Ultra-thin micro-battery packaging and handling

Abstract

The present invention provides a microbattery and a method for forming a microbattery. The microbattery and method solve at least one or both of the edge sealing problem for the edge of a stack forming part of a microbattery and the overall sealing of a single battery for a microbattery in a batch process. In an example, a transferable solder forming device and a sealing structure are proposed to provide a metal shell for a solid-state thin film microbattery. The proposed exemplary process involves depositing or pre-forming a low-temperature solder shell separately from the microbattery. The solder shell can then be transferred to each battery cell using hot compression, wherein a processor device is used in a batch process in the example. These exemplary embodiments can address the temperature tolerance constraints of solid-state thin film batteries during processing, metal sealing and packaging.

Description

Background Art

[0001] The present invention relates generally to battery design, construction and use, and more particularly to the handling, sealing and packaging of microbatteries.

[0002] Microbatteries are small, typically single-cell batteries with a wide range of uses, including wearable devices such as wireless earbuds, headphones or hearing aids, watches, calculators, implantable devices such as pacemakers, and other products. Uses range from consumer products to medical and industrial uses.

[0003] However, ultra-thin battery substrates for microbatteries can be very fragile. Such ultra-thin batteries can be, for example, thin-film Li batteries with thicknesses ranging from 0.01 mm to 1 mm. It would be beneficial to address these and other issues with microbatteries. Summary of the invention

[0004] This section is intended to be exemplary and not intended to be limiting.

[0005] In an exemplary embodiment, a microbattery includes a microbattery structure formed in a stack. The stack includes a plurality of surfaces. The microbattery includes a first terminal on one of the surfaces and coupled to an anode of a battery in the microbattery structure. The microbattery includes a second terminal on one of the surfaces and coupled to a cathode of a battery in the microbattery structure. The microbattery also includes a metal-containing film covering at least one surface of the stack.

[0006] Another exemplary embodiment is a method for forming a microbattery. The method includes mounting a thin film battery panel to a processor, the thin film battery panel including a stack having a plurality of microbattery structures formed therein. The thin film battery panel has a surface on an adhesive layer, and the adhesive layer is on a release layer on the processor. The stack includes layers of a substrate, a polymer, and a cover plate. The method includes cutting through the plurality of layers of the stack to at least partially separate the plurality of microbattery structures, and molding solder on the surfaces of the plurality of layers of the stack that have been cut through. The method further includes singulating the plurality of microbattery structures into corresponding individual microbattery units.

[0007] Yet another exemplary embodiment is a method for forming a microbattery. The method includes mounting a plurality of individual cells including a microbattery structure onto a processor. The microbattery structure includes a stack including layers of a substrate, a polymer, and a cover plate. The mounting mounts the microbattery structure on a release layer on the processor. The method includes molding solder on surfaces of the plurality of individual cells and on exposed surfaces of the release layer to produce solder-covered cells. The method also includes singulating the solder-covered cells into a plurality of individual cells. The singulation cuts at least through the solder and reaches the release layer to separate the individual cells. The method includes releasing the plurality of individual cells to form corresponding individual microbatteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 shows hermetic edge sealing of a microbattery, which requires metal deposition and where the microbattery is susceptible to short circuiting when electroplating is used;

[0009] Figure 2 is a schematic diagram of an exemplary proposed method of multiple panel transfer;

[0010] Figure 3 An exemplary embodiment with partial cutting before metal is shown;

[0011] Figure 4 An exemplary embodiment with full cut before metal is shown;

[0012] Figure 5 Other exemplary embodiments with full dicing prior to metal and final liquid crystal polymer (LCP) encapsulation are shown;

[0013] Figure 6 Another embodiment of sorting and placing the sorted units on a glass processor is shown;

[0014] Figure 7 shows solder molding around the cell in an exemplary embodiment;

[0015] Figure 8 is a diagrammatic representation of steps taken during exemplary hot stamping / solder molding and singulation;

[0016] Fig. 9 An alternative technique for hot stamping / solder molding and singulation in an exemplary embodiment is shown;

[0017] Fig.10 is an exemplary embodiment in which a microbattery structure forming process is performed with a "face-up" microbattery; and

[0018] Fig.11 It shows that Fig.10 The face-up approach in can facilitate testing. DETAILED DESCRIPTION

[0019] The word "exemplary" is used herein to mean "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. All of the embodiments described in this detailed description are exemplary embodiments provided to enable persons skilled in the art to make or use the invention and do not limit the scope of the invention which is defined by the claims.

[0020] As an introduction, ultra-thin battery substrates are very fragile. Such ultra-thin batteries can be, for example, thin-film Li batteries with thicknesses ranging from 0.01 mm to 1 mm. For example, during formation and processing, these types of batteries typically require a process temperature window of less than 180C. A processing solution is needed to mold or seal a large number of microbatteries in parallel. In addition, for microbatteries, airtight or near-airtight packaging is desired. However, airtight edge sealing requires metal deposition, and microbatteries are prone to short circuits when electroplating is used. Therefore, dry processes are preferred.

[0021] Steering Figure 1 , Figure 1 The airtight edge seal of the microbattery is illustrated, which requires metal deposition and in which the microbattery is prone to short circuit when using electroplating. Two microbattery structures 10-1, 10-2 are shown at the top, and the microbattery structure 10-2 is shown after the wafer is cut. Only the elements of the microbattery structure 10-2 are marked, but the other microbattery structures 10-1 are similar. The microbattery structure 10-2 includes two through holes 110-1 and 110-2, a current collector 115, a cathode 120 formed at least partially in a solid electrolyte 150, and an anode 125 formed at least partially outside the electrolyte 150 but adjacent to the electrolyte. The via 111 electrically couples the anode 125 to the contact 175, which itself is electrically coupled to the through hole 110-2. The current collector 115 is electrically coupled to the through hole 110-1. These are formed in a stack 180, which includes a substrate 130, a polymer (e.g., a sealing adhesive) 135 and a cover plate 140. The cover plate can be an ultra-thin ceramic, glass, silicon, a high temperature metal film, or an inorganic 2D layered film, such as a graphene film composite. The substrate can be, for example, an ultra-thin ceramic, glass, silicon, a high temperature metal film, or an inorganic 2D layered film, such as a graphene film composite. Typically, the cover plate and the substrate are made of the same material to avoid stress, although this is only an option.

[0022] Figure 1 It is shown that after a single microbattery 10 has been primarily formed into a battery 190, there are two locations where sealing may be problematic. One is location 195 for via sealing issues. The other is location 196 for edge sealing issues.

[0023] Thin film battery substrates with airtight via connections have solved the via sealing problem. However, the edge sealing problem has not been solved. These problems should be solved.

[0024] Exemplary embodiments herein address these and other issues. That is, exemplary embodiments herein address at least one or both of edge sealing issues and overall sealing of individual cells in a batch process.

[0025] In certain exemplary embodiments, a transferable solder molding apparatus and sealing structure is proposed to provide a metal housing for a solid-state thin film microbattery. The proposed exemplary process involves depositing or preforming a low temperature solder housing separately from the microbattery. The solder housing can then be transferred to each battery cell using thermal compression, where a processor device is employed in a batch process. These exemplary embodiments can address temperature tolerance constraints of solid-state thin film batteries during processing, metal sealing, and packaging.

[0026] In one example, first, a suitable processor (glass, Si, Kapton film, etc.) is prepared for the deposition of low-temperature solder (indium, indium-Sn, indium-Sn-bismuth, etc.) to match the microbattery array. Then, a hot compression process with alignment is applied to bond the template to the microbattery substrate. The template is then released. Each individual battery cell is then hermetically sealed with a metal housing.

[0027] The remainder of this disclosure can be divided into the following broad categories. Figure 2 Shown is how a panel such as a thin film battery (or more typically, a microbattery) (TFB) cell can be transferred to a processor via a thin film battery panel transfer. Figure 3 , 4 5 show different processes for producing cells with edge (and overall) seals. These methods are used for TFB (thin film batteries or more commonly "microbatteries") panels, and differ at least in the method of performing a "partial" or "full" cut through the stack in which the microbattery structure is formed. Figure 6 It shows how a single cell (also called a microbattery structure) can be transferred to a processor. Figure 7 , 8 Figures 1 and 2 show different processors that use solder molded sealing edges around the unit and possibly an overall seal. These methods are used for singulated and sorted units. Figure 7 The detailed structure after solder molding is shown. Figure 8 A method of using a solder film is described. Fig. 9 A method using solder transfer is described. Fig.10 and Fig.11 The microbattery structure formation process is carried out using a "face-up" microbattery.

[0028] Steering Figure 2 , which is a schematic diagram of an exemplary proposed method of multi-panel transfer. An array 200 of microbattery structures 100 is illustrated on a processor structure 210. Figure 2 An exemplary embodiment of a micro battery unit transferred to a handler structure 210 (hereinafter referred to as including a glass handler, but this is only an example and Si, kapton film, etc. may be used) is shown, where the component 100-1 of the array 200 has been placed with a thin film battery panel, where the thin film battery unit (in Figure 2 1 and 2. The thin film battery panel 220 is initially built on the processor structure 210 (referred to as a microbattery structure in the example). Reference numeral 240 indicates the removal of the thin film battery panel 220 after the structure 100 in the region 100-1 has been transferred to the processor structure 210 and has been processed to produce individual units (shown as microbattery structures 100). An exemplary process for creating individual units is described below. Note that the thin film battery panel 220 can be removed (as shown by reference numeral 240), but can also be placed on the processor structure 210. In this example, there are four panels 220-1 to 220-4 in the corresponding regions 100-1 to 100-4.

[0029] In more detail, the cells (microbattery structures 100) are formed in panel 220-1, and panels 220-1 to 220-4 in this example are attached to processor 210. After cutting, each panel is removed and the cells are left.

[0030] As far as terminology is concerned, the term "unit" is used herein to refer to a microbattery structure that has been encapsulated on its sides and separated from other microbattery structures. However, this is done without limitation, as the microbattery structure 100 can be referred to as a "unit" because they are separated. However, for the sake of clarity, the microbattery structure and unit definitions are used herein. It should be noted that using these definitions, a unit will include a microbattery structure (e.g., and its corresponding stack 380).

[0031] Steering Figure 3, which shows an exemplary embodiment with partial cutting before the metal. Specifically, there is a partial cutting in step 2, which is before the (metal) solder molding process in step 4. In step 1, the stack 380 of thin film microbattery structures, which in this example includes two microbattery structures 100-1 and 100-2, is mounted on a temporary adhesive 610, which itself is mounted (or formed) on a laser releasable coating 615, which is also mounted (or formed) on a glass processor 620. In step 2, there is a process of cutting through the cover plate 140 and the polymer (e.g., sealing adhesive) 135 and partially cutting into the substrate 130. This cutting can be performed by programmed laser beam scanning with visual alignment. In step 3, the seed layer 630 is sputtered. In step 4, cells 500-1 and 500-2 are formed by singulating microbattery structures 100-1 and 100-2 into cells 500-1 and 500-2 using a laser. Seed layer 630 may be, for example, titanium (approximately in is angstrom) and copper (approx. Angstroms). The Ti / Cu stack is a typical seed layer for plating used for soldering. Terminals 540 are also labeled, and one terminal 540 is shown for each through hole 110 (not labeled in this figure).

[0032] In step 5, a solder forming process is performed. Layer 640 is formed by this process. In step 6, a layer release process releases the cells 500-1, 500-2 to become microbatteries 590-1, 590-2. The microbatteries herein are considered to be cells that have been released from and separated from the processor. Note that this should not be considered limiting, as the cell 500 can potentially be used as a battery even if not released from the processor 620, but for the sake of clarity, this terminology will be adhered to herein.

[0033] Additionally, edge portion 390 of cell (e.g. microbattery) 590 has a thin portion of substrate 130 adjacent the edge (due to the cutting that occurred in step 2) and a thick portion toward the center of the cell's length LC. The cell's length LC is shown, and the front face of the cell has terminals 540.

[0034] Figure 4 An exemplary embodiment with full cut before metal is shown. This embodiment is similar in some respects to Figure 3 but different from Figure 3 For example, compare Figure 4 and Figure 3 , there is a full cut through the substrate 130 in step 2, and Figure 3In the embodiment of the present invention, the full cut through the substrate 130 does not occur until step 4. Again, this cut can be performed by programmed laser beam scanning with visual alignment. Another difference is that in Figure 3 In step 1, the stack 380 is mounted on the temporary adhesive 610, but in this example, the temporary adhesive 610 is patterned into islands 612-1, 612-2, each of which is positioned to be substantially aligned with and formed below and overlying the corresponding microbatteries 100-1, 100-2 and the resulting units 500-1, 500-2 after cutting in step 2. The alignment and formation do not need to be "perfect", but should allow for proper singulation in steps 2-5. In step 2, a process is performed that completely cuts through the substrate 130 and the polymer 135 (and the cover plate 140). This results in the units 500-1 and 500-2 still attached to the glass processor 620.

[0035] In step 3, a seed layer 630 is sputtered onto the exposed surface. In step 4, a solder forming process is performed, which can be IMS (injection molded solder) or plating, to form layer 640. The final step of this portion of the process flow occurs in step 5, where a laser is used to release the cells 500-1, 500-2 from the laser releasable coating 615 and produce individual corresponding microbatteries 590-1, 590-2. Note that for this and other steps where a laser is used to release the cells, some cleaning may be performed, e.g., to remove residual laser releasable coating and temporary adhesive. There are two cleaning methods, e.g., depending on the thickness to be removed: 1) low power laser ablation scan to remove adhesive (e.g., thinner materials), and / or 2) oxygen plasma etching (e.g., thicker materials).

[0036] The length LC of the cell is shown, and the front face of the cell has terminals 540. The length LS of the stack is also shown.

[0037] Steering Figure 5 , which shows another exemplary embodiment with full cutting before metal and final liquid crystal polymer (LCP) encapsulation. In step 1, the stack 380 is mounted to a temporary adhesive 610 (using islands 612-1 and 612-2) with the LCP layer 650 on the glass processor 620. In step 2, a process is used to completely cut through the substrate 130 and polymer 135 (and cover 140). This can be a laser and / or chemical etching process. This is a "full cut" and forms the units 500-1 and 500-2. In step 3, a process is used to sputter a seed layer 630 on the exposed surface. In step 4, a solder molding process such as IMS or plating is performed to form layer 640.

[0038] Figure 5The process in then performs (see step 5) LCP overmolding (a process in which a combination of two or more different materials is used to produce a single component) or injection molding (a manufacturing process in which a component is produced by injecting molten material into a mold) and joins to the planar layer, which forms an LCP layer 660 on the exposed surface, including joining with the LCP layer 650. Joining may involve other operations, such as heating to a specific temperature range for a specific period of time. This joining essentially produces a single polymer film 660+650. Overmolding thus structurally connects the two units 500-1, 500-2 via the LCP layer 660 and fills the previously unfilled area 570 that existed between the previously singulated units 500.

[0039] In step 6, a laser singulation process is used, which releases the cells 500-1 and 500-2 to form respective microbatteries 590-1, 590-2 and opens the LCP layer 650 over the pads or vias. This example shows openings 680 over the vias 110 and reaching at least some portion of the terminals 540. There is an additional option of filling the positive (pos) and negative (neg) connections (i.e., openings 680) with conductors (solder or metal - such as plated Cu / Ni / gold).

[0040] Go to Figure 6 , which shows another embodiment of picking and placing the sorted units onto the glass processor. This further demonstrates the use of a temporary adhesive to hold the singulated units. In this example, the unit 500-2 has been placed onto the island 612-2 of the temporary adhesive 610, and the reference numeral 90 indicates that the arm for picking and placing is to place the unit 500-2 onto the island 612-1 of the temporary adhesive 610. This results (see reference numeral 10) in that the sorted units 500-1, 500-2 are placed onto the temporary adhesive 610, which itself is on the laser releasable coating 615 of the glass processor 620.

[0041] Figure 7 The solder molding around the cells 500-1, 500-2 in an exemplary embodiment is shown. Figure 7 , units 500-1 and 500-2 have been formed by processing, and they are separate forms of the corresponding microbattery structures 100-1, 100-2. That is, the microbattery structures 100-1, 100-2 are formed using layers and separated into corresponding units 500-1, 500-2 using singulation. Units 500-1 and 500-2 are shown as being formed on a release layer 615, which itself is formed on a glass processor 620. Units 500-1, 500-2 are attached to the release layer 615 via a temporary adhesive 610. The temporary adhesive 610 is below a portion of the unit 500, which is void and not covered by the solder 520.

[0042] like Figure 7 As shown, there are multiple options for solder molding, including one or more of the following: use of a temporary adhesive; use of injection molding; or use of a preformed metal foil. Note that a temporary adhesive 610 can be added by the techniques herein, for example in an island 612 or via layers and patterning. In more detail, the temporary adhesive is only used to temporarily hold the unit to allow the solder molding process to proceed. The temporary adhesive can be dispensed by one or more of a syringe, printing, stenciling, spraying, or photolithographic patterning. This applies to all embodiments where a temporary adhesive 610 is used.

[0043] Injection molding refers to injecting the solder alloy around the unit by known injection molding techniques. Preformed metal foil is another possible technique also described with respect to other figures, but uses a preformed metal foil applied to the unit (e.g., see the following description) Figure 8 ).

[0044] After release from release layer 615, each of cells 500-1 and 500-2 will become a microbattery, although only a single microbattery 590 is shown. For ease of reference and clarity, reference numerals used previously are used herein, such as in Figure 1 That is, similar elements are labeled with the same reference numerals, although the elements may only be similar and may have differences, such as in composition. Microbattery 590 (and corresponding unit 500-1 or 500-2) includes the following items, all covered by solder 520: top cover 530; anode 125; sealing adhesive 555; solid electrolyte 150; cathode 120; via 111, contact 175 and current collector 115. All of these elements are formed on substrate 130, which is partially surrounded by solder 520. Terminals 540 are shown, such as through holes 110 extending through substrate 130 to contact current collector 115 or contact 175. Cathode 120 is at least partially formed within solid electrolyte 150, and anode 125 is at least partially formed outside electrolyte 150 but adjacent to electrolyte 10. Via 111 electrically couples anode 125 to contact 175, which itself is electrically coupled to through-hole 110-2. Current collector 115 is electrically coupled to through-hole 110-1. Cap 530 is Figure 1 The cut version of the cover plate 140 is shown in FIG. The sealing adhesive 555 is Figure 1 An example of polymer 135.

[0045] Figure 8 is an illustration of the steps taken during an exemplary hot stamping / solder molding and singulation. After the transfer in step 310, (a portion of) the processor structure 210 is shown. The term "post-transfer" refers to the process of transferring the processor structure 210 to the substrate. Figure 2Or after the microbattery structure 100 in 6 is transferred to the glass processor 620. That is, the thin film microbattery structure is first built on the panel, and then these microbattery structures are singulated and transferred to the glass processor. In this example, the processor structure 210 includes a release layer 615 and a glass processor 620. Eight microbattery structures 100-1 to 100-8 are shown in this example. In step 320, a foil 350 is applied to the top of the structure 100. The low temperature solder foil can be In, InSn, SnBi, indium-Sn-bismuth, etc. For example, the melting point of In is 157C and the melting point of InSn is 119C. Low temperature solder can be defined as, for example, less than 160C. The top surface 301 and side surface 302 of the microbattery structure 100 are shown, and the top surface 361 of the release layer 615 is also shown.

[0046] In step 330, there is a solder molding operation (which can also be, for example, a hot stamping operation) that molds the solder foil 350 to the surfaces 301, 302, and 361. As is known, during the molding process, molten solder is injected into the surface and the solder will flow to fill any gaps, and then a compression process is applied to form the final shape. In hot stamping, a preformed thin solder film is first laminated on the top surface. As the temperature increases, the solder film will melt and flow to any gaps. Each individual battery cell is then hermetically sealed with a metal housing. Step 340 shows the result after final singulation (e.g., by laser cutting), in which each of the microbattery structures 100-1 to 100-8 is divided into corresponding units 500-1 to 500-8. After this (or after additional processing), a release process is performed in box 360 to form a microbattery.

[0047] refer to Fig. 9, which shows an alternative technique for hot stamping / solder forming and singulation. This technique begins after transfer 310. In step 420, a temporary structure 480 (which can be a plate, film, template, etc.) is applied to the processor structure 210, where the microbattery structure 100 is on the structure 210. There is a preformed (and pre-patterned) low-temperature solder 450 added as islands 460-1 to 460-8. The application in step 420 is performed so that the islands 460-1 to 460-8 are substantially aligned with the corresponding microbattery structures 100-1 to 100-8. That is, in an exemplary embodiment, step 330 is an illustration of a hot compression process with alignment, which is applied to bond the temporary structure 480 including the islands 460 to the microbattery substrate. The structure 480 is then released in step 435. The pattern and width W1 of the spots 460 are designed relative to the pattern and width W2 of the microbattery structures 100 so that after solder molding in step 430, the solder 450 encapsulates each microbattery structure 100 after temporary structure removal 435 and after the resulting singulation 440. That is, the side 302 of the microbattery structure 100 is encapsulated to the top surface 361 of the release layer 615, and the top surface 301 is also encapsulated, but there is a situation where the microbattery structures 100-1 to 100-8 are singulated into corresponding units 500-1 to 500-8. In addition, the solder molding 430 is defined and performed to achieve such encapsulation. That is, the preformed solder islands will define the total volume and thickness of the molding. After singulation (or after additional processing), a release process is performed in frame 360 ​​to form a microbattery.

[0048] Fig.10 630. In the "face up" microbattery orientation, the face including the through holes 110-1 and 110-2 and the corresponding terminals 540-1, 540-2 are facing away from the surface 1010 of the substrate 630. See FIG. Fig. 9 and units 1000-1 and 1000-2. Only Fig. 9 Applicable to this exemplary embodiment, the predefined solder frame (rather than the solder island) must also be repositioned to align only with the gap. Otherwise, the solder will short the two terminals 540. These units 1000 have a temporary adhesive 610 residing in the indicated position. This orientation can be achieved using one or more of the following techniques: use of a temporary adhesive 610; use of injection molding; and / or use of a pre-deposited solder frame.

[0049] refer to Fig.11 , the figure shows that Fig.10 The face-up approach in FIG. 1000 can facilitate testing 1120. In this example, unit 1000-1 has two probes 1110-1 and 1110-2 for contacting respective terminals 540-1, 540-2. Units 1000-1 and 1000-2 are shown after temporary adhesive 610 has been removed from the "top" surface 131 of substrate 130 and from around terminals 540-1 and 540-2. Thus, probe 1110 can be used to test a microbattery. Laser release 1030 is also shown, producing a separated microbattery, wherein microbattery 1090 is shown.

[0050] Although in the above embodiment, the terminals 540 and corresponding through-holes 110 are illustrated as being on the same side (one side with the substrate 130, which is merely exemplary), the terminals 540 (eg, and corresponding through-holes 110) may be on opposite sides or even on sides perpendicular to each other.

[0051] In the foregoing description, many specific details, such as specific structures, components, materials, dimensions, processing steps and techniques are described to provide a thorough understanding of the exemplary embodiments disclosed herein. However, it will be understood by those of ordinary skill in the art that the exemplary embodiments disclosed herein can be practiced without these specific details. In addition, the details of the known structures or processing steps may be omitted or may not be described to avoid blurring the presented embodiments. It will be understood that when an element as a layer, region or substrate is referred to as "on" or "above" another element, it may be directly on another element, or there may also be an intermediate element. On the contrary, when an element is referred to as "directly on" or "directly above another element", there is no intermediate element. It should also be understood that when an element is referred to as "under" or "below" another element, it may be directly under or below another element, or there may be an intermediate element. On the contrary, when an element is referred to as "directly under" or "directly below another element", there is no intermediate element.

[0052] In various embodiments, the following has been shown:

[0053] A solder molded thin film Li battery (e.g., thickness: 0.01 mm–1 mm);

[0054] A temporary processor method for solid-state thin-film microbatteries;

[0055] Use low temperature solder molding to avoid thermal shock to thin film Li-microbatteries;

[0056] Overmolding microbatteries using preformed solder foil;

[0057] Pre-depositing patterned solder using IMS to transfer and over-mold microbatteries;

[0058] Using IMS and LCP overmolding or injection molding to provide environmental and biocompatible encapsulation that supports low / no O2 and H2O transport with the IMS, and environmental and biocompatible packaging with the LCP; and / or

[0059] Use of pre-patterned adhesives for temporary bonding of thin film Li-microbatteries.

[0060] The flow charts and block diagrams in the accompanying drawings show the architecture, functions and operations of the possible implementations of the system, method and computer program product according to various embodiments of the present invention. To this end, each box in the flow chart or block diagram may represent a module, segment or part of an instruction, which includes one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the box may not occur in the order marked in the figure. For example, depending on the functions involved, the two blocks shown in succession can actually be executed substantially simultaneously, or these blocks can sometimes be executed in reverse order. It should also be noted that each box in the block diagram and / or flow chart, and the combination of the boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs a specific function or action or performs a combination of dedicated hardware and computer instructions.

[0061] In a preferred embodiment of the invention described herein, there is provided a method for forming a microbattery, comprising: mounting a plurality of individual cells comprising a microbattery structure onto a processor, the microbattery structure comprising a stack, the stack comprising layers of a substrate, a polymer, and a cover, wherein the mounting mounts the microbattery structure onto a release layer on the processor; molding solder on surfaces of the plurality of individual cells and on exposed surfaces of the release layer to produce solder-covered cells; singulating the solder-covered cells into the plurality of individual cells, the singulation at least cutting through the solder and cutting through to the release layer to separate the individual cells; and releasing the plurality of individual cells to form respective individual microbatteries. Molding solder may include applying a low temperature solder foil on top surfaces of the individual cells and on the release layer, and performing a solder molding process to mold the solder foil to the exposed surfaces of the cells and to the exposed surface of the release layer. Molding solder may include: applying a temporary structure including an island of low temperature solder foil on the top surface of the individual cells and on the release layer, wherein the island of low temperature solder foil is defined to encapsulate the corresponding individual cells; performing a solder molding process to mold the solder foil to the exposed surface of the cells; and performing a process of releasing the temporary structure. The stack may be mounted so that the cover is closer to the processor than the substrate, and the substrate is opposite to the cover, and the method may also include: forming a through hole through the substrate and connected to the positive and negative nodes of the microbattery cells formed in the stack; and forming a terminal coupled to the through hole, wherein the terminal is formed on the surface of the substrate and opposite to the surface of the stack on the release layer.

Claims

1. A microbattery comprising: A microbattery structure formed in a stack, the stack comprising a plurality of surfaces formed using a plurality of layers, the plurality of surfaces comprising a substrate layer and a cover layer, a first side of the plurality of surfaces being a surface of the substrate layer, a second side of the plurality of surfaces being a surface of the cover layer, the first side and the second side being on opposite sides of the stack, and side surfaces of the plurality of surfaces being opposite edges of the stack spanning between the substrate layer and the cover layer; a first terminal on the first side and coupled to an anode of a battery in the microbattery structure; a second terminal located on the first side and coupled to a cathode of the battery in the microbattery structure; as well as A metal-containing film covers the side surface, at least a portion of the second side adjacent to the edge, and a portion of the first side of the stacked body, but does not cover the first terminal and the second terminal.

2. The microbattery according to claim 1, wherein: The metal-containing film includes solder.

3. The microbattery according to claim 1, wherein: The plurality of surfaces include two side surfaces, and the metal-containing film covers at least two sides of the surface of the stacked body. 4 . The microbattery of claim 3 , wherein the plurality of surfaces include a front side where the first terminal and the second terminal are located and another side opposite the front side, and wherein the metal-containing film additionally covers another side of the stack.

5. The microbattery according to claim 4, wherein: The stack includes a substrate, a polymer, and multiple layers of a cover sheet, the cover sheet layer being on the other side of the stack and covered by the metal-containing film, and the substrate being on the front side; The stack has a length between two sides, and the layers are parallel along the length; removing at least the polymer layer and the cover layer from over a region of the substrate adjacent to an edge of the microbattery; The metal-containing film comprises a metal; and A solder film covers the surface of the metal-containing film.

6. The microbattery according to claim 5, wherein: The substrate is thicker at about the midpoint of the length and thinner at the ends of the stack, and at least the polymer and top cover layer are removed from over the thinner regions of the substrate adjacent the edges of the microbattery.

7. The microbattery according to claim 4, wherein: The stack includes a substrate, a polymer, and multiple layers of a cover sheet, the cover sheet layer being on the other side of the stack and covered by the metal-containing film, and the substrate being on the front side; The stack has a length between two sides, and the layers are parallel along the length; The metal-containing film includes a metal; A solder film covers the surface of the metal-containing film; and The substrate on the front side has a surface that is not covered by the metal-containing film or the solder film.

8. The microbattery according to claim 4, wherein: The stack includes a substrate, a polymer, and multiple layers of a cover sheet, the cover sheet layer being on the other side of the stack and covered by the metal-containing film, and the substrate being on the front side; The stack has a length between two sides, and the layers are parallel along the length; The metal-containing film includes a metal; A solder film covers the surface of the metal-containing film; a polymer covers the surface of the solder film; The substrate on the front side is at least partially covered with an adhesive, and the front side includes two terminals coupled to vias, the vias extending through the substrate layer; a polymer film covering a surface of the solder film and a surface of the adhesive opposite to a surface of the adhesive covering the substrate; as well as A plurality of openings are formed in the polymer film to expose at least a portion of respective terminals.

9. The microbattery according to claim 8, wherein: The opening is filled with a conductor.

10. The microbattery according to claim 4, wherein: The stack includes a substrate, a polymer, and multiple layers of a cover sheet, the cover sheet layer being on the other side of the stack and covered by the metal-containing film, and the substrate being on the front side; The stack has a length between two sides, and the layers are parallel along the length; The metal-containing film comprises solder; and The metal-containing film covers a portion of the substrate, and the remaining portion of the substrate has a surface that is not covered by the metal-containing film.

11. The microbattery according to claim 1, wherein: The thickness of the microbattery is in the range of 0.01 mm to 1 mm.

12. A method for forming a microbattery, comprising: mounting a thin film battery panel onto a processor, the thin film battery panel comprising a stack having a plurality of microbattery structures formed therein, wherein the thin film battery panel has a surface on an adhesive layer, and the adhesive layer is on a release layer on the processor, wherein the stack comprises layers of a substrate, a polymer, and a cover sheet; cutting through the plurality of layers of the stack to at least partially separate the plurality of microbattery structures; molding solder on the surfaces of the plurality of layers of the stacked body that have been cut through; as well as singulating the plurality of microbattery structures into corresponding individual microbattery units; The adhesive layer is not covered by solder.

13. The method according to claim 12, wherein: cutting through the plurality of layers of the stack to at least partially separate the plurality of microbattery structures cutting through the plurality of layers of the stack but leaving at least a portion of the layers between the plurality of microbattery structures; Molding solder on the surfaces of the plurality of layers of the stacked body that have been cut through further comprises: forming a seed layer on the exposed surface of the stack that has been cut through; singulating the plurality of microbattery structures into units; and molding solder onto exposed surfaces of the singulated units, the molded solder causing the singulated units to be attached to the processor via the adhesive layer; Singulating the plurality of microbattery structures into corresponding individual microbattery cells also includes releasing by releasing the cells using a laser to form the individual microbattery cells.

14. The method of claim 12, wherein: The mounting includes mounting the thin film battery panel onto the processor, wherein the islands of the adhesive layer have been formed on the release layer, and the islands are substantially aligned with and formed to cover corresponding microbattery structures; cutting through a plurality of layers of the stack to at least partially separate the plurality of microbattery structures cutting through all layers of the stack to singulate the microbattery structures into units; Molding solder on the surfaces of the plurality of layers of the stacked body that have been cut through further comprises: forming a seed layer on the exposed surfaces of the singulated units; and molding solder on the exposed surfaces of the singulated units; Singulating the plurality of microbattery structures into corresponding individual microbattery cells also includes releasing by releasing the cells using a laser to form the individual microbattery cells.

15. The method according to claim 14, wherein: Molding the solder is performed via one or both of plating or molding using injection molding.

16. The method of claim 12, wherein: The mounting includes mounting the thin film battery panel onto the handler, wherein islands of the adhesive layer have been formed on the release layer, and the islands are substantially aligned with and formed to cover corresponding microbattery structures, and wherein the adhesive layer is on a polymer film and the polymer film is on the release layer on the handler; cutting through a plurality of layers of the stack to at least partially separate the plurality of microbattery structures cutting through all layers of the stack to singulate the microbattery structures into units, but not completely cutting through the polymer film; Molding solder on the surfaces of the plurality of layers of the stacked body that have been cut through further comprises: forming a seed layer on exposed surfaces of the singulated units; molding solder on exposed surfaces of the singulated units, the molding solder being performed to remove the solder from the exposed surfaces of the polymer film; The method further includes performing overmolding of a polymer over the exposed surface of the solder and over the exposed surface of the second polymer layer, wherein the performing of the overmolding fills unfilled locations between the singulated cells and joins the overmolded polymer to the polymer film on the release layer to produce a single polymer film; and Singulating the plurality of microbattery structures into corresponding individual microbattery cells further includes singulating the cells by cutting completely through the individual polymer film using laser singulation, and releasing by using laser release of the cells to form the individual microbattery cells.

17. The method according to claim 16, wherein: The substrate is on the front side of the stack, the substrate is on the adhesive layer, wherein there are multiple terminals on the front side and the multiple terminals are coupled to through holes extending through the substrate layer, and the method further includes cutting through the polymer film and through the opening of the adhesive layer to expose at least a portion of the corresponding terminal. The method of claim 17 , further comprising filling the opening with a conductor.

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