CN119631578A - Method of forming an electronic component having a conformal coating, electronic component, and film precursor for a conformal coating - Google Patents

Abstract

A method of forming an electronic component having a conformal coating includes providing a component preform including solder paste between a substrate and an electronic component, providing a film in solid form adjacent the component preform, the film including a polymeric material, heating the solder paste to reflow the solder paste to form a solder joint between the substrate and the electronic component, and heating the film adjacent the component preform to adhere the film to the component preform to form a conformal coating at least partially coating the electronic component.

Description

Method of forming an electronic component having a conformal coating, electronic component, and film precursor for a conformal coating

The present invention relates to a method of forming an electronic component having a conformal coating and a film for use as a precursor to the conformal coating of the electronic component.

A conformal coating is a coating that may be formed over a component of an electronic assembly for purposes such as providing a physical layer that protects the assembly from environmental factors such as, for example, humidity, condensation, salt spray, and corrosive gases.

Conventional methods of forming conformal coatings on electronic components include liquid-applied coatings, vacuum-applied materials (such as in batch processes), and two-component coatings (such as foams, UV curable compositions, and Room Temperature Vulcanizing (RTV) silicones).

The most common method of forming conformal coatings on electronic components involves applying a liquid applied coating by dipping, spraying, dispensing, or other methods suitable for controlled application of liquid coatings. Such methods may also involve providing the coating precursor in the form of pellets or rods, and then melting and dispensing the coating precursor onto a substrate or circuit board. Dispensing the melted coating precursor may involve, for example, spraying the melted coating precursor onto the area to be coated. Dipping and brushing techniques are also known. The coating may then be further dried or cured by various methods including the application of heat, the application of radiation, chemical reactions, or simple solvent evaporation.

However, problems with such coating methods may include additional processing time and equipment required to dispense the liquid coating and may result in challenges in terms of coverage and thickness uniformity, insufficient accuracy in coating placement, additional energy input typically required to cure the liquid coated coating, which shortens the life of the coated component in addition to inefficiency, and many materials used for such liquid coated coatings contain hazardous solvents or other components that are released into the environment, thereby posing a threat to the user and environment. Furthermore, additional pre-coating steps may be required, such as cleaning, masking or rubberizing to prevent coating of unwanted surfaces.

For example, US5510138a discloses a similar hot melt conformal coating process. In US5510138a, the conformal coating system is a liquid at the high temperatures at which the coating system is applied to the electronic component. In other words, the hot liquid coating is applied to the substrate at an elevated temperature, wherein the hot liquid coating solidifies upon cooling. Optionally, additional crosslinking mechanisms may be incorporated, which may require additional energy input. Thus, the above outlined drawbacks of additional processing and energy input are applicable.

US2017/0309799A1 relates to a vacuum lamination process for forming a conformally coated article and an associated conformally coated article formed thereby. US 5475379a relates to solid phase conformal coatings suitable for use with electronic devices. WO 95/28822A1 relates to conformal shells and methods of forming the same. US 5102712a relates to a method for conformal coating of printed circuit boards. US 9900988B1 relates to a protection layering method for board EMU shielding and thermal management. US 2018/0211848A1 relates to an electronic product and a method of manufacturing the same. US10568215A relates to PCBA encapsulation by thermoforming. US2003/0193113A1 relates to an apparatus and a method for protecting electronic circuits. US2020/0267844A1 relates to an adhesive circuit patterning method.

Accordingly, there is a need to provide an improved method of forming conformal coatings on electronic components that is more time-efficient and energy-efficient, that is simpler and that preferably reduces the number of process steps.

The present invention seeks to address at least some of the problems associated with the prior art or at least to provide a commercially acceptable alternative solution to the prior art.

The present invention provides a method of forming an electronic component having a conformal coating and a film for use as a precursor to a conformal coating for an electronic component according to the appended claims of the present invention.

In particular, in a first aspect, the present invention provides a method of forming an electronic component having a conformal coating, the method comprising providing a component preform comprising solder paste between a substrate and an electronic component, providing a film in solid form adjacent the component preform, the film comprising a polymeric material, heating the solder paste to reflow the solder paste to form a solder joint between the substrate and the electronic component, and heating the film adjacent the component preform to adhere the film to the component preform to form a conformal coating at least partially coating the electronic component.

Each aspect or embodiment as defined herein may be combined with any other aspect or embodiment unless explicitly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous.

The inventors have surprisingly found that electronic components with conformal coatings can be formed by the methods of the invention. In particular, it has surprisingly been found that a conformal coating can be provided by providing a film in solid form adjacent to a component preform and heating the film adjacent to the component preform to adhere the film to the component preform, thereby forming a conformal coating that at least partially coats an electronic component. Furthermore, it has been found that such a method may exhibit certain advantages over conventional methods of forming conformal coatings.

In particular, such a method can surprisingly avoid the need for additional process steps and equipment requirements (e.g., dispensing, buffering, and curing/drying), utilize existing processes (e.g., reflow profiles), minimize thermal degradation of the parts/components, improve coverage and uniformity of the coating, and also avoid the need for some pre-coating process steps (such as masking or rubberizing to prevent coating of unwanted surfaces). The present invention eliminates the need to dispense material, for example, in liquid form.

Furthermore, advantageously, this method also avoids the use of solvents that may be toxic (since they are not applied in liquid form). This is because the polymer material films handled generally have low toxicity. In addition, placing the film in solid form can be quick and accurate, especially compared to liquid coating methods. This may also eliminate the need for additional steps, as existing equipment and similar processes may be used for the reflow profile.

Such a method may also advantageously eliminate mess and hazardous waste due to disposal of the liquid product, reduce health and safety requirements, save space required for additional equipment (e.g., a hot melt coating applicator), and thus also reduce energy consumption of the overall process.

As used herein, the term "electronic component" may encompass a system or device that includes one or more electronic components that are electronically connected to one another and configured to perform a function. Electronic components are terms of art known. For example, the electronic assembly may include a Printed Circuit Board (PCB) on which one or more electronic components are mounted.

As used herein, the term "conformal coating" may generally encompass a thin layer of polymeric material that may cover an electronic component, which generally conforms to the contours or topography of the electronic component, in order to help physically protect the components and/or substrate of the electronic component from, for example, moisture, dust, chemicals, and/or extreme temperatures. Generally, conformal coatings are well known to the skilled person.

As used herein, the term "component preform" may encompass a precursor of an electronic component, for example wherein one or more electronic components are arranged in their desired positions but wherein solder paste has not reflowed.

As used herein, the term "solder paste" may include, for example, solder powder mixed with flux. Solder pastes are well known to the skilled person and for the purposes of the present invention the type of solder paste used is not particularly limited. Preferably, however, the solder paste is substantially free of rosin or resin, more preferably, the solder paste is free of rosin or resin. Instead of solder paste, it is also possible to use, for example, sintered powder or a solder film.

As used herein, the term "substrate" may encompass any object, such as a PCB, in which electronic components may typically be mounted. The substrate may typically comprise, for example, an electrically insulating plastic material. Suitable substrates are known to the skilled person.

As used herein, the term "electronic component" may encompass any substantially discrete device or physical entity in an electronic system for affecting an electron or its associated field. A non-exhaustive list of electronic components includes, for example, resistors, capacitors, light emitting diodes, transistors, field Effect Transformers (FETs), bottom Termination Components (BTCs), metal Electrode Leadless Faces (MELFs), small Outline Integrated Circuits (SOICs), and Quad Flat Packages (QFP). However, the type of electronic component is not important for the purposes of the present invention.

Solder paste is located between the substrate and the electronic component. However, as the skilled person will appreciate, the solder paste may not merely be located directly between the substrate and the electronic component. For example, solder paste may also be located around the electronic component.

As used herein, the term "film" may encompass a layer or sheet, typically a thin layer or sheet (e.g., about 30 μm to about 1mm (or greater) in thickness). The membrane may be flat, i.e. planar, or more typically have a three-dimensional shape so as to conform to the contour of the component on which the membrane is placed. The film is in solid form and can substantially retain its shape at room temperature (such as at about 20 ℃). However, the membrane may also be flexible. Preferably, the film consists essentially of, or more preferably consists of, a polymeric material. As used herein, the term "consisting essentially of" may encompass that additional specific components may be present, i.e., those components that do not substantially affect the basic properties of the film.

For example, providing the film in solid form near the component preform may include providing the film in solid form at or near the intended location of the conformal coating to be formed. For example, the film may be disposed opposite (and facing) the face of the substrate on which the electronic components are disposed, and preferably substantially parallel, more preferably parallel, to the face of the substrate on which the electronic components are disposed. In other words, the film may be provided in solid form near the electronic component and/or the substrate. In this context, the term "nearby" may encompass a shortest distance between objects of, for example, 0mm to 50mm, preferably 0mm to 20mm, more preferably 0mm to 10mm, even more preferably 0.01mm to 5mm, and still more preferably 0.05mm to 2mm. A shortest distance between objects of 0mm may cover objects touching each other. As used herein, the term "in solid form" may encompass films that are solid when provided adjacent to a component preform.

Once the conformal coating has been formed, the polymeric material can generally exhibit high thermal stability and yet be highly electrically insulating.

As used herein, the term "solder joint" may encompass solid attachments that form between a substrate and an electronic component, for example, as the reflowed solder paste cools.

As used herein, the term "coating" may encompass directly coating an electronic component (e.g., in direct contact with an electronic component) and/or indirectly coating an electronic component (e.g., providing a physical barrier between the electronic component and the environment without physically contacting the electronic component).

In general, the step of heating the film in the vicinity of the component preform to adhere the film to the component preform may involve heating the film to soften and/or melt the film, which may then adhere to the component preform while maintaining the desired topographical coverage. In other words, the adhered film may become a conformal coating.

As will be clear from the description of the invention outlined herein, the step of heating the film in the vicinity of the component preform is performed after the step of providing the film in solid form in the vicinity of the component preform. In other words, the film may be softened or melted, for example, in situ. However, unless otherwise specified, in the broadest embodiment of the present invention, the step of heating the solder paste to reflow the solder paste may be performed at any time after the step of providing the component preform.

In a preferred embodiment, the film and solder paste are heated simultaneously. Preferably, the solder paste is reflowed after the step of heating the film in the vicinity of the component preform to adhere the film to the component preform. For example, if the solder paste has a reflow temperature that is above the softening temperature of the film, heating the film and the solder paste simultaneously may be compatible with embodiments in which the solder paste is reflowed after heating the film in the vicinity of the component preform to adhere the film to the component preform. That is, even if the solder paste is heated simultaneously with the film, the solder paste can reflow after the film is heated. More preferably, the solder paste reflows while heating the film in the vicinity of the component preform to adhere the film to the component preform. In other words, it is preferable to use heat from the welding process to melt the film at the same time in place. Advantageously, such a process may provide further improvements over the processes of the prior art over the broadest embodiments of the present invention. This is because, for example, further process steps, i.e. further additional heating steps, can be avoided. Thus, this method of forming a conformal coating can be very effective. This is because the coating can be applied without first reflowing the solder paste, thereby saving time, energy and cost. In other words, the method may preferably involve a single heating step that may cause reflow of the solder paste to form the solder joints and cause the film to adhere to the component preform to form the conformal coating.

In an alternative preferred embodiment, heating the solder paste occurs before the film is provided in solid form in the vicinity of the component preform (i.e. the component preform on which the solder paste has reflowed). In other words, in this embodiment, reflow (or consolidation) of the solder paste preferably occurs before the film is provided in solid form near the component preform. In other words, in this embodiment, the weld is preferably formed prior to forming the conformal coating on the component preform (i.e., adhering the film to the component preform). Of course, it should be understood that since the solder paste has reflowed when the film is provided in solid form, it can be said that the film is provided in solid form in the vicinity of the component preform on which the solder paste has reflowed (i.e., the component preform now being in the form of an electronic component (i.e., an electronic component provided by heating the solder paste to reflow the solder paste to form solder joints between the substrate and the electronic component). Preferably, heating the solder paste occurs before heating the film in the vicinity of the component preform (or the resulting electronic component, as the case may be). This is possible because, for example, typically the melting point of the film may be lower than the melting point of the solder joint. This embodiment may be more preferred when, for example, "weak" solders are used in order to reduce the risk of "hot tear" defects in, for example, solder joints. However, the alternative embodiment described above may be more preferred as it may require less time and energy input, as described herein.

In other words, in this alternative preferred embodiment, the present invention provides a method of forming an electronic component having a conformal coating, the method comprising:

Providing a component preform comprising solder paste between a substrate and an electronic component;

heating the solder paste to reflow the solder paste to form solder joints between the substrate and the electronic component (i.e., to form an electronic assembly);

providing a film in solid form in the vicinity of the component preform (i.e., the electronic component) on which the solder paste has reflowed, the film comprising a polymeric material, and

The film in the vicinity of the component preform (i.e., the electronic component) on which the solder paste has reflowed is heated to adhere the film to the component preform (i.e., the electronic component) on which the solder paste has reflowed, thereby forming a conformal coating that at least partially coats the electronic component. The component preform on which solder paste has reflowed may encompass an electronic component.

Preferably, providing the film in solid form adjacent to the component preform includes providing the film in solid form and at a non-elevated temperature, preferably at room temperature. As used herein, the term "non-elevated temperature" may encompass neither intentional nor intentional heating of the film when the film is provided (initially) in solid form near the component preform. In other words, the term "elevated" may be relative to room temperature. Thus, at or during this step of the process, the film may have a temperature of, for example, about 10 ℃ to about 30 ℃, more preferably about 15 ℃ to about 25 ℃, more preferably about 20 ℃. This means that the film can be simply provided in solid form and no additional heating step is required. This can reduce the complexity of the process and reduce the time, energy and cost requirements for forming the conformal coating.

Preferably, heating the film in the vicinity of the component preform to adhere the film to the component preform includes adhering the film to a substrate of the component preform. In other words, the film is preferably adhered to the substrate of the component preform to form a conformal coating. This arrangement can advantageously form a strong conformal coating. Alternatively or additionally, heating the film in proximity to the component preform to adhere the film to the component preform may include adhering the film to an electronic component of the component preform.

Preferably, the conformal coating at least partially coats the weld spot, more preferably, the conformal coating completely coats the weld spot. Such conformal coatings may provide the best protection for electronic components.

Preferably, the conformal coating encapsulates the electronic component entirely between the film and the substrate. As used herein, the term "fully encapsulated" may encompass the electronic component being fully enclosed (directly or indirectly) by the combination of the substrate and the conformal coating (i.e., the adhered film). In other words, the film preferably forms a tent-like shape over the electronic component, with the base of the tent-like shape in contact with the substrate. Thus, the conformal coating also preferably completely encapsulates the solder joint. Such conformal coatings may provide the best protection for electronic components.

Preferably, heating the solder paste includes heating the component preform. In other words, to heat the solder paste, it may be necessary to heat the entire assembly preform. Alternatively, the solder paste may be directly heated. The method of heating the solder paste is not particularly limited, and the method of heating the film is also not particularly limited. Heating the component preform may also include simultaneously heating the film in the vicinity of the component preform.

Preferably, providing the film in solid form adjacent to the component preform includes contacting the component preform with the film in solid form, more preferably contacting the substrate of the component preform with the film in solid form. The film may also contact the electronic components of the component preform. Direct contact of the component preform with the film may assist in adhering the film to the component preform.

Preferably, heating the film includes softening and/or at least partially melting the film. Softening and/or at least partially melting the film may help adhere the film to the component preform. Softening and/or at least partially melting the film may also help conform the film to the contours of the component preform in order to obtain a more effective and desired coating. The rheological properties of the melted film may advantageously help to hold the film in a desired position on the component preform or electronic component during the heating step, thereby conforming the film to the contours of the component preform or electronic component.

Preferably, the polymeric material is a thermoplastic material. Thus, the conformal coating can be heated to allow easy removal of the conformal coating. This may, for example, contribute to the recyclability of the electronic component.

Alternatively, the polymeric material is preferably a thermoset material. For example, such materials or plastics may be useful in forming conformal coatings that are particularly elastic and resistant. Typical thermoset materials suitable for use in the present invention may include urethane, epoxy, acrylate, and silicone moieties. The thermoset material can be cured or set by any suitable method known to the skilled person, such as, for example, by heat from a reflow profile, moisture from the environment, and/or UV radiation. Thus, the method preferably further comprises curing the polymeric material. Curing the polymeric material may generally and preferably be performed after the conformal coating is formed.

Preferably, the polymeric material is crosslinkable. Typical crosslinkable polymeric materials suitable for use in the present invention may include urethane, epoxy, acrylate and silicone moieties.

Preferably, the method does not include reflowing the solder paste prior to the step of heating the film adjacent the component preform. In other words, as described above, the conformal coating is preferably formed prior to or simultaneously with reflowing the solder paste. This may advantageously reduce the number of method steps required to form an electronic component having a conformal coating.

Preferably, the film is not heated prior to the step of providing the film in solid form adjacent to the component preform. In other words, the film is preferably not heated immediately prior to the step of providing the film in solid form adjacent to the component preform. That is, the film is preferably initially provided in a solid form in the vicinity of the component preform in an unheated state. This does not exclude any heating that may be required in the manufacture of the film, such as, for example, molding the film into a particular shape or forming a polymeric material. Thus, this may reduce the number of heating steps that may be required for the method compared to, for example, a hot melt coating process.

Preferably, the film is preformed to be at least partially complementary to the shape of the component preform or the (resulting) electronic component. In other words, the film is preferably configured to be at least partially complementary to the shape of the component preform or the (resulting) electronic component. The film may be at least partially complementary to the shape of the component preform or at least a portion of the (resulting) electronic component (e.g., one or more of the electronic components). The film may also be fully complementary to the component preform or (resulting) electronic component to be coated. In other words, for example, the film may be shaped (such as in three dimensions) according to the contours of the component preform or (resulting) electronic component, and cut according to the dimensions of the component preform or (resulting) electronic component. In other words, the film is preferably provided in a 3-dimensional preformed solid form. Advantageously, the amount of polymeric material required may thus be minimized and no excess material may be wasted. Furthermore, the preformed film may help adhere the film more strongly to the component preform or electronic component, as this may provide, for example, a greater contact surface area between the film and the component preform or electronic component. In addition, less melting/heating of the film is required, as less movement of the film may be required to obtain a conformal coating. This may therefore save additional time, energy and costs.

More preferably, the film is preformed to be at least partially complementary to the shape of the component preform or the particular electronic component of the (resulting) electronic component. More preferably, the assembly preform comprises a plurality of electronic components, and the method comprises providing a plurality of films, wherein the films are provided in solid form adjacent each of the electronic components. In other words, the resulting electronic assembly may include a plurality of conformal coatings, each formed from a separate film, each film preformed according to the one or more electronic components it will coat. Thus, one film may be intended to at least partially coat one or more electronic components. This may also enable a reduction in the amount of polymer material required. Further, for example, such a method may enable the use of different polymer material compositions for different films. Thus, the coating requirements (i.e., depending on the sensitivity of the component to moisture or other environmental factors) may be related to the particular electronic component to which the film is to be applied. This can result in a particularly effective conformal coating produced by an effective method. In other words, the resulting conformal coating can include a sub-coating.

Preferably, the method further comprises preforming the film by die cutting or molding. Suitable die cutting and molding methods are known to the skilled artisan.

Preferably, providing the component preform includes printing and/or dispensing solder paste on the substrate. Suitable methods of printing solder paste are known to the skilled person. Preferably, the method further comprises contacting the electronic component with solder paste, preferably by a pick-and-place method. Pick-and-place methods are known to the skilled person and may involve, for example, picking up an electronic component from one location (e.g. using a pick-and-place machine or robot) and placing it in another location (such as at a desired location on solder paste on a substrate) to form an assembly preform.

Preferably, providing the film in solid form adjacent to the component preform includes disposing the film by a pick-and-place method. Advantageously, the film can thus be provided in desired locations quickly and efficiently, thereby reducing the time required to form a conformal coating. Disposing the film may include positioning the film at or on a desired location on the component preform.

Preferably, heating the solder paste includes heating the solder paste to a temperature at or above the reflow temperature of the solder paste for 1 minute to 5 minutes, such as for 1 minute to 3 minutes. Typical solder paste reflow temperatures may be, for example, about 150 ℃ to about 250 ℃. When the film and the solder paste are heated simultaneously, then heating the film and the solder paste may include, for example, heating the film and the solder paste to a softening temperature of the film or above the softening temperature of the film for 1 minute to 5 minutes, such as for 1 minute to 3 minutes. Typical softening temperatures of the films of the present invention may be, for example, from about 130 ℃ to about 200 ℃.

Preferably, the polymeric material comprises one or more of a polyolefin, a polyamide, a silicone, a urethane, an epoxy, and an acrylic polymer. Suitable polymeric materials are known to the skilled person.

Preferably, the assembly preform comprises two or more electronic components.

Preferably, the substrate comprises a printed circuit board. Preferably, the electronic components include one or more of resistors, capacitors, light emitting diodes, transistors, field Effect Transformers (FETs), bottom Termination Components (BTCs), metal Electrode Leadless Faces (MELFs), small Outline Integrated Circuits (SOICs), and Quad Flat Packages (QFPs). Preferably, the electronic component comprises a QFP.

In another aspect of the invention, there is provided an electronic component having a conformal coating formed by the method of any preceding claim.

In another aspect of the invention, a film for use as a precursor to a conformal coating of an electronic component is provided, the film comprising a polymeric material and being preformed to be at least partially complementary to the shape of a component preform. That is, the film may be preformed to at least partially complement the shape of a component preform of the electronic component, the component preform comprising solder paste between the substrate and the electronic component. In other words, the component preform may be a precursor of an electronic component, for example a precursor in which one or more electronic components are arranged in their desired positions but in which solder paste has not yet reflowed, as described herein. In other words, the film may be preformed to be at least partially complementary to the shape of the (resulting) electronic component. Preferred embodiments and associated advantages of the membranes described herein in relation to the first aspect are equally applicable to the membranes of this aspect. Such a film may enable the advantages associated with the methods described herein to be achieved.

The foregoing detailed description has been provided by way of illustration and description, and is not intended to limit the scope of the appended claims. Many variations of the preferred embodiments of the invention shown herein will be apparent to those of ordinary skill in the art and still fall within the scope of the appended claims and their equivalents.

Claims (31)

1. A method of forming an electronic component having a conformal coating, the method comprising:

providing a component preform comprising solder paste between a substrate and an electronic component;

Providing a film in solid form adjacent to the component preform, the film comprising a polymeric material;

Heating the solder paste to reflow the solder paste to form a solder joint between the substrate and the electronic component, and

The film in the vicinity of the component preform is heated to adhere the film to the component preform, thereby forming a conformal coating that at least partially coats the electronic component.

2. The method of claim 1, wherein the film and the solder paste are heated simultaneously.

3. The method of claim 1 or claim 2, wherein the solder paste reflows after heating the film near the component preform to adhere the film to the component preform.

4. The method of claim 1, wherein heating the solder paste occurs prior to providing a film in solid form near the component preform.

5. The method of any preceding claim, wherein providing a film in solid form adjacent to the component preform comprises providing the film in solid form and at a non-elevated temperature, preferably at room temperature.

6. The method of any preceding claim, wherein heating the film in proximity to the component preform to adhere the film to the component preform comprises adhering the film to the substrate of the component preform.

7. The method of any preceding claim, wherein the conformal coating at least partially coats the solder joint.

8. The method of any preceding claim, wherein the conformal coating fully encapsulates the electronic component between the film and the substrate.

9. The method of any preceding claim, wherein heating the solder paste comprises heating the component preform.

10. The method of any preceding claim, wherein providing a film in solid form adjacent to the component preform comprises contacting the component preform with the film in solid form, preferably contacting the substrate of the component preform with the film in solid form.

11. The method of any preceding claim, wherein heating the film comprises softening and/or at least partially melting the film.

12. The method of any preceding claim, wherein the polymeric material is a thermoplastic material.

13. The method of any one of claims 1 to 11, wherein the polymeric material is a thermoset material.

14. The method of claim 13, further comprising curing the polymeric material.

15. The method of any preceding claim, wherein the polymeric material is crosslinkable.

16. A method according to any one of claims 1 to 3 or claims 5 to 15, wherein prior to the step of heating the film in the vicinity of the component preform, the method does not include reflowing the solder paste.

17. The method of any preceding claim, wherein the film is not heated prior to the step of providing the film in solid form adjacent to the component preform.

18. The method of any preceding claim, wherein the film is preformed to be at least partially complementary to the shape of the component preform.

19. The method of claim 18, wherein the film is preformed to be at least partially complementary to a shape of a particular electronic component of the component preform.

20. The method of claim 19 wherein the component preform comprises a plurality of electronic components and the method comprises providing a plurality of films, wherein a film is provided in solid form adjacent each of the electronic components.

21. The method of any one of claims 18 to 20, wherein the method further comprises preforming the film by die cutting or molding.

22. The method of any preceding claim, wherein providing a component preform comprises printing and/or dispensing the solder paste on the substrate.

23. The method of claim 22, further comprising contacting the electronic component with the solder paste, preferably by a pick-and-place method.

24. The method of any preceding claim, wherein providing a film in solid form adjacent the component preform comprises disposing the film by a pick-and-place method.

25. The method of any preceding claim, wherein heating the solder paste comprises heating the solder paste to a temperature at or above a reflow temperature of the solder paste for 1 minute to 5 minutes.

26. The method of any preceding claim, wherein the polymeric material comprises one or more of a polyolefin, a polyamide, a silicone, a urethane, an epoxy, and an acrylic polymer.

27. The method of any preceding claim, wherein the component preform comprises two or more electronic components.

28. The method of any preceding claim, wherein the substrate comprises a printed circuit board.

29. A method according to any preceding claim, wherein the electronic component comprises a quad flat package.

30. An electronic component having a conformal coating formed by the method of any preceding claim.

31. A film for use as a precursor to a conformal coating of an electronic component, the film comprising a polymeric material and being preformed to be at least partially complementary to the shape of the component preform.