GB2343059A

GB2343059A - A method for tracking printed circuit boards on multi-board panels through a production process

Info

Publication number: GB2343059A
Application number: GB9904255A
Authority: GB
Inventors: John Charles Casey
Original assignee: JERSEYFIELD Ltd
Current assignee: JERSEYFIELD Ltd
Priority date: 1998-10-21
Filing date: 1999-02-24
Publication date: 2000-04-26
Also published as: GB9904255D0

Abstract

A method for tracking printed circuit boards 2 during production, wherein a plurality of printed circuit boards 2a to 2e of different types are formed on a single multi-board panel 1 comprises the step of simultaneously forming with conductive tracks the printed circuit boards 2 a plurality of corresponding first identifiers 8a to 8e for identifying the printed circuit boards 2a to 2e, respectively.

Description

"A method for tracking printed circuit boards on multi-board panels through a production process" The present invention relates to a method for tracking printed circuit boards on multi-board panels through a production process, and in particular, the invention relates to a method for tracking printed circuit boards on multi-board panels through a production process where a plurality of printed circuit boards of different types are formed on each panel. The invention also relates to a panel formed by the method according to the invention, and the invention further relates to a printed circuit board formed according to the method.

In the production of printed circuit boards, in order to optimise the usage of raw material, it is now common practice to produce a number of different types of printed circuit boards on a single panel. Typically, three or four different types of boards may be produced on a single panel, and in general, two to four of each type of printed circuit board are formed on a panel.

Indeed, where the printed circuit boards are relatively small, more than four printed circuit boards of the same type may be formed on the panel. Typical panel sizes are of the order of 400cms by 500cms, and accordingly, depending on the size of the printed circuit boards, up to twelve, and in certain cases more printed circuit boards may be formed on each panel.

Needless to say, in the event of relatively large printed circuit boards, then the number of printed circuit boards which may be formed on a panel is correspondingly reduced.

In selecting the types and numbers of each type of printed circuit board to be formed on a panel, one must take account of the overall number of printed circuit boards of each type required in a batch, delivery dates by which the printed circuit boards are required, and most importantly usage of material of the panel.

Computer programmes are known which optimise between these various parameters.

Such computer programmes design the layout of the printed circuit boards on the panel based on the above parameters. One or two transparencies, depending on whether the printed circuit boards are double or single sided, are printed which comprise a positive or negative image of the panel including the conductive tracks of the respective printed circuit boards at their appropriate locations on the panel. The image may be positive or negative, depending on the process to which the panel is to be subjected. The transparency or transparencies are secured to the panel and maintained in registration therewith. Initially, mechanical operations which are to be carried out on the panel, for example, drilling of holes and the like are carried out. From here on, the formation of printed circuit boards on a panel will be well known to those skilled in the art. On the printed circuit boards having been formed on the panel, the panel is machined for facilitating detaching of the boards subsequently from the panel by hand. Care must be taken in detaching the boards from the panel to avoid printed circuit boards of different types being mixed up. This, in general, requires an operator comparing the printed circuit boards of the panel with their original drawings so that the board type and customer identity can be obtained from the drawing. This, it will be appreciated, is a time consuming task, and is prone to error, particularly, where two or more different types of boards are formed on the same panel which appear to be substantially similar to each other.

In which case, an operator could quite easily mix up such types of boards. Furthermore, in addition to the problem of identifying the printed circuit boards at the end of the production process, it is also difficult to identify the printed circuit boards during the production process, and it is also difficult to track printed circuit boards during a production process.

There is therefore a need for a method for tracking printed circuit boards on multi-board panels through a production process which overcomes these problems.

The present invention is directed towards providing such a method for tracking printed circuit boards on multi-board panels through a production process. The method is also directed towards providing a panel produced according to the method, and a printed circuit board produced from the panel.

According to the invention there is provided a method for tracking printed circuit boards on multi-board panels through a production process wherein a plurality of printed circuit boards of different types are formed on a single panel, the method comprising the steps of: forming the printed circuit boards on the panel, and simultaneously with forming the printed circuit boards, forming on the panel a plurality of first identifying means, one first identifying means being provided for each different type of printed circuit board for identifying the printed circuit board or boards of that type on the panel, each first identifying means being located adjacent one of the printed circuit boards of the corresponding type, and each first identifying means comprising an identification of the type of the corresponding printed circuit board, and the number of printed circuit boards of that type being formed on the panel, so that the panel and the printed circuit boards can be tracked through the production process.

In one embodiment of the invention each first identifying means comprises a code for identifying the type of printed circuit board to which it corresponds, and a numeral which identifies the number of printed circuit boards of that type being formed on the panel.

In another embodiment of the invention the method further comprises the step of forming a list of the codes of the first identifying means of each of the printed circuit boards on the panel, the list of the codes being formed simultaneously with the formation of the printed circuit boards, and being located adjacent each other for quick reference for facilitating quick identification of the printed circuit boards on the panel.

In a further embodiment of the invention a second identifying means is formed on the panel simultaneously with the formation of the printed circuit boards, the second identifying means comprising an identification of the batch of panels of which the panel is one. Preferably, the second identifying means identifies the batch of panels by a job number.

In another embodiment of the invention a third identifying means is formed on the panel simultaneously with the formation of the printed circuit boards, the third identifying means comprising an identification of the customer or customers of the printed circuit boards being formed on the panel.

In a further embodiment of the invention a fourth identifying means is formed on the panel simultaneously with the formation of the printed circuit boards, the fourth identifying means identifying the production process to which the panel is to be subjected.

Preferably, each identifying means is formed by etching the panel simultaneously with etching the panel to form the conductive tracks of the printed circuit boards.

In one embodiment of the invention the method comprises the step of forming a printed transparency of the panel, the printed transparency being associated with the panel for forming the printed circuit boards, the method comprising the further step of printing each of the identifying means which are to be formed on the panel on the transparency so that the identifying means and the printed circuits of the boards are formed simultaneously on the panel.

Ideally, each identifying means comprises one or more characters, and preferably, the characters are letters or numerals or both.

In one embodiment of the invention the third identifying means comprises the name of the customer or customers for which the printed circuit board or boards are being produced.

In another embodiment of the invention a margin is defined around the panel, and at least some of the identifying means are located in the margin.

Preferably, the codes of the first identifying means which are formed in a list are formed adjacent to each other in the margin.

Ideally, some of the first identifying means are formed in the margin.

Additionally the invention provides a panel comprising a plurality of printed circuit boards of different types, and corresponding first identifying means, the panel being formed using the method according to the invention.

Further, the invention provides a printed circuit board produced from the panel according to the invention, and the invention also provides a printed circuit board produced using the method according to the invention.

Further, the invention provides a printed circuit board produced using the method according to the invention and produced from the panel according to the invention.

The invention will be more clearly understood from the following description of some preferred embodiments thereof, which are given by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is a plan view of a front face of a panel according to the invention comprising a plurality of printed circuit boards, Fig. 2 is a plan view of a rear face of the panel of Fig. 1, Figs. 3 and 4 are plan views of printed transparencies for use in the production of the panel of Fig. 1, Fig. 5 is a plan view of a front face of a panel according to another embodiment of the invention comprising a plurality of printed circuit boards, Fig. 6 is a plan view of a rear face of the panel of Fig. 5, and Figs. 7 and 8 are plan views of printed transparencies for use in the production of the panel of Fig. 5.

Referring to the drawings and initially, to Figs. 1 and 2, there is illustrated a multi-board panel according to the invention indicated generally by the reference numeral 1 in which a plurality of double-sided printed circuit boards 2 are formed. The panel 1 has a front major face 3 and a rear major face 4. In this embodiment of the invention five different types of printed circuit boards 2 are formed in the panel 1, and the different types of printed circuit boards 2 are designated by the reference numerals 2a, 2b, 2c, 2d, and 2e. Three printed circuit boards 2 of type 2a are formed in the panel 1, two printed circuit boards 2 of type 2b are formed in the panel 1, four printed circuit boards 2 of type 2c are formed in the panel 1, one printed circuit board 2 of type 2d and six printed circuit boards 2 of the type 2e are formed in the panel 1. The panel 1 is a double-sided panel having a layer of resin filled glass cloth laminated between a pair of outer layers of copper foil which are subsequently etched for forming the electrically conductive tracks on the front and rear faces of the printed circuit boards 2, which correspond to the front and rear faces 3 and 4, respectively of the panel 1. For convenience in the drawings, the actual electrically conductive tracks are not illustrated on the printed circuit boards 2, rather the outline of the printed circuit boards 2 are illustrated in block representation. Such double-sided printed circuit boards and double-sided panels will be well known to those skilled in the art, and it is not intended to describe the printed circuit boards 2 or the construction of the panel 1 in further detail.

The panel 1 comprises a central area 5 within which the printed circuit boards 2 are formed, and a margin area 6 which surrounds the central area 5. In the method according to the invention for tracking the printed circuit boards 2 in the panel 1, through the production process, a plurality of first identifying means, namely, first identifiers 8 are formed on the front face 3 of the panel 1 simultaneously with the formation of the circuits of the printed circuit boards 2 on the front face 3 for identifying the respective printed circuit boards 2a, 2b, 2c, 2d and 2e. Since there are five types of printed circuit boards 2, there are likewise five identifiers 8, namely, identifiers 8a to 8e which correspond to the printed circuit boards 2a to 2e, respectively. A second identifying means, namely, a second identifier 10 is also formed on the front faces 3 of the panel 1 simultaneously with the formation of the circuits of the printed circuit boards 2 on the front face 3 for identifying the batch to which the panel 1 belongs.

Each first identifier 8 is formed on the front face 3 of the panel 1 by etching into the copper foil simultaneously during the etching process for forming the electrically conductive tracks of the circuits on the front face 3 of the panel 1. The first identifiers 8 each comprise a code 11, in this case a four digit code which is the type number of the corresponding printed circuit board 2. The four digit code 11 of each first identifier 8 is followed by a multiplier symbol, which in turn is followed by a numeral 12 which indicates the number of printed circuit boards 2 of the type corresponding to the code 11 which are formed in the panel 1. Each first identifier 8 is located as closely as is conveniently possible to one of the corresponding printed circuit boards 2 to which it relates. In this way, the printed circuit boards 2a to 2e can readily easily be identified by their first identifiers 8a to 8e. In this embodiment of the invention four of the first identifiers 8 are located in the central area 5, and one of the first identifiers 8 is located in the margin area 6.

The second identifier 10 is also formed on the front face 3 of the panel 1 by etching into the copper foil of the panel 1 simultaneously during the etching of the foil to form the electrically conductive tracks of the printed circuit boards 2 on the front face 3. The second identifier 10 is located in the margin area 6 and comprises a letter, in this case, the letter P followed by three digits. The three digits are the job or batch number to which the panel 1 belongs, and the letter P identifies the type of process to which the panel 1 is to be subjected during formation of the printed circuit boards 2 in the panel 1. Another identical second identifier 10 is also formed in the margin area 6 on the rear face 4 simultaneously with the formation of the circuits of the printed circuit boards 2 on the rear face 4.

Additionally, for providing a quick method of identifying the types of printed circuit boards 2 which are formed in the panel 1, a list 14 of the type codes 11 of the first identifiers 8 is formed in the margin area 6 on the front and rear faces 3 and 4 of the panel 1, also by etching simultaneously during etching of the circuits of the printed circuit boards 2 on the respective front and rear faces 3 and 4.

The method for producing the panel 1 will now be described, it being assumed that the normal production methods for producing a plurality of printed circuit boards on a multi-board panel will be known to those skilled in the art, and accordingly, only those aspects of the production method relevant to the invention will be described. Initially, a pair of transparencies, namely, a front transparency 20 and a rear transparency 21 (see Figs. 3 and 4) are printed under the control of a computer for use in forming the front and rear faces 3 and 4 of the panel during production of the panel 1.

For convenience, the images of the conductive tracks of the printed circuit boards are not illustrated on the transparencies 20 and 21. The outline of the printed circuit boards are illustrated in block representation only. In this embodiment of the invention a positive image of the front face of the panel 1 is printed on the front transparency 20 and a positive image of the rear face of the panel 1 is printed on the rear transparency 21. Whether the transparencies 20 and 21 are printed with positive or negative images will depend on the photosensitive material which is used subsequently in the method for forming the images on the respective faces 3 and 4 of the panel 1 prior to etching. This aspect of the method will be well known to those skilled in the art. Images 23 of the first identifiers 8a to 8e are provided on the front transparency 20 for use in the formation of the front face of the panel 1, while images 24 and 25 of the second identifier 10 and the list 14 of codes 11, respectively, are provided on the front and rear transparency 20 and 21.

The panel 1 with the transparencies 20 and 21 secured thereto is subjected to the appropriate production method of drilling and formation of an electrically insulating layer of photosensitive material. The first and second identifiers 8 and 10 and the list 14 of codes 11 are formed simultaneously on the panel 1 by etching as the electrically conductive tracks of printed circuit boards 2a to 2e are being formed by etching.

When the formation of the printed circuit boards 2 has been completed, the panel 1 is then subjected to machining for cutting the printed circuit boards 2 from the panel 1. The machining process is such that the printed circuit boards 2 are not completely cut from the panel 1, but rather, cuts are formed in such a way that the printed circuit boards 2 are connected to the panel 1 by one or two thin connections which are of size to facilitate the boards 2 being detached from the panel 1 without damage to the panel 1 or boards 2. An operator receiving the panel 1 with the printed circuit boards 2 so machined, detaches the printed circuit boards 2 by hand, and the operator stacks the printed circuit boards 2 of the same type into respective stacks.

By virtue of the fact that the first identifiers 8a to 8e are provided on the panel 1 adjacent one of the relevant printed circuit boards 2a to 2e, respectively, to which they relate, and the fact that the number of boards of each type is included in the first identifiers 8, the operator can readily easily identify and differentiate the printed circuit boards 2a to 2e, one from the other. By looking up a reference table (not shown) which cross-references the printed circuit boards by their type code number with details of the customers for which the printed circuit boards 2 are being manufactured, an operator can readily easily identify the customers to which the respective printed circuit boards 2a to 2e are to be dispatched. As well as stacking the printed circuit boards 2a to 2e into respective stacks, the operator can also arrange the stacks of printed circuit boards 2a to 2e, respectively, in groups according to customer.

Referring now to Figs. 5 and 6 there is illustrated a multi-board panel 30 according to another embodiment of the invention. The panel 30 is substantially similar to the panel 1 and similar components and features are identified by the same reference numerals. The panel 30 is also suitable for forming double-sided printed circuit boards 2 and is provided with front and rear faces 3 and 4 which are defined by outer layers of copper foil between which a resin filled glass cloth insulating layer is laminated. In this embodiment of the invention four different types of printed circuit boards 2 are formed in the panel 30, namely, printed circuit boards 2a, 2b, 2c and 2d. Three printed circuit boards 2 of type 2a are formed in the panel 1, two printed circuit boards 2 of type 2b are formed in the panel 1, four printed circuit boards 2 of type 2c are formed in the panel 30, and two printed circuit boards 2 of the type 2d are formed in the panel 30.

The first identifiers 8a to 8d are formed on the front surface 3 of the panel 30 by etching the foil simultaneously with the etching of the foil to form the electrically conductive tracks of the printed circuit boards 2 on the front face 3. In this embodiment of the invention the first identifiers 8a to 8d are formed in the margin area 6. The first identifiers 8a to 8d are similar to the first identifiers 8a to 8e of the panel 1. The second identifier 10 is formed only on the rear face 4 of the panel 30, and is formed in the margin area 6 by etching from the foil simultaneously with the etching to form the electrically conductive tracks of the printed circuit boards 2 on the rear face 4.

In this embodiment of the invention a third identifying means, namely, a third identifier 31 is formed in the margin 6 on the rear face 4 of the panel 30 for identifying the customer or customers of the printed circuit boards 2 which are formed in the panel 1. Each third identifier 31 is followed by the type codes 11 of the printed circuit boards 2 for that customer. In this embodiment of the invention the third identifiers 31 comprise letters which spell the name of the customer. In this case two of the printed circuit boards 2 are for one customer, and the other two printed circuit boards are for the other customer.

Also in this embodiment of the invention a fourth identifying means, namely, a fourth identifier 32 is formed in the margin area 6 on the rear face 4 of the panel 30 for identifying specific details of the process to which the panel 1 is to be subjected in the formation of the printed circuit boards 2. The fourth identifier 34 is also simultaneously formed by etching from the foil simultaneously during formation of the electrically conductive tracks on the rear face 4 of the panel 1 of the printed circuit boards 2. In this embodiment of the invention the fourth identifier 32 comprises alpha-numeric characters. The first character is a letter which indicates the broad type of printed circuit boards which are to be formed from the panel 1. The three digits which follow the first letter indicate the production route through which the panel 1 passes from one production station to the next.

Otherwise, the panel 30 is similar to the panel 1.

Figs. 7 and 8 illustrate front and rear transparencies 20 and 21, respectively, for forming the front and rear faces 3 and 4, respectively, of the panel 30. Images 35 and 36 on the rear transparency 21 form the third and fourth identifiers 31 and 32, respectively.

The advantages of the invention are many. Firstly, the printed circuit boards 2 on the panel 1 can readily be identified as a result of the formation of the first identifiers 8. This, thus, virtually eliminates any danger of printed circuit boards of different types being mixed when they are being detached from the panel 1. Additionally, during any part of the production process, should it be necessary to identify the type of board or boards which are on a panel, or the batch to which it belongs, this can readily easily be achieved by checking the first identifiers 8 and/or the list of codes of the first identifiers 8 in the margin of the panel, and/or the second identifier 10 as the case may be.

By providing the second identifier 10 which identifies the batch number on the panel 1, should a panel for any reason be removed from the job batch to which it belongs, the panel can readily be identified and returned to its batch.

The provision of the name or names of the customer or customers on the panel 1 further facilitates sorting of the printed circuit boards 2 as they are being detached from the panel 1, and as well as that, assists in checking on printed circuit boards on the panel at any stage in the production process.

Another advantage is achieved by providing the fourth identifier 12 which indicates the specific production process to which the panel is to be subjected, in that it enables each operator to determine precisely to which work station the panel is to be transferred after each operation has been completed. All that is required of an operator is to check the production process number of the fourth identifier 12 and by comparing the production process number with production process numbers in a master look-up table (not shown) which lists production process numbers against the corresponding production process steps of the processes, the operator can immediately determine the next operation to which the panel is to be subjected.

This, thus, enables the operator to check that the next work station to which the panel is being transferred is the appropriate work station.

While the method according to the invention has been described with reference to a single multi-board panel, it will readily be apparent to those skilled in the art that in general, the panel will be one of a batch of panels, which may range in number from a few panels to hundreds of panels. However, typically a batch of panels will comprise fifty to one hundred and fifty panels.

It will also be appreciated that where the panel is a double-sided panel for use in the production of doublesided printed circuit boards, two transparencies, one for each side of the panel will be provided for each panel of a batch. Needless to say, where a panel is a single-sided panel for use in the production of singlesided printed circuit boards, one transparency will be provided for each panel.

It will of course be appreciated that while the method has been described for use in tracking panels with double-sided printed circuit boards, the method according to the invention may be used in the production of multi-layered printed circuit boards. In which case, each panel forming a layer of a multilayered printed circuit boards will be provided with the first identifiers at least and may be provided with second, third and fourth identifiers.

While the first to the fourth identifiers have been described as being formed in specific areas of the panel, the identifiers may be formed in any other suitable location.

While it is advantageous to provide the second, third and fourth identifiers, the important benefits resulting from the invention are achieved by providing the first identifiers.

Claims

CLAIMS 1. A method for tracking printed circuit boards on multi-board panels through a production process wherein a plurality of printed circuit boards of different types are formed on a single panel, the method comprising the steps of: forming the printed circuit boards on the panel, and simultaneously with forming the printed circuit boards, forming on the panel a plurality of first identifying means, one first identifying means being provided for each different type of printed circuit board for identifying the printed circuit board or boards of that type on the panel, each first identifying means being located adjacent one of the printed circuit boards of the corresponding type, and each first identifying means comprising an identification of the type of the corresponding printed circuit board, and the number of printed circuit boards of that type being formed on the panel, so that the panel and the printed circuit boards can be tracked through the production process.
2. A method as claimed in Claim 1 in which each first identifying means comprises a code for identifying the type of printed circuit board to which it corresponds, and a numeral which identifies the number of printed circuit boards of that type being formed on the panel.
3. A method as claimed in Claim 2 in which the method further comprises the step of forming a list of the codes of the first identifying means of each of the printed circuit boards on the panel, the list of the codes being formed simultaneously with the formation of the printed circuit boards, and being located adjacent each other for quick reference for facilitating quick identification of the printed circuit boards on the panel.
4. A method as claimed in any preceding claim in which a second identifying means is formed on the panel simultaneously with the formation of the printed circuit boards, the second identifying means comprising an identification of the batch of panels of which the panel is one.
5. A method as claimed in Claim 4 in which the second identifying means identifies the batch of panels by a job number.
6. A method as claimed in any preceding claim in which a third identifying means is formed on the panel simultaneously with the formation of the printed circuit boards, the third identifying means comprising an identification of the customer or customers of the printed circuit boards being formed on the panel.
7. A method as claimed in any preceding claim in which a fourth identifying means is formed on the panel simultaneously with the formation of the printed circuit boards, the fourth identifying means identifying the production process to which the panel is to be subjected.
8. A method as claimed in any preceding claim in which each identifying means is formed by etching the panel simultaneously with etching the panel to form the conductive tracks of the printed circuit boards.
9. A method as claimed in any preceding claim in which the method comprises the step of forming a printed transparency of the panel, the printed transparency being associated with the panel for forming the printed circuit boards, the method comprising the further step of printing each of the identifying means which are to be formed on the panel on the transparency so that the identifying means and the printed circuits of the boards are formed simultaneously on the panel.
10. A method as claimed in any preceding claim in which each identifying means comprises one or more characters.
11. A method as claimed in Claim 10 in which the characters are letters or numerals or both.
12. A method as claimed in any of Claims 6 to 11 when dependent on Claim 6 in which the third identifying means comprises the name of the customer or customers for which the printed circuit board or boards are being produced.
13. A method as claimed in any preceding claim in which a margin is defined around the panel, and at least some of the identifying means are located in the margin.
14. A method as claimed in Claim 13 when dependent on Claim 3 in which the codes of the first identifying means which are formed in a list are formed adjacent to each other in the margin.
15. A method as claimed in Claim 13 or 14 in which some of the first identifying means are formed in the margin.
16. A method for tracking printed circuit boards on multi-board panels through a production process, the method being substantially as described herein with reference to and as illustrated in the accompanying drawings.
17. A panel comprising a plurality of printed circuit boards of different types, and corresponding first identifying means, the panel being formed using the method as claimed in any preceding claim.
18. A panel comprising a plurality of different types of printed circuit boards, and corresponding first identifying means, the panel being substantially as described herein with reference to and as illustrated in the accompanying drawings.
19. A printed circuit board produced from the panel as claimed in Claim 17 or 18.
20. A printed circuit board produced using the method of any of Claims 1 to 16.
21. A printed circuit board as claimed in Claim 20 and produced from the panel as claimed in Claim 17 or 18.