Patent Description:
Surface-mount devices, such as integrated circuits (IC) (e.g., analog signal ICs, digital signal ICs, or mixed signal ICs), typically comprise a set of electronic components, such as transistors or other suitable components, inseparably integrated on a relatively small portion of semiconductor material (e.g., silicon or other suitable material). Modern ICs may integrate millions or billions of electronic components and may be used in various applications, such as desktop computers, laptop computers, mobile computing devices, tablet computing devices, home appliances, stereos, medical devices, and a plurality of other electronic devices.

In such applications, an IC is typically connected, using surface-mount technology (SMT) (e.g., solder or other thermally conductive material applied to conductive pads disposed on a side of the IC facing the printed circuit board), to a printed circuit board (PCB) substrate, which electrically connects other ICs and electronic components on the PCB. Typically, solder and flux (e.g., a paste that promotes solder flow) are applied to the PCB (e.g., using a printing process or other suitable manufacturing process) to secure and electrically connect the IC, and other electronic components, to the PCB (e.g., typically referred to as a PCB assembly (PCBA) when the ICs and electronic components are secured and electrically connected to the PCB) as described in <CIT>, <CIT>, <CIT> and in <CIT>.

Typically, a conformal coating material is applied to the PCB after the IC and/or other electronic components are soldered to the PCB. The conformal coating material typically includes polymers and other suitable material. The conformal coating material, when applied to the PCB, typically forms a thin layer that protects components of the PCB from moisture, dust, chemicals, and/or surface electrical changes. However, during application of the conformal coating material (e.g., such as a low viscosity conformal coating material), some of the conforming coating material may flow between the IC, or other electronic components, and the PCB. This may cause accelerated solder fatigue to solder connections that connect the IC, or other electronic components, to the PCB.

This disclosure relates generally to conformal coating control systems and methods.

An aspect of the disclosed embodiments is a conformal coating control method. The method includes arranging at least one conformal control surface feature on a surface of a printed circuit board proximate perimeter pads of an integrated circuit. The method also includes soldering, to the printed circuit board, the integrated circuit. The method also includes applying a conformal coating material to the printed circuit board, wherein the conformal coating material is at least partially restricted from flowing between the integrated circuit and the printed circuit board by solder flux residue accumulated proximate the conformal control surface feature.

In the method, the at least one conformal control surface feature may include a solder mask material.

Also in the method, the perimeter pads of the integrated circuit may define channels between the integrated circuit and the printed circuit board.

In the method, the solder mask material may partially fill at least some of the channels defined by the perimeter pads of the integrated circuit.

Also in the method, the solder mask material may partially fill each of the channels defined by the perimeter pads of the integrated circuit.

In the method, the at least one conformal control surface feature may include at least one solderable member arranged proximate the perimeter pads of the printed circuit board and proximate a corner of the integrated circuit.

Additionally in the method, the at least one solderable member may include a <NUM> degree angle bracket.

Within the method, the integrated circuit may include a quad-flat no-leads package.

Another aspect of the disclosed embodiments is a system for conformal coating control. The system includes a printed circuit board and an integrated circuit disposed on a surface of the printed circuit board, wherein a solder mask material is disposed on the surface of the printed circuit board proximate perimeter pads of the integrated circuit. The system also includes at least one solderable member disposed on the printed circuit board proximate the integrated circuit. The system also includes a conformal coating material that is applied to the printed circuit board, wherein the conformal coating material is at least partially restricted from flowing between the integrated circuit and the printed circuit board by solder flux residue accumulated proximate of the solder mask material and the at least one solderable member.

In the system, the solder mask material may reduce a stand-off gap height between the integrated circuit and the printed circuit board.

Within the system, the perimeter pads of the integrated circuit may define channels between the integrated circuit and the printed circuit board.

Also within the system, the solder mask material may partially fill at least some of the channels defined by the perimeter pads of the integrated circuit.

In the system, the solder mask material may partially fill each of the channels defined by the perimeter pads of the integrated circuit.

Additionally in the system, the at least one solderable member may be arranged proximate a corner of the integrated circuit.

In the system, the at least one solderable member may include a <NUM> degree angle bracket.

Also in the system, the integrated circuit may include a quad-flat no-leads package.

Another aspect of the disclosed embodiments is a conformal coating control method. The method includes applying a solder mask material into channels on a printed circuit board defined by an integrated circuit. The method also includes arranging, on the printed circuit board and proximate a corner of the integrated circuit, a solderable member. The method also includes soldering, to the printed circuit board, the integrated circuit, wherein soldering the integrated circuit to the printed circuit board causes solder flux residue to accumulate proximate the solder mask material and the solderable member. The method also includes applying a conformal coating material to the printed circuit board, wherein the conformal coating material is at least partially restricted, by the solder flux residue, from flowing between the integrated circuit and the printed circuit board.

In the method, the solder mask material may reduce a stand-off gap height between the integrated circuit and the printed circuit board.

Also in the method, the solderable member may include a <NUM> degree angle bracket.

Additionally in the method, the integrated circuit may include a quad-flat no-leads device.

These and other aspects of the present disclosure are provided in the following detailed description of the embodiments, the appended claims, and the accompanying figures.

The following discussion is directed to various embodiments of the invention. Although one or more of these embodiments may be preferred, the embodiments disclosed should not be interpreted, or otherwise used, as limiting the scope of the disclosure, including the claims. In addition, one skilled in the art will understand that the following description has broad application, and the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to intimate that the scope of the disclosure, including the claims, is limited to that embodiment.

As described, surface-mount devices, such as integrated circuits (IC) (e.g., analog signal ICs, digital signal ICs, or mixed signal ICs), typically comprise a set of electronic components, such as transistors or other suitable components, inseparably integrated on a relatively small portion of semiconductor material (e.g., silicon or other suitable material). ICs may include microprocessors, microcontrollers, memory chips, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), sensors, power management circuits, operation amplifiers, analog-to-digital converters, digital-to-analog converters, and the like. In some embodiments, the ICs may include a flat no-leads package, such as a quad-flat no-leads package, a dual-flat no-leads package, or other suitable no-leads package. Modern ICs may integrate millions or billions of electronic components and may be used in various applications, such as desktop computers, laptop computers, mobile computing devices, tablet computing devices, home appliances, stereos, medical devices, and a plurality of other electronic devices.

An IC is typically connected, using surface-mount technology (e.g., solder or other thermally conductive material applied to conductive pads disposed on a side of the IC facing the printed circuit board), to the printed circuit board (PCB) substrate, which electrically connects other ICs and electronic components (e.g., resistors, capacitors, indictors, transformers, power resistors, large area passives, and the like) the PCB. For example, one or more leads of the IC may be soldered to the substrate to electrically connect the IC to the other ICs and electronic components on the PCB and/or to one another. The solder, such as a lead alloy solder or other suitable solder, provides a conductive path for electrons to flow to and from the IC via the substrate. Typically, solder and flux (e.g., a paste that promotes solder flow) are applied to the PCB (e.g., using a dipping process or other suitable manufacturing process) to secure and electrically connect the IC, and other electronic components, to the PCB (e.g., typically referred to as a PCB assembly (PCBA) when the ICs and electronic components are secured and electrically connected to the PCB).

Typically, a conformal coating material is applied to the PCB after the IC and/or other electronic components are soldered to the PCB. The conformal coating material typically includes acrylic material, epoxy material, polyurethane material, silicone material, fluorinated poly-para-xylylene material, non-fluorinated poly-para-xylylene material, amorphous fluoropolymer material, or other suitable material. The conformal coating material may be applied to the PCB by brushing the conformal coating material onto the PCB, by spraying the conformal coating material onto the PCB, by dispensing the conformal coating material onto the PCB, by dipping the PCB in the conformal coating material, or by other suitable application processes. The conformal coating material, when applied to the PCB, typically forms a thin layer (e.g., <NUM> micrometers to <NUM> micrometers) that conforms to contours of the PCB. The conformal coating material protects components (e.g., such as ICs and other electronic components) of the PCB from moisture, dust, chemicals, and/or surface electrical changes.

However, during application of the conformal coating material, some of the conforming coating material may flow between the IC, or other electronic components, and the PCB. For example, a stand-off gap may be defined between a surface of the IC facing the PCB and the PCB. The conformal coating material may flow into the stand-off gap during application of the conforming coating material to the PCB. This may cause accelerated solder fatigue to solder connections that connect the IC, or other electronic components, to the PCB. Accordingly, systems and methods, such as those described herein, that control the flow of conformal coating material during the application of the conformal coating material to the PCB, may be desirable. In some embodiments, as will be described, the system and methods disclosed herein include may include using surface features on the PCB that cause solder paste flux residue to accumulate proximate the IC and/or other electronic components. The solder paste flux residue may restrict the flow of conformal coating material from flowing between the IC and/or other electronic components, during application of the conformal coating material to the PCB.

<FIG> generally illustrates a printed circuit board assembly (PCBA) <NUM> according to the principles of the present disclosure. The PCBA <NUM> may be used in any suitable application, such as a desktop computer, a laptop computer, a mobile computing device, a tablet computing device, a home appliance, a stereo, a medical device, or any other suitable electrical device. Additionally, or alternatively, the PCBA <NUM> may interact with a plurality of other PCBAs.

The PCBA <NUM> includes an integrated circuit (IC) <NUM> and a printed circuit board (PCB) <NUM>. The IC <NUM> may include a plurality of electronic components inseparably integrated and/or disposed on a segment of semiconductor material, such as silicon or other suitable semiconductor material. The IC <NUM> may comprise a microprocessor, a microcontroller, a memory chip, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a sensor, a power management circuit, an operation amplifier, an analog-to-digital converter, a digital-to-analog converter, or other suitable IC. Additionally, or alternatively, the IC <NUM> may comprise an analog signal IC, a digital signal IC, or a mixed signal IC. In some embodiments, the IC <NUM> may include a flat no-leads package, such as a quad-flat no-leads package, a dual-flat no-leads package, or other suitable no-leads package. In some embodiments, the IC <NUM> may include a <NUM> millimeter by <NUM> millimeter quad-flat no-leads package, a <NUM> millimeter by <NUM> millimeter quad-flat no-leads package, <NUM> millimeter by <NUM> millimeter quad-flat no-leads package, or other suitable quad-flat no-leads package.

The IC <NUM> may include an exposed pad disposed on a bottom surface of the IC <NUM> (e.g., a surface that faces the PCB <NUM>). The exposed pad may include a plurality of leads adapted to be electrically connected to the PCB <NUM>. For example, thermal conductive material such as solder, may be applied between a respective lead and a portion of a substrate on the PCB <NUM>. It should be understood that while only the IC <NUM> is described herein, the principles of the present disclosure apply to any number of ICs and any suitable electronic components. For example, while not illustrated, the PCBA <NUM> may include one or more power resistors, one or more large area passives, other suitable electronic components, or a combination thereof.

The PCB <NUM> may be adapted to mechanically support the IC <NUM> and/or other ICs and electronic components, and to electrically connect such components. The PCB <NUM> may include, as described, substrates, pads, and other features that may be etched into one or more layers of conductive material, such as copper or other suitable conductive material. The layers of conductive material of the PCB <NUM> may be laminated onto or sandwiched between layers of non-conductive material.

In some embodiments, the PCBA <NUM> includes one or more stand-off gaps <NUM>. The stand-off gaps <NUM> may be defined by a surface of the IC <NUM> that faces the PCB <NUM> and a surface of the PCB <NUM> that faces the IC <NUM>. The PCBA <NUM> may include one or more power sources <NUM>. The power sources <NUM> may include current sources, voltage sources, or other suitable power source. The power sources <NUM> may include a power circuit comprising a voltage source, one or more resistors, one or more capacitors, and/or one or more other suitable electronic components. In some embodiments, the PCBA <NUM> includes a high side power source <NUM> and a low side power source <NUM>, however, the PCBA <NUM> may omit either of the high side power source <NUM> or the low side power source <NUM>. When power (e.g., voltage and/or current) is supplied by one of the power sources <NUM>, the power flows through the components of the IC <NUM> and into the substrate of the PCB <NUM> via the solder connections between the IC <NUM> and the substrate of the PCB <NUM>.

In some embodiments, the PCBA <NUM> may include additional or few components than illustrated and/or described herein. For example, the PCBA <NUM> may include a pedestal (e.g., a heat sink) and a PCBA case or housing. The PCBA housing may be configured to house or enclose the IC <NUM>, PCB <NUM>, and/or the pedestal. The pedestal may be disposed on a side of the PCB <NUM> opposite the IC <NUM>. The PCB <NUM> may be attached to the pedestal using a suitable thermal interface material (e.g., thermal glue or other thermally conductive material). The pedestal may include a heat sink configured to draw heat generated by the IC <NUM> away from the IC <NUM>.

A conformal coating material may be applied to the PCB <NUM> after the IC <NUM> and/or other electronic components are connected to the PCB <NUM> using solder or other suitable thermal conductive material. The conformal coating material includes acrylic material, epoxy material, polyurethane material, silicone material, fluorinated poly-para-xylylene material, non-fluorinated poly-para-xylylene material, amorphous fluoropolymer material, or other suitable material. The conformal coating material may be applied to the PCB <NUM> by brushing the conformal coating material onto the PCB <NUM>, by spraying the conformal coating material onto the PCB <NUM>, by dispensing the conformal coating material onto the PCB <NUM>, by dipping the PCB <NUM> in the conformal coating material, or by other suitable application processes. The conformal coating material, when applied to the PCB <NUM>, forms a thin layer (e.g., <NUM> micrometers to <NUM> micrometers) that conforms to contours of the PCB <NUM>. As described, the conformal coating material protects the IC <NUM> and/or other electronic components connected of the PCB <NUM> from moisture, dust, chemicals, other contaminants, changes in temperature, and the like. As will be described, the PCB <NUM> may include one or more conformal control surface features configured to restrict or control flow of the conformal coating material proximate the IC <NUM> and/or other electronic components.

<FIG> generally illustrates a cutaway top view of a printed circuit board (PCB) <NUM> according to the principles of the present disclosure. The IC <NUM> may be connected, via solder or other suitable thermal conductive material, to the PCB <NUM>. It should be understood that, while only IC <NUM> is described as being connected to the PCB <NUM>, additional ICs and/or other electronic components may be connected to the PCB <NUM>. Accordingly, the principles of the present disclosure described herein apply to any suitable electronic component connected to the PCB <NUM>.

The IC <NUM> may include exposed pad <NUM> disposed on the surface of the IC <NUM> facing the PCB <NUM> adapted to be connected, via solder or other thermal conductive material, to a corresponding pad or a portion of a substrate on the PCB <NUM>. In some embodiments, the IC <NUM> includes a plurality of perimeter pads <NUM> disposed along a perimeter of the IC <NUM>. The perimeter pads <NUM> are adapted to be connected, via solder or other thermal conductive material, to corresponding pads or corresponding portions of the substrate of the PCB <NUM>. The perimeter pads <NUM> may include any suitable dimensions. For example, a perimeter pad <NUM> may include a <NUM> millimeter width and a <NUM> millimeter length, <NUM> millimeter width and a <NUM> millimeter length, or any suitable dimensions.

The perimeter pads <NUM> define channels <NUM> between the IC <NUM> and the PCB <NUM>. The channels <NUM> may include any suitable dimensions. For example, the channels <NUM> may include a <NUM> millimeter width, <NUM> millimeter width, or any other suitable dimension. As described, the exposed pad <NUM> and/or the perimeter pads <NUM> define the stand-off gap <NUM> between the IC <NUM> and the PCB <NUM>. The IC <NUM> includes one or more corners <NUM> (e.g., four corners or any suitable number of corners corresponding to a shape of the IC <NUM>), as is illustrated in <FIG>. Each respective corner <NUM> of the IC <NUM> are proximate a corresponding gap <NUM>. The gap <NUM> may be defined by the surface of the IC <NUM> facing the PCB <NUM>, the PCB <NUM>, and one or more perimeter pads <NUM> proximate the respective corner <NUM> corresponding to the gap <NUM>.

During application of the conformal coating material, a portion of the conformal coating material may flow into the channels <NUM> and/or one or more gaps <NUM>. The portion of conformal coating material may fill or partially fill the stand-off gap <NUM>, the channels <NUM>, and/or the gaps <NUM>. This may accelerate solder fatigue of the solder connections between the IC <NUM> and the PCB <NUM> (e.g., due to physical expansion of the solder during thermal cycling). In order to control the flow of the conformal coating material (e.g., restrict, at least partially, the flow of conformal coating material into the stand-off gap <NUM>, the channels <NUM>, and/or the gaps <NUM>) during application of the conformal coating material, the PCB <NUM> may include one or more surface features as is generally illustrated in <FIG>.

In some embodiments, the surface features may include a solder mask material <NUM>. The solder mask material <NUM> may include a thin lacquer-like layer of polymer or other suitable material. In some embodiments, the solder mask material <NUM> may be applied to all or substantially of respective gaps between respective pads on the PCB <NUM> corresponding to the perimeter pads <NUM> (e.g., before the IC <NUM> is brought into contact with the PCB <NUM> to define the channels <NUM>). Additionally, or alternatively, the solder mask material <NUM> may be applied to a portion of the surface of the PCB <NUM> corresponding to respective gaps <NUM>. When the IC <NUM> is seated onto the PCB <NUM> (e.g., brought into contact with the PCB <NUM>), the solder mask material <NUM> may fill or substantially fill each respective channel <NUM> and/or each respective gap <NUM>, as is generally illustrated in <FIG>. The solder mask material <NUM>, by filling or substantially filling each respective channel <NUM> and/or each respective gap <NUM> may reduce the stand-off gap <NUM> between the IC <NUM> and the PCB <NUM> (e.g., by filling or substantially filling space within the stand-off gap <NUM>).

Solder is then applied to the PCB <NUM> and the IC <NUM> in order to electrically connect the IC <NUM> to the PCB <NUM>. When the solder is applied to the PCB <NUM>, solder flux residue accumulates proximate the solder mask material <NUM> that is applied to the PCB <NUM>. The conformal coating material is then applied to the PCB <NUM> and the IC <NUM>. The solder flux residue accumulated proximate the solder mask material <NUM> blocks the flow of conformal coating material and prevents, at least some, of the conformal coating material from flowing into the channels <NUM> and/or the gaps <NUM>.

In some embodiments, the solder mask material <NUM> may be applied a portion of the respective gaps between respective pads on the PCB <NUM> corresponding to the perimeter pads <NUM> (e.g., before the IC <NUM> is brought into contact with the PCB <NUM> to define the channels <NUM>). Additionally, or alternatively, the solder mask material <NUM> may be applied to a portion of the surface of the PCB <NUM> corresponding to respective gaps <NUM>. When the IC <NUM> is seated onto the PCB <NUM>, the solder mask material <NUM> may partially fill each respective channel <NUM> and/or each respective gap <NUM>, as is generally illustrated in <FIG>. The solder mask material <NUM>, by filling or substantially filling each respective channel <NUM> and/or each respective gap <NUM>, may reduce the stand-off gap <NUM> between the IC <NUM> and the PCB <NUM> (e.g., by filling or substantially filling space within the stand-off gap <NUM>).

When the solder is applied to the PCB <NUM>, solder flux residue accumulates proximate the solder mask material <NUM> that is applied to the PCB <NUM>. The conformal coating material is then applied to the PCB <NUM> and the IC <NUM>. The solder flux residue accumulated proximate the solder mask material <NUM> partially blocks the flow of conformal coating material and prevents, at least some, of the conformal coating material from flowing into the channels <NUM> and/or the gaps <NUM>, while allowing, at least some, of the conformal coating material to flow into a portion of the channels <NUM> and/or the gaps <NUM> not blocked by the solder flux residue.

In some embodiments, the solder mask material <NUM> may fill or substantially fill some of the channels <NUM> and may partially fill others of the channels <NUM>. In some embodiments, the solder mask material <NUM> may fill or substantially fill some of the channels <NUM> and not others of the channels <NUM>. In some embodiments, the solder mask material <NUM> may partially fill some of the channels <NUM> and not others of the channels <NUM>.

In some embodiments, as is generally illustrated in <FIG> and <FIG>, the surface features may include a solderable member <NUM> attached to the surface of the PCB <NUM>. The solderable member <NUM> may include a solderable land and may comprise any suitable material, such as copper, zinc, brass, or other suitable solderable material. The solderable member <NUM> may include a straight member, a curved member, an angled member, or other suitable solderable member. For example, the solderable member <NUM> may include an angled bracket such as a <NUM>° or substantially <NUM>°-angled bracket, or other suitable angled bracket.

In some embodiments, one or more solderable members <NUM> may be disposed on the surface of the PCB <NUM> proximate respective corners <NUM> of the IC <NUM>. For example, solderable members <NUM> may be attached to portions of the PCB <NUM> (e.g., before the IC <NUM> is brought into contact with the PCB <NUM>, defining the gaps <NUM>) corresponding to respective corners <NUM> of the IC <NUM>. The PCB <NUM> may include one solderable member <NUM>, two solderable members <NUM>, three solderable members <NUM>, four solderable members <NUM>, or any suitable number of solderable members <NUM>. In some embodiments, the PCB <NUM> may include one or more solderable members <NUM> disposed proximate any other portion of the IC <NUM> other than the corners <NUM> and/or a combination of other portions of the IC <NUM> and one or more of the corners <NUM> of the IC <NUM>.

When the solder is applied to the PCB <NUM>, solder flux residue accumulates proximate the solderable members <NUM> disposed on the PCB <NUM>. The conformal coating material is then applied to the PCB <NUM> and the IC <NUM>. The solder flux residue accumulated proximate the solderable members <NUM> blocks the flow of conformal coating material and prevents, at least some, of the conformal coating material from flowing into the respective gaps <NUM> (e.g., gaps <NUM> corresponding to solderable members <NUM> disposed on the PCB <NUM>).

In some embodiments, the PCB <NUM> may include a combination of solder mask material <NUM> and one or more solderable members <NUM>. When the solder is applied to the PCB <NUM>, solder flux residue accumulates proximate the solder mask material <NUM> applied to the PCB <NUM> and proximate solderable members <NUM> disposed on the PCB <NUM>. The conformal coating material is then applied to the PCB <NUM> and the IC <NUM>. The solder flux residue accumulated proximate the solder mask material <NUM> and the solderable members <NUM> blocks the flow of conformal coating material and prevents, at least some, of the conformal coating material from flowing into the channels <NUM> having solder mask material <NUM> partially or substantially filled with solder mask material <NUM> and the gaps <NUM> corresponding the solderable members <NUM> disposed on the PCB <NUM>. It should be understood that the PCB <NUM> may include any combination of any amount of solder mask material <NUM> and any number of solder members <NUM>.

<FIG> is a flow diagram generally illustrating a conformal coating control method <NUM> according to the principles of the present disclosure. At <NUM>, the method <NUM> arranges at least one conformal control surface feature on a printed circuit board. As described, the conformal control surface feature may include solder mask material <NUM> (e.g., applied to various portions of the PCB <NUM> corresponding to perimeter pads <NUM> of the IC <NUM> and/or respective gaps <NUM>) one or more solder members <NUM>, or a combination thereof. In some embodiments, the solder mask material <NUM> may partially fill or substantially fill the all of the channels <NUM>, partially fill some of the channels <NUM> and substantially fill others of the channels <NUM>, partially fill some of the channels <NUM> and not fill others of the channels <NUM>, substantially fill some of the channels <NUM> and not fill others of the channels <NUM>, or any combination thereof. In some embodiments, the PCB <NUM> may include any suitable number of solderable members <NUM> disposed proximate respective corners <NUM> of the IC <NUM> and/or proximate other suitable portions of the IC <NUM>. In some embodiments, the PCB <NUM> includes any suitable combination of solder mask material <NUM> and solderable members <NUM>.

At <NUM>, the method <NUM> solders an integrated circuit to the printed circuit board. As described, the IC <NUM> is soldered to the PCB <NUM>. When the IC <NUM> is soldered to the PCB <NUM>, solder residue flux accumulates proximate the conformal control surface features applied to the PCB <NUM>. At <NUM>, the method <NUM> applies conformal coating material to the printed circuit board. As described, conformal coating material is applied to the IC <NUM> and the PCB <NUM>. When the conformal coating material is applied to the IC <NUM> and the PCB <NUM>, the solder flux residue accumulated proximate the conformal control surface features at least partially blocks or controls the flow of conformal coating material, such that the conformal coating material is restricted from flowing into the channels <NUM> and/or the gaps <NUM>.

In some embodiments, a conformal coating control method includes arranging at least one conformal control surface feature on a surface of a printed circuit board proximate perimeter pads of an integrated circuit. The method also includes soldering, to the printed circuit board, the integrated circuit. The method also includes applying a conformal coating material to the printed circuit board, wherein the conformal coating material is at least partially restricted from flowing between the integrated circuit and the printed circuit board by solder flux residue accumulated proximate the conformal control surface feature.

In some embodiments, the at least one conformal control surface feature includes a solder mask material. In some embodiments, the perimeter pads of the integrated circuit define channels between the integrated circuit and the printed circuit board. In some embodiments, the solder mask material partially fills at least some of the channels defined by the perimeter pads of the integrated circuit. In some embodiments, the solder mask material partially fills each of the channels defined by the perimeter pads of the integrated circuit. In some embodiments, the at least one conformal control surface feature includes at least one solderable member arranged proximate the perimeter pads of the printed circuit board and proximate a corner of the integrated circuit. In some embodiments, the at least one solderable member includes a <NUM> degree angle bracket. In some embodiments, the integrated circuit includes a quad-flat no-leads package.

In some embodiments, a system for conformal coating control includes a printed circuit board and an integrated circuit disposed on a surface of the printed circuit board, wherein a solder mask material is disposed on the surface of the printed circuit board proximate perimeter pads of the integrated circuit. The system also includes at least one solderable member disposed on the printed circuit board proximate the integrated circuit. The system also includes a conformal coating material that is applied to the printed circuit board, wherein the conformal coating material is at least partially restricted from flowing between the integrated circuit and the printed circuit board by solder flux residue accumulated proximate of the solder mask material and the at least one solderable member.

In some embodiments, the solder mask material reduces a stand-off gap height between the integrated circuit and the printed circuit board. In some embodiments, the perimeter pads of the integrated circuit define channels between the integrated circuit and the printed circuit board. In some embodiments, the solder mask material partially fills at least some of the channels defined by the perimeter pads of the integrated circuit. In some embodiments, the solder mask material partially fills each of the channels defined by the perimeter pads of the integrated circuit. In some embodiments, the at least one solderable member is arranged proximate a corner of the integrated circuit. In some embodiments, the at least one solderable member includes a <NUM> degree angle bracket. In some embodiments, the integrated circuit includes a quad-flat no-leads package.

In some embodiments, a conformal coating control method includes applying a solder mask material into channels on a printed circuit board defined by an integrated circuit. The method also includes arranging, on the printed circuit board and proximate a corner of the integrated circuit, a solderable member. The method also includes soldering, to the printed circuit board, the integrated circuit, wherein soldering the integrated circuit to the printed circuit board causes solder flux residue to accumulate proximate the solder mask material and the solderable member. The method also includes applying a conformal coating material to the printed circuit board, wherein the conformal coating material is at least partially restricted, by the solder flux residue, from flowing between the integrated circuit and the printed circuit board.

In some embodiments, the solder mask material reduces a stand-off gap height between the integrated circuit and the printed circuit board. In some embodiments, the solderable member includes a <NUM> degree angle bracket. In some embodiments, the integrated circuit includes a quad-flat no-leads device.

The above discussion is meant to be illustrative of the principles and various embodiments of the present invention. Numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications.

The word "example" is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as "example" is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, use of the word "example" is intended to present concepts in a concrete fashion. As used in this application, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". That is, unless specified otherwise, or clear from context, "X includes A or B" is intended to mean any of the natural inclusive permutations. That is, if X includes A; X includes B; or X includes both A and B, then "X includes A or B" is satisfied under any of the foregoing instances. In addition, the articles "a" and "an" as used in this application and the appended claims should generally be construed to mean "one or more" unless specified otherwise or clear from context to be directed to a singular form. Moreover, use of the term "an implementation" or "one implementation" throughout is not intended to mean the same embodiment or implementation unless described as such.

Implementations the systems, algorithms, methods, instructions, etc., described herein can be realized in hardware, software, or any combination thereof. The hardware can include, for example, computers, intellectual property (IP) cores, application-specific integrated circuits (ASICs), programmable logic arrays, optical processors, programmable logic controllers, microcode, microcontrollers, servers, microprocessors, digital signal processors, or any other suitable circuit. In the claims, the term "processor" should be understood as encompassing any of the foregoing hardware, either singly or in combination. The terms "signal" and "data" are used interchangeably.

As used herein, the term module can include a packaged functional hardware unit designed for use with other components, a set of instructions executable by a controller (e.g., a processor executing software or firmware), processing circuitry configured to perform a particular function, and a self-contained hardware or software component that interfaces with a larger system. For example, a module can include an application specific integrated circuit (ASIC), a Field Programmable Gate Array (FPGA), a circuit, digital logic circuit, an analog circuit, a combination of discrete circuits, gates, and other types of hardware or combination thereof. In other embodiments, a module can include memory that stores instructions executable by a controller to implement a feature of the module.

Further, in one aspect, for example, systems described herein can be implemented using a general-purpose computer or general-purpose processor with a computer program that, when executed, carries out any of the respective methods, algorithms, and/or instructions described herein. In addition, or alternatively, for example, a special purpose computer/processor can be utilized which can contain other hardware for carrying out any of the methods, algorithms, or instructions described herein.

Further, all or a portion of implementations of the present disclosure can take the form of a computer program product accessible from, for example, a computer-usable or computer-readable medium. A computer-usable or computer-readable medium can be any device that can, for example, tangibly contain, store, communicate, or transport the program for use by or in connection with any processor. The medium can be, for example, an electronic, magnetic, optical, electromagnetic, or a semiconductor device. Other suitable mediums are also available.

Claim 1:
A conformal coating control method (<NUM>), comprising:
arranging (<NUM>) at least one conformal control surface feature (<NUM>, <NUM>) on a surface of a printed circuit board (<NUM>) proximate perimeter pads (<NUM>) of an integrated circuit (<NUM>);
soldering (<NUM>), to the printed circuit board (<NUM>), the integrated circuit (<NUM>); and
applying (<NUM>) a conformal coating material to the printed circuit board (<NUM>), wherein the conformal coating material is at least partially restricted from flowing between the integrated circuit (<NUM>) and the printed circuit board (<NUM>) by solder flux residue accumulated proximate the conformal control surface feature (<NUM>, <NUM>) and,
wherein the at least one conformal control surface feature includes at least one solderable member (<NUM>) arranged proximate the perimeter pads (<NUM>) of the printed circuit board (<NUM>) and proximate a corner (<NUM>) of the integrated circuit (<NUM>), the solderable member (<NUM>) including a solderable land and comprising a solderable material and,
wherein the at least one solderable member (<NUM>) includes a <NUM> degree angle bracket.