GB2150361A - Circuit board - Google Patents
Circuit board Download PDFInfo
- Publication number
- GB2150361A GB2150361A GB08429524A GB8429524A GB2150361A GB 2150361 A GB2150361 A GB 2150361A GB 08429524 A GB08429524 A GB 08429524A GB 8429524 A GB8429524 A GB 8429524A GB 2150361 A GB2150361 A GB 2150361A
- Authority
- GB
- United Kingdom
- Prior art keywords
- circuit board
- terminals
- connecting material
- material layer
- electronic components
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K1/00—Printed circuits
- H05K1/02—Details
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/30—Assembling printed circuits with electric components, e.g. with resistor
- H05K3/32—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits
- H05K3/321—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by conductive adhesives
- H05K3/323—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by conductive adhesives by applying an anisotropic conductive adhesive layer over an array of pads
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K1/00—Printed circuits
- H05K1/18—Printed circuits structurally associated with non-printed electric components
- H05K1/181—Printed circuits structurally associated with non-printed electric components associated with surface mounted components
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
- H05K2201/01—Dielectrics
- H05K2201/0104—Properties and characteristics in general
- H05K2201/0129—Thermoplastic polymer, e.g. auto-adhesive layer; Shaping of thermoplastic polymer
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
- H05K2201/10—Details of components or other objects attached to or integrated in a printed circuit board
- H05K2201/10613—Details of electrical connections of non-printed components, e.g. special leads
- H05K2201/10621—Components characterised by their electrical contacts
- H05K2201/10636—Leadless chip, e.g. chip capacitor or resistor
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K2203/00—Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
- H05K2203/04—Soldering or other types of metallurgic bonding
- H05K2203/0425—Solder powder or solder coated metal powder
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/36—Assembling printed circuits with other printed circuits
- H05K3/361—Assembling flexible printed circuits with other printed circuits
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Landscapes
- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Manufacturing & Machinery (AREA)
- Electric Connection Of Electric Components To Printed Circuits (AREA)
- Wire Bonding (AREA)
Abstract
In a circuit board, a wiring pattern (2) is formed on an insulating plastic film (1), and connecting terminals (2a, 2b, 2c, 2d) are formed at end portions of the wiring pattern (2). Connecting material layers (3a, 3b, 3c, 3d) are uniformly formed on the connecting terminals to connect the circuit board to electronic components (6, 7, 8, 9). The connecting material layers are kept in a dry state at room temperature, have a substantially insulating property in every direction, and have conductivity along the direction of thickness thereof when they have been heated, compressed and melted. Connecting terminals (6a, 7a, 8a, 9a) of the electronic components are positioned on the connecting material layers and the layers are then partially bonded by thermocompression, so that the electronic components are electrically connected to the circuit board. The connecting material is a thermoplastic adhesive (4) containing conductive particles (5). <IMAGE>
Description
SPECIFICATION
Circuit board
The present invention relates to a circuit board and, more particularly, to a circuit board having a connecting layer.
Heat seals are conventionally known as a means for connecting electronic components to connecting terminals of a circuit board. A heat seal is arranged such that hot-melt type conductive and insulating adhesives are formed alternatively or in islands. One end of the heat seal is connected to an electronic component, and the other end thereof is connected to a connecting terminal of the circuit board, thereby electrically connecting the electronic component to the circuit board. Another means is also proposed wherein an anisotropic adhesive tape having a conductivity in an urged direction is directly adhered to a connecting terminal of a circuit board.
In electrical connections using a heat seal, the heat seal has a complicated construction and is expensive. The two end portions of the heat seal must be connected to the electronic component and to the circuit board resulting in complicated assembly. In addition, when electric connections are made by using the anisotropic adhesive tape, the number of adhesion steps is increased and the electronic component must be connected to the connecting terminal within a predetermined period so as to obtain a predetermined adhesive force after the adhesive tape is applied to the connecting terminal.
This electrical connection method is not suitable for an automatic assembly line.
It is an object of the present invention to provide a circuit board wherein an electronic component can be efficiently connected to a connecting terminal of the circuit board at low cost.
In order to achieve the above object of the present invention, there is provided a circuit board comprising: an insulating plastic film; a wiring pattern formed on said insulating plastic film; a plurality of connecting terminals connected to said wiring pattern; and a connecting material layer formed on at least said plurality of connecting terminals to a substantially uniform thickness, kept in a dry state at room temperature, having an insulating property in every direction, and having a conductivity along a direction of thickness thereof when said connecting material layer is partially heated, pressed and melted, said connecting material layer being arranged to connect the electronic component to said circuit board.
This invention can be more fully understood from the following detailed description when taken in conjunction with the accompanying drawings, in which:
Figure 1 is an exploded perspective view showing a circuit board and different electronic components connected thereto;
Figure 2 is an enlarged sectional view showing a structure of a connecting material layer shown in
Figure 1;
Figure 3 is an enlarged sectional view showing a main part in a state wherein a terminal of the electronic component is connected to a connecting terminal of the circuit board;
Figure 4 is an enlarged sectional view showing the main part in a state wherein a terminal of a display element is connected to a connecting terminal of the circuit board;;
Figure 5 is an enlarged sectional view showing the main part in a state wherein a terminal of a semiconductor IC is connected to a connecting terminal of the circuit board;
Figure 6 is an enlarged sectional view showing the main part in a state wherein a terminal of a sub-circuit board is connected to a connecting terminal of the circuit board; and
Figure 7 is an enlarged sectional view showing the main part in a state wherein a terminal of a chip component is connected to a connecting terminal of the circuit board.
Figure 1 is an exploded perspective view of a circuit board and different electronic components connected thereto. Reference numeral 1 denotes a board which comprises a plastic film made of a material such as polyester, vinyl chloride and polyimide, and which has a thickness of 50 to 150 ym. A predetermined wiring pattern 2 is formed on the upper surface of the board 1. The wiring pattern 2 is obtained so that a conductive material such as a metal film or a carbon ink is formed by etching or printing. The conductive material extends slightly upward from an upper surface 1a of the board 1 and also extends along the upper surface 1 a. Reference numerals 2a, 2b, 2c and 2d denote connecting terminals at an end portion of the wiring pattern 2 or terminals connected to the wiring pattern 2.The terminals 2a, 2b, 2c and 2d extend slightly upward from the upper surface 1 a of the board 1. Reference numerals 3a, 3b, 3c and 3d denote connecting material layers for mounting the electronic components on the connecting terminals 2a, 2b, 2c and 2d, respectively. The connecting material layers 3a, 3b, 3c and 3d comprise a mixture obtained by mixing metal microparticles of nickel, aluminum, solder or the like, or graphite particles in a hot melt type insulating adhesive. The connecting material layers 3a, 3b, 3c and 3d are formed by screen printing on the connecting terminals 2a, 2b, 2c and 2d to a uniform thickness and are dried at a temperature of 70 to 1 30 C.
Figure 2 is an enlarged sectional view showing the construction of the connecting layer. Reference numeral 3 represents 3a, 3b, 3c and 3d. Reference numeral 4 denotes a hot melt type insulating adhesive. Reference numerals 5 denote conductive particles mixed in the hot melt insulating adhesive 4.
As is apparent from Figure 2, the conductive particles 5 are dispersed uniformly in the adhesive 4. At least one of the upper and lower surfaces of the conductive particles 5 is covered with the hot melt type adhesive 4 which can be reactivated. The same dispersion state as that of the conductive particles 5 in Figure 2 is obtained even if the connecting material layer 3 is cut in a direction perpendicular to the direction of the section shown in Figure 2. The conductive particles 5 are mixed uniformly in a dispersed state. Therefore, the connecting material layer 3 has an insulating property along every direction.The insulating material layer 3 may have a thickness of about 30 clam, and the size of the conductive particles 5 may be 20 iim along the direction of a long side of the layer 3 and 10 to 20 um along the direction of a short side thereof. However, the thickness of the layer and the particle size are not limited to these values. The hot melt type adhesive 4 constituting the connecting material layer 3 can be melted at a relatively low temperature of about 100 to 150"C.
Referring to Figure 1, reference numerals 6,7,8 and 9 denote electronic components connected to the connecting terminals 2a, 2b, 2cant 2d of the board 1, respectively. The electronic components 6, 7, 8 and 9 comprise a display element such as a liquid crystal display element, a semiconductor IC, a sub-circuit board, and a chip component, respectively. The display element 6, the semiconductor IC 7, the sub-circuit board 8 and the chip commponent 9 have terminals 6a, 7a, 8a and 9a to be connected to the connecting terminals 2a, 2b, 2c and 2d. In order to mount the respective electronic components on the circuit board 1, the terminals of the respective electronic components are positioned on the respective connecting material layers 3a, 3b and 3c so as to correspond to the respective connecting terminals of the circuit board 1.Thereafter, the terminals of the electronic components and the connecting material layers 3a, 3b and 3c are heated and urged by a jig from the lower surface of the board 1 and are bonded. The bonding operation will be described in detail with reference to Figure 3. Figure 3 is an enlarged sectional view showing the main part when the display element 6 is connected to the circuit board 1. The connecting terminals 2a on the board 1 are positioned to correspond to the electrode terminals 6a of the display element 6 through the connecting material layer 3a printed on the entire surfaces of the terminals 2a. The board 1 is heated by a heating press jig 10 from a lower surface 1 b of the board 1.
Since the board 1 comprises a thin plasticfilm, heat is conducted to the connecting layer 3a, and the hot melt adhesive 4 is melted. As previously described, the respective connecting terminals 2a extend upward from the upper surface 1 a of the board 1, and the terminals 6a of the display element 6 extend therefrom. In other words, the opposing surfaces between the connecting terminals 2a and the terminals 6a have small gaps. For this reason, the hot melt type adhesive 4 between these terminals 2a and 6a flows toward a region where the terminals do not oppose each other. The conductive particles 5 are exposed between the terminal surfaces and are connected thereto, so that the connecting material layer 3a provides conductivity along the direction of thickness thereof.The terminals 6a of the display element 6 are electrically connected to the connecting terminals 2a of the circuit board 1 through the conductive particles 5. When the heating press jig 10 is removed from the circuit board 1 and it is cooled, the connecting material layer 3a is solidified, so that the display element 6 is fixed on the circuit board 1.
In this manner, the mounting state of the display element 6 on the board 1 is illustrated as a sectional view in Figure 4. Other electronic components are mounted on the circuit board 1 in the same manner as the display element 6. Figures 5, 6 and 7 are sectional views showing mounting states wherein the semiconductor IC 7, the sub-circuit board 8 and the chip component 9 are mounted on the circuit board 1, respectively. The terminals 7a of the semiconductor IC 7 are positioned through the connecting material layer 3b on the connecting terminals 2b of the board 1, which have the same pitch as the terminals 7a. The terminals 7a and the corresponding terminals 2b are subjected to thermocompression bonding. The connecting layer 3b may be formed on an entire surface portion for mounting the semiconductor IC 7 or may be printed on a portion corresponding to the terminals 2b.The terminals 8a of the sub-circuit board 8 are connected to a wiring pattern (not shown) and are connected to the connecting terminals 2c of the circuit board 1 through the connecting material layer 3c. The subcircuit board 8 comprises a hard plastic board made of a material such as phenolic resin. However, the sub-circuit board 8 may comprises a flexible plastic film. When the sub-circuit board 8 comprises the hard board, thermocompression bonding is performed from the lower surface of the circuit board 1.
However, when the sub-circuit board 8 comprises a flexible plastic film, thermocompression bonding may be performed from the upper surface 8b of the sub-circuit board 8. In this case, the connecting material layers 3c may be formed on the sub-circuit board 8. The terminals 9a and 9b of the chip component 9 are fixed on the corresponding connecting terminals 2d of the board 1 through the connecting material layer 3d. The terminals 9a will not extend upward from the chip component 9.
However, the connecting terminals 2d extend upward from the upper surface of the board 1, so that the terminals 9a and 2d are electrically connected through the conductive particles 5.
When the electronic components such as the display element 6, the semiconductor IC 7, the sub-circuit board 8 and the chip component 9 are mounted on the circuit board 1, each electronic component is positioned and bonded by thermocompression or a plurality of electronic components may be simultaneously positioned and bonded by thermocompression. The latter method increases the connection efficiency.
Electronic equipment having a connection structure between the circuit board and the electronic components according to this embodiment are exemplified by compact electronic calculators, electronic games and so on. However, the present invention is not limited to these applications. The present invention has a great advantage in electronic equipment having a single electronic component. In addition, the electronic components to be mounted on the circuit board are not limited to those exemplified above. The electronic components may include various electronic components such as a solar battery and a buzzer. In the above embodiment, the connecting terminals extend upward from the circuit board. However, when the terminals of the electronic component extend therefrom, the connecting terminals of the circuit board need not extend upward from the surface thereof. Roll coating may be used in place of screen printing as a means for connecting the connecting material layer on the connecting terminals of the circuit board.
As has been made apparent by the above description, since the connecting means is formed on the circuit board, the terminals of the electronic components are positioned in correspondence with the connecting terminals of the circuit board and are bonded thereto by thermocompression, thereby improving the connection efficiency. In addition, the connecting material layer has a simple structure wherein the conductive particles are uniformly mixed in the hot melt type insulating adhesive. The resultant equipment becomes cost effective.
Claims (5)
1. A circuit board comprising:
an insulating plastic film;
a wiring pattern formed on said insulating plastic film; and
a plurality of connecting terminals connected to a wiring pattern; characterized by further comprising
a connecting material layer formed on at least said plurality of connecting terminals to a substantially uniform thickness, kept in a dry state at room temperature, having an insulating property in every direction, and having a conductivity along a direction of thickness thereof when said connecting material layer has been partially heated, pressed and melted, said connecting material layer being arranged to connect an electronic component to said circuit board.
2. A circuit board according to claim 1, characterized in that said connecting material layer is printed on said plurality of connecting terminals.
3. A circuit board according to claim 1,characte- rized in that said connecting material layer is formed such that conductive particles are uniformly dispersed in a hot melt adhesive material which is reactivated upon heating.
4. A circuit board according to claim 3, characterized in that said connecting material layer has a thickness of about 30 um, and said conductive particles have a size of 10 to 20 um.
5. A circuit board, substantially as hereinbefore described with reference to the accompanying drawings.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1983182803U JPS6090867U (en) | 1983-11-26 | 1983-11-26 | Wiring board with electrical connection means |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB8429524D0 GB8429524D0 (en) | 1985-01-03 |
| GB2150361A true GB2150361A (en) | 1985-06-26 |
| GB2150361B GB2150361B (en) | 1988-01-27 |
Family
ID=16124696
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08429524A Expired GB2150361B (en) | 1983-11-26 | 1984-11-22 | Circuit board |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JPS6090867U (en) |
| KR (1) | KR890000596Y1 (en) |
| GB (1) | GB2150361B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2633485A1 (en) * | 1988-06-24 | 1989-12-29 | Toshiba Kk | METHOD AND APPARATUS USING FICTIONAL TRACKS FOR CONNECTING ELECTRONIC COMPONENTS |
| DE4206700A1 (en) * | 1992-03-04 | 1993-09-16 | Vdo Schindling | Contacting device for conductor paths arranged on carrier and flexible conductor sheet - has carrier and flexible sheet positioned so as to overlap each other and conductor paths respectively parallel to each other can be connected conducting with each other |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2068645A (en) * | 1980-01-31 | 1981-08-12 | Rogers Corp | Electrical interconnection |
-
1983
- 1983-11-26 JP JP1983182803U patent/JPS6090867U/en active Pending
-
1984
- 1984-04-13 KR KR2019840003391U patent/KR890000596Y1/en not_active IP Right Cessation
- 1984-11-22 GB GB08429524A patent/GB2150361B/en not_active Expired
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2068645A (en) * | 1980-01-31 | 1981-08-12 | Rogers Corp | Electrical interconnection |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2633485A1 (en) * | 1988-06-24 | 1989-12-29 | Toshiba Kk | METHOD AND APPARATUS USING FICTIONAL TRACKS FOR CONNECTING ELECTRONIC COMPONENTS |
| DE4206700A1 (en) * | 1992-03-04 | 1993-09-16 | Vdo Schindling | Contacting device for conductor paths arranged on carrier and flexible conductor sheet - has carrier and flexible sheet positioned so as to overlap each other and conductor paths respectively parallel to each other can be connected conducting with each other |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8429524D0 (en) | 1985-01-03 |
| KR890000596Y1 (en) | 1989-03-11 |
| KR850004578U (en) | 1985-07-22 |
| GB2150361B (en) | 1988-01-27 |
| JPS6090867U (en) | 1985-06-21 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |