WO2018209595A1

WO2018209595A1 - Positive temperature coefficient device

Info

Publication number: WO2018209595A1
Application number: PCT/CN2017/084709
Authority: WO
Inventors: Cheng Hu; Yu Tian; Bing Wang; Chuanrong MIAO; Jack BU
Original assignee: Littelfuse Electronics Shanghai Co Ltd
Current assignee: Littelfuse Electronics Shanghai Co Ltd
Priority date: 2017-05-17
Filing date: 2017-05-17
Publication date: 2018-11-22
Anticipated expiration: 2019-11-17

Abstract

Provided herein are positive temperature coefficient (PTC) devices including an angled or L-shaped terminal. In one approach, an assembly includes a protection component disposed between a first conductive foil layer and a second conductive foil layer, wherein the first and second conductive foil layers are electrically connected to the protection component by a plurality of leads extending from each of the first and second conductive foil layers. The assembly may further include an L-shaped terminal having a first section directly coupled to the first conductive foil layer and a second section coupled to an electrode of a battery cell. The assembly may further include a printed circuit board coupled to the second conductive foil layer. As configured, the battery cell may be oriented substantially perpendicularly to a top surface of the printed circuit board.

Description

POSITIVE TEMPERATURE COEFFICIENT DEVICE

Field of the Disclosure

The disclosure relates generally to battery protection devices, and more particularly, to a positive temperature coefficient (PTC) device including an L-shaped terminal.

Background of the Disclosure

With rapid development of the electronic, communication and computer industries, there is an increasing use of portable electronic devices. Many portable electronic devices employ secondary (e.g., rechargeable) batteries as power sources. Batteries, such as lithium batteries, are sensitive to faults caused by external short circuits, uncontrolled charging, abuse of over-charging, and the like. In order to provide an over-temperature or over-current protection for a battery cell, various protection devices have been developed. One such protection device includes a positive temperature coefficient (PTC) device, which may contain PTC elements such as a PTC conductive polymer, e.g., a composition comprising an organic polymer and, dispersed or otherwise distributed therein, a particulate conductive filler, e.g., carbon black, or a metal or a conductive metal compound. Such devices may be referred to as polymer PTC, or PPTC resistors or resistive devices.

While PTC devices subscribe to the trend of increasingly smaller size and higher integration density, because the size of PTC devices is decreasing, so is the area for mounting with other components, such as battery cells. Therefore, how to increase the connection with the printed circuit board and/or the battery cell (s) , while maintaining device integrity and reliability, is a critical problem to be addressed.

Summary

In view of the foregoing, what is needed is a positive temperature coefficient (PTC) device including an angled or L-shaped terminal directly connected to an electrode of a battery cell. In one approach, the PPTC device includes a number of vias and leads extending through the structure, designed to increase the adhesive strength of the L-shaped terminal.

In one approach, an apparatus according to embodiments of the disclosure includes a protection component disposed within an opening of a core housing, and an encapsulation layer disposed over the protection component, the encapsulation layer provided within the opening of the core housing. The apparatus may further include a first conductive foil layer disposed over a first side of the encapsulation layer, and a second conductive foil layer disposed over a second side of the encapsulation layer, wherein the first and second conductive foil layers are electrically connected to the protection component. The apparatus may further include a terminal having a first section directly coupled to the first conductive foil layer and a second section extending substantially perpendicularly from the first section.

In another approach, a positive temperature coefficient (PTC) device according to embodiments of the disclosure may include a protection component disposed within an opening of a core housing, and an encapsulation layer disposed over the protection component, the encapsulation layer provided within the opening of the core housing. The PTC device may further include a first conductive foil layer disposed over a first side of the encapsulation layer, and a second conductive foil layer disposed over a second side of the encapsulation layer, wherein the first and second conductive foil layers are electrically connected to the protection component. The PTC device may further include a terminal having a first section directly coupled to the first conductive foil layer and a second section extending substantially perpendicularly from the first section, wherein the second section is directly coupled to an electrode of a battery cell.

In yet another approach, a positive temperature coefficient (PTC) assembly according to embodiments of the disclosure may include a protection component disposed between a first conductive foil layer and a second conductive foil layer, wherein the first and second conductive foil layers are electrically connected to the protection component by a plurality of leads extending from each of the first and second conductive foil layers. The PTC assembly may further include a terminal having a first section directly coupled to the first conductive foil layer and a second section extending substantially perpendicularly from the first section, wherein the second section is directly coupled to an electrode of a battery cell. The PTC assembly may further include a printed circuit board coupled to the second conductive foil layer.

Brief Description of the Drawings

The accompanying drawings illustrate approaches of the disclosed embodiments so far devised for the practical application of the principles thereof, and in which:

FIGs. 1A-B are isometric views of a device, such as a PTC device, according to an approach of the disclosure；

FIG. 2 is side cross-section view of the device of FIG. 1A according to an approach of the disclosure；

FIG. 3 is an end cross-section view of the device of FIG. 1A according to an approach of the disclosure；

FIG. 4 depicts an exploded perspective view of the device of FIGs. 1A-B according to an approach of the disclosure；

FIGs. 5A-B are perspective views of another device according to an approach of the disclosure；

FIG. 6 is a side cross-sectional view of the device of FIG. 5A according to an approach of the disclosure；

FIG. 7 is an end cross-sectional view of the device of FIG. 5A according to an approach of the disclosure；

FIG. 8 depicts an exploded perspective view of the device of FIGs. 5A-B according to an approach of the disclosure； and

FIG. 9 depicts a side view of a PTC assembly according to an approach of the disclosure.

The drawings are not necessarily to scale. The drawings are merely representations, not intended to portray specific parameters of the disclosure. The drawings are intended to depict typical embodiments of the disclosure, and therefore should not be considered as limiting in scope. In the drawings, like numbering represents like elements.

Furthermore, certain elements in some of the figures may be omitted, or illustrated not-to-scale, for illustrative clarity. Furthermore, for clarity, some reference numbers may be omitted in certain drawings.

Detailed Description

Embodiments in accordance with the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings. The system/circuit may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the system and method to those skilled in the art.

For the sake of convenience and clarity, terms such as "top, " "bottom, " "upper, " "lower, " "vertical, " "horizontal, " "lateral, " "longitudinal, " "above, " and "below" will be used herein to describe the relative placement and orientation of various components and their constituent parts. Said terminology will include the words specifically mentioned, derivatives thereof, and words of similar import.

As used herein, an element or operation recited in the singular and proceeded with the word "a" or "an" should be understood as not excluding plural elements or operations, unless such exclusion is explicitly recited. Furthermore, references to "one embodiment" of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.

As stated above, provided herein are positive temperature coefficient (PTC) devices including an angled or L-shaped terminal. In one approach, an assembly includes a protection component disposed between a first conductive foil layer and a second conductive foil layer, wherein the first and second conductive foil layers are electrically connected to the protection component by a plurality of leads extending from each of the first and second conductive foil layers. The assembly may further include an L-shaped terminal having a first section directly coupled to the first conductive foil layer and a second section coupled to an electrode of a battery cell. The assembly may further include a printed circuit board directly coupled to the second conductive foil layer. As configured, the battery cell may be oriented substantially perpendicularly to the printed circuit board.

Furthermore, described herein is a PTC device in which the protection circuit, including active protection components (e.g., integrated circuits or sensors) and passive protective components (e.g. PTCs, negative temperature coefficient (NTC) , or fuses) is embedded in a core housing made of PCB FR-4 material or molding case, and encapsulated with a coating, such as epoxy or encapsulation. The active and passive components are connected with a conductive layer and/or a via hole to form the protection circuit.

Turning now to FIGS. 1A-4, illustrated is an embodiment of an apparatus or device 100 in accordance with the present disclosure. As shown, the device 100, such as a PTC device or a polymeric PTC device, includes a protection component 102 disposed within an opening 104 of a core housing 106. The device 100 further includes an encapsulation layer 110 disposed over the protection component 102, the encapsulation layer 110 provided partially or entirely within the opening 104 of the core housing 106. The illustrated PTC device 100 may be located in, for example, a charge/discharge circuit of a secondary cell, and used as a circuit protection device to interrupt an excess current when such current passes through the circuit.

The PTC material of protection component 102 may be made of a positive temperature coefficient conductive composition comprising a polymer and a conductive filler. The polymer of the PTC material may be a crystalline polymer selected from the group consisting of polyethylene, polypropylene, polyoctylene, polyvinylidene chloride and a mixture thereof. The conductive filler may be dispersed in the polymer and is selected from the group consisting of carbon black, metal powder, conductive ceramic powder and a mixture thereof. Furthermore, to improve sensitivity and physical properties of the PTC material, the PTC conductive composition may also include an additive, such as a photo initiator, cross-link agent, coupling agent, dispersing agent, stabilizer, anti-oxidant and/or nonconductive anti-arcing filler.

As stated above, the core housing 106 encases the protection component 102. In some embodiments, the core housing 106 extends entirely around an outer perimeter of the encapsulation layer 110. For example, the opening 104 of the core housing 106 may be dimensioned to receive the encapsulation layer 110 therein. Although not limited to any particular shape or configuration, the core housing 106 may have a generally rectangular shape. In some embodiments, the core housing 106 is made from a FR-4 glass-reinforced epoxy laminate. In other embodiments, the core housing 106 is made from a ceramic or a moldable material.

The device 100 further includes a first conductive foil layer 112 disposed over a first side 114 of the encapsulation layer 110, and a second conductive foil layer 118 disposed over a second side 120 of the encapsulation layer 110. In embodiments, the first and second conductive foil layers 112, 118 are electrically connected to the protection component 102. Furthermore, each of the first and second conductive foil layers 112, 118 may include one or more layers of conductive material joined together. For example, as more clearly shown in FIGs. 3-4, the first conductive foil layer 112 may include an inner layer 113 coupled to an outer layer 115, while the second conductive foil layer 118 may similarly include an inner layer 119 coupled to an outer layer 121.

As further shown, the device 100 may include a terminal 130 including a first section 132 directly coupled to the first conductive foil layer 112 (e.g., the outer layer 115) and a second section 134 extending substantially perpendicularly from the first section 132. In embodiments, the terminal 130 is an electrically conductive component having a substantially L-shaped side profile. The terminal 130 may include an opening 136, as shown, or may be a solid piece of material. The first section 132 may be joined to the second section 134 at a joint or elbow 140, which may have an increased thickness relative to the first and

second sections

132, 134 to provide more stability and durability when the terminal 130 is joined with other components.

In some embodiments, the horizontally oriented first section 132 of the terminal 130 is electrically connected to the outer layer 115 of the first conductive foil layer 112, which is formed atop or adjacent an upper side of a first bonding layer 148. Such connection may be carried out in any appropriate manner as long as both electric and physical connections are achieved. For example, welding (e.g., resistance welding) , soldering, connecting with an electrically conductive adhesive or an electrically conductive paste, or the like, may be employed. It is noted that the L-shaped terminal 130 forms an angle of 90 degrees between the first section 132 and the second section 134. In other embodiments, however, the angle between the first section 132 and the second section 134 may be approximately 45° to 135°.

When the device 100 is electrically connected to other electric elements (for example, a wiring on a substrate, a pad, a land, an element, an electrode of a battery cell, etc. ) , an electrical connection may be formed between the vertical second section 134 and the other electric element. Due to the shape of the terminal 130, high temperature heat applied when the electric connection is formed (for example, heat by means of heating upon connecting with soldering, welding, an electrically conductive adhesive or the like) is supplied primarily to the vertical second section 134 and not directly to the horizontal first section 132. In other words, an amount of heat transferred to the first section 132 is reduced, which decreases the likelihood of damage to other layers of the device 100.

The device 100 may further include the first bonding layer 148 coupled to a first side 150 of the core housing 106, and a second bonding layer 152 coupled to a second side 154 of the core housing 106. In embodiments, the first and second bonding layers 148, 152 enclose the protection component 102 within the opening 104 of the core housing 106. In some embodiments, the first and second bonding layers 148, 152 are directly coupled to opposite sides of the frame of the core housing 106 and the encapsulation layer 110 so to sandwich those components therebetween. Furthermore, in the example shown, the protection component 102 may be disposed directly atop the second bonding layer 152. In some embodiments, the first and second bonding layers 148, 152 are layers of epoxy. The first and second bonding layers 148, 152 may be coupled to the core housing 106, for example, by injection molding.

The device 100 may further include a plurality of

leads

147, 149 extending from each of the first and second conductive foil layers 112, 118, respectively, wherein the plurality of

leads

147, 149 are electrically connected to the protection component 102. For example, the plurality of leads 147 may extend through a plurality of vias formed through each of the encapsulation layer 110 and the first bonding layer 148, while the plurality of leads 149 may extend through vias formed in the second bonding layer 152. More specifically, as more clearly shown shown in FIG. 4, the first and second bonding layers 148, 152 may be provided with

vias

156 and 158, respectively, while the encapsulation layer 110 may include a plurality of vias 160. The leads 147 may further extend through vias 161 of the inner layer 113 of the first conductive foil 112, while leads 149 may extend through vias 163 of the inner layer 119 of the second conductive foil layer 118. During use, the plurality of

leads

147, 149 provide an electrical connection between the terminal 130 and the protection component 102. In some embodiments, one or more of the

vias

156, 158, 160, 161, and 163 may be formed by mechanical drilling, followed by electro or electroless plating. In other embodiments, the vias may be filled with a conductive paste.

In some embodiments, the protection component 102 is selected from the non-limiting group consisting of: fuses, PTCs, NTCs, ICs, sensors, MOSFETS, resistors, and capacitors. Of these protection components, ICs and sensors are considered to be active protection components, while PTCs, NTCs, and fuses are considered to be passive components. In the embodiment shown, the protection component 102 may be a polymeric PTC. It will be appreciated, however, that this arrangement is non-limiting, and the number and configuration of protection components may vary depending on the application.

The encapsulation layer 110 may be positioned or formed within the core housing 106 so as to cover the protection component 102. In some embodiments, the encapsulation layer 110 may be an injectable epoxy, which is deposited within the opening 104 so as to partially or completely fill the opening 104 and cover the protection component 102. As shown, the encapsulation layer 110 may include vias 160 to provide a connection between the terminal 130, the first conductive layer 112, and the protection component 102. In some embodiments, the encapsulation layer 110 may be a multiple-layer structure with different layers providing different functions. For example, one example 3-layer structure of the encapsulation layer 110 may include a first layer which is oxidization-resistant epoxy, a second layer that is humidity-resistant epoxy, and a third layer that is corrosion-resistant epoxy. It will be appreciated, however, that this tri-layered arrangement is non-limiting, and the number and layers of the encapsulation layer 110 may vary depending on the application.

Turning now to FIGS. 5A-8, illustrated is another example embodiment of an apparatus or device 200 in accordance with the present disclosure. As shown, the device 200, such as a PTC device, includes a protection component 202 disposed within an opening 204 of a core housing 206. The device 200 further includes an encapsulation layer 210 disposed over the protection component 202, the encapsulation layer 210 provided within the opening 204 of the core housing 206. The device 200 further includes a first conductive foil layer 212 disposed over a first side 214 of the encapsulation layer 210, and a second conductive foil layer 218 disposed over a second side 220 of the encapsulation layer 210.

In example embodiments, the first and second conductive foil layers 212, 218 are electrically connected to the protection component 202. As shown, each of the first and second conductive foil layers 212, 218 may include one or more layers of conductive material joined together. For example, as more clearly shown in FIG. 8, the first conductive foil layer 212 may include an inner layer 213 coupled to an outer layer 215, while the second conductive foil layer 218 may similarly include an inner layer 219 coupled to an outer layer 221. In some embodiments, the inner layer 213 and/or the outer layer 215 includes respective upper planar sheets 223A-B, end walls 225A-B, and lower flanges 227A-B. Once the device 200 is assembled, one or more of the lower flanges 227A-B may extend along a bottom surface 231 of a second bonding layer 252, beneath the encapsulation layer 210, as more clearly shown in FIG. 5B and FIG. 6. In some embodiments, the lower flange 227A is generally planar with the second conductive foil layer 218.

As further shown, the device 200 may include a terminal 230 including a first section 232 directly coupled to the first conductive foil layer 212 and a second section 234 extending substantially perpendicularly from the first section 232. In example embodiments, the terminal 230 is an electrically conductive component having a substantially L-shaped side profile. The terminal 230 may include an opening 236, as shown, or may be a solid piece of material. The first section 232 may be joined to the second section 234 at a joint 240, which may have an increased thickness relative to the first and

second sections

232, 234 to provide more stability and durability when joined with other components.

The device 200 may further include a first bonding layer 248 coupled to a first side 250 of the core housing 206, and the second bonding layer 252 coupled to a second side 254 of the core housing 206. In example embodiments, the first and second bonding layers 248, 252 enclose the protection component 202 within the opening 204 of the core housing 206. More specifically, the first and second bonding layers 248, 252 are directly coupled to opposite sides of the frame of the core housing 206 and the encapsulation layer 210 so to sandwich those components therebetween. In some embodiments, the first bonding layer 248 may be disposed directly atop/adjacent the protection component 202. In some embodiments, the first and second bonding layers 248, 252 are layers of epoxy. The first and second bonding layers 248, 252 are coupled to the core housing 206, for example, by injection molding.

As further shown, the device 200 may include a pair of

cutouts

266, 268 provided on opposite ends of the protection component 202. In some embodiments, the pair of

cutouts

266, 268 extend through each of the core housing 206, the first conductive foil layer 212, and the first and second bonding layers 248, 252. In some embodiments, each of the pair of

cutouts

266, 268 may include a rounded indentation that extends inwardly towards the protection component 202. The first conductive foil layer 212 represents an outermost layer/surface of each

cutout

266, 268. The pair of

cutouts

266, 268 are provided to increase the adhesive strength between the terminal 230, the first bonding layer 248, and the first conductive foil layer 212.

The device 200 may further include a plurality of

leads

247, 249 extending from each of the first and second conductive foil layers 212, 218, respectively, wherein the plurality of

leads

247, 249 are electrically connected to the protection component 202 and to the terminal 230. The plurality of leads 247 may extend through a plurality of vias formed through the first bonding layer 248, while the plurality of leads 249 may extend through a plurality of vias formed through the encapsulation layer 210 and the second bonding layer 252. More specifically, the first and second bonding layers 248, 252 may be provided with

vias

256 and 258, respectively, while the encapsulation layer 210 may include a plurality of vias 260. In some embodiments, leads 247 may extend through vias 261 of the inner layer 213 of the first conductive foil layer 212, while leads 249 may extend through vias 263 of the inner layer 219 of the second conductive foil layer 218.

During use, the plurality of

leads

247, 249 provide an electrical connection between the terminal 230 and the protection component 202. Furthermore, the

leads

247 and 249 connect together each inner and outer layer of the first and second conductive foil layers 212, 218, and provide increased adhesive strength between the first and second bonding layers 248, 252 and the first and second conductive foil layers 212, 218. In some embodiments, one or more of the

vias

256, 258, 260, 261, and 263 may be formed by mechanical drilling, followed by electro or electroless plating. In other embodiments, the vias may be filled with a conductive paste.

As stated above, the core housing 206 encases the protection component 202. In some embodiments, the core housing 206 extends entirely around an outer perimeter of the encapsulation layer 210. For example, the opening 204 of the core housing 206 is dimensioned to receive the encapsulation layer 210 therein. As shown, the encapsulation layer 210 may be positioned or formed within the core housing 206 so as to cover the protection component 202. In some embodiments, the encapsulation layer 210 may be an injectable epoxy, which is deposited within the opening 204 so as to partially or completely fill the opening 204 and cover the protection component 202. As shown, the encapsulation layer 210 may include vias 260 to provide a connection between the terminal 230, the first conductive layer 212, and the protection component 202.

Turning now to FIG. 9, a PTC assembly 301 will be described in greater detail. As shown, the assembly 301 includes a device 300, which may be a PPTC device. The device 300 includes many or all of the features previously described in relation to the device 100 and the device 200. As such, only certain aspects of the device 300 will hereinafter be described for the sake of brevity.

In this embodiment, the device 300 includes a terminal 330 including a first section 332 directly coupled to a first conductive foil layer 312 and a second section 334 extending substantially perpendicularly from the first section 332. As shown, the second section 334 is coupled to an electrode 370 of a battery cell 372. The assembly 301 further includes a printed circuit board (PCB) 374 directly coupled to a second conductive foil layer 318 of the device 300. In some embodiments, the battery cell 372 is oriented perpendicular, or substantially perpendicular, to a top surface 378 of the PCB 374. Stated another way, a plane defined by a surface 380 of battery cell 372 is normal to a plane defined by the top surface 378 of the PCB 374. By providing an L-shaped 330 terminal 330, and orienting the battery cell 372 relative to the device 300, as shown, connection between the battery cell 372 and the PCB 374 is made easier, while the overall footprint of the assembly 301 may be reduced.

While the present disclosure has been described with reference to certain approaches, numerous modifications, alterations and changes to the described approaches are possible without departing from the sphere and scope of the present disclosure, as defined in the appended claims. Accordingly, it is intended that the present disclosure not be limited to the described approaches, but that it has the full scope defined by the language of the following claims, and equivalents thereof. While the disclosure has been described with reference to certain approaches, numerous modifications, alterations and changes to the described approaches are possible without departing from the spirit and scope of the disclosure, as defined in the appended claims. Accordingly, it is intended that the present disclosure not be limited to the described approaches, but that it has the full scope defined by the language of the following claims, and equivalents thereof.

Claims

An apparatus, comprising:

a protection component disposed within an opening of a core housing；

an encapsulation layer disposed over the protection component, the encapsulation layer provided within the opening of the core housing；

a first conductive foil layer disposed over a first side of the encapsulation layer；

a second conductive foil layer disposed over a second side of the encapsulation layer, the first and second conductive foil layers electrically connected to the protection component； and

a terminal including a first section directly coupled to the first conductive foil layer and a second section extending substantially perpendicularly from the first section.
The apparatus of claim 1, further comprising:

a first bonding layer coupled to a first side of the core housing； and

a second bonding layer coupled to a second side of the core housing, wherein the first and second bonding layers enclose the protection component within the opening of the core housing.
The apparatus of claim 2, further comprising a plurality of leads extending from each of the first and second conductive foil layers, wherein the plurality of leads are electrically connected to the protection component.
The apparatus of claim 3, further comprising a plurality of vias formed through each of the encapsulation layer, the first bonding layer, and the second bonding layer.
The apparatus of claim 4, wherein the plurality of leads extend through the plurality of vias.
The apparatus of claim 4, further comprising a pair of cutouts provided on opposite ends of the protection component, wherein the pair of cutouts extend through each of: the core housing, the first conductive foil layer, and the first and second bonding layers.
The apparatus of claim 1, further comprising a printed circuit board coupled to the second conductive foil layer.
The apparatus of claim 1, wherein the first conductive foil layer includes a plurality of layers, and wherein one of the plurality of layers is partially disposed over the second side of the encapsulation layer.
The apparatus of claim 1, wherein the second section of the terminal is coupled to an electrode of a battery cell.
A positive temperature coefficient (PTC) device, comprising:

a protection component disposed within an opening of a core housing；

an encapsulation layer disposed over the protection component, the encapsulation layer provided within the opening of the core housing；

a first conductive foil layer disposed over a first side of the encapsulation layer；

a second conductive foil layer disposed over a second side of the encapsulation layer, the first and second conductive foil layers electrically connected to the protection component； and

a terminal including a first section directly coupled to the first conductive foil layer and a second section extending substantially perpendicularly from the first section, wherein the second section is coupled to an electrode of a battery cell.
The PTC device of claim 10, further comprising:

a first bonding layer coupled to a first side of the core housing； and

a second bonding layer coupled to a second side of the core housing, wherein the first and second bonding layers enclose the protection component within the opening of the core housing.
The PTC device of claim 11, further comprising:

a lead extending from each of the first and second conductive foil layers, wherein the lead connects with the protection component； and

a plurality of vias formed through the encapsulation layer, the first bonding layer, and the second bonding layer, wherein the lead extends through one or more of the plurality of vias.
The PTC device of claim 11, further comprising a pair of cutouts provided on opposite ends of the protection component, wherein the pair of cutouts extend through each of the core housing, the first conductive foil layer, and the first and second bonding layers.
The PTC device of claim 10, wherein the second conductive foil layer is directly coupled to a printed circuit board.
The PTC device of claim 10, wherein the first conductive foil layer includes a plurality of layers, and wherein one of the plurality of layers is partially disposed over the second side of the encapsulation layer.
A positive temperature coefficient (PTC) assembly, comprising:

a protection component disposed between a first conductive foil layer and a second conductive foil layer, wherein the first and second conductive foil layers are electrically connected to the protection component by a plurality of leads extending from each of the first and second conductive foil layers；

a terminal including a first section directly coupled to the first conductive foil layer and a second section extending substantially perpendicularly from the first section, wherein the second section is directly coupled to an electrode of a battery cell； and

a printed circuit board coupled to the second conductive foil layer.
The PTC assembly of claim 16, further comprising:

a core housing；

a first bonding layer coupled to a first side of the core housing； and

a second bonding layer coupled to a second side of the core housing, wherein the first and second bonding layers enclose the protection component within an opening of the core housing.
The PTC assembly of claim 17, further comprising an encapsulation layer disposed over the protection component, the encapsulation layer positioned within the opening of the core housing.
The PTC assembly of claim 18, further comprising a plurality of vias formed through each of: the encapsulation layer, the first bonding layer, and the second bonding layer, wherein the plurality of leads extend through one or more of the plurality of vias.
The PTC assembly of claim 16, wherein the battery cell is oriented substantially perpendicularly to a top surface of the printed circuit board.