GB2259584A - Photographic production of marks - Google Patents
Photographic production of marks Download PDFInfo
- Publication number
- GB2259584A GB2259584A GB9203930A GB9203930A GB2259584A GB 2259584 A GB2259584 A GB 2259584A GB 9203930 A GB9203930 A GB 9203930A GB 9203930 A GB9203930 A GB 9203930A GB 2259584 A GB2259584 A GB 2259584A
- Authority
- GB
- United Kingdom
- Prior art keywords
- photo
- symbol mark
- sensitive
- printed
- marking
- 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.)
- Withdrawn
Links
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 14
- 239000011248 coating agent Substances 0.000 claims abstract description 25
- 238000000576 coating method Methods 0.000 claims abstract description 25
- 239000000758 substrate Substances 0.000 claims abstract description 25
- 238000007639 printing Methods 0.000 claims abstract description 22
- 238000000034 method Methods 0.000 claims abstract description 20
- 230000015572 biosynthetic process Effects 0.000 claims description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- 239000004411 aluminium Substances 0.000 description 2
- 239000000839 emulsion Substances 0.000 description 2
- 229920000728 polyester Polymers 0.000 description 2
- 238000007650 screen-printing Methods 0.000 description 2
- 229910000679 solder Inorganic materials 0.000 description 2
- 238000005476 soldering Methods 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 239000012670 alkaline solution Substances 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 230000008602 contraction Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000003292 diminished effect Effects 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
-
- 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
- H05K1/0266—Marks, test patterns or identification means
-
- 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
- H05K2203/05—Patterning and lithography; Masks; Details of resist
- H05K2203/0502—Patterning and lithography
- H05K2203/0514—Photodevelopable thick film, e.g. conductive or insulating paste
-
- 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
- H05K2203/12—Using specific substances
- H05K2203/122—Organic non-polymeric compounds, e.g. oil, wax or thiol
-
- 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
- H05K2203/16—Inspection; Monitoring; Aligning
- H05K2203/161—Using chemical substances, e.g. colored or fluorescent, for facilitating optical or visual inspection
-
- 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
- H05K3/10—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern
- H05K3/12—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern using thick film techniques, e.g. printing techniques to apply the conductive material or similar techniques for applying conductive paste or ink patterns
- H05K3/1216—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern using thick film techniques, e.g. printing techniques to apply the conductive material or similar techniques for applying conductive paste or ink patterns by screen printing or stencil printing
Landscapes
- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Printing Methods (AREA)
- Screen Printers (AREA)
Abstract
In the described method it is possible to clearly form a symbol mark 2 free from blurring during the manufacture of a printed wiring board, and to slenderise the line of the symbol mark. A photo-sensitive coating 3 is printed en a marking surface 1a of a printed substrate 1 by the use of a photo-sensitive developing type of ink, and is then exposed through film 8 bearing symbol mark 2 and developed in order to form the desired symbol mark. The printing of the photo-sensitive coating is preferably done through a stencil screen mesh which has been produced by exposing the screen to the original mark 2 by projection printing to produce an enlarged symbol mark (Figs 1-4). <IMAGE>
Description
"METHOD OF MANUFACTURING A PRINTED WIRING BOARD"
The present invention relates to a method of manufacturing a printed wiring board, and more specifically, is directed to the step of applying printed markings during the manufacturing of such printed wiring boards.
A printed wiring board is usually obtained by forming a printed wiring circuit made from conductors on one side or both sides of a printed substrate, and by mounting desired components onto the printed wiring circuit.
For the purpose of indicating the kind, number, and mounting location of the components, and the letters and signs of the road map, symbols and other markings are applied on the printed substrate of the printed wiring circuit.
The marking is required to be clear and is prohibited from straying onto the land portion.
Marking is generally effected by means of a printing method using a stencil screen, which will be described hereinafter.
In the conventional method of forming the marking by the use of the stencil screen, a photosensitive emulsion is applied on the screen including an aluminium hollow frame to which a mesh such as polyester or stainless steel mesh is attached under a uniform tension, and is exposed to light to thereby form a photo-sensitive film.
Then, an off-image for the printing is directly disposed on the screen by means of the steps of ultra-violet exposure to the film surface and development while bringing the film surface of the positive or negative film of the symbol mark for the object into close contact with the photo-sensitive film. An ink for symbol printing is placed on the thus configured stencil screen, and is squeezed onto the printed substrate through the off-image by means of a squeegee, thereby printing the image onto the position of the printed substrate at which the mark is to be printed, to obtain the symbol mark.
Disclosed in Japanese Examined Patent
Publication No. 54-41102 as well as symbol plotting, is a technique in which "a resist layer with soldering" is printed simultaneously with the symbol printing between lands having relatively narrow intervals so as to prevent the solder bridge extending between the lands at the time of device mounting such as soldering.
However, the printing method which is employed for the execution of the marking step required in the manufacturing step of the printed wiring board, involves the following problems:
(1) The plotting resolution is poor in that the image obtained through the stencil screen is up to 0.15 mm (design value) in service effective line width.
(2) Image plotting by means of the printing method often brings about blurred ink due to its characteristics.
(3) The stencil screen formed from the mesh subjected to tension has a larger expansion and contraction movement of itself. Also, it is difficult to demand an accuracy having less deviation since there are a lot of factors in the steps such as printing pressure of the squeegee which greatly influences the printing accuracy.
Thus, the present invention was conceived in order to overcome the above disadvantages in the conventional marking, and seeks to provide a method of manufacturing a printed wiring board capable of executing the printing of the symbol mark with a higher accuracy which can cope with a higher-density mounting of components following a higher-density circuit of the printed wiring board, without lowering the productivity thereof.
According to the invention, there is provided a method of manufacturing a printed wiring board wherein a marking (symbol mark) is applied to one or both sides of the printed wiring board, said method comprising the steps of forming a coating of a photosensitive developing type of ink on the marking surface of the printed substrate; exposing the photosensitive coating which has formed in the preceding step through an exposure film for the marking formation; and forming a symbol mark by developing the photo-sensitive coating after said exposure.
In the method of the invention, a photosensitive coating is formed on a marking surface of the printed substrate and is exposed for the development to form the symbol mark. The present invention therefore has the advantage that the blur phenomenon which would be caused by the printing method is prevented. In addition, the symbol mark having a higher accuracy and higher quality can be formed while improving thinning of the line of the symbol mark such as letters and figures.
Furthermore, ease of design restriction on the symbol mark and improvement of the design freedom can be achieved.
For a better understanding of the present invention reference will now be made by way of example to the accompanying drawings, in which:
Figure 1 is a plan view of the printed substrate;
Figure 2 is a plan view of the stencil screen;
Figure 3 is a plan view showing the printing state of the photo-sensitive coating;
Figure 4 is a plan view of the printed substrate showing the forming state of the photosensitive coating;
Figure 5 is a sectional view taken along a line A-A of Figure 4;
Figure 6 is a plan view showing an exposure state of the photo-sensitive coating;
Figure 7 is a sectional view taken along a line B-B of Figure 6;
Figure 8 is a plan view of the printed substrate showing a symbol mark after the development of the photo-sensitive coating; and
Figure 9 is a sectional view taken along a line C-C of Figure 8.
The method of forming a symbol mark during the manufacture of a printed wiring board in accordance with the present invention will now be described based on an embodiment thereof with reference to the accompanying drawings.
The following description is directed to the case where a desired printed wiring circuit (not shown) is firstly formed on a marking surface of the printed substrate on which a solder resist (not shown) is provided.
In the case where the symbol mark 2 showing a number 1 is formed at a predetermined position on the marking surface la of the printed substrate 1 as shown in Figure 1, a stencil screen 4 is made for the application of a photo-sensitive coating 3 of the photo-sensitive developing ink onto the marking surface la of the printed substrate 1 as shown in
Figure 2.
Such stencil screen 4 may be manufactured in the same manner as the conventional stencil screen on which the symbol mark is printed. That is, under tension there is arranged a fibrous cloth (mesh) 5 woven from a fibre such as polyester or stainless steel and provided inside a rectangular parallelepiped frame 8 (not shown) formed from an aluminium hollow frame, to thereby form a screen 6. A photo-sensitive emulsion is then applied on the screen 6 to form a photo-sensitive film (not shown).
Afterward, the film surface for the exposure of positive or negative film is brought into close contact with the photo-sensitive film for the ultraviolet exposure and development, whereby the off-image 7 for printing can be formed on the screen 6.
The off-image 7 on the screen 6 is formed in such a manner that there can be printed the number 1 bolder than the symbol mark 2 to be formed on the marking surface 1a of the printed substrate 1 shown in
Figure 1.
Using the thus-configured stencil screen 4, the photo-sensitive coating 3 is formed by positioning at the location in which the symbol mark 2 of the printed substrate 1 is arranged as shown in Figures 4 and 5. Printing is then performed by applying a photo-sensitive developing type of ink (for example
PSR-500/MW-3 supplied by OYO KAGAKU KOGYO K.K. or the like) on the marking surface la of the printed substrate 1 in the same manner as the conventional stencil screen printing method while disposing the stencil screen 4 on the front of the marking surface la of the printed substrate 1, as shown in Figure 3.
The ink is dried to form the photo-sensitive coating 3 of the photo-sensitive developing ink on the front of the marking surface la of the printed substrate 1 so as to be positioned at the location where the symbol mark 2 is to be formed (refer to
Figures 4 and 5).
Figure 4 shows, in a broken line, the size of the symbol mark 2 to be actually formed, in comparison with the photo-sensitive coating 3.
The photo-sensitive coating 3 positioned at the location where the symbol mark 2 is formed of the printed substrate 1 and composed of the bold number 1 is printed and formed by means of stencil screen 4, and exposed for development, to thereby form the symbol mark 2 as shown in Figures 8 and 9.
That is, in order to form the symbol mark 2 by exposing and developing the photo-sensitive coating 3 of the printed substrate 1, a film 8 for exposing the symbol mark (a positive or negative film capable of exposing the symbol mark 2 to the photo-sensitive coating 3 as shown in Figure 6) is firstly fixed while positioning the photo-sensitive film 3 and the exposed portion of the symbol mark 2 of the film 8. Next, the photo-sensitive coating 3 is exposed by the irradiation of a radiating light for the exposure such as ultra-violet rays from the upper side of the exposure film 8, as shown in Figure 7.
By developing with an alkaline solution, organic solvent and the like after the exposure, the symbol mark 2 designating the number 1 can be formed at the predetermined location of the marking surface la of the printed substrate 1 as shown in Figures 8 and 9. The setting reaction of the thus-formed symbol mark 2 can be accelerated, dependent upon the ink characteristics, by means of heating, ultra-violet irradiation or the like.
In the above-described method, the bold letter of the actually formed symbol mark 2 is printed through the photo-sensitive coating 3 while positioning it at a location where the symbol mark is formed. Alternatively, and in order to form a plurality of symbol marks 2 or a plurality of further widely distributed symbol marks 2, the photo-sensitive developing ink may be applied over the marking surface la of the printed substrate 1 by means of a spray, roll-coater or the like to form a photo-sensitive coating layer (not shown) over the marking surface la, and then exposed through the exposure film for development. A plurality of symbol marks can be formed at one time in this manner.
In this case, it is not required to provide the stencil screen for the formation of the photosensitive coating 3 corresponding to the symbol mark 2, whereas the region to be developed is widened to bring about a reduction of production costs.
As is apparent from the above description, the adoption of the present invention greatly improves the clearness of the symbol plotting, which would not be obtained by the conventional printing method.
That is, the planar central portion having the largest thickness of the ink coating is exposed for development in the state plotted by the printing, thereby deleting the portion blurred by the printing, to obtain a symbol mark having a clearness and a higher accuracy.
Furthermore, blurring of the symbol letter arising from the printing during the process of manufacturing the printed wiring board at present causes considerable difficulties. In the abovedescribed method, there is basically no blur, which greatly contributes to the product yield. In addition, it is possible to slenderise (0.05mm) and reduce the dimension due to the highly accurate finish, which results in a relaxation of design restrictions and an improvement in design freedom.
Furthermore, as compared to the screen printing method, the present embodiment involves very many fewer control factors for positional accuracy, by virtue of the use of the photographic method from exposure to the development. Consequently, positional accuracy is remarkably improved as compared to the prior art.
As described earlier, the present embodiment can also be obtained by the wide application of the ink using a spray, rolL coater, or the like and the exposure for development of the same. Instead, the application of the ink may be restricted by a partial printing, whereby the portion to be deleted after development can be diminished, in other words, the amount of the ink to be used can be reduced, which leads to cost-saving.
In the method of manufacturing the printed wiring board of the present invention, the formed symbol mark is free from the blur, and clearness is improved, which contributes to the slenderisation of the letters to be plotted and the higher positional accuracy of the plotting. Thus, the control factors concerning the positional accuracy are decreased, design restrictions are eased, and production yields can be improved.
Claims (4)
1. A method of manufacturing a printed wiring board wherein a marking (symbol mark) is applied to one or both sides of the printed wiring board, said method comprising the steps of:
forming a coating of a photo-sensitive developing type of ink on the marking surface of the printed substrate;
exposing the photo-sensitive coating which has formed in the preceding step through an exposure film for the marking formation; and
forming a symbol mark by developing the photo-sensitive coating after said exposure.
2. A method according to claim 1, wherein said photo-sensitive developing ink is restrictively applied at the position to be marked on the marking surface of the printed substrate, or alternatively, partially applied in the region enclosing a plurality of marking positions.
3. A method according to claim 1, wherein said step of forming the photo-sensitive coating includes a printing step for applying the photo-sensitive developing ink on the marking surface of the printed substrate through a stencil screen.
4. A method according to claim 1, substantially as hereinbefore described.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25964391A JPH06255232A (en) | 1991-09-11 | 1991-09-11 | Manufacture of printed wiring board |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB9203930D0 GB9203930D0 (en) | 1992-04-08 |
| GB2259584A true GB2259584A (en) | 1993-03-17 |
Family
ID=17336912
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9203930A Withdrawn GB2259584A (en) | 1991-09-11 | 1992-02-24 | Photographic production of marks |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPH06255232A (en) |
| GB (1) | GB2259584A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001098829A1 (en) * | 2000-06-21 | 2001-12-27 | Rauno Salmi | A method for individualised marking of circuit boards |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1044807A (en) * | 1964-02-06 | 1966-10-05 | Columbia Ribbon & Carbon | Heat transferable sheets for use in thermographic processes |
| GB1091473A (en) * | 1965-04-02 | 1967-11-15 | Keuffel & Esser Co | Copying material |
| EP0087582A2 (en) * | 1982-02-26 | 1983-09-07 | International Business Machines Corporation | Optical lithography process for creating patterns in a silicon semiconductor substrate |
| GB2131767A (en) * | 1982-12-16 | 1984-06-27 | Wiggins Teape Group Ltd | Marking packaging |
| GB2237896A (en) * | 1986-11-06 | 1991-05-15 | Westinghouse Electric Corp | Method of applying and curing photosensitive paints |
-
1991
- 1991-09-11 JP JP25964391A patent/JPH06255232A/en active Pending
-
1992
- 1992-02-24 GB GB9203930A patent/GB2259584A/en not_active Withdrawn
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1044807A (en) * | 1964-02-06 | 1966-10-05 | Columbia Ribbon & Carbon | Heat transferable sheets for use in thermographic processes |
| GB1091473A (en) * | 1965-04-02 | 1967-11-15 | Keuffel & Esser Co | Copying material |
| EP0087582A2 (en) * | 1982-02-26 | 1983-09-07 | International Business Machines Corporation | Optical lithography process for creating patterns in a silicon semiconductor substrate |
| GB2131767A (en) * | 1982-12-16 | 1984-06-27 | Wiggins Teape Group Ltd | Marking packaging |
| GB2237896A (en) * | 1986-11-06 | 1991-05-15 | Westinghouse Electric Corp | Method of applying and curing photosensitive paints |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001098829A1 (en) * | 2000-06-21 | 2001-12-27 | Rauno Salmi | A method for individualised marking of circuit boards |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06255232A (en) | 1994-09-13 |
| GB9203930D0 (en) | 1992-04-08 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |