Patent Application
20200053889
Embodiments of the subject matter described herein relate generally to compact electronic devices, including medical devices and components. More particularly, embodiments of the subject matter relate to a low-cost design suitable for a physiological characteristic sensor component, and a related fabrication methodology.
The prior art is replete with a wide variety of compact and portable electronic devices, along with related fabrication techniques. For example, the prior art includes a number of medical devices and components that include electronic circuits, processor chips, batteries, sensor elements, and other features contained within a protective housing or case. Plastic overmolding techniques can be utilized to manufacture certain types of electronic devices in a quick and cost-effective manner. Unfortunately, conventional overmolding methodologies can be time consuming, which adversely impacts manufacturing throughput. In addition, some conventional overmolding methodologies result in high temperature and high pressure conditions, which can be undesirable when overmolding sensitive electronic components or devices (such as batteries or other items that might be compromised or degraded by high temperature and/or high pressure).
Accordingly, it is desirable to have an improved overmolding manufacturing process that is suitable for use with electronic devices having sensitive components. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.
A method of fabricating an electronic medical device is disclosed here. An exemplary embodiment of the method begins by providing a printed circuit board assembly having a printed circuit board, electronic components mounted to the printed circuit board, and a battery mounted to the printed circuit board. The method continues by forming a protective inner shell, surrounding at least a portion of the printed circuit board assembly, to obtain a protected circuit board assembly, wherein the protective inner shell encases the electronic components and the battery. The method continues by overmolding the protected circuit board assembly with a thermoplastic elastomer or a thermoplastic polyurethane material to form an outer shell surrounding at least a portion of the protected circuit board assembly.
An electronic medical device is also disclosed here. An embodiment of the medical device includes a printed circuit board assembly, a protective inner shell, and an outer shell. The printed circuit board assembly includes a printed circuit board, electronic components mounted to the printed circuit board, a battery mounted to the printed circuit board, and an interface compatible with a physiological characteristic sensor component. The protective inner shell surrounds at least a portion of the printed circuit board assembly. The protective inner shell is formed by overmolding the printed circuit board assembly with a first material having low pressure and low temperature molding properties. The outer shell surrounds at least a portion of the protective inner shell. The outer shell is formed by overmolding the protective inner shell with a second material that is different than the first material.
This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
A more complete understanding of the subject matter may be derived by referring to the detailed description and claims when considered in conjunction with the following figures, wherein like reference numbers refer to similar elements throughout the figures.
The following detailed description is merely illustrative in nature and is not intended to limit the embodiments of the subject matter or the application and uses of such embodiments. As used herein, the word “exemplary” means “serving as an example, instance, or illustration.” Any implementation described herein as exemplary is not necessarily to be construed as preferred or advantageous over other implementations. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description.
Certain terminology and descriptors may be used in the following description for the purpose of reference only, and thus are not intended to be limiting. For example, terms such as “upper,” “lower,” “above,” and “below” refer to directions in the drawings to which reference is made. Terms such as “front,” “back,” “rear,” “side,” “outboard,” and “inboard” describe the orientation and/or location of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import. Similarly, the terms “first,” “second,” and other such numerical terms referring to structures do not imply a sequence or order unless clearly indicated by the context.
The subject matter described here relates to the manufacturing and assembly of an electronic device. More specifically, the embodiment of the electronic device described here is a low-cost, compact, disposable medical device component. The exemplary embodiment presented here is realized as a wireless transmitter component that is compatible with, and couples to, a physiological characteristic sensor device (e.g., a glucose sensor product). Accordingly, the non-limiting embodiment described below relates to a transmitter device module for a glucose sensor of the type used by diabetic patients. It should be appreciated that the concepts, manufacturing techniques, and methodologies mentioned here need not be limited to sensor devices or medical devices, and that the concepts and manufacturing technology described here can also be applied to the fabrication of other types of devices if so desired.
The recorder 102 is one type of electronic medical device that can be fabricated using the techniques and methodology described here. The manufacturing process described here is particularly suitable for a low-cost and disposable version of the recorder 102 because the process uses relatively inexpensive materials and isn't very time consuming (which results in high manufacturing throughput). A wireless transmitter for the sensor 100 is another type of electronic medical device that can be fabricated using the techniques and methodology described here, and the following description can be utilized for these and other device types if so desired.
It should be appreciated that the fabrication process 200 may include any number of additional or alternative tasks, and that the fabrication process 200 may be incorporated into a more comprehensive procedure or process having additional functionality not described in detail herein. Moreover, one or more of the tasks shown in
The fabrication process 200 begins by providing, creating, or obtaining a printed circuit board assembly (task 202).
Referring again to
In accordance with exemplary embodiments, the protective inner shell 316 is formed by way of an initial/first overmolding procedure that overmolds the PCBA 300 with a hotmelt material having low pressure and low temperature molding properties. The protruding sections 318 remain exposed because they serve to support the PCBA 300 within the mold during the initial overmolding procedure. In this regard, the PCBA 300 (provided at task 202) is placed into a first mold that allows the hotmelt material to be introduced around the sections of the PCBA 300 that are to be encapsulated. In certain preferred embodiments, the hotmelt material is a polyimide or polyamide material (such as the TECHNOMELT PA6208 adhesive by HENKEL and similar materials) that can be molded at a low pressure and a low temperature that do not degrade, compromise, or damage, the electronic components 304 or the batteries 306. For example, the initial overmolding procedure can be performed at a hotmelt material molding melt temperature within the range of about 180° C. to 230° C., and at a hotmelt material molding pack pressure within the range of about 200 to 1000 psi. These exemplary temperature and pressure ranges are appropriate for overmolding the PCBA 300 without harming, degrading, or otherwise compromising any of the components mounted to the printed circuit board 302. In practice, the material utilized for the initial overmolding procedure can be molded with a low enough thermal mass such that the material can be cooled quickly (to reduce the likelihood of adversely impacting the underlying circuit board components).
The protective inner shell 316 protects the underlying electronic components 304 and batteries 306 against heat and pressure associated with any subsequent overmolding steps and any other fabrication steps that can potentially damage or compromise the underlying elements. Moreover, for certain embodiments, the protective inner shell 316 can be suitably designed and fabricated to hermitically seal and/or to fluidly seal the underlying electronic components 304 and batteries 306. Furthermore, the material used to form the protective inner shell 316 can be selected such that it protects the underlying components from mechanical vibration, impact, and the like.
Referring again to
In
In accordance with exemplary embodiments, the outer shell 330 is formed by way of an additional overmolding procedure that overmolds the protected circuit board assembly 314 with a thermoplastic elastomer material such as a polypropylene material, or with a thermoplastic polyurethane material. In this regard, the protected circuit board assembly 314 is placed into a second mold that allows the thermoplastic elastomer material to be introduced around the sections of the protected circuit board assembly 314 that are to be encased. In contrast to the initial overmolding procedure, the second overmolding procedure can be performed at a thermoplastic elastomer molding melt temperature within the range of about 150° C. to 300° C., and at a thermoplastic elastomer molding in-cavity pressure within the range of about 800 to 1500 psi. As mentioned above, the protective inner shell 316 protects the underlying electronic components 304 and batteries 306 against the higher heat and pressure associated with the second overmolding step and any other fabrication steps that can potentially damage or compromise the underlying elements.
Although not always required, the device fabrication process 200 described here continues by performing a final overmolding procedure to fill in any remaining voids, spaces, or holes (task 208). In this regard, the final overmolding step fills in the void 334 shown in
After the final overmolding procedure, the process 200 may continue by preparing the electronic device for packaging (task 210). For example, the electronic device can be cleaned, laser etched, marked, tested, sterilized, and the like. Thereafter, the process 200 may continue by packaging the electronic device in an appropriate manner (task 212) that is suitable for storage, shipping, display, etc.
While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or embodiments described herein are not intended to limit the scope, applicability, or configuration of the claimed subject matter in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the described embodiment or embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope defined by the claims, which includes known equivalents and foreseeable equivalents at the time of filing this patent application.
