Printed circuit board with resist coating defining reference marks

• US 6,365,841 B1
• Filed: 07/17/1998
• Issued: 04/02/2002
• Est. Priority Date: 07/17/1997
• Status: Expired due to Fees

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Takigami, Kotaro
• Primary Examiner(s): Cuneo, Kamand
• Application Number:
  US09/116,947
• Time in Patent Office: 1,355 Days
• Field of Search: 174/250, 174/260, 361/760, 361/767, 361/771, 361/777, 361/779, 361/783, 361/808, 361/811
• US Class Current: 174/260
• CPC Class Codes: H05K 1/0266 Marks, test patterns or identification means
• CPC Class Codes: H05K 1/0269 for visual or optical inspection
• CPC Class Codes: H05K 2201/09781 Dummy conductors, i.e. not used for normal transport of current; Dummy electrodes of components
• CPC Class Codes: H05K 2201/099 Coating over pads, e.g. solder resist partly over pads
• CPC Class Codes: H05K 2201/09918 Optically detected marks used for aligning tool relative to the PCB, e.g. for mounting of components
• CPC Class Codes: H05K 2203/166 Alignment or registration; Control of registration
• CPC Class Codes: H05K 3/303 Surface mounted components, e.g. affixing before soldering, aligning means, spacing means H05K3/32 takes precedence
• CPC Class Codes: H05K 3/3452 Solder masks
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing
• CPC Class Codes: Y10T 29/4913 Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49131 by utilizing optical sighting device
• CPC Class Codes: Y10T 29/49144 by metal fusion

Abstract

A printed circuit board includes a first mark 2 formed by a thin conductor, a second mark 3 formed by a resist 8, a land 6 which is partially coated by the resist 8 and a land 7 which is not coated by the resist 8. The second mark 3 is formed when the land 6 is partially coated by the resist 8. A device 4, which corresponds to the land 6, is mounted at a position apart from a center O2 of the second mark 3 by a predetermined distance L1. A device 5, which corresponds to the land 7, is mounted at a position apart from a center O1 of the first mark 2 by a predetermined distance L2. Therefor, the devices 4, 5 can be properly mounted on the printed circuit board 1 in spite of a positional error of the resist 8.

Claims

1. A printed circuit board, comprising:

a first land, partially coated with a resist which defines an uncoated area, for mounting a first device thereon, the first land being formed of a conductor;

a second land, not coated with the resist, for mounting a second device thereon, the second land being formed of the conductor;

a first mark, formed by said resist, for use in mounting the first device on the uncoated area of the first land;

a second mark, formed of said conductor, for use in mounting the second device on the second land;

a first device mounted a first distance from the first mark on a center of the uncoated area of the first land; and

a second device mounted a second distance from the second mark on a center of the second land.

2. The printed circuit board claimed in claim 1, wherein said first and second marks are completely separated from each other.

3. The printed circuit board claimed in claim 1, wherein said first and second marks are partially overlapped with each other.

4. The printed circuit board claimed in claim 1, wherein said first mark is one of a quadrangle, circle and triangle shape, and said second mark is also one of a quadrangle, circle and triangle shape.

5. The printed circuit board claimed in claim 1, wherein said first mark is formed on a central area of the second mark.

6. The printed circuit board claimed in claim 5, wherein said first and second marks are quadrangular in shape.

7. The printed circuit board claimed in claim 5, wherein a plurality of sets of said first and second marks are formed.

8. The printed circuit board claimed in claim 5, wherein a set of said first and second marks are formed at each corner of four corners on the printed circuit board.

9. A printed circuit board for facilitating device placement thereon, comprising:

at least one first land, partially coated with a resist, for mounting a first device thereon, the first land being formed of a conductor;

at least one second land, not coated with the resist, for mounting a second device thereon, the second land being formed of the conductor;

a first reference mark, formed of the resist, defining a first reference position used in mounting the first device on the first land; and

a second reference mark, formed of the conductor, defining a second reference position used in mounting the second device on the second land.

10. The printed circuit board as in claim 9, wherein the first reference position is at a center of the first reference mark, and the second reference position is at a center of the second reference mark.

11. The printed circuit board as in claim 9, wherein the first reference mark is located on top of and within a perimeter of the second reference mark.

12. The printed circuit board as in claim 9, wherein the first and second reference marks are at a corner of the printed circuit board.

13. The printed circuit board as in claim 9, wherein the first reference position is one which remains a constant distance from a center of an area of the first land and not coated with the resist, even when the resist is misaligned.

14. The printed circuit board as in claim 9, further comprising:

a first device mounted a first distance from the first reference position on a center of an uncoated area of the first land; and

a second device mounted a second distance from the second mark on a center of the second land.

15. A printed circuit board for facilitating device placement thereon, comprising:

a mounting means for receiving a device, the mounting means being partially covered with a resist, the resist defining a mounting area on the mounting means;

a reference means for defining a reference position which remains a constant distance from a center of the mounting area when the resist and the mounting area are shifted, the reference position being used in mounting the device on the mounting area; and

a device mounted on the center of the mounting area.

16. The printed circuit board as in claim 15, wherein the reference means is made of the resist.