EP0452506A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
METHOD OF PRODUCING A FLEXIBLE CIRCUIT BOARD FOR MOUNTING IC's
Assignee: Nippon Mektron KK
•
Filing: 1990-11-02
•
Granted: —
•
Expires: 2010-11-02
Abstract
Abstract A flexible circuit board for mounting IC has conductor bumps on the rear surface, and they penetrate the flexible circuit board to connect a circuit wiring pattern. The surfaces of the bumps can be coated with a bonding metal depending on the structure of the bumps. Bare IC chips are easily connected to the bumps of the circuit board by a thermal or ultrasonic bonding method. When such bumps or protrusions for bonding to IC pads are provided on the flexible circuit board, tiny holes are preferably formed in the insulating substrate by excimer laser means. The bumps are formed by plating means such as soldering or by a suitable treatment for filling the holes with an electrically conductive material. Further, the bumps should desirably be formed in a semi-spherical shape by the reflow treatment.
Inventors
- 👤 Chikafumi Oomachi
- 👤 Yasuyuki Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 21:17
CPC Classifications
H; H05; H05K; H05K1/00; H05K1/02; H05K1/11; H05K1/111; H05K1/112; H05K1/113; H10; H10W; H10W70/00; H10W70/01; H10W70/05; H10W70/095; H10W70/40; H10W70/453; H10W70/60; H10W70/62; H10W70/63; H10W70/635; H10W70/67; H10W70/688; H10W72/00; H10W72/071; H10W72/077; H10W72/701; H05K1/03; H05K1/0393; H05K2201/00; H05K2201/03; H05K2201/0332; H05K2201/0388; H05K2201/0394; H05K2201/09; H05K2201/09209; H05K2201/095; H05K2201/09563; H05K2201/10; H05K2201/10613; H05K2201/10621; H05K2201/10674; H05K3/00; H05K3/40; H05K3/42; H05K3/423; H10W72/072; H10W72/07251; H10W72/20; H10W72/251; H10W72/252; H10W90/00; H10W90/701; H10W90/721; H10W90/724; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/4913; Y10T29/49144; Y10T29/49155; Y10T29/49165
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
66 words
An IC-mounting flexible circuit board comprising a desired circuit wiring pattern on one side of an insulating base, and conductive members passing through said insulating base and electrically junctioned to respective desired regions of said circuit wiring pattern, wherein said conductive member protrudes from the other side of said insulating base to form an IC pad junction protrusion which functions as a bump for IC bonding.
Claim 2
Dependent Claim
29 words
An IC-mounting flexible circuit board as claimed in claim 1, wherein said junction protrusion is formed with a conductive plating member that is readily joined to an IC pad.
Claim 3
Dependent Claim
21 words
An IC-mounting flexible circuit board as claimed in claim 1, wherein said junction protrusion is formed with a copper plated member.
Claim 4
Dependent Claim
34 words
An IC-mounting flexible circuit board as claimed in claim 3, wherein the protruding end portion of said junction protrusion is coated with a conductive deposited layer that is readily joined to an IC pad.
Claim 5
Dependent Claim
39 words
An IC-mounting flexible circuit board as claimed in claim 1, wherein said junction protrusion comprises a copper plated member and a solder member deposited on said copper plated member and protruding from the other side of said insulating base.
Claim 6
Dependent Claim
29 words
An IC-mounting flexible circuit board as claimed in one of the claims described above, wherein a resistant conductive layer is provided on the surface of said circuit wiring pattern.
Claim 7
Dependent Claim
21 words
An IC-mounting flexible circuit board as claimed in one of the claims described above, wherein said junction protrusions are disposed zigzag.
Claim 8
Dependent Claim
33 words
An IC-mounting flexible circuit board as claimed in one of the claims described above, wherein said circuit wiring pattern is constructed without an adhesive layer between said wiring pattern and said insulating base.
Claim 9
Dependent Claim
105 words
A process for producing an IC-mounting flexible circuit board, said process comprising the steps of boring a hole reaching a conductive layer from the insulating base side of a one-sided non-adhesive flexible conductive laminated board having no adhesive layer between a flexible insulating base and said conductive layer, forming junction protrusions for respective IC pads, each junction protrusion being formed by filling said hole with a conductive member by plating and having one end tightly joined to said conductive layer and the other protruding from said insulating base, and applying a desired circuit wiring patterning process to said conductive layer relative to said junction protrusions.
Claim 10
Dependent Claim
36 words
A process for producing an IC-mounting flexible circuit board as claimed in claim 9, wherein said conductive member is plated with gold, tin, lead·tin alloy or the like that is readily joined to an IC pad.
Claim 11
Dependent Claim
22 words
A process for producing an IC-mounting flexible circuit board as claimed in claim 9, wherein said conductive member is plated with copper.
Claim 12
Dependent Claim
60 words
A process for producing an IC-mounting flexible circuit board as claimed in claim 11, wherein said process includes the step of depositing a plating layer on the protruding end portion of said junction protrusion formed with said conductive member, said plating layer being made of gold, tin, lead·tin alloy or the like that is readily joined to an IC pad.
Claim 13
Dependent Claim
44 words
A process for producing an IC-mounting flexible circuit board as claimed in claim 9, wherein the step of forming said junction protrusion comprises forming a solder member protruding from said insulating base by filling said hole with copper plating before depositing said copper plating.
Claim 14
Dependent Claim
167 words
A process for producing an IC-mounting flexible circuit board, said process comprising the steps of preparing a both-sided non-adhesive flexible conductive laminated board having conductive layers on both sides of a flexible insulating base respectively without having an adhesive layer between said flexible insulating base and each conductive layer, applying a desired circuit wiring patterning process to one side of one of both said conductive layers, forming a conductive-layer removing portion necessary for forming a hole in the other side of the other conductive layer, said hole reaching the desired region of said circuit wiring pattern from said insulating base, forming said hole in said insulating base portion exposed in the removing portion, removing the unnecessary conductive layer left on said hole side, and forming each IC pad junction protrusion by filling the hole with a conductive member by plating, said IC pad junction protrusion having one end tightly joined to the desired region of said circuit wiring pattern and the other protruding from said insulating base.
Claim 15
Dependent Claim
193 words
A process for producing an IC-mounting flexible circuit board, said process comprising the steps of preparing a both-sided non-adhesive flexible conductive laminated board having conductive layers on both sides of a flexible insulating base respectively without having an adhesive layer between said flexible insulating base and each conductive layer, forming a resist pattern corresponding to a desired circuit wiring pattern on one side of one of both said conductive layer, forming a conductive-layer removing portion necessary for forming a hole in the other side of the other conductive layer, said hole reaching the desired region of the conductive layer corresponding to said circuit wiring pattern from said insulating base, forming said hole in said insulating base portion exposed in said removing portion, removing the unnecessary conductive layer left on said hole side, forming each IC pad junction protrusion by filling said hole with a conductive member by plating, said IC pad junction protrusion having one end tightly joined to the desired region of the conductive layer corresponding to said circuit wiring pattern and the other protruding from said insulating base, and using said resist pattern to apply a desired circuit wiring patterning process.
Claim 16
Dependent Claim
26 words
A process for producing an IC-mounting flexible circuit board as claimed in claim 15, wherein said resist pattern is formed with an etching resistant conductive member.
Claim 17
Dependent Claim
25 words
A process for producing an IC-mounting flexible circuit board as claimed in claim 15, wherein said resist pattern is formed with an etching resist member.
Claim 18
Dependent Claim
33 words
A process for producing an IC-mounting flexible circuit board as claimed in claim 17, wherein said etching resist member is formed with the use of a dry photoresist film having a protective film.
Claim 19
Dependent Claim
44 words
A process for producing an IC-mounting flexible circuit board as claimed in any one of the claims 14 - 17, wherein one conductive layer is thickly formed on the formation side of said circuit wiring pattern, whereas the other conductive layer is thinly formed.
Claim 20
Dependent Claim
38 words
A process for producing an IC-mounting flexible circuit board as claimed in any one of the claims 9 - 19, wherein the step of forming said hole is processed by a chemical resin etching or excimer laser means.
Claim 21
Dependent Claim
29 words
A process for producing an IC-mounting flexible circuit board as claimed in any one of the claims 9 - 20, wherein said IC pad junction protrusions are disposed zigzag.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.