Packaging and handling of ultra-thin microbatteries

Abstract

Microbatteries and methods for forming microbatteries are provided. The microbatteries and methods address at least one or both of edge sealing issues for the edges of stacks forming portions of the microbattery and overall sealing for individual cells of the microbattery in a batch process. A movable solder forming apparatus and sealing structure is proposed in one example to provide a metal casing for a solid-state thin-film microbattery. The exemplary proposed process includes depositing or preforming a low-temperature solder casing separately from the microbattery. A handler apparatus in one example can then transfer the solder casing to each battery cell using thermal compression in a batch process. These exemplary embodiments can address temperature tolerance constraints for solid-state thin-film batteries during handling, metal sealing, and packaging.

Description

[Technical field]

[0001] The present invention relates generally to the design, construction and use of batteries, and more specifically to the handling, sealing and packaging of microbatteries. [Background technology]

[0002] Microbatteries are small, typically single-cell batteries that have a wide range of applications, including wearable products such as wireless earbuds, earpods or hearing aids, watches, calculators, implanted devices such as pacemakers, and other products. Applications range from consumer products to medical and industrial applications.

[0003] However, ultra-thin battery substrates for microbatteries 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. It would be beneficial to address this and other issues with microbatteries. Summary of the Invention

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

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

[0006] An additional exemplary embodiment is a method for forming a microbattery. The method includes mounting a thin film battery panel on a handler, the thin film battery panel comprising a stack having a plurality of microbattery structures formed therein. The thin film battery panel has a surface on an adhesive layer, the adhesive layer being disposed on a release layer on the handler. The stack comprises a substrate, a polymer, and a cover plate layer. The method includes cutting through the layers of the stack to at least partially separate the plurality of microbattery structures, and forming solder on a surface of the layers of the cut stack. The method further includes singulating the plurality of microbattery structures into corresponding individual microbattery cells.

[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 on a handler. The microbattery structure includes a laminate including a substrate, a polymer, and a cover plate layer. The mounting mounts the microbattery structure on a release layer on the handler. The method includes molding solder on a surface of the plurality of individual cells and on an exposed surface of the release layer to create solder coated cells. The method further includes singulating the solder coated cells into a plurality of individual cells. The singulating cuts at least through the solder to the release layer to separate the individual cells. The method includes peeling the plurality of individual cells to form individual microbatteries. [Brief description of the drawings]

[0008] [Figure 1] 1 illustrates edge hermetic sealing of a microbattery that requires metal deposition and is prone to shorting if electroplating is used. [Diagram 2] FIG. 1 illustrates an exemplary proposed approach for multiple panel movement. [Figure 3A] 1 illustrates an exemplary embodiment with a partial cut prior to the metal. [Figure 3B]1 illustrates an exemplary embodiment with a partial cut prior to the metal. [Figure 4A] 1 shows an exemplary embodiment with a full cut before the metal. [Figure 4B] 1 shows an exemplary embodiment with a full cut before the metal. [Figure 5A] 13 shows another exemplary embodiment with a full cut before metal and final liquid crystal polymer (LCP) encapsulation. [Figure 5B] 13 shows another exemplary embodiment with a full cut before metal and final liquid crystal polymer (LCP) encapsulation. [Figure 6] 13 shows an alternative embodiment in which the sorted cells are picked and placed on a glass handler. [Figure 7] 1 illustrates a solder mold around the cell in an exemplary embodiment. [Figure 8] FIG. 1 is a diagram of the steps performed during hot embossing / solder forming and singulation. [Figure 9] 1 illustrates alternative techniques for hot embossing / solder forming and singulation in an exemplary embodiment. [Figure 10] 1 illustrates an exemplary embodiment in which the microbattery structure formation process is performed with the microbattery "face up." [Figure 11] It is shown that the face up approach in FIG. 10 can facilitate inspection. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. All embodiments described in this detailed description are exemplary embodiments provided to enable any person skilled in the art to make or use the invention and are not intended to limit the scope of the invention, which is defined in the claims.

[0010] As a preamble, 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 handling, these types of batteries typically require a process temperature window of less than 180°C. Handling solutions are needed to mold or seal large numbers of microbatteries in parallel. Additionally, hermetic or near-hermetic packaging is desirable for microbatteries. However, edge hermetic sealing requires metal deposition, which makes the microbatteries susceptible to shorting if electroplating is used.

[0011] Referring now to FIG. 1, this shows the edge hermetic sealing of a microbattery, which requires metal deposition and is prone to shorts if electroplating is used. Two microbattery structures 10-1, 10-2 are shown at the top, with the microbattery structure 10-2 shown after cutting the wafer. Only the elements of the microbattery structure 10-2 are labeled, but the other microbattery structure 10-1 is similar. The microbattery structure 10-2 comprises two through vias 110-1 and 110-2, a current collector 115, a cathode 120 formed at least partially inside the solid electrolyte 150, and an anode 125 formed at least partially outside the electrolyte 150 but abutting the electrolyte. The via 111 electrically couples the anode 125 to a contact 175, which is itself electrically coupled to the through via 110-2. The current collector 115 is electrically coupled to the through via 110-1. These are formed in a laminate 180 comprising a substrate 130, a polymer (e.g. sealing adhesive) 135 and a copper plate 140. The cover plate can be an ultra-thin ceramic, glass, silicon, high temperature metal film or an inorganic 2D laminate film such as a graphene film composite. The substrate can be an ultra-thin ceramic, glass, silicon, high temperature metal film or an inorganic 2D laminate film such as a graphene film composite. Typically the cover plate and the substrate are made of the same material to avoid stresses, but this is only one option.

[0012] 1 shows that after a single microbattery 10 is formed, primarily as a cell 190, there are two places where sealing can be an issue: at location 195 for via sealing issues, and at location 196 for edge sealing issues.

[0013] Thin film battery substrates with hermetic via connections address the via sealing issue, but the edge sealing issue remains. These issues must be addressed.

[0014] Exemplary embodiments herein address these and other issues, i.e., address at least one or both of individual cell end sealing issues and global sealing in batch processes.

[0015] In certain exemplary embodiments, a movable solder forming apparatus and sealing structure is proposed to provide a metal casing for a solid-state thin-film microbattery. The proposed exemplary process includes deposition or pre-forming of a low-temperature solder casing separate from the microbattery. The solder casing can then be transferred to each battery cell using thermal compression by a handler apparatus in a batch process. These exemplary embodiments can address temperature tolerance constraints for solid-state thin-film batteries during handling, metal sealing, and packaging.

[0016] In one example, a first suitable handler (glass, Si, Kapton film, etc.) is prepared for deposition of a low temperature solder (Indium, Indium Sn, Indium Sn Bismuth, etc.) that conforms to the array of microbatteries. Then an aligned thermo-compression process is applied to bond the template to the microbattery substrate. The template is then peeled off. Then each individual battery cell is hermetically sealed by a metal casing.

[0017] The remainder of this disclosure can be divided into broad categories as follows: Figure 2 shows how a panel such as a thin film battery (or more typically, a microbattery) (TFB) cell can be transferred to a handler by a thin film battery panel transfer. Figures 3A, 3B, 4A, 4B, 5A, and 5B show various processes for creating cells with edge (or full) sealing. These approaches are for TFB (thin film battery, or more generally "microbattery") panels and differ at least in the approach when a "partial" or "full" cut is made through the stack from which the microbattery structure is formed. Figure 6 shows how individual cells (also called microbattery structures) can be transferred onto a handler. Figures 7, 8, and 9 show various processes for edge sealing with solder molding around the cells and possibly full sealing. These approaches are for singulated and sorted cells. Figure 7 shows the detailed structure after solder molding. Figure 8 shows the approach using solder film. Figure 9 shows the approach by solder transfer. 10 and 11 show the case where the microbattery structure formation process is carried out with the microbattery "face up".

[0018] Reference is now made to FIG. 2, which is a diagram of an exemplary proposed approach for multiple panel transfer. An array 200 of microbattery structures 100 is shown on top of a handler structure 210. FIG. 2 shows an exemplary embodiment of a microbattery cell transfer to a handler structure 210 (possibly including a glass handler underneath, but this is only an example, Si, Kapton film, etc. could also be used), where a portion 100-1 of the array 200 is placed by a thin-film battery panel, and the thin-film battery cells (shown as microbattery structures in FIG. 2) are built first. Reference numeral 240 indicates that the thin-film battery panel 220 is removed after the structures 100 in area 100-1 are transferred to the handler structure 210 and processed to create individual cells shown as microbattery structures 100. An exemplary process for creating individual cells is described below. Note that the thin-film battery panel 220 can be removed (as in reference numeral 240), but can also be placed on top of the handler structure 210. In this example, four panels 220-1 to 220-4 are present in corresponding regions 100-1 to 100-4.

[0019] In additional detail, the cells (microbattery structure 100) are formed in panel 220-1, and panels 220-1 through 220-4 are mounted on a handler 210 in this example. After cutting, each panel is removed, leaving the cells.

[0020] With regard to terminology, the term "cell" is used herein to refer to a microbattery structure that has an encapsulated aspect and is separate from other microbattery structures. This is done without limitation, but the microstructures 100 could be referred to as "cells" since they are separate. However, for clarity, the definitions of microbattery structure and cell are used herein. It should be noted that by these definitions, a cell is meant to include a microbattery structure (e.g., its corresponding stack 380).

[0021] 3A and 3B, these figures show an exemplary embodiment with a partial cut before the metal. In particular, there is a partial cut in step 2 before the (metal) solder forming process in step 4. In step 1, a stack 380 of thin-film microbattery structures, including two microbattery structures 100-1 and 100-2, is mounted on a temporary adhesive 610, which in this example is itself placed (or formed) on a laser-peelable coating layer 615, which is further placed (or formed) on a glass handler 620. In step 2, a process of cutting through the cover plate 140 and the polymer (e.g., sealing adhesive) 135 to a portion of the substrate 130 is performed. Such cutting can be performed by scanning a programmed laser beam with visual alignment. In step 3, a seed layer 630 is sputtered. In step 4, cells 500-1 and 500-2 are created by singulating microbattery structures 100-1 and 100-2 into cells 500-1 and 500-2 using a laser. Seed layer 630 could be, for example, titanium (about 300 Å, where Å is angstroms) and copper (about 1000 Å, angstroms). A Ti / Cu stack is a typical seed layer for plating solder. Terminals 540 are also marked, one terminal 540 shown for each through via 110 (not marked in this view).

[0022] In step 5, a solder molding process is performed. Layer 640 is formed by this process. In step 6, a delamination process delaminates cells 500-1 and 500-2 to become microbatteries 590-1, 590-2. In this specification, a microbattery is considered to be a cell that has been delaminated from the handler and separated from the handler. Note that this should not be considered limiting as cell 500 can be used as a battery even if it is not delaminated from handler 620 in some cases, but this term is used herein for clarity.

[0023] Note that the end 390 of the cell (e.g., microbattery) 590 has a thinner portion of the substrate 130 adjacent the end and a thicker portion toward the center of the length LC of the cell. The length LC of the cell is shown, and the face side of the cell has terminal 540.

[0024] 4A and 4B show an exemplary embodiment with a full cut before the metal. This embodiment is similar to the embodiment of FIG. 3, but differs in certain respects. For example, comparing FIG. 4 to FIG. 3, in step 2 there is a full cut through the substrate 130, whereas in FIG. 3 the full cut through the substrate 130 is not made until step 4. Again, such cutting can be done by a programmed laser beam scanning with visual alignment. Another difference is that in step 1 of FIG. 3 the laminate 380 is mounted on a 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, formed beneath and over the corresponding microbatteries 100-1, 100-2 and the resulting cells 500-1, 500-2 after the cutting in step 2 is made. This alignment and formation need not be "perfect", but does allow for proper singulation in steps 2-5. In step 2, a process is performed that cuts completely through substrate 130 and polymer 135 (and cover plate 140). This results in cells 500-1 and 500-2, which are still attached to glass holder 620.

[0025] In step 3, a seed layer 630 is sputtered onto the exposed surface. In step 4, a solder molding process is performed, which can be IMS (injection molded solder) or plating, to form layer 640. The final step in this portion of the process flow is performed in step 5, where a laser is used to peel the cells 500-1, 500-2 from the laser strippable coating layer 615 to create individual corresponding microbatteries 590-1, 590-2. It should be noted that with this and other steps of peeling the cells with a laser, some cleaning can be performed, for example, to remove residual laser strippable coating layer and temporary adhesive. For example, depending on the thickness to be removed, there are two approaches to cleaning: 1) low power laser ablation scanning to remove adhesive (e.g., thinner materials), or 2) oxygen plasma etching (e.g., thicker materials), or both.

[0026] The length LC of the cell is shown, with the front side of the cell having terminal 540. The length LS of the stack is also shown.

[0027] 5A and 5B, which show another exemplary embodiment with a full cut before metal and final liquid crystal polymer (LCP) encapsulation. In step 1, the laminate 380 is mounted (with islands 612-1 and 612-2) on a temporary adhesive 610 with an LCP layer 650 on a glass handler 620. In step 2, a process is used to cut all the way through the substrate 130 and polymer 135 (and cover plate 140). This can be a laser or chemical or both etching process. This is the "full cut" and forms the cells 500-1 and 500-2. In step 3, a process is used to sputter a seed layer onto the exposed surfaces. In step 4, a solder forming process such as IMS or plating is performed to form layer 640.

[0028] 5A and 5B process then proceeds with overmolding (a process where a single part is created using a combination of two or more different materials) or injection molding (a manufacturing process for creating a part by injecting molten material into a mold) of LCP and bonding (see step 5) to the planar layer, thereby forming an LCP layer 660 covering the exposed surfaces, including bonding with the LCP layer 650. This bonding may include other operations such as heating to a certain temperature range for a certain time. This bonding essentially creates a single polymer film, 660+650. Thus, the overmolding structurally connects the two cells 500-1, 500-2 via the LCP layer 660, filling the previously unfilled area 570 that existed between the previously singulated cells 500.

[0029] In step 6, a laser singulation process is used to peel the cells 500-1 and 500-2 to form corresponding microbatteries 590-1, 590-2 and open the LCP layer 650 over the pads or vias. This example shows an opening 680 over the through via 110, for at least some portion of the terminal 540. There is an additional option to fill the positive (pos) and negative (neg) connections with conductors (solder or metal, e.g. plated Cu / Ni / Au).

[0030] Referring to FIG. 6, this figure shows another embodiment of picking and placing the selected cells on a glass handler. This figure further shows the use of a temporary adhesive to hold the singulated cells. In this example, cell 500-2 is already placed on island 612-2 of temporary adhesive 610, and reference number 90 indicates an arm for picking cell 500-1 and placing it on island 612-1 of temporary adhesive 610. This results in the selected cells 500-1, 500-2 being placed on the temporary adhesive 610 on top of the laser-peelable coating layer 615 of the glass handler 620 (see reference number 10).

[0031] FIG. 7 illustrates solder molding around cells 500-1, 500-2 in one exemplary embodiment. With reference to FIG. 7, cells 500-1, 500-2 are fabricated and are separated versions 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 the corresponding cells 500-1, 500-2 using singulation. Cells 500-1, 500-2 are shown formed on a release layer 615 formed on a glass handler 620. Cells 500-1, 500-2 are attached to the release layer 615 via a temporary adhesive 610. The temporary adhesive 610 underlies the portions of cells 500 that are gaps and are not covered by solder 520.

[0032] There are many options for the solder forming shown in FIG. 7, including one or more of using a temporary adhesive, using injection molding, or using a preformed metal foil. Note that the temporary adhesive 610 can be applied through the techniques herein, for example, to the islands 612, or through layer and patterning. More specifically, the temporary adhesive is only used to temporarily hold the cells together to allow the solder forming process. The temporary adhesive can be applied by one or more of a syringe, printing, stencil, spray coating, or photolithographic patterning. This is true for all embodiments herein where the temporary adhesive 610 is used.

[0033] Injection molding means injecting the solder alloy around the cells by known injection molding techniques. Preformed foil is another possible technique that is also described with respect to other figures, but uses a preformed foil that is applied to the cells (see, for example, FIG. 8 described below).

[0034] Although only a single microbattery 590 is shown, after release from the release layer 615, each of the cells 500-1 and 500-2 becomes a microbattery. For ease of reference and clarity, reference numbers previously used in FIG. 1 and the like are used here as well. That is, similar elements are marked with the same reference numbers, but the elements are only similar and may differ in composition, etc. The microbattery 590 (and the corresponding cell 500-1 or 500-2) comprises a top cover 530, an anode 125, a sealing adhesive 555, a solid electrolyte 150, a cathode 120, vias 111, contacts 175, and a current collector 115, all of which is covered by solder 520. All of these elements are formed on a substrate 130 that is partially surrounded by solder 520. A terminal 540 is shown as well as a through via 110 that extends through the substrate 130 to contact either the current collector 115 or the contact 175. Cathode 120 is at least partially formed within solid electrolyte 150, and anode 125 is at least partially formed outside of, but abuts, electrolyte 150. Via 111 electrically couples anode 125 to contact 175, which is itself electrically coupled to through via 110-2. Current collector 115 is electrically coupled to through via 110-1. Top cover 530 is a cut version of cover plate 140 shown in FIG. 1. Sealing adhesive 555 is an example of polymer 135 of FIG. 1.

[0035] FIG. 8 is a diagram of steps performed during an exemplary hot embossing / solder forming and singulation. The handler structure 210 (part thereof) is shown after transfer in step 310. The term "after transfer" means after transfer of the microbattery structures 100 onto the glass handler 620 as in FIG. 2 or FIG. 6. That is, thin-film microbattery structures are first built on a panel, then these microbattery structures are singulated and transferred onto the glass handler. The handler structure 210 comprises in this example a release layer 615 and a glass handler 620. In this example, eight microbattery structures 100-1 to 100-8 are shown. In step 320, a foil 350 is applied onto 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 157° C. and the melting point of InSn is 119° C. Low temperature solder may be defined, for example, to mean below 160° C. The top surface 301 and side surface 302 of the microbattery structure 100 are shown, as is the top surface 361 of the release layer 615.

[0036] In step 330, a solder forming operation (which can also be, for example, a hot embossing operation) is performed, which causes the solder foil 350 to be formed on the surfaces 301, 302, and 361. As is known, in the forming process, molten solder is injected onto the surface, where it will flow to fill any gaps, and then a compression process is applied to form the final shape. In hot embossing, a preformed thin solder film is first laminated over the top surface. When the temperature is increased, the solder film melts and will flow into any gaps. Then, each individual battery cell is hermetically sealed with a metal casing. Step 340 shows the final singulation result, for example by laser cutting, and each of the microbattery structures 100-1 to 100-8 is separated into its corresponding cell 500-1 to 500-8. After this (or after additional processing), a peeling process is performed in block 360 to form the microbatteries.

[0037] Referring to FIG. 9, this figure shows an alternative technique of hot embossing / solder forming and singulation. This technique starts after the transfer 310. In step 420, a temporary structure 480, which can be a plate, film, template, etc., is applied to the handler structure 210 with the microbattery structure 100 on the structure 210. There is preformed (and prepatterned) low temperature solder 450 applied as islands 460-1 to 460-8. In step 420, the islands 460-1 to 460-8 are applied to substantially align with the corresponding microbattery structures 100-1 to 100-8. That is, step 420 is an example of a thermocompression process with alignment applied to bond the temporary structure 480 with islands 460 to the microbattery substrate in an exemplary embodiment. The structure 480 is then peeled off in step 435. The pattern and width W1 of the blobs 460 are designed relative to the pattern and width W2 of the microbattery structures 100 such that after solder molding in step 430, the solder 450 encapsulates each microbattery structure 100 after temporary structure removal (435) and the resulting singulation (440). That is, the side surface 302 of the microbattery structure 100 is encapsulated on the top surface 361 of the release layer 615, and the top surface 301 is also encapsulated, while the singulation of the microbattery structures 100-1 to 100-2 into the corresponding cells 500-1 to 500-8 is performed. The solder molding (430) is also defined and performed to allow this 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 block 360 to form the microbatteries.

[0038] FIG. 10 is an exemplary embodiment in which the microbattery structure formation process is performed in a "face up" position for the microbattery. The previous examples used a "face down" position for the microbattery, where the "face" includes the through vias 110-1 and 110-2. In these examples, the "face" is "down" and faces the surface of the substrate 620. In the face up position for the microbattery, the face including the vias 110-1 and 110-2 and the corresponding terminals 540-1 and 540-2 is away from the surface 1010 of the substrate 620. See FIG. 10 and cells 1000-1 and 1000-2. Only FIG. 10 can be applied to this exemplary embodiment, and the given solder frame (instead of the solder island) needs to be repositioned to align only with the gap. Otherwise, the solder will short the two terminals 540. These cells 1000 have the temporary adhesive 610 in a designated position. This orientation can be achieved using one or more of the following techniques: use of the temporary adhesive 610, use of injection molding, and / or use of a pre-deposited solder frame.

[0039] Referring to Fig. 11, this figure shows that the face-up approach of Fig. 10 can facilitate testing 1120. In this example, cell 1000-1 has two probes 1110-1 and 1110-2 that are used to contact the corresponding terminals 540-1, 540-2. Cells 1000-1 and 1000-2 are shown after the temporary adhesive 610 has been removed from the "top" surface 131 of substrate 130 and around terminals 540-1 and 540-2. The probes 1110 can then be used to test the microbatteries. Laser delamination 1130 is also shown, resulting in a microbattery 1090 of the separated microbatteries.

[0040] In the above embodiment, the terminals 540 and the corresponding through vias 110 are shown on the same side (the side on which the substrate 130 is located), but this is merely an example. The terminals 540 (e.g., and the corresponding through vias 110) may be on opposite sides or on orthogonal sides to one another.

[0041] In the foregoing description, numerous specific details are set forth, such as particular structures, components, materials, dimensions, processing steps, and techniques, to provide a thorough understanding of the exemplary embodiments disclosed herein. However, one of ordinary skill in the art will recognize that the exemplary embodiments disclosed herein may be practiced without these specific details. Additionally, details of well-known structures or processing steps may be omitted or not described in order to avoid obscuring the proposed embodiments. When an element, such as a layer, region, or substrate, is referred to as being "on" or "above" another element, it should be understood that it may be directly above the other element, or that there may be intervening elements. In contrast, when an element is referred to as being "directly on" or "directly above" another element, no intervening elements are present. Additionally, when an element is referred to as being "below" or "below" another element, it should be understood that it may be directly below or below the other element, or that there may be intervening elements. In contrast, when an element is referred to as being "directly below" or "directly below" another element, there are no intervening elements present.

[0042] What has been shown includes, in various embodiments, the following: Solder-molded thin-film Li batteries (e.g., thickness: 0.01mm to 1mm), A temporary handler approach for solid-state thin-film microbatteries; Using low temperature solder forming to avoid thermal shock for thin film Li microbatteries; Use of preformed solder foils for overmolding microbatteries; Use of IMS to pre-deposit patterned solder for transferring and overmolding microbatteries; Use of IMS and LCP overmolding or injection molding to provide environmentally and biocompatible encapsulation supporting low / no O2 and HO transport with the IMS and environmentally and biocompatible packaging with the LCP; and / or Use of pre-patterned adhesive for temporary bonding of thin-film Li microbatteries.

[0043] The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of instructions that includes one or more instructions for implementing the specified logical function(s). In some alternative implementations, the functions shown in the blocks may be performed in a different order than that shown in the figures. For example, two blocks shown in succession may in fact be executed substantially simultaneously, or the blocks may sometimes be executed in the opposite order, depending on the functionality involved. Furthermore, it should be noted that each block of the block diagrams or flowchart illustrations or both, and combinations of blocks in the block diagrams or flowchart illustrations or both, may be implemented by a dedicated hardware-based system that performs the specified functions or acts, or executes a combination of dedicated hardware and computer instructions,

[0044] In a preferred embodiment of the invention described herein, a method is provided for forming a microbattery, comprising mounting a plurality of individual cells including a microbattery structure on a handler, the microbattery structure comprising a laminate including substrate, polymer, and cover plate layers, mounting the microbattery structure on a release layer on the handler, molding solder on surfaces of the plurality of individual cells and on an exposed surface of the release layer to create solder coated cells, singulating the solder coated cells into a plurality of individual cells, cutting at least through the solder to the release layer to separate the individual cells, and peeling the plurality of individual cells to form corresponding individual microbatteries. Molding the solder can include applying a low temperature solder foil over the top surfaces of the individual cells and on the release layer, and performing a solder molding process to mold the solder foil onto the exposed surfaces of the cells and the exposed surface of the release layer. Molding the solder includes applying a temporary structure including islands of low temperature solder foil over the top surface of each cell and over the release layer, the islands of low temperature solder foil being defined to encapsulate a corresponding individual cell, performing a solder molding process to mold the solder foil onto the exposed surfaces of the cells, and performing a process to peel the temporary structure. The stack can be attached such that the cover plate is closer to the handler side than the substrate, the substrate being opposite the cover plate, the method further including forming through vias that penetrate the substrate and connect to positive and negative nodes of the microbattery cells formed in the stack, and forming terminals that are coupled to the through vias, the terminals being formed on a surface of the substrate and opposite a surface of the stack that is on the release layer.

Claims

1. a microbattery structure formed within a stack having a plurality of surfaces, the stack including a substrate layer and a cover plate layer, the substrate layer being disposed on a front surface side of the stack, the cover plate layer being disposed on another surface side opposite the front surface side of the substrate layer, the plurality of surfaces including two side surfaces; A first terminal provided on the front surface side and coupled to an anode of a battery of the microbattery structure; a second terminal provided on the front surface side and coupled to a cathode of the battery of the microbattery structure; a metal-containing film covering at least the two side surfaces and the other side surface of the stack; a solder film covering a surface of the metal-containing film; A microbattery comprising:

2. The microbattery of claim 1 , wherein the metal-containing film comprises a solder.

3. the laminate includes a polymer layer between the substrate layer and the cover plate layer; the laminate has a length between the two sides, the substrate layer, the polymer layer and the cover plate layer being parallel along the length; At least the polymer layer and the cover plate layer are removed from an area on the substrate layer adjacent an edge of the microbattery. The microbattery of claim 1 .

4. 4. The microbattery of claim 3, wherein the substrate layer is thicker near a midpoint of the length and thinner at the ends of the stack, and at least the polymer layer and cover plate layer are removed over the thinner areas of the substrate layer adjacent the ends of the microbattery.

5. the laminate includes a polymer layer between the substrate layer and the cover plate layer; the laminate has a length between the two sides, the substrate layer, the polymer layer and the cover plate layer being parallel along the length; the substrate layer on the front surface side has a surface that is not covered by the metal-containing film or the solder film; The microbattery of claim 1 .

6. the laminate includes a polymer layer between the substrate layer and the cover plate layer; the laminate has a length between the two sides, the substrate layer, the polymer layer, and the cover plate layer being parallel along the length; a polymer covers a surface of the solder film; the substrate layer on the front side is at least partially covered with an adhesive, the front side comprising two terminals coupled to through vias extending through the substrate layer; a polymer film covering a surface of the solder film and a surface of the adhesive opposite a surface of the adhesive covering the substrate layer; an opening is formed in the polymer film to expose at least a portion of a corresponding terminal; The microbattery of claim 1 .

7. The microbattery of claim 6 , wherein the openings are filled with a conductor.

8. The microbattery of claim 1 , wherein the microbattery has a thickness in the range of 0.01 mm to 1 mm.

9. mounting a thin film battery panel on a handler, the thin film battery panel including a stack having a plurality of microbattery structures formed therein, the thin film battery panel having a surface on an adhesive layer, the adhesive layer being disposed on a release layer on the handler, the stack including a substrate layer, a polymer layer, and a cover plate layer; cutting through a plurality of layers of the stack to at least partially separate the plurality of microbattery structures; forming solder on a surface of the layers of the cut laminate; Singulating the plurality of microbattery structures into corresponding individual microbattery cells; Including, the cutting cuts through a plurality of layers of the stack but leaves at least a portion of the layers between the plurality of microbattery structures; Molding solder onto the surfaces of the layers of the cut laminate includes: forming a seed layer on the exposed surface of the cut laminate; Singulating the plurality of microbattery structures into cells; molding solder onto exposed surfaces of the singulated cells, the molding of solder attaching the singulated cells to the handler via the adhesive layer; Further comprising: and singulating the plurality of microbattery structures into corresponding individual microbattery cells further comprises delaminating cells by using laser delamination to form the individual microbattery cells. A method for forming a microbattery.

10. mounting a thin film battery panel on a handler, the thin film battery panel including a stack having a plurality of microbattery structures formed therein, the thin film battery panel having a surface on an adhesive layer, the adhesive layer being disposed on a release layer on the handler, the stack including a substrate layer, a polymer layer, and a cover plate layer; cutting through a plurality of layers of the stack to at least partially separate the plurality of microbattery structures; forming solder on a surface of the layers of the cut laminate; Singulating the plurality of microbattery structures into corresponding individual microbattery cells; Including, the attaching includes attaching the thin-film battery panel onto the handler with islands of the adhesive layer formed on the release layer, the islands 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 comprises cutting through all layers of the stack to singulate the microbattery structures into cells; Molding solder onto the surfaces of the layers of the cut laminate includes: forming a seed layer on exposed surfaces of the singulated cells; forming solder on exposed surfaces of the singulated cells; Further comprising: and singulating the plurality of microbattery structures into corresponding individual microbattery cells further comprises delaminating cells by using laser delamination to form the individual microbattery cells. A method for forming a microbattery.

11. The method of claim 10 , wherein forming the solder is performed by one or both of plating or forming using injection molding.

12. mounting a thin film battery panel on a handler, the thin film battery panel including a stack having a plurality of microbattery structures formed therein, the thin film battery panel having a surface on an adhesive layer, the adhesive layer being disposed on a release layer on the handler, the stack including a substrate layer, a polymer layer, and a cover plate layer; cutting through a plurality of layers of the stack to at least partially separate the plurality of microbattery structures; forming solder on a surface of the layers of the cut laminate; Singulating the plurality of microbattery structures into corresponding individual microbattery cells; Including, The attaching includes attaching the thin-film battery panel onto the handler with islands of the adhesive layer formed on the release layer, the islands aligned with and formed to cover corresponding microbattery structures, the adhesive layer disposed on a polymer film, the polymer film disposed on the release layer on the handler; cutting through the layers of the stack to at least partially separate the microbattery structures includes cutting through all layers of the stack to singulate the microbattery structures into cells, but not completely cutting through the polymer film; Molding solder onto the surfaces of the layers of the cut laminate includes: forming a seed layer on exposed surfaces of the singulated cells; forming solder on exposed surfaces of the singulated cells; and forming the solder such that the solder is removed from the exposed surface of the polymer film; further comprising overmolding a polymer onto the exposed surfaces of the solder and onto the exposed surfaces of the polymer film, said overmolding filling unfilled locations between the singulated cells and bonding an overmolded polymer to the polymer film on the release layer to create a unitary polymer film; singulating the plurality of microbattery structures into corresponding individual microbattery cells includes singulating cells by cutting completely through the single polymer film using laser singulation, and exfoliating the cells using laser exfoliation to form the individual microbattery cells. A method for forming a microbattery.

13. 13. The method of claim 12, wherein the substrate layer is on a front side of the laminate, the substrate layer overlies the adhesive layer, the front side having terminals coupled to through vias extending through the substrate layer, the method further comprising cutting openings through the polymer film and through the adhesive layer to expose at least a portion of a corresponding terminal.

14. The method of claim 13 further comprising filling the opening with a conductor.

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