METHOD OF MAKING A MOLDED INTERCONNECT DEVICE
A method of forming a molded interconnect device (MID) is provided. The method includes the steps of performing a molding stage, performing a circuit forming stage, and performing a plate stage. As a part of the molding stage, a palladium-catalyzed material is injection molded into a palladium-catalyzed substrate of a desired shape. As a part of the circuit forming stage, both a metallization step and a circuit patterning step are performed. As a part of the plating stage, both an electrolytic plating step and a circuit isolation step are performed.
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This application is a continuation of U.S. patent application Ser. No. 16/315,244, filed on Jan. 4, 2019, which is a national stage of International Application No. PCT/US2017/040721, filed Jul. 5, 2017, which claims priority to both U.S. Provisional Patent Application Ser. No. 62/359,365, filed on Jul. 7, 2016, and U.S. Provisional Patent Application Ser. No. 62/435,305, filed on Dec. 16, 2016, the contents of all of which are incorporated herein in their entireties.
BACKGROUND ARTMolded interconnect devices (“MIDs”) are three-dimensional manufactured parts that typically include plastic components and electronic circuit traces. A plastic substrate or housing is created and electrical circuits and devices are plated, layered, or implanted upon the plastic substrate. MIDs typically have fewer parts than conventionally manufactured devices, which results in space and weight savings. Applications for MIDs include mobile telephones, automated teller machines, steering wheel components for automobiles, RFID components, lighting, medical devices and many other consumer and/or commercial products.
Current processes for manufacturing MIDs include two-shot molding, laser direct structuring technology (LDS), microscopic integrated processing technology (MIPTEC), and a laser developed additive technology. Each of these manufacturing processes have been known in the art for some time, yet each has its own drawbacks such that many individuals believe that further improvements to manufacturing MIDs would be beneficial.
Two-shot molding involves the use of two separate plastic parts, typically one platable and one non-platable. The platable part forms the circuitry, and the non-platable part fulfills mechanical functions and completes the molding. The two parts are fused together and circuits are created through use of electroless plating. The platable plastic is metallized, while the non-platable plastic remains non-conductive.
LDS technology involves the steps of injection molding (using any of a variety of dielectric thermoplastic materials, including polyamide, polycarbonate, and liquid crystal polymer), laser activation of the thermoplastic material, and then metallization (electroless plating). The laser etches a wiring pattern onto the part and prepares it for metallization. With LDS, only a single thermoplastic material is required thereby making the molding step a one-shot process, and generally preferable as compared to the two-shot molding process.
MIPTEC technology, which is offered by Panasonic Corporation, involves a molding stage, a circuit forming stage, a plating stage, and a cutting stage.
The molding stage includes injection-molding the intended shape using a thermoplastic resin, such as polyphthalamide (PPA).
The circuit forming stage includes two steps, namely: (1) metallization; and (2) patterning. Thin copper film is formed in the base metallization process (copper-strike). A laser is then used to remove the copper and outline the circuit pattern, with the wavelength and exposure time of the laser optimized to achieve copper removal without damaging the substrate.
The plating stage includes two or three steps, namely: (1) electrolytic copper plating; (2) optional soft etching; and (3) electrolytic nickel and gold plating. First, copper is electrically plated to form the circuit pattern. Then, if desired, soft etching is applied to remove unnecessary copper-strike that was not removed by the laser in the circuit forming stage. Finally, nickel and gold are plated on the electrolytically-plated copper, forming the circuit pattern to help prevent oxidation and corrosion.
An optional cutting stage then includes dicing the sheet form into individual MIDs.
Thus, MIPTEC technology, like LDS technology, has only a one-shot molding process, but also provides MIDs which can be fine patterned and bare chip mounted.
The laser developed additive technology is similar to the MIPTEC technology, but allows for other thermoplastic materials, such as polyamide (PA), polycarbonate (PC) and acrylonitrile butadiene styrene (ABS) or liquid crystal polymer (LCP), to be used in the process. Like polyphthalamide (PPA), however, these thermoplastic materials are all dielectric materials and require the separate and extra step of surface activation treatment prior to the circuit forming stage. This extra step adds both time and expense to these technologies.
MIPTEC and LDS technology processes have limitations, and in some circumstances even impossibilities, in connection with plating features that are not within a line-of-sight. For instance, as illustrated in
A first preferred embodiment of a manufacturing process includes the steps of: injection molding a palladium-catalyzed material, such as, for example, resins or epoxy molding compounds into a palladium-catalyzed substrate of a desired shape; forming a thin copper film over exterior and exposed surfaces of the palladium-catalyzed substrate; ablating or removing some of the copper film from the palladium-catalyzed substrate to provide first, second and optional third portions of the copper film; electrolytically plating each of the first, second and third portions of the copper film to form metallic-plated first, second and third portions; and ablating or removing the second portion in order to isolate the metallic-plated first portion from the metallic-plated third portion, where the metallic-plated first portion comprises a circuit portion of portion of a molded interconnect device (MID), and where the metallic-plated third portion comprises a Faraday cage portion of the MID.
A second preferred embodiment of a manufacturing process includes the steps of: injection molding a palladium-catalyzed material, such as, for example, resins or epoxy molding compounds into a palladium-catalyzed substrate of a desired shape; forming a thin copper film over exterior and exposed surfaces of the palladium-catalyzed substrate; ablating or removing some of the copper film from the palladium-catalyzed substrate to provide first, second and optional third portions of the copper film; electrolytic copper plating; soft etching to remove any unnecessary copper; electrolytic nickel plating; electrolytic gold plating; and ablating or removing the second portion in order to isolate the metallic-plated first portion from the metallic-plated third portion, where the metallic-plated first portion comprises a circuit portion of the MID, and where the metallic-plated third portion comprises a Faraday cage portion of the MID.
A third preferred embodiment of a manufacturing process includes the steps of: injection molding a palladium-catalyzed material, such as, for example, resins or epoxy molding compounds into a palladium-catalyzed substrate of a desired shape; forming a thin copper film over exterior and exposed surfaces of the palladium-catalyzed substrate; ablating or removing some of the copper film from the palladium-catalyzed substrate to provide ablated sections and first, second and optional third portions of the copper film; electrolytically plating each of the first, second and third portions of the copper film with copper plating; non-selectively adding solder resist; selectively removing the solder resist from parts of the first portion which will form contact points for connection of the MID to an associated device or assembly, such as a printed circuit board, and from the ablated sections; electrolytically plating the contact points with nickel plating and gold plating to form metallic-plated first, second and third portions; and ablating or removing the second portion in order to isolate the metallic-plated first portion from the metallic-plated third portion, where the metallic-plated first portion comprises a circuit portion of the MID, and where the metallic-plated third portion comprises a Faraday cage portion of the MID.
A fourth preferred embodiment of a manufacturing process includes the steps of: injection molding a palladium-catalyzed material, such as, for example, resins or epoxy molding compounds into a palladium-catalyzed substrate of a desired shape; forming a thin copper film over exterior and exposed surfaces of the palladium-catalyzed substrate; ablating or removing some of the copper film from the palladium-catalyzed substrate to provide ablated sections and first, second and optional third portions of the copper film; electrolytically plating each of the first, second and third portions of the copper film with copper plating, nickel plating and gold plating; non-selectively adding solder resist; selectively removing the solder resist from parts of the first portion which will form contact points for connection of the MID to an associated device or assembly, such as a printed circuit board, and from the ablated sections; and ablating or removing the second portion in order to isolate the metallic-plated first portion from the metallic-plated third portion, where the metallic-plated first portion comprises a circuit portion of the MID, and where the metallic-plated third portion comprises a Faraday cage portion of the MID.
Each manufacturing process results in an MID having a palladium-catalyzed substrate, a circuit portion, and an optional Faraday cage portion, where the Faraday cage portion and the circuit portion may be isolated from one another.
These and other aspects and features of the disclosure are described in further detail below.
The present disclosure is directed to novel manufacturing processes 100, 200, 300, 400 for forming a molded interconnect device (MID) 50. The manufacturing processes 100, 200, 300, 400 are useful for the creation of MIDs, such as printed circuit boards, flex circuits, connectors, thermal management features, electromagnetic interference (EMI) shielding, high current conductors, radio frequency identification (RFID) apparatuses, antennas, wireless power, sensors, MEMS apparatuses, LEDs, microprocessors and memory, ASICs, passives, and other electrical and electro-mechanical apparatuses.
Attention is directed to
The molding stage of the manufacturing process 100 advantageously includes only a single step, which step will be referenced by reference numeral 110. Step 110 is an injection-molding step where a palladium-catalyzed material (sometimes called palladium-doped in the art), such as, for example, resins or epoxy molding compounds, is injection-molded in the form of a sheet 112 containing a plurality of connected substrates 114 (each formed in the intended shape) for production purposes. Each substrate 114 may be formed in a desired three-dimensional shape. In some embodiments, each substrate 114 is formed of the same three-dimensional shape.
The circuit forming stage of the manufacturing process 100 includes two steps, which steps will be referred to as steps 120 and 130.
Step 120 is a metallization step where a thin copper film 122 is formed over the exterior and exposed surfaces of the palladium-catalyzed substrates 114 to form a first assembly 123. Metallization step 120 is commonly referred to as copper-striking.
Step 130 is a circuit patterning step where a laser (not shown) ablates or removes portions of the copper film 122 from the first assembly 123 to expose portions 131, 132 of the substrate 114 and form a second assembly 133. This action defines and outlines a circuit pattern within the remaining copper film 122 to be provided for the MID 50.
The plating stage of the manufacturing process 100 includes two steps, which steps will be referred to as steps 140 and 150.
Step 140 is an electrolytic plating step where a probe (not shown) is attached/connected to one of the first, second and third portions 134, 136, 138 and electricity is run through the first, second and third portions 134, 136, 138 and desired metallic molecules from a desired metallic bath are drawn to and secured to the first, second and third portions 134, 136, 138, until the desired metallic plating of the first, second and third portions 134, 136, 138 is built up to the desired thickness, thus forming metallic-plated first, second and third portions 144, 146, 148 (it is to be understood that metallic-plated third portion 148 will only be formed if third portion 138 is provided), thereby forming a third assembly 143.
It is to be understood that the electrolytic plating step 140 can include the electrolytic plating of any metal(s) as desired. In a preferred embodiment, the electrolytic plating step 140 begins with a step 141 wherein a copper material is electrolytic plated onto the first, second and third portions 144, 146, 148 to form a copper plating 173, followed by a step 171 wherein a nickel material is electrolytic plated onto the copper material 173 to form a nickel plating 174, followed by a step 172 wherein a gold material is electrolytic plated onto the nickel material 147 to form a gold plating 175, as illustrated in
Step 150 is a circuit isolation step where a laser (not shown) ablates or removes the formed second (bus) portion(s) 136/146, beginning with second portion 146, and finishing with second portion 136, until the surface of the substrate 114 is provided between the first and third portions 144, 148, thereby providing portions 152 of the substrate 114 which are visible, and thereby forming a fourth assembly 153. The ablated sections 152 are connected to or continuous with the ablated sections 132 such that the first portion 144 (namely the circuit pattern) is isolated from the third portion 148 (namely the Faraday cage portion).
Step 160 is a cutting step where the sheet 112 is diced in order to separate each of the MIDs 50. The sheet 112 can be diced along saw streets 162 (the saw streets 162 are not shown in
Either before or after step 160 of the manufacturing process 100 is performed, one or more of the MIDs 50 can then be inspected, as desired and in any of a number of known manners, to ensure that the MIDs 50 are suitable for their intended use. The MIDs 50 may then be packaged and shipped. If desired, further electronic components may be electrically connected and secured to the first portion 144, namely the circuit portions, before the MIDs 50 are packaged and shipped. It is to be understood that the sheet 112 of MIDs 50 could be packaged and shipped prior to the cutting step 160 being performed.
Attention is directed to
Attention is directed to
Step 380 is a solder resist addition step where solder resist 337 is added non-selectively onto the entire assembly, including the copper plating 173 and the ablated sections 131, 132 as shown in
Attention is directed to
Step 490 is a solder resist addition step where solder resist 337 is added non-selectively onto the entire assembly, including the gold plating 175 and the ablated sections 131, 132 as shown in
The manufacturing processes 100, 200, 300, 400 of forming the MIDs 50 are advantageous as compared to the prior-known MID manufacturing processes, especially as compared to the MIPTEC and laser developed additive technology processes. More specifically, as the injection-molded material is infused with palladium, it is then unnecessary to perform any type of surface activation treatment to the substrate 114 of the type which is required in all prior-known MID manufacturing processes. Thus, the manufacturing processes 100, 200, 300, 400 removes a step which is needed in all prior-known MID manufacturing processes, thereby saving both manufacturing costs and manufacturing time.
MIPTEC and LDS technology processes also have limitations, and in some circumstances even impossibilities, in connection with plating features that are not within a line-of-sight. For instance, as illustrated in
Furthermore, it has been determined that the manufacturing processes 100, 200, 300, 400 provide for improved plating adhesion as compared to the prior-known MID manufacturing processes, thereby making the MIDs 50 formed from the manufacturing processes 100, 200, 300, 400 more robust and reliable than the MIDs formed from the prior-known MID manufacturing processes.
Advantageously, each of the manufacturing processes 100, 200, 300, 400 may provide an MID 50 having a Faraday cage configuration, where the third portions 148 provide the Faraday cage configuration which is useful in providing better EMI shielding for any packaged integrated circuit application. To aid in the provision of the Faraday cage configuration, each substrate 114 provided in the sheet 112 may have one or more vias (not shown) formed along saw street, namely where the sheet 112 is diced during step 160 to provide the individual MIDs 50. These vias allow for the metallization and electrolytic plating, of steps 120 and 140/140a, respectively, of all sides of the MIDs 50. It is to be understood that the size/shape of the Faraday cage configuration, if provided, may vary as desired.
All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
The use of the terms “a” and “an” and “the” and “at least one” and similar referents in the context of describing the disclosure (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The use of the term “at least one” followed by a list of one or more items (for example, “at least one of A and B”) is to be construed to mean one item selected from the listed items (A or B) or any combination of two or more of the listed items (A and B), unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All processes described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the disclosure, and does not pose a limitation on the scope of the disclosure unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the disclosure.
Preferred embodiments of this disclosure are described herein, including the best mode known to the inventors for carrying out the disclosure. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the disclosure to be practiced otherwise than as specifically described herein. Accordingly, this disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.
Claims
1. A method of forming a molded interconnect device (MID), the method comprising the steps of:
- a) performing a molding stage, wherein a palladium-catalyzed material is injection molded into a palladium-catalyzed substrate of a desired shape;
- b) performing a circuit forming stage, wherein b1) a metallization step is performed, and b2) a circuit patterning step is performed; and
- c) performing a plating stage, wherein c1) an electrolytic plating step is performed, and c2) a circuit isolation step is performed to provide the MID.
2. The method as defined in claim 1, wherein the metallization step of step b1) comprises forming a thin copper film over an exposed surface of the palladium-catalyzed substrate.
3. The method as defined in claim 1, wherein the circuit pattering step of step b2) comprises removing some of the copper film from the palladium-catalyzed substrate to provide first and second portions of the copper film which are separated from one another.
4. The method as defined in claim 3, wherein the removal of some of the copper film in step b2) is performed by a laser.
5. The method as defined in claim 3, wherein the at least first and second portions of the copper film provided in step b2) are separated from one another by at least one exposed portion of the palladium-catalyzed substrate.
6. The method as defined in claim 3, wherein the electrolytic plating step of step c1) comprises electrolytic copper plating, electrolytic nickel plating, and electrolytic gold plating.
7. The method as defined in claim 3, wherein the electrolytic plating step of step c1) comprises electrolytically plating the first portion of the copper film to form a metallic-plated first portion.
8. The method as defined in claim 7, wherein the current isolation step of step c2) comprises removing the second portion of the copper film.
9. The method as defined in claim 8, wherein the removal of the second portion of the copper film in step c2) is performed by a laser.
10. The method as defined in claim 8, wherein the removal of the second portion of the copper film in step c2) is performed by soft etching.
11. The method as defined in claim 8, wherein step c) further comprises steps c3) and c4), wherein in step c3) a solder resist addition step is performed, wherein in step c4) a solder resist removal step is performed, and wherein step c4) is performed after step c3) is performed.
12. The method as defined in claim 11, wherein steps c3) and c4) are performed before step c2) is performed.
13. The method as defined in claim 3, wherein the circuit patterning step of step b2) further provides a third portion of the copper film which separates the first portion of the copper film from the second portion of the copper film, the third portion of the copper film connecting the first portion of the copper film to the second portion of the copper film.
14. The method as defined in claim 13, wherein the first portion of the copper film forms a circuit patter, wherein the second portion of the copper film is a Faraday cage portion, and wherein the third portion of the copper film is a bus portion.
15. The method as defined in claim 13, wherein the electrolytic plating step of step c1) comprises electrolytically plating the first, second and third portions of the copper film to form metallic-plated first, second and third portions.
16. The method as defined in claim 15, wherein the current isolation step of step c2) comprises removing the metallic-plated third portion to electrically isolate the metallic-plated first portion from the metallic-plated third portion.
17. The method as defined in claim 16, wherein the removal of the metallic-plated third portion in step c2) is performed by a laser.
18. The method as defined in claim 16, wherein the removal of the metallic-plated third portion in step c2) is performed by soft etching.
19. The method as defined in claim 16, wherein step c) further comprises steps c3) and c4), wherein in step c3) a solder resist addition step is performed, wherein in step c4) a solder resist removal step is performed, and wherein step c4) is performed after step c3) is performed.
20. The method as defined in claim 19, wherein steps c3) and c4) are performed before step c2) is performed.
21. A method of forming a molded interconnect device (MID), the method comprising the steps of:
- a) injection molding a palladium-catalyzed material into a palladium-catalyzed substrate of a desired shape;
- b) forming a thin copper film over exposed surfaces of the palladium-catalyzed substrate;
- c) removing some of the copper film from the palladium-catalyzed substrate to provide first and second portions of the copper film and at least one exposed portion of the palladium-catalyzed substrate, the first and second portions of the copper film being separated from one another by the at least one exposed portion of the palladium-catalyzed substrate;
- d) electrolytically plating the first portion of the copper film to form a metallic-plated first portion; and
- e) removing the second portion of the copper film to provide the MID.
22. A method of forming a molded interconnect device (MID), the method comprising the steps of:
- a) injection molding a palladium-catalyzed material into a palladium-catalyzed substrate of a desired shape;
- b) forming a thin copper film over exposed surfaces of the palladium-catalyzed substrate;
- c) removing some of the copper film from the palladium-catalyzed substrate to provide first, second and third portions of the copper film, the second portion of the copper film connecting the first portion of the copper film to the third portion of the copper film;
- d) electrolytically plating the first, second and third portions of the copper film to form metallic-plated first, second and third portions; and
- e) removing the metallic-plated second portion in order to isolate the metallic-plated first portion from the metallic-plated third portion to provide the MID.
Type: Application
Filed: May 20, 2022
Publication Date: Sep 1, 2022
Applicant: Molex, LLC (Lisle, IL)
Inventors: Tsuey Choo CHANG (Lisle, IL), Steven ZEILINGER (Freeland, MI), Hyun-Jong KO (Seoul), Patrick RILEY (LaGrange, IL), SukMin KANG (Gwangmyeong)
Application Number: 17/749,137