JPH03163893A - Footprint board for mounting smd additionally - Google Patents

Abstract

PURPOSE:To reduce the number of kinds and rationalize the production of the title board by using two pieces of boards respectively provided with footprints for an SMD arranged in one rows at prescribed intervals at locations at different distances from both edges in a butted state and selecting the facing interval of the footprints so that the boards can be used commonly for two kinds of SMDs. CONSTITUTION:Two pieces of boards 5 respectively provided with foot prints 6 for SMD 1 arranged in one rows at prescribed intervals at locations at different distances from both edges are used in a butted state and the facing interval of the foot prints 6 is selected, so that the substrates can be used commonly to two kinds of SMDs 1. Thus the SMDs 1 are mounted by joining the two pieces of boards to each other with a double coated adhesive tape and the interval between facing footprints 6 can be made selectable among the three kinds of intervals, A+A, B+B, and A+B, with the A and B respectively being distances from both edges. Thus intervals for 300 mil and 25 mil can be obtained. Therefore, the number of kinds can be reduced and the production can be rationalized.

Description

[Detailed description of the invention] [Summary] Regarding the footprint board for adding an SMD, the purpose is to share the footprint board for adding an SMD, reduce the number of types, and rationalize production. A board used to additionally attach SMDs of two types of SOP type packages that are the same but have different opposing terminal spacing, and the footprint for the SMD is
These are boards arranged in a line at predetermined intervals at different distances from both edges, and can be used commonly for two types of SMD by pressing two of the boards against each other and selecting the spacing between the footprints facing each other. Configure it as follows.

[Industrial application field]

The present invention relates to a footprint board for adding an SMD.

As electronic communication devices become smaller and more sophisticated, SMDs are increasingly being used for components mounted on printed circuit boards that make up circuits.

In addition, circuits may be changed later on the printed circuit board assembled in this way, and it is impossible to replace the printed circuit board now, so it is necessary to somehow add an SMD to the empty space and process the changes. It is desirable that this can be done reliably and at low cost.

[Conventional technology]

FIG. 2 shows a conventional example of an SMD addition method.

A conventional example of additionally mounting an SOP type SMDI is, as shown in FIG. The SM
The auxiliary printed board 55 to which the DI is soldered is adhered to the empty part, and the other end of the connection wiring 9 is connected to a predetermined printed wiring by soldering to complete the process.

Of course, if you want to add another type of SMD, glue an auxiliary printed board large enough to mount it on the printed board, and change the wiring with one end connected to the end of that footprint to print the circuit. Connect it to the wiring.

[Problem to be solved by the invention]

However, (1) In this method, the size of the auxiliary printed board 55 and the layout of the footprint are determined according to the SMD to be added.

■ Also, in the SOP type SMDI, even if the spacing between the terminals 3 is the same, the dimension from tip to tip of the opposing terminals 3 is 300 rnil (E I A J series) and 25 mm.
0mil (ANS I series), and in this case also a separate auxiliary printed board 55 is used.

(2) For this reason, there are many types of auxiliary printed boards 55, and mistakes are likely to occur, resulting in unnecessary increase in inventory and time required for manufacturing and processing each time.

■ Therefore, whether the shape types of SMDs to be added are restricted and the variety of dedicated types is suppressed, or whether it is for SOP type SMDs or 300
For mil and 250mil, and two terminal type SMD
There was a limit of at least three types.

There were problems such as.

In view of these problems, the present invention aims to share the additional footprint board for SMD, reduce the number of types, and rationalize production.

[Means to solve the problem]

The above-mentioned problems are as shown in Fig. 1: (1) The board 5 used to additionally attach the SMDI of two types of SOP type packages with the same spacing between the terminals 3 but different spacing between the terminals 3 facing each other. Then, the footprints 6 for SMDI are arranged in a row at predetermined intervals at different distances from both edges of the substrates 5, and two of the substrates 5 are butted against each other, and the footprints 6 are placed opposite each other. Select the interval and
SMD of the present invention that can be commonly used for two types of SMD I
Solved by additional footprint board.

(2) Also, on the opposite side of the board 5, a chip-type two-terminal SMD
This problem is solved by the footprint board for adding an SMD described in item (1) 5 above, which is provided with a footprint 7 for 2.

[For production]

That is, the board 5 has a footprint 6 for an SOP type SMD 1 biasedly provided on one side, and a footprint 7 for a chip type two-terminal SMD 2 on the opposite side if necessary, so that only an SMDI can be used. For the addition of SMD1 and two-terminal SMD2, the latter type of board 5 can cover the restricted use of the additional SMD.

For SMDI installation, two boards 5 are butted and glued together. At this time, the dimensions between the opposing footprints 6 are A+A, where A and B are the distances from both edges.
There are three types to choose from: B+B and A+B, so 300mi
It becomes possible to obtain one for 250mil and one for 250mil.

In the case of the two-terminal SMD 2, the board 5 is also used and it is attached to the footprint 7 on the back side.

6 In this way, the SMD 1 or the two-terminal SMD 2 is attached to the board 5, and the connection wiring 9 is soldered to each footprint 6.7, and then the board 5 is adhesively fixed to the empty part of the printed board 8, and the connection wiring is attached. Solder the other end of 9 to the modified printed wiring.

In this way, it is possible to share the footprint board for adding an SMD, reduce the number of types, and rationalize production.

〔Example〕

The present invention will be specifically described below with reference to embodiments shown in the drawings. The same reference numerals indicate the same objects throughout the figures. Figure 1 (
A) is a configuration diagram of an embodiment of the present invention, FIG. .

In this example, the most used additional SMD is:
There are 14-terminal, 16-terminal, and 20-terminal SOP-type SMDI, and 2-terminal SMD2 such as chip-type resistors and capacitors, which are designed to be commonly used.

As shown in FIG. 1(b) and FIG. 1(C), the substrate 5 includes 5
x14mm square glass epoxy resin 0.4++
+m thick double-sided printed board, the surface is as shown in Figure fb): 1.
The elongated footprints 6 are arranged in a row at a pitch of 27 mm.
O pieces are arranged, Δ=1.3 mm from both edges, B=
0.7 mm, and L-shaped marks 6l are provided at both corners of the A side to prevent mishandling.

Therefore, as shown in figure (d), the dimension between the two substrates 5 is A.
If it is set to +A, it can be used for 300mil 1, and if it is set to <B+B as shown in Figure (e), it can be used for 250mil.

Further, on the back surface of the substrate 5, two footprints 7 of 4.5 mm' are provided with an interval of 3 mm in the longitudinal direction.
This footprint 7 is further divided into four insulated cross shapes each having a width of 1ffIm at the center.

There is one large chip-type two-terminal SMD2 in the longitudinal direction,
Furthermore, up to a total of four small-sized devices can be mounted, two per watt print 7 in the transverse direction.

Thus, when soldering the SMD 1, the two boards 5 are butted and adhered in advance using the double-sided adhesive tape 81, and the connection wiring 9 is also soldered to the footprint 6, and the printed board 8 is Glue and fix the back side to the empty space.

Further, the two-terminal SMD 2 is also soldered to one board 5 together with the connection wiring 9, and fixed to the printed board 8 using double-sided adhesive tape 8l.

The above embodiment shows an example, and in particular, the number and dimensions of the footprints 6 of the substrate 5, and the shape, dimensions, and arrangement of the footprints 7 on the back surface are not limited to those described above.

The number of footprints 6 is IO, and it is commonly used for SOP type SMDI with 20 terminals or less, but most of them have 14 terminals, and in rare cases when 20 terminals are used, it is better to use 7 or board 5. is desirable because it is smaller in size.

Further, the footprint 7 may be divided and arranged in plural pieces according to the mainstream type of two-terminal SMD 2 used.

(Effects of the Invention) As described above, according to the present invention, it is possible to share the additional foot print board for SMD, and it is possible to
The two-terminal SMD2 for 00mil 1 and 250mil can be shared, and all types of two-terminal SMD2s used can be mounted with high efficiency, reducing the number of types and streamlining production, resulting in remarkable effects.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention, and FIG. 2 shows a conventional method for adding an SMD. In the figure, l is SMD, 2 is two-terminal SMD, 3 is terminal,
5 is a board, 6.7 is a footprint, 8 is a printed board, 9 is a connection wiring, 31.32 is a terminal row, 55 is an auxiliary printed board, 6l is a mark, and 81 is a double-sided adhesive tape.

Claims (2)

[Claims] (1) SMD (1
) is a board (5) used for additionally mounting the SMD (1), on which the footprints (6) for the SMD (1) are arranged in a line at predetermined intervals at different distances from both edges.
In 5), by using two of the substrates (5) against each other and selecting the opposing spacing of the footprints (6), it can be commonly used for two types of the SMDs (1). SMD
Additional footprint board. (2) Chip-type two-terminal SMD on the opposite side of the board (5)
The footprint board for adding an SMD according to claim (1), characterized in that a footprint (7) for (2) is provided.