Method for producing article with functional coating, and corresponding article

Abstract

The invention relates to a method for producing an article with a functional coating and a corresponding article. The method comprises the steps of: (i) providing a three-dimensional body of the article on a substrate; and (ii) forming, as at least a part of the functional coating, a dam at least partially covering the side or side of the three-dimensional body and having a predetermined height and thickness on the periphery of the three-dimensional body by using a first functional material on the substrate.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing an article with a functional coating and the corresponding article, and is particularly applicable to the field of semiconductor component or printed circuit board assembly (PCBA) packaging. Background Art

[0002] Semiconductor components (such as integrated circuits / IC chips) or printed circuit board assemblies (PCBAs) widely require electromagnetic interference (EMI) shielding or thermal conductivity, and inkjet printing or spraying is a feasible method to provide EMI shielding or thermal conductivity functions on the surface of semiconductor components or PCBAs (including the top and side surfaces of their three-dimensional substrates).

[0003] EMI / thermal functional coatings (generally referred to as functional coatings or coatings) need to have a minimum thickness to ensure functional properties, especially on the sides of three-dimensional substrates. However, in the prior art, inkjet printing and spraying must sacrifice a lot of UPH (units per hour) production efficiency to achieve the minimum thickness of the functional coating on the side, because the jet head (print head or spray head) must be rotated to a specific angle for side coating. At the same time, since the coating cannot be cured in a short time, the coating liquid will flow from the top to the bottom of the side under the action of gravity, resulting in poor uniformity on the side after complete curing. In order to achieve better uniformity, the inkjet print head or nozzle must spray more time and accurately calculate the spray amount so that multiple sprays can offset the influence of gravity, thereby ultimately obtaining a better balance between uniformity and minimum thickness of the side. This requires a lot of complex control system software, a lot of pre-coating preparation work and a high-cost mechanical system. At the same time, since multiple coatings must be performed on the side, the UPH production efficiency will definitely be affected. Summary of the invention

[0004] The present invention aims to overcome at least one of the above-mentioned defects and / or other problems existing in the prior art, and in particular to provide a method for improving the side coating efficiency of a three-dimensional object while ensuring the minimum thickness and uniformity of the functional coating on the side of the three-dimensional object.

[0005] According to one aspect of the present invention, a method for manufacturing an article with a functional coating is provided, comprising the following steps: (i) providing a three-dimensional body of the article on a substrate; and (ii) forming a dam having a predetermined height and thickness on the substrate at the periphery of the three-dimensional body using a first functional material as at least a part of the functional coating, the dam at least partially covering the side or side of the three-dimensional body.

[0006] "Dam" is widely used in the field of semiconductor or PCBA packaging. It is usually a continuum built by adhesive material by dispensing around multiple electronic components on the printed circuit board of PCBA, for example, or another specially set fixed structure, which is used to provide a space around the electronic components, in which liquids such as insulating materials can be poured, so that the dam can contain and control the movement of the internal liquid to prevent the internal liquid from flowing out of the area surrounded by the dam. However, the existing dam will be removed after the internal liquid is completely solidified. The present invention creatively conceives to use the dam itself as a functional coating on the side of a three-dimensional object to provide functions such as EMI shielding or thermal conductivity or magnetic noise shielding. Compared with the method of printing or spraying a functional coating on the side of a three-dimensional object in the prior art, the use of a dam as a functional coating can ensure the minimum thickness and uniformity of the coating on the side of the object, while greatly improving the generation efficiency of the functional coating on the side of the object.

[0007] According to an exemplary configuration, the first functional material includes a conductive material or a thermal conductive material or a magnetic noise shielding material (such as a magnetic material), such as a conductive paste (such as solder paste), a conductive adhesive, a magnetic powder (such as nickel powder) slurry or a metal frame. Thus, the article can be provided with functions such as EMI shielding or thermal conductivity or magnetic noise shielding.

[0008] According to an exemplary configuration, in the step (ii), the dam is formed by using the first functional material through dispensing, injection molding or electroplating. These methods can form the dam reliably and conveniently.

[0009] According to an exemplary embodiment, the dam has a thickness of at least 200 micrometers. The material and method of forming the dam can ensure the minimum thickness and uniformity of the functional coating formed thereby, and can flexibly and quickly adjust the coating thickness to a greater thickness than in the prior art.

[0010] According to an exemplary configuration, the method further comprises the following steps: (iii) applying a second functional material, especially a conductive material or a thermal conductive material or a magnetic noise shielding material, such as a conductive ink, preferably a MOD ink (metal-organic decomposition ink), to the top or top surface of the three-dimensional body, for example, by inkjet printing, spraying, spin coating, or dipping, and curing the applied second functional material, for example, by UV (ultraviolet) irradiation and / or heating, to form at least another part of the functional coating. In this way, in addition to forming the functional coating on the side of the three-dimensional object by using the dam, the functional coating can also be formed on the top surface of the three-dimensional object by conventional means.

[0011] According to an exemplary configuration, in the step (iii), the second functional material applied at least partially covers the top of the dam so that the functional coating part formed by the first functional material and the functional coating part formed by the second functional material are interconnected, especially electrically connected. By interconnecting the functional coatings on the side and top surfaces of the three-dimensional object to form a whole, the functional coating can be kept structurally intact and functionally complete as a whole.

[0012] According to an exemplary configuration, the thickness of the functional coating portion formed of the second functional material is 50 to 3500 nanometers.

[0013] According to an exemplary configuration, the three-dimensional body of the article comprises an electronic component or a collection of multiple electronic components located on the substrate, the substrate is preferably a printed circuit board, and the dam is formed on the printed circuit board. The method according to the present invention is particularly suitable for selectively functionally encapsulating any electronic component on a PCBA.

[0014] According to an exemplary configuration, the method further includes: pouring at least one filling material within the dam to encapsulate the electronic components surrounded by the dam and achieve one or more functions, such as providing insulation or reworkability. The filling material can be, for example, at least one material that achieves at least one function, such as insulation or reworkable insulation or thermal conductivity, by a single material or a combination of multiple materials. The dam used as a functional coating in the present invention can still be used to contain and control the flow of internal liquid like a normal dam, thereby facilitating the use of filling materials to encapsulate the electronic components on the PCBA.

[0015] According to an exemplary configuration, the three-dimensional body of the article includes a semiconductor chip or a microwave filter. The method according to the present invention is also applicable to EMI shielding or thermal conductive packaging of a single semiconductor chip, and can also be extended to functional packaging of any other article with irregular surfaces.

[0016] According to an exemplary configuration, in step (ii), the dam is formed adjacent to the side surface of the semiconductor chip or microwave filter. This dam formation method is particularly conducive to heat dissipation from the side surface of the object concerned.

[0017] Another aspect of the present invention provides an article with a functional coating produced by a method according to any one of the above-mentioned methods, the article comprising: a three-dimensional body located on a substrate; and a dam on the substrate at least partially covering the side or side of the three-dimensional body at the periphery of the three-dimensional body and having a predetermined height and thickness, the dam being formed of a first functional material to serve as at least a part of the functional coating.

[0018] Another aspect of the present invention provides an article with a functional coating, comprising: a three-dimensional body located on a substrate; and a dam on the substrate at the periphery of the three-dimensional body at least partially covering the side or side of the three-dimensional body and having a predetermined height and thickness, the dam being formed by a first functional material to constitute at least a part of the functional coating, the first functional material comprising a conductive material or a thermally conductive material or a magnetic noise shielding material, such as a conductive paste (such as solder paste), a conductive glue, a magnetic powder (such as nickel powder) slurry or a metal frame, and the dam having a thickness of at least 200 microns.

[0019] According to an exemplary configuration, the article also includes: a coating covering the top or top surface of the three-dimensional body, the coating being formed by a second functional material to constitute at least another part of the functional coating, the second functional material including a conductive material or a thermally conductive material or a magnetic noise shielding material, and the thickness of the coating being 50 to 3500 nanometers.

[0020] According to an exemplary configuration, the article includes printed circuit board electronic components, semiconductor chips, or microwave filters encapsulated by the functional coating.

[0021] The above-mentioned various articles according to the present invention also have the many technical advantages or effects described above with respect to the method according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be described in detail below by way of exemplary embodiments with reference to the accompanying drawings, in which:

[0023] Figure 1 is a schematic illustration of an embodiment of the method according to the present invention.

[0024] Figure 2 yes Figure 1 The illustrated embodiment is a schematic diagram of a PCBA packaging structure.

[0025] Figure 3 is a schematic illustration of another embodiment of the method according to the present invention.

[0026] The accompanying drawings are schematic only and are not necessarily drawn to scale. They only show those parts necessary to illustrate the invention, while other parts may be omitted or only briefly mentioned. In addition to the parts shown in the accompanying drawings, the present invention may also include other parts. DETAILED DESCRIPTION

[0027] Embodiments according to the present invention are described below with reference to the accompanying drawings. In the following description, many specific details are set forth so that those skilled in the art can more fully understand the present invention. However, it is obvious to those skilled in the art that the implementation of the present invention may not have some of these specific details. In addition, it should be understood that the present invention is not limited to the specific embodiments introduced. On the contrary, any combination of the following features and elements may be considered to implement the present invention, regardless of whether they relate to different embodiments. Therefore, the following features, embodiments and advantages are for illustrative purposes only and should not be regarded as elements or limitations of the claims unless clearly stated in the claims.

[0028] Figure 1 Taking the manufacture of PCBA as an example, various steps of an exemplary method according to the present invention are schematically shown. It should be noted that the various steps shown in various embodiments are not necessarily required, but one or more steps may be omitted or the order of related steps may be changed depending on the situation.

[0029] In step 1, a PCBA is provided, which exemplarily includes a printed circuit board 1 as a substrate, an IC chip 3 and another electronic component 2 carried on the printed circuit board 1. Here, the three-dimensional body of the PCBA to be provided with a functional coating includes an assembly of the IC chip 3 and the electronic component 2. In this embodiment, the functional coating to be provided may be, for example, an EMI shielding layer and / or a thermal conductive layer and / or a magnetic noise shielding layer.

[0030] In step 2, a dam 4 is formed around the three-dimensional body including the IC chip 3 and the electronic component 2 using a first functional material as at least a part of the functional coating to be provided. To this end, the dam 4 can be a functional continuum with a certain height and thickness formed on the printed circuit board 1. The dam 4 at least partially covers the side of the three-dimensional body, or in other words, the dam 4 is located on the side of the IC chip 3 or the electronic component 2, so that when viewed from the side of the IC chip 3 or the electronic component 2, the dam 4 can at least partially cover the IC chip 3 or the electronic component 2. The first functional material forming the dam 4 can include a conductive material or a thermal conductive material or a magnetic noise shielding material, so as to provide EMI shielding or thermal conductive or magnetic noise shielding functions. More specifically, the first functional material can be, for example, a conductive paste (such as solder paste), a conductive glue, a magnetic powder (such as nickel powder) paste or a metal frame. Here, the solder paste is a mixture of a powdered solder and a flux. Solder is essentially a metal alloy consisting of two or more metals, whereas flux is a cream-like material consisting of different chemicals. Preferably, lead-free solder is used.

[0031] The method of forming the dam 4 using the first functional material may include but is not limited to dispensing, injection molding or electroplating. The material and method of forming the dam can ensure that it can efficiently achieve the sufficient minimum thickness required for the functional coating, and the thickness can be formed relatively uniformly. Advantageously, the thickness of the dam 4 can reach at least 200 microns.

[0032] In step 3, the PCBA obtained in step 2 is placed under the irradiation of a UV lamp 8 or in a furnace 9, so as to accelerate the curing of the first functional material forming the dam 4 or improve its curing effect by UV irradiation or heating.

[0033] In step 4, a filling head 5 can be used to fill the space surrounded by the dam 4 around the IC chip 3 and the electronic components 2 with a filling material 6 (the oblique line portion in the figure) so as to encapsulate the IC chip 3 and the electronic components 2. The filling material 6 can be, for example, an insulating material (which can be at least partially a reworkable material), such as an insulating glue, and after the filling material 6 is cured, it can provide insulation, waterproofing and other effects for the IC chip 3 and the electronic components 2. The filling material 6 can also include more than one material, so as to achieve a variety of different functions by changing the order or structure of various materials as needed. Here, the dam 4 also plays the role of accommodating and controlling the flow of internal liquid (filling material) as a general dam. The filling height of the filling material 6 can be flexibly adjusted according to the requirements of the overall thickness of the PCBA, for example, the filling height can be flush with or slightly lower than the height of the chip on the printed circuit board, and such a filling height can minimize the overall thickness of the PCBA. The height of the filling material 6 within the dam 4 can be greater than or equal to the height of the dam 4. In addition, the dam 4 can be formed on the ground wire of the PCBA. Since the thickness of the dam 4 can be flexibly adjusted, combined with the above-mentioned potting and filling method, it can meet the need to completely fill the small gap between the ground wire and the electronic components, making the target packaging area of ​​the PCBA (the area surrounded by the dam 4) more compact.

[0034] In step 5, the PCBA obtained in step 4 is placed under the irradiation of a UV lamp 8 or in a furnace 9, so as to accelerate the curing of the filling material poured into the dam 4 or improve its curing effect by UV irradiation or heating.

[0035] In step 6, a second functional material is applied to the top or top surface of the three-dimensional body of the PCBA to be equipped with a functional coating. At this time, the three-dimensional body includes an IC chip 3 and an electronic component 2 as well as a solidified filling material 6. The second functional material also particularly includes a conductive material or a thermally conductive material or a magnetic noise shielding material, so as to also provide corresponding EMI shielding or thermally conductive or magnetic noise shielding functions. For example, the second functional material can be a conductive ink, preferably a MOD ink. MOD ink has the following advantages: (1) Excellent electrical conductivity and thermal conductivity, which can provide excellent EMI shielding performance and thermal conductivity; (2) Environmentally friendly, does not contain nanoparticles, and minimizes EHS (environment, health, safety) issues; (3) High stability, no precipitation occurs; (4) Can prevent nozzle clogging problems (better than nanoparticle ink); (5) Easy to adjust the viscosity of the ink to adjust the ink jetting properties, and adjust the composition to adjust the sintering temperature. The second functional material can be applied to the top or top surface of the three-dimensional body, for example, by inkjet printing, spraying, spin coating, dip coating, etc., to form another part of the functional coating. In Figure 1 In the embodiment shown, the second functional material is applied by inkjet printing using a print head 7 .

[0036] In step 6, the applied second functional material is advantageously made to at least partially cover the top of the dam 4, so that the functional coating part formed by the first functional material (i.e., the dam 4) and the functional coating part formed by the second functional material are connected to each other, especially electrically connected. By connecting the two functional coatings into a whole in this way, the functional coating can be kept structurally intact and functionally complete as a whole.

[0037] In step 7, the PCBA area obtained in step 6 is subjected to UV irradiation, for example, by a UV lamp 8, so that the functional coating part formed by the second functional material is cured. UV irradiation can completely dry the coating and slow down the sintering of the coating.

[0038] The above steps 6 and 7 can be repeated multiple times, that is, after applying the second functional material once, UV irradiation is performed once, and then the second functional material is applied again and UV irradiation is performed again, and this is repeated multiple times until the thickness of the functional coating part formed by the second functional material reaches its target thickness. For example, the final thickness of the functional coating part formed by the second functional material can be 50 to 3500 nanometers.

[0039] In step 8, the curing effect of the second functional material can be improved or further accelerated by heating, thereby improving the UPH production efficiency. Figure 1 In the illustrated embodiment, the PCBA obtained in step 7 may be placed in a furnace 9 for baking heating.

[0040] The above steps 3, 5, 7 and 8 are optional or replaceable, and other methods known in the art may also be used to solidify the relevant materials.

[0041] Optionally, before applying the second functional material, the top surface of the three-dimensional body may be plasma treated or coated with a primer to improve adhesion to the second functional material.

[0042] Figure 2 yes Figure 1 The PCBA of the embodiment shown is a cross-sectional view after the filling material 6 is poured into the space surrounded by the dam 4 and the second functional material is applied, wherein the electronic components in the space are omitted. The dam 4 formed by the first functional material is erected on the printed circuit board 1 ( Figure 2 4 (not shown), and has a height H and a thickness T when viewed from its cross section. The height H is measured from the upper surface of the printed circuit board 1 (substrate). The thickness T is, for example, above 200 microns, preferably 200 to 300 microns. The functional coating portion 10 formed by the second functional material covers the top of the dam 4 and is connected to the dam 4 as a whole to form a complete functional coating. The thickness of the functional coating portion 10 is, for example, below 20 microns. The first and second functional materials can play a role in EMI shielding or thermal conductivity or magnetic noise shielding, for example, including conductive or thermal conductive or magnetic noise shielding materials. Figure 2 In the case shown in part (a), only a filling material 6 is poured into the space surrounded by the dam 4, which is, for example, an insulating material that can play the role of insulation, anti-peeling and waterproofing, or can also be a reworkable material. Figure 2 In the case shown in part (b) of FIG. 4 , two kinds of filling materials 6a and 6b are poured into the space surrounded by the dam 4, wherein the filling material 6a may be the above-mentioned insulating material, and the filling material 6b may be a reworkable material or may be used to prevent bubbles, etc. The sum of the thicknesses of the filling materials 6a and 6b may be greater than or equal to the height T of the dam 4. As required, more kinds of other filling materials may be poured into the space surrounded by the dam 4, for example, below the filling material 6b, to achieve more functions.

[0043] Figure 3is a schematic diagram of the method according to the present invention applied to a single semiconductor IC chip. In this embodiment, a dam is formed around the side of the IC chip by dispensing, injection molding, spraying, etc. on a substrate (not shown) carrying the IC chip, for example, using a first functional material such as solder paste or conductive glue, and a second functional material such as MOD ink is applied to the top surface of the IC chip by a print head to form another part of the functional coating. The MOD ink layer covers the top of the dam formed by the solder paste or conductive glue so that the two parts of the functional coating are connected to each other. In addition, in this embodiment, the dam is formed adjacent to the side of the IC chip, so that the dam as a part of the functional coating is particularly conducive to the heat dissipation of the IC chip. The above-mentioned semiconductor IC chip may include SoC and SiP chips.

[0044] The method according to the present invention is not limited to EMI shielding or thermal packaging of PCBA or a single semiconductor chip as described above, but can also be extended to functional packaging of any other items with irregular surfaces. For example, irregular items such as microwave filters need to be coated with a uniform conductive and thermal conductive layer on the surface including the side, but it is difficult for ordinary coating methods to provide a uniform coating of sufficient thickness on the side. The present invention is particularly suitable for functional packaging of the side of such items with irregular surfaces.

[0045] The method according to the present invention has achieved significant technical effects compared with the prior art. The following Table 1 shows the effect comparison between the method according to the present invention and the prior art when manufacturing a PCBA with a functional coating:

[0046] Table 1

[0047] Prior art The present invention Uniformity of side covering ≥±25％ Up to ±15% Average thickness of side cladding 350 nm At least 200 microns UPH:PCBA / hour 275 1925

[0048] The method according to the present invention can improve the efficiency of generating the functional coating while ensuring the minimum thickness and uniformity of the functional coating on the side of the three-dimensional object. Compared with the inefficient and uneven coating method of the prior art, the method according to the present invention can conveniently and efficiently generate a functional coating with a target thickness. The method according to the present invention has the following advantages in particular:

[0049] The target material thickness of the side of three-dimensional objects can be adjusted flexibly and quickly;

[0050] Efficient production;

[0051] Reduce the requirements for coating equipment, and two-dimensional (2D) coating equipment can meet the needs;

[0052] Provide better compact design.

[0053] According to the above method of the present invention, an article with a functional coating can be obtained accordingly, which includes a three-dimensional body, and a dam having a predetermined height and thickness at least partially covering the side or side of the three-dimensional body at the periphery of the three-dimensional body, wherein the dam is formed by a first functional material to serve as at least a part of the functional coating. As mentioned above, such a dam can reach a thickness of at least 200 microns, which fully meets the thickness requirements of the side functional coating, and is much thicker than the thickness of the top functional coating of 50 to 3500 nanometers. The three-dimensional articles in the prior art must be subjected to multiple time-consuming and labor-intensive compensatory coatings on the side to achieve a 1:1 thickness ratio between the top functional coating and the side functional coating. In comparison, the three-dimensional article according to the present invention greatly increases the thickness of the side functional coating, and has a high UPH and low cost.

[0054] Although the present invention is disclosed as above with preferred embodiments, the present invention is not limited thereto. Any changes and modifications made by any person skilled in the art without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention, so the protection scope of the present invention should be based on the scope defined by the claims.

Claims

1. A method for manufacturing an article with a functional coating, comprising the following steps: (i) providing a three-dimensional body of the article on a substrate; and (ii) forming a dam having a predetermined height and thickness on the substrate at the periphery of the three-dimensional body using a first functional material as at least a part of the functional coating so as to at least partially cover the side or side surface of the three-dimensional body.

2. The method according to claim 1, wherein: The first functional material includes a conductive material, a thermal conductive material, or a magnetic noise shielding material, such as a conductive paste, a conductive glue, a magnetic powder slurry, or a metal frame.

3. The method according to claim 1 or 2, wherein: In the step (ii), the dam is formed by using the first functional material through dispensing, injection molding or electroplating.

4. The method according to any one of claims 1 to 3, wherein: The dam has a thickness of at least 200 microns.

5. The method according to any one of claims 1 to 4, further comprising the following steps: (iii) applying a second functional material, especially a conductive material or a thermally conductive material or a magnetic noise shielding material, such as a conductive ink, preferably a MOD ink, to the top or top surface of the three-dimensional body, for example by inkjet printing, spraying, spin coating, or dip coating, and curing the applied second functional material, for example by UV irradiation and / or heating, to form at least another part of the functional coating.

6. The method according to claim 5, wherein: In the step (iii), the applied second functional material at least partially covers the top of the dam so that the functional coating portion formed by the first functional material and the functional coating portion formed by the second functional material are connected to each other, especially electrically connected.

7. The method according to claim 5 or 6, wherein: The thickness of the functional coating portion formed of the second functional material is 50 to 3500 nanometers.

8. The method according to any one of claims 1 to 7, wherein: The three-dimensional body of the article comprises an electronic component or a collection of multiple electronic components located on the substrate, and the substrate is preferably a printed circuit board, and the dam is formed on the printed circuit board.

9. The method according to claim 8, further comprising: At least one filling material is poured into the dam to encapsulate the electronic components surrounded by the dam and to achieve one or more functions, such as providing insulation or reworkability.

10. The method according to any one of claims 1 to 7, wherein: The three-dimensional body of the article includes a semiconductor chip or a microwave filter.

11. The method according to claim 10, wherein: In the step (ii), the dam is formed adjacent to a side surface of the semiconductor chip or the microwave filter.

12. An article with a functional coating prepared by the method according to any one of claims 1 to 11, the article comprising: a three-dimensional body located on a substrate; and A dam having a predetermined height and thickness is formed on the substrate and at least partially covers the sides or lateral surfaces of the three-dimensional body at the periphery of the three-dimensional body, wherein the dam is formed of a first functional material to serve as at least a part of the functional coating.

13. An article with a functional coating, comprising: a three-dimensional body located on a substrate; and A dam having a predetermined height and thickness is provided on the substrate and at least partially covers the sides or side surfaces of the three-dimensional body at the periphery of the three-dimensional body, wherein the dam is formed by a first functional material to constitute at least a part of the functional coating, wherein the first functional material comprises a conductive material or a thermally conductive material or a magnetic noise shielding material, such as a conductive paste, a conductive glue, a magnetic powder slurry or a metal frame, and the dam has a thickness of at least 200 microns.

14. The article of claim 13, further comprising: A coating covering the top or top surface of the three-dimensional body, wherein the coating is formed by a second functional material to constitute at least another part of the functional coating, wherein the second functional material includes an electrically conductive material, a thermally conductive material, or a magnetic noise shielding material, and the thickness of the coating is 50 to 3500 nanometers.

15. The article according to claim 13 or 14, wherein The article includes printed circuit board electronic components, semiconductor chips or microwave filters encapsulated by the functional coating.

Images