step C, the surface to be bonded of at least one semiconductor element is bonded to the bonding paste, and the bonding paste is cured to form a functional layer.

The effect of the present invention: firstly forming a patterned adhesive on a first substrate, and then bonding and curing a semiconductor element to be bonded with the adhesive to the adhesive to form a functional layer on the semiconductor element. It is easier to control the thickness uniformity of the functional layer formed on the surface of the semiconductor element.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are represented by the same numbers.

The method for bonding heterogeneous materials of a semiconductor element according to the present invention can be applied to forming a packaging structure on a semiconductor element surface with a functional layer having a material different from that of a junction surface of the semiconductor element. The packaging structure can be determined according to its structure and application. Follow-up process.

Referring to FIGS. 1 and 2, a first embodiment of a method for bonding heterogeneous materials of a semiconductor element according to the present invention takes the semiconductor element as a semi-finished product of a photovoltaic element, and the semi-finished product of the photovoltaic element needs to be subjected to subsequent processes after forming the functional layer as an example. It is explained, however, that the actual implementation of the semiconductor device is not limited to this aspect.

The semi-finished product of the photovoltaic element has a substrate 2, a bottom electrode 41, and an actuation layer 3 formed on the bottom electrode 41. The actuation layer 3 is a semiconductor film structure, and can emit light with a predetermined wavelength after receiving electrical energy. . Since the relevant film structure and material of the semi-finished product of the photovoltaic element are well known to those skilled in the art and are not the focus of the present invention, they will not be described further here.

It should be noted that the aforementioned semi-finished photovoltaic element is only used to illustrate the bonding method of the present invention, and its structure is not particularly limited in practical implementation. For example, the semi-finished photovoltaic element structure may also have a photovoltaic element with a horizontal conduction structure. That is, it is not necessary to have the bottom electrode 41.

The first implementation includes the following steps:

In step 11, a first substrate 100 is prepared.

In detail, the purpose of the first substrate 100 is to form a coating layer, which can be subsequently removed. The first substrate 100 may be selected from substrate materials such as glass, ceramic substrate, or flexible substrate, but is not limited thereto.

Then, step 12 is performed to form a patterned adhesive 101 on the first substrate 100.

In detail, the step 12 is a screen printing method in which a printing adhesive is printed on the surface of the first substrate 100 using a screen having a predetermined pattern, and a pattern is formed on the first substrate 100 with the screen. The patterned adhesive 101 is corresponding to the pattern. Because the bonding glue 101 is formed by screen printing, its film thickness and pattern can be controlled by printing parameters and pattern design of the screen, which can be more precisely controlled and has more variety of pattern changes. In this embodiment, the patterned bonding glue 101 has a plurality of bonding glue blocks 102 arranged in an array and spaced from each other. Wherein, each bonding rubber block 102 may have at least one hollowed-out area according to the needs of practical applications, and each bonding rubber block 102 has a rubber bonding surface 102a for bonding with the first bonding surface 3a of the subsequent semiconductor element. The surface area of the rubber block bonding surface 102a and the first bonding surface 3a of the semiconductor element are substantially the same, or the surface area difference between the two bonding surfaces is not greater than 10%.

Specifically, the printing material includes a main material, and the main material may be selected from light-transmitting organic or inorganic materials. For example, the printing material may be selected from epoxy resin, silicone, or high temperature resistant (> 150 ° C). UV-resistant fluorine-containing polymer materials, etc. In addition, the printing adhesive material may be further added to the main material with other functional additive materials, such as wavelength conversion materials or quantum dot materials, to pattern the pattern. The adhesive 101 may have different characteristics. For example, when the printing adhesive material includes the main material and the wavelength conversion material, and the semiconductor element is a light-emitting component, the patterned bonding adhesive 101 can be subsequently used to change the color of light emitted from the light-emitting component, and when the The printing adhesive material includes the main material and the wavelength conversion material, and when the semiconductor element is a light emitting component, the transmissivity of the bonding adhesive 101 after curing with respect to the converted light wavelength can reach more than 50%.

In addition, it should be noted that the purpose of forming the hollowed-out area in the bonding rubber block 102 is to meet the requirements of subsequent processes. For example, the hollowed-out area can be used to form electrodes or perform electrical connection processes on the semi-finished photovoltaic device. Therefore, If subsequent processes are not required, the hollowed-out area need not be formed.

Then, step 13 is performed, a plurality of semiconductor elements are bonded to the patterned adhesive 101 and the patterned adhesive 101 is cured to form a functional layer 5, and a second layer is formed on the second bonding surface of the semiconductor elements. The substrate 200, wherein the second bonding surface is far from the first bonding surface 3 a, the first substrate 100 and the bonding adhesive 101.

The following details the step 13 and supplements it with reference to FIGS. 2 and 3 at the same time. The step 13 uses a "unit" operation mode to make "a semi-finished photovoltaic element" into a unit, and the semi-finished photovoltaic element may include the at least one actuation layer 3, the bottom electrode 41, and the sub-substrate 2, as described above. When a semi-finished photovoltaic element semi-finished product is selected (not shown), the semi-finished photovoltaic element semi-finished product may include the sub-substrate 2 and the actuation layer 3. The functions of the actuation layer 3, the bottom electrode 41, and the sub-substrate 2 are: Those skilled in the art are familiar and will not repeat them here. The semi-finished products of the photovoltaic elements of the plurality of units are respectively oriented with the first bonding surfaces 3a of the semi-finished products of the bonding elements 102 to the bonding surfaces 102a of the bonding blocks 102, and the bonding blocks 102 are bonded to the semi-finished products of the photovoltaic elements, and then the bonding is performed. The glue 101 is cured to form the functional layer 5, and then the second substrate 200 is formed on the second bonding surfaces of the semiconductor elements. In this embodiment, the second bonding surface of the semi-finished product of the photovoltaic element is the surface 2 a of the sub-substrate 2 away from the first substrate 100.

Hereinafter, referring to FIG. 2 and FIG. 3 for further description. The functional layer 5 has a plurality of curing blocks 51 formed by curing the bonding rubber blocks 102, and each curing block 51 has at least one hollowed-out area 511 corresponding to the hollowed-out area of the bonding rubber block 102. The second substrate 200 is made of a material that can be easily removed, such as a photo-deadhesive tape or a thermal de-adhesive tape. In this embodiment, the second substrate 200 is described by taking a UV tape that can be debonded after being irradiated with UV light as an example.

Then, step 14 is performed, the first substrate 100 is removed, and an upper electrode 42 or a plurality of upper electrodes 42 (not shown) are formed from the hollow area 511 of each of the curing blocks 51.

Specifically, in step 14, the first substrate 100 is removed by mechanical peeling or laser ablation to expose the surface of the functional layer 5. Since the removal of the temporary substrate by mechanical peeling or laser ablation is well known to those skilled in the art, it will not be described in detail.

Then, a conductive material may be formed in the hollowed-out areas 511 of the solidified blocks 51 by screen printing or dispensing. After the conductive material is cured, the conductive materials may be formed in the hollowed-out areas 511 and connected to the active layer 3 respectively. Waiting on the electrode 42 to obtain a plurality of photovoltaic elements.

Finally, step 15 is performed to separate the photovoltaic elements from the second substrate 200.

Specifically, in this embodiment, the second substrate 200 is selected from a photo-debonding tape. Therefore, the step 15 is to irradiate the second substrate 200 with UV light, so that the second substrate 200 is in a region irradiated by UV light. The adhesiveness is lost, and the photovoltaic elements in the area are separated from the second substrate 200 and separated from the second substrate 200, so that a single photovoltaic element having the functional layer 5 formed on the top surface of the operating layer 3 can be obtained.

Referring to FIGS. 4 and 5, a second embodiment of a method for bonding heterogeneous materials of a semiconductor device according to the present invention is substantially the same as the first embodiment, except that the second embodiment is formed in the crystal at step 13. The semi-finished products of the plurality of optoelectronic elements on the circle are directly bonded to the bonding rubber blocks 102. After step 14, step 16 is performed, and step 15 shown in FIG. 1 is not performed.

In detail, the step 13 is to directly use a plurality of photovoltaic elements having the bottom electrode 41 and the active layer 3 formed on a wafer (the wafer is regarded as the second substrate 200) by a semiconductor process. The semi-finished product, the semi-finished products of the optoelectronic elements are bonded with the first bonding surface 3a and the rubber block bonding surface 102a of the bonding rubber blocks 102; in step 16, the second substrate 200 (wafer) is cut by a cutting method, so that The photovoltaic elements are separated from each other, and a single photovoltaic element having the functional layer 5 formed on the top surface of the actuation layer 3 is obtained. It is worth noting that when a semi-finished photovoltaic element semi-finished product is selected (not shown), the bottom electrodes 41 can be omitted.

In addition, it should be noted that when the semiconductor elements of the first embodiment and the second embodiment described above do not need to perform other processes on the surface forming the functional layer 5 afterwards, it is only necessary to execute After the first substrate 100 is removed, the step 15 or step 16 can be performed without forming the upper electrodes 42 again.

A third embodiment of the method for bonding heterogeneous materials according to the present invention is described below with reference to FIGS. 4 and 6. The third embodiment includes steps 71 to 75, and the steps 71 to 75 are similar to the steps 11 to 16 of the second embodiment, respectively, and the same parts are not described herein. The third embodiment is special in that the semi-finished products of the optoelectronic elements in step 73 are not bonded to the bonding rubber blocks 102 in a "unit" operation manner, but a second substrate 200 is first prepared, and The semi-finished photoelectric element is fixed on the surface of the second substrate 200 at a position corresponding to the bonding rubber blocks 102 on the surface of the first substrate 100, and then the second substrate 200 carrying the semi-finished photovoltaic element and the semi-finished product are loaded. The first substrate 100 carrying the bonding rubber blocks 102 is aligned and solidified, or a second substrate 200 is prepared first. A plurality of semi-finished products of the optoelectronic components have been fixed on the surface of the second substrate 200 in advance. The bonding rubber blocks 102 on the surface of the first substrate 100 are formed on the surface of the first substrate 100 at positions corresponding to the semi-finished products of the photovoltaic elements, and then the second substrate 200 carrying the semi-finished products of the photovoltaic elements is loaded. It is aligned with the first substrate 100 on which the bonding rubber blocks 102 are loaded, and is cured.

That is, the third embodiment is different from the second embodiment in that the semi-finished products of photovoltaic elements are not directly formed on the original growth wafer through a semiconductor process, but the semi-finished products of semiconductors are transferred to a The substrate (that is, the second substrate 200) of the growing wafer is then fixed (crystallized) on the semi-finished products of the optoelectronic elements on the second substrate 200 for subsequent steps. In this embodiment, the second substrate 200 can be made of a material different from the original grown wafer and has better heat dissipation properties, such as alumina or aluminum nitride, which can further improve the reliability and efficiency of the photovoltaic elements separated from each other after cutting. For the bonding of heterogeneous materials applied when the semiconductor element pitch (<0.1mm) and the semiconductor element surface area (<0.01mm2) are small, this method can more easily improve the process yield and production efficiency.

In addition, it should be noted that, in some embodiments, when the first substrate 100 is transparent and there is no need to perform other processes on the actuation layer 3 after the functional layer 5 is formed, the bonding rubber blocks 102 and After the semiconductor elements 3 are bonded, it is not necessary to remove the first substrate 100, but the component after the first substrate 100 and the second substrate 200 are combined can be regarded as a module, and the first substrate can be made. 100 serves as a protective layer for protecting the semiconductor elements and the curing block 51. This method corresponds to the bonding of heterogeneous materials when the semiconductor element pitch (<0.1mm) and the semiconductor element surface area (<0.01mm ² ) are small, which can more easily improve the process yield and production efficiency. For example, when the functional layer 5 includes a wavelength conversion material, the transmittance of the first substrate 100 with respect to the converted light wavelength is greater than 50%.

With reference to FIGS. 1, 5, 6, and 7, in some embodiments, steps 12 and 72 may also be performed by multiple screen printing methods, and the first substrate 100 may be printed with different patterns or different patterns. Materials, or patterned adhesive 101 with different combinations. For example, three or more screen printings may be used to form three or more types of printing adhesives that are respectively mixed with wavelength conversion materials that emit different wavelengths, and are formed on the first substrate 100 and formed on the first substrate 100, respectively. Three or more types of bonding rubber blocks 102 having a predetermined pattern distribution and emitting different wavelengths, respectively. In FIG. 7, the bonding rubber blocks 102 which can emit three different wavelengths of red light, green light, and blue light after light color wavelength conversion are arranged in a staggered manner, and the wavelength conversion material can be formed after the wavelength conversion material has different concentrations. Three or more types of white rubber light-emitting adhesive blocks 102 (in Fig. 7, R, G, and B are used to indicate that the adhesive rubber blocks 102 can emit different wavelengths, and W ¹ to W ^{3 are used to} indicate that they can emit white light with different color temperatures) As an example, the bonding rubber block 102) is not limited to this structural aspect in actual implementation. Therefore, taking step 16 of the first embodiment or step 75 of the third embodiment as an example, it can be cut along the gap of each bonding rubber block 102 (such as cutting along the AA and BB lines shown in FIG. 7), The minimum light emitting unit 102b having the functional layer 5 of red (or other light color) is obtained; or, it can be cut along the lines A'-A 'and B'-B' shown in FIG. 7 to form a plurality of different Or a composite light emitting unit 102c composed of the functional layer 5 of the same wavelength conversion material. Among them, the number of the smallest light-emitting units 102b included in each composite light-emitting unit 102c can be determined according to actual needs and applications, and is not limited to the methods disclosed in this figure.

In summary, according to the present invention, the functional layer 5 to be formed on the surface of the semiconductor element and having a different material from the surface is firstly formed with a plurality of bonding rubber blocks 102 on the first substrate 100 by screen printing. The iso-bonding block 102 is formed by screen printing. Therefore, the thickness of the functional layer 5 formed after the bonding-block 102 is subsequently connected to the semiconductor elements and cured is good. When the semiconductor element is a light-emitting element and the functional layer 5 contains a wavelength conversion material, since the overall thickness of the functional layer 5 formed on the surface of the light-emitting element by this method is good, the light-emitting element can be improved. Uniformity of light color finally emitted to the outside. In addition, since the functional layer 5 is obtained after the bonding rubber block 102 is hardened, the pattern of the bonding rubber block 102 can be controlled in advance by the design of the printing screen, and the thickness can also be controlled by the screen printing parameters. Can have better process convenience, so it can indeed achieve the purpose of cost invention.

However, the above are only the preferred embodiments of the present invention. When the scope of implementation of the present invention cannot be limited by this, all simple equivalent changes and modifications made in accordance with the scope of the patent application and the content of the patent specification of the present invention are Still within the scope of the invention patent.

11 ~ 16‧‧‧step

51‧‧‧cured block

71 ~ 75‧‧‧step

511‧‧‧hollow area

2‧‧‧ daughter board

100‧‧‧first substrate

2a‧‧‧ surface

101‧‧‧Adhesive

3‧‧‧action layer

102, R, G, B, W ¹ ~ W ³ ‧‧‧

3a‧‧‧Element first joint surface

102a‧‧‧Plastic block joint surface

41‧‧‧ bottom electrode

102b‧‧‧Minimal light emitting unit

42‧‧‧up electrode

102c‧‧‧ composite light emitting unit

5‧‧‧ functional layer

200‧‧‧ second substrate

Other features and effects of the present invention will be clearly presented in the embodiment with reference to the drawings, wherein: FIG. 1 is a text flow chart illustrating the first embodiment of the present invention; FIG. 2 is a schematic flow chart to assist the explanatory diagram 1; FIG. 3 is a schematic plan view to help explain the bonding block in FIG. 2; FIG. 4 is a text flow chart to explain the second embodiment of the present invention; FIG. 5 is a schematic flow chart to help explain FIG. 4; A flowchart illustrates a third embodiment of the present invention; and FIG. 7 is a schematic plan view illustrating another arrangement of the bonding glue.

Claims (9)

A method for bonding heterogeneous materials of a semiconductor element includes: step A, preparing a first substrate; step B, forming a patterned bonding adhesive on the first substrate; and step C, bonding at least one surface of the semiconductor element to be bonded It is bonded with the bonding glue and cured, so that the bonding glue forms a functional layer, and a second substrate is bonded to a surface of the at least one semiconductor element away from the first substrate, so that the at least one semiconductor element is clamped. It is fixed between the first substrate and the second substrate, wherein the at least one semiconductor element has an actuation layer made of a semiconductor material, the actuation layer can emit light with a predetermined wavelength to the outside after receiving electrical energy, and the bonding adhesive It is bonded to the surface of the actuation layer, and includes a main material and an additive material dispersed in the main material. The main material is selected from light-transmitting organic or inorganic materials, the additive material is a wavelength conversion material, and the material of the glue and the The materials to be joined are different; step D, removing the first substrate; and step E, separating the at least one semiconductor element from the second substrate. The method for bonding heterogeneous materials of a semiconductor device according to claim 1, wherein the step B is to form the patterned adhesive using a screen printing method. The method for bonding heterogeneous materials of a semiconductor device according to claim 1, wherein the first substrate can be selected from glass, alumina, aluminum nitride, or a flexible substrate. The method for bonding heterogeneous materials of a semiconductor device according to claim 1, wherein the step D is to remove the first substrate by mechanical peeling or laser ablation. The method for bonding heterogeneous materials of a semiconductor element according to claim 1, wherein the bonding glue has a plurality of bonding glue blocks spaced apart from each other and arranged in an array, and the step C is to separately separate the plurality of semiconductor elements from the bonding glue. Block junction. The method for bonding heterogeneous materials of a semiconductor device according to claim 5, wherein each bonding rubber block has at least one hollowed-out area on the surface of the semiconductor device correspondingly bonded to the bonding rubber block. According to the method for bonding heterogeneous materials of a semiconductor element according to claim 1, wherein the bonding adhesive has a plurality of bonding rubber blocks, and the wavelength conversion materials of the bonding rubber blocks may be partially different. According to the method of claim 1, the method further includes a step F. The step F is to cut the second substrate to separate the semiconductor elements from each other. According to the method of claim 1, the first substrate is transparent, and the transmittance of the first substrate with respect to the converted light wavelength is greater than 50%.