JPS59148B2 - Stack mounting structure of electronic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mounting structure for an electronic device, particularly a large-sized computer, and more particularly to a structure for positioning a mounting unit.

In recent years, electronic computers have become increasingly larger and more sophisticated.
The density of its constituent elements has also increased from LSI to ultra-LSI.

For this reason, the number of mutual connections between printed circuit boards (hereinafter referred to as "daughter boards"), which are mounting units, has increased dramatically. There will be a shortage of numbers. On the other hand, as electronic computers become faster,
The delay time based on the interconnect line length has become a very large proportion of the propagation delay time (element switching time + delay time based on the interconnect line length) that determines the throughput of the device. In order to solve these problems, the following stack mounting structure has already been proposed by the present applicant. This is provided with connection terminals on at least two sides parallel to the insertion direction of the daughter board on which the circuit elements are mounted,
A motherboard having a connector corresponding to the connection terminal of the daughterboard is arranged on at least two sides of the support frame parallel to the daughterboard insertion direction, and the daughterboard is inserted and connected to the motherboard to connect the plurality of daughterboards in a direction perpendicular to the daughterboard surface. This is an excellent mounting structure that achieves high density and high speed by increasing the number of connection terminals on each daughter board and shortening the interconnection line length. However, in this stacked mounting structure, unlike the conventional plug-in type connector in which connection is made at the same time as the daughter board is inserted, a so-called zero insertion force type connector is usually used in which connection is made after the daughter board is inserted. .

In this case, in order for the terminals of the daughter board to be accurately connected to the corresponding connectors on the motherboard, it is necessary that the daughter board be correctly positioned with respect to the motherboard when inserted. For this reason, in the past, when assembling electronic equipment, the relative mounting accuracy between the motherboards had to be very strictly controlled, making assembly difficult. SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to solve this problem, and specifically to provide a structure that allows a daughter board to be positioned well with respect to a motherboard without making the relative mounting accuracy of the motherboard too strict.

In order to achieve this object, the present invention has a stack structure as described above, in which the daughter board is inserted in the direction (X direction).
Two sets of guides are provided for positioning the daughter board, and one set of guides is for positioning the daughter board in the direction perpendicular to the insertion direction (Y direction). It is designed to be dynamic and efficient.

The X-direction positioning guide consists of mutually abuttable guide members provided separately on the daughter board and motherboard, and the Y-direction positioning guide consists of guide members separately provided on the daughter board and motherboard that can fit together. configured. Hereinafter, the present invention will be described in detail based on embodiments with reference to the accompanying drawings.

FIG. 1 is a perspective view showing an embodiment of a stack mounting structure according to the present invention, and FIG. 2 is a plan view thereof. In these figures, the symbol A indicates the daughter board, and the symbols B1, B2, and B3 indicate the motherboard. Daughterboard A is a nearly square multilayer printed wiring board on which a large number of LSI elements (not shown) are mounted, and multiple daughterboards A are inserted into motherboards B1 to B3 in the direction of arrow X as shown in the figure. in the vertical direction of the daughterpod plane (
It is mounted in the vertical direction (in the figure). Motherboard B1-B
3 is also a multilayer printed wiring board, which is arranged on the right side, back side, and left side, respectively, when viewed in the insertion direction (X direction) of the daughter board A, and is fixed to the support column F with screws W. The motherboards B1 to B3 are for supplying power to the daughterboard A from the outside, inputting signals, and connecting the daughterboards to each other. That is, daughter board A has its insertion direction (
A plurality of pads (connection terminals) Pl, P2, and P3 are provided on the right side, rear side, and left side, respectively, when viewed in the X direction.
On the other hand, the motherboards B1 to B3 have so-called zero insertion force connectors or flexible connectors.
Connectors Cl, C2, and C3, such as connectors, are provided corresponding to the pads P1 to P3 of the daughter board, respectively, and the daughter board A is inserted in the direction of the arrow X and the motherboards B1 to B3 are aligned in a predetermined manner as shown in FIG. By setting the pads P1-P3 to the connectors C1-C3, the daughterboard A is interconnected via the motherboards B1-B3 and connected to an external power source and the like. In the illustrated example, the external power source is connected to the pillar F.
The power is supplied to the motherboards B1 to B3 via. Furthermore, although a cooling means is actually provided, it is not particularly relevant to the present invention, so illustration and description thereof will be omitted. Now, as mentioned above, connect daughter board A to motherboard B1.
-B3, it is necessary to align the pads P1-P3 with the connectors C1-C3, respectively, and the present invention provides a positioning structure for this purpose.

The positioning structure of the present invention generally includes two sets of contact type guides for positioning the daughter board A in the insertion direction (X direction) and one for positioning the daughter board A in the direction perpendicular to the insertion direction (Y direction). A pair of mating guides are provided for this purpose. That is, as shown in FIGS. 1 and 2, the daughterboard A is provided with stopper blocks SBl and SB2 at the left and right corners of the front side when viewed in the insertion direction motherboard Bl,
B3 is provided with stopper pins SP1 and SP2, respectively. Of these, Stoppa Block SBl and Stoppa Block SBl
The pins SP1 constitute a set of abutting guides whose mutual abutting surfaces are each located at a certain equal distance a from the pad P1 and the connector C1. Therefore, the pad P1 and the connector C1 are positioned in the pitch direction (X direction) by the contact between the stopper block SB1 and the stopper SP1. Also Stoppa Protsuk SB
2 and the stopper pin SP2 constitute another set of abutting guides whose mutual abutting surfaces are spaced apart by a constant and equal distance b, each consisting of a pad P3 and a connector C3. Therefore, due to the contact between stopper block SB2 and stopper pin SP2, pad P3 and connector C3
Positioning is performed in the pitch direction (X direction). still,
For the distances a and b mentioned above, a=b or a\b
Either of these is good (0). Further, the daughterboard A is provided with a guide block GB at the rear right corner when viewed in the insertion direction X, and correspondingly, a guide pin GP is provided on the motherboard B2 at the rear. These guide block GB and guide pin GP can be fitted into the guide groove (or hole) G of the former, and together constitute a fitting type guide. The center lines of guide block GB and guide pin GP are aligned with pad P2 and connector C2, respectively.
Therefore, by fitting them together, the positioning of the pad P2 and the connector C2 in the pitch direction (Y direction) is achieved. According to the positioning structure described above, when the daughterboard A is inserted into the motherboards B1 to B3 in the direction of the arrow X as shown by the dotted line in FIG.
Pl) positions the pad P1 and the connector C1 in the pitch direction (X direction), and the second set of contact type guides (SB2, SP2) positions the pad P3 and the connector C3 in the pitch direction (X direction). X direction) positioning is done,
Further, the mating guides (GB, GP) position the pad P2 and the connector G2 in the pitch direction (Y direction), and as a result, the pads P1 to P3 and the connectors C1 to C
3, and a reliable connection between the daughter board A and the motherboards B1 to B3 is possible.

The important function of the positioning structure according to the present invention described above is that even if there is some deviation in the relative mounting positions of the three motherboards B1 to B3, the pads and connectors can be well aligned as described above. .

This function will be explained with reference to FIG. Figure 3a
When the daughter board A is inserted in the direction of the arrow X as shown in the figure, the mating guide ((8, GP) is first mated with the pad P2 and the connector C2 in the pitch direction (Y direction) as described above. Positioning is performed. At this point, the two sets of contact guides (SBl and SPl, SB2 and SP2) are not in contact again. Therefore, if daughter board A is further inserted, if the right side is Motherboard B1
is the distance toward the front of the motherboard B3 on the left side in the insertion direction w
If the first set of contact type guides (SB
1, SP1) come into contact with each other, and as described above, the pad P1 and the connector C1 are positioned in the pitch direction (X direction). However, in this state, the second set of contact type guides (SB
2, SP2) is not in contact. So daughter board A
When further pushed in the direction of arrow It rotates in the direction of arrow Z while remaining in contact, thereby causing the second set of contact type guides (SB2, SP2)
When the pads P3 and connectors C2 come into contact with each other, the pads P3 and the connectors C2 are positioned in the pitch direction (X direction) as described above, and thereby the pads P1 to P3 and the connectors C1 to C3 are aligned. However, in the above case, the motherboard Bl
, B3, the rotation of the daughter board A due to the displacement w of the pads P1 to P3 and the connectors C1 to C3 will be disturbed.

However, this problem can be easily solved by taking measures as described below. If we consider misalignment due to the rotation of the daughter board A, for example, the frontmost pad PX of the pads P1 (see FIG. 2), the situation is expressed as shown in FIG. 4. In the figure, the solid line position indicates the standard position, and the dotted line indicates the rotation position. Further, the symbol m indicates the distance between the mating guide (GB, GP), which is the center of rotation, and the pad PX, and the symbol θ indicates the rotation angle of the daughter board A around the mating guide (i.e., the connector CX The deviation angle of the pad PX relative to the pad PX is shown. When the daughter board A is rotated (indicated by the dotted line Here, if the distance between the stopper blocks SBl and SB2 of daughterboard A is l as shown in FIGS. 2 and 3, then the rotation angle θ of daughterboard A based on the positional deviation w of motherboards Bl and B3 is given by the following equation. expressed. However, since l>>w, COSO! = -1, therefore p = 0, and misalignment in the pitch direction can be virtually ignored.

This also does not impair the high density of the pads due to the miniaturization of the pad pitch. On the other hand, since Slnθ2w/l, q=w−m/l. m-! If you think about it, it is q-w. In order to compensate for this shift q in the longitudinal direction of the pad, the length L of the pad Px should be made larger than 2w. Increasing the length of the pad does not pose much of a problem in increasing the density of the pad, and can be easily achieved. By simply increasing the length of the pad as described above, the above-mentioned problem of misalignment caused by rotation of the daughter board A can be easily solved. As described above, according to the alignment structure of the present invention,
Even if there is some deviation in the relative mounting position of the motherboard, the pads of the daughterboard can be individually aligned with the connectors of the motherboard, and therefore the relative mounting accuracy of the motherboard does not have to be so strict, making it easier to assemble electronic equipment. This has become dramatically easier, and by properly positioning the daughter board and motherboard, a reliable connection between the two can always be achieved.

In the embodiment, the motherboard is arranged on three sides (B1 to B3).
), but the present invention is equally applicable to a structure in which the motherboard is provided only on two opposing sides (Bl, B3) on the left and right with respect to the daughterboard insertion direction.

In this case, the guide pin GB provided on the rear motherboard B2 in the illustrated example may be fixed to either the left or right motherboard using a suitable support. In addition, in the illustrated example, block-shaped guide members SBl, SB2, and GB are arranged on the daughter board side, and pin-shaped guide members SPl, S
Although P2 and GP are arranged on the motherboard side, which side they are arranged on is arbitrary.

Further, the shape, material, etc. of these guide members can be selected fairly freely. Further, although the illustrated example is a so-called edge type connector in which the connection terminal of the motherboard A is a pad, the present invention is equally applicable to a case where a so-called one-piece type connector is used. . In this case, in order to compensate for the misalignment caused by the rotation of the daughter board described above, the terminal length of the connector may be set to be twice or more the relative positional shift w of the motherboard.
As described above, the present invention provides an excellent positioning structure in a stack mounting structure of electronic equipment, and its technical and economical effects are very large.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the stack mounting structure according to the present invention, and FIG. 2 shows the daughter board and motherboard in the embodiment of FIG. 1 before (solid line) and after insertion (
A plan view shown in a state indicated by a dotted line. FIG. 3 is a schematic plan view showing step by step the insertion and connection of the daughter board to the motherboard, and FIG. 4 is an explanatory view showing how the pads and connectors become misaligned due to rotation of the daughter board. In the figure, A is a daughter board, Bl,
B2, B3 are motherboards, Cl, C2, C3 are connectors, Pl, P2, P3 are pads, SBl, SB2 are stopper blocks, SPl, SP2 are stopper pins, G
B indicates a guide pin, GP indicates a guide pin, and X indicates the insertion direction of the daughter board.

Claims (1)

[Claims] 1 A daughter board on which a circuit element is mounted is provided with connection terminals on at least two sides parallel to the insertion direction (X direction), and a motherboard having a connector corresponding to the connection terminals of the daughter board is provided at least in the daughter board insertion direction (X direction) of the supporting machine frame. In a stack mounting structure of an electronic device in which a plurality of daughter boards are mounted in a direction perpendicular to the daughter board surface by inserting and connecting a daughter board to the motherboard, the daughter board is arranged on two planes parallel to Guide members that can abut each other and constitute two sets of guides for positioning in the (X direction) are arranged separately on the daughter board and the motherboard, and also for positioning in the direction (Y) perpendicular to the insertion direction of the daughter board. 1. A stack mounting structure for an electronic device, characterized in that mutually fitable guide members constituting a set of guides are separately arranged on a daughter board and a mother board, respectively.