USOO7676921B2 (12) United States Patent (10) Patent No.: US 7,676,921 B2 Kim et al. (45) Date of Patent: Mar. 16, 2010 (54) METHOD OF MANUFACTURING PRINTED (56) References Cited CIRCUIT BOARD INCLUDING EMBEDDED CAPACTORS U.S. PATENT DOCUMENTS 5,010,641 A 4, 1991 Sisler (75) Inventors: Jin Cheol Kim, Gyeonggi-do (KR); Min 5,079,069 A 1/1992 Howard et al. Soo Kim, Kyunggi-do (KR); Jun Rok 6,005,197 A * 12/1999 Kola et al. .................. 174,260 Oh, Seoul (KR): Tae Kyoung Kim, 6,577,490 B2 * 6/2003 Ogawa et al. ............... 361,766 Gyeonggi-do (KR) 6,663,946 B2 12/2003 Seri et al. 6,764.931 B2 * 7/2004 Iijima et al. ................. 438,584 (73) Assignee: Samsung Electro-Mechanics Co., Ltd., 2004/O150966 A1 8, 2004 Hu Kyunggi-Do (KR) 2004/0231885 A1* 11/2004 Borland et al. ................ 29,846 (*) Notice: Subject to any disclaimer, the term of this FOREIGN PATENT DOCUMENTS patent is extended or adjusted under 35 JP 6-152137 5, 1994 U.S.C. 154(b) by 168 days. JP 2002-344146 11, 2002 JP 2003-5 1427 2, 2003 (21) Appl. No.: 11/670,463 * cited by examiner (22) Filed: Feb. 2, 2007 Primary Examiner Donghai D. Nguyen (65) Prior Publication Data (74) Attorney, Agent, or Firm Darby & Darby PC US 2007/O24O3O3 A1 Oct. 18, 2007 (57) ABSTRACT Related U.S. Application Data A method of manufacturing a printed circuit board including (62) Division of application No. 11/031,508, filed on Jan. 6, embedded capacitors, composed of a polymer condenser 2005, now Pat. No. 7, 186,919. laminate including a plurality of polymer condenser layers, each of which has a polymer sheet and a conductor pattern (30) Foreign Application Priority Data formed on the polymer sheet, and a via hole for interlayer Aug. 16, 2004 (KR) ............................... 2004-64291 connection therethrough, and a circuit layer formed on either Dec. 10, 2004 (KR) ............................. 2004-104210 Surface or both Surfaces of the polymer condenser laminate and having a circuit pattern and a via hole for interlayer (51) Int. Cl. connection therethrough. The printed circuit board manufac HOK 3/10 (2006.01) tured by the method of the current invention has higher (52) U.S. Cl. .......................... 29/852; 29/25.42: 29/832; capacitance density per unit area than conventional embed 174/260: 361/306.3: 361/763 ded capacitor printed circuit boards, whereby capacitors hav (58) Field of Classification Search ................ 29/25.41, ing various capacitance values, such as multilayered ceramic 29/25.42, 831, 832, 841, 846, 852; 174/250, capacitors having high capacitance, can be embedded in the 174/255, 260 262; 257/296, 306–308: 361/301.4, printed circuit board, instead of being mounted thereon. 361/306.3, 763, 766: 438/584 See application file for complete search history. 5 Claims, 9 Drawing Sheets 34 35 32 E: E: Z ŽižZ. 44 43 U.S. Patent Mar. 16, 2010 Sheet 1 of 9 US 7,676,921 B2 FIG. 1a PRIOR ART 43a 64a 43 4b. EEE SHES; Siili iSEEH8; 3:33:1 REEEEEEEEEEEEEEEEE|3:ESSB3. 3333333333E383 FIG 1b. PRIOR ART 43a 4a da 43b 45 44b 2 (e and in Nation? RNS 3:S NEis 42 :::REEE::FE: 46a 46 3a 45a 4. NSS SEESSESS;GN ENESSEE E:: SNEN3:34: EBERREEEEEEEEEEEE E: SIESEE Englisi U.S. Patent Mar. 16, 2010 Sheet 2 of 9 US 7,676,921 B2 FIG. 1d. PRIOR ART The first ayer EEE SEBRESE: SES The Second SRAES3RRENSEESSyy SiO3:31:3EESSENSERISAS layer 42 The third ayer SN 2. FIG. 1e PRIOR ART 52a 49a 52b 49b 51a 47 50 5f 48b. & R& ayer Egg SES SNA SNS Th; ayerSecond SiiNii SGN is 42 The third EEEEEEEEEER: : ESIEEE13SHEEEEEEEEE:ESSESSIEEERS: ayer S W M T S SS S Thisayer forth i E. 883 SEESR / 33 U.S. Patent Mar. 16, 2010 Sheet 4 of 9 US 7,676,921 B2 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ----------eyrreyre---a-Harryrhares - - ... K - d - leads-as ;É 141 44 43 Žiž 44 43 U.S. Patent Mar. 16, 2010 Sheet 5 Of 9 US 7,676,921 B2 • G. s .. a 43 2. N. Y. 23%-3 5:232; 44 43 U.S. Patent Mar. 16, 2010 Sheet 6 of 9 US 7,676,921 B2 FIG. 6b FIG. 6c 63a ZZZZZ 63 FIG. 6d. U.S. Patent Mar. 16, 2010 Sheet 7 of 9 US 7,676,921 B2 2 FIG. 6f U.S. Patent Mar. 16, 2010 Sheet 8 of 9 US 7,676,921 B2 73a & - - - - - - - - - + 4 + 4 as a - - - - - - - 0 4 is a 4 8 d - - - - - - 8 - s ( 4 0. 8 w - - - - - - - - - - - - d - 8 a - - - - - • (- - - - - - - - - - - - 4 - - - - - - - - - + · · · · · · · · · · · · { * 72a s wn w y se w y ap p & 0 . 4 - d - - - - 0 + · · · · · · · 8 - - - - - - - - - - - - - 8 7. {- - - - - - - - - - w - - - - - - - w - - - 4 4- 4 - 4 - 4 - - - - - - a - 8 8 . 0. 8 - - - - - - - - - - - - - - - - - - - - - - - - 73b s (s s : s s & 9 - - - - - - - - - - - d - - - - - - - - - 0 - 4 - 0 - 0 0 - - - - - - - - - - - - - - - - - 0 0 -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - d w - - - - - : U.S. Patent Mar. 16, 2010 Sheet 9 Of 9 US 7,676,921 B2 FIG. 7b 71. t . is Ni---- 4 Y - - - - - - - - - - - - ***''' versarracase 72 FIG 7C 74 71 FIG 76 a -- 4 4 - - - - FIG. 8a. 49 - d - d - - - - d A - . 0 . - - - - - - 82 th. d - - - - - - ) 81 to a 4 {- AX - (h 82 - - - - - - - > . a- - - - - - - 0 - 0 h - - - - - US 7,676,921 B2 1. 2 METHOD OF MANUFACTURING PRINTED In techniques of manufacturing PCBs including embedded CIRCUIT BOARD INCLUDING EMBEDDED passive components, passive components such as resistors or CAPACTORS capacitors are provided in PCBs using novel materials and processes, to Substitute for conventional chip resistors and CROSS-REFERENCE TO PRIORAPPLICATION 5 chip capacitors. That is, the PCB including embedded passive components means that the passive component, for example, This application is a Divisional of U.S. patent application capacitor, is embedded in the inner layer of the PCB. Regard Ser. No. 11/031,508, filed Jan. 6, 2005, issued as U.S. Pat. No. less of the size of the PCB itself, if the capacitor as the passive 7,186,919 on Mar. 6, 2007, which claims priority under 35 component is incorporated in the PCB, this is called an U.S.C. S 119 to Korean Patent Application Nos. 2004-64291 10 embedded capacitor. Such a substrate is referred to as an filed on Aug. 16, 2004 and 2004-104210 filed Dec. 10, 2004. embedded capacitor PCB. The major characteristic of the The content of the applications are incorporated herein by embedded capacitor PCB is that the capacitor is intrinsically reference in their entireties. provided in the PCB without the need to mount the capacitor on the PCB. INCORPORATION BY REFERENCE 15 FIGS. 1a to 1e show a conventional process of manufac turing a PCB including embedded polymer film type capaci The present application claims priority under 35 U.S.C. tors, in which a polymer capacitor paste is applied on a S119 to Korean Patent Application Nos. 2004-64291 filed on substrate and then hot dried (or cured), to realize the PCB Aug. 16, 2004 and 2004-104210 filed Dec. 10, 2004. The including the embedded polymer film type capacitor. content of the applications are incorporated herein by refer In a first step, a copper foil layer of an inner layer 41 of the ence in their entireties. PCB comprising a FR-4 reinforced base sheet 42 is coated with a dry film, followed by being exposed and developed. BACKGROUND OF THE INVENTION Then, the copper foil layer is etched to form anodic copper foils 44a and 44b, cathodic copper foils 43a and 43b, and 1. Field of the Invention 25 spaces therebetween (FIG. 1a). The present invention relates generally to a printed circuit In a second step, capacitor pastes 45a and 45b composed of board (PCB) in which a condenser laminate or a capacitor is a polymer that contains ceramic powder having a high dielec embedded. More specifically, the present invention relates to tric constant are applied on the cathodic copper foils 43a and a PCB including embedded polymer condenser laminates, 43b by a screen printing process, and then dried or cured which is capable of manifesting higher capacitance density 30 (FIG.1b). Herein, the screen printing is performed by apply per unit area than conventional PCBs including embedded ing a media such as ink on a stencil Screen using a squeeze, capacitors, so that capacitors having various capacitance val thereby transferring a pattern to a substrate. ues, for example, multilayered ceramic capacitors (MLCCs) At this step, the spaces between the anodic copperfoils 44a having high capacitance, can be embedded in the PCB, and 44b and the cathodic copper foils 43a and 43b are covered instead of being mounted on the PCB; and a method of manu 35 with the capacitor pastes 45a and 45b. facturing the same. In a third step, a conductive paste including silver or copper 2. Description of the Related Art is formed into anodes 46a and 46b using a screen printing In general, capacitors store energy in the form of an electric process, and dried or cured (FIG. 1c). field. When a DC voltage source is applied to a capacitor, the In a fourth step, the capacitor layer subjected to first to third capacitor is charged but the current flow stops. On the other 40 steps of the inner layer 41 of the PCB is inserted between hand, if an AC Voltage source is connected to a capacitor, the insulating layers 47a and 47b, followed by being laminated current flows through the capacitor depending on the fre (FIG. 1d). quency of the applied AC signal and the value of the capacitor In a fifth step, a through hole and laser blind via holes 49a while the capacitor is charged and discharged.