JP2004213682A - Memory module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a memory module capable of preventing wrong insertion in the case of mounting an insulation substrate to a socket. <P>SOLUTION: The memory module is provided with the rectangular insulation substrate (10) having first and third sides opposed to each other and second and fourth sides opposed to each other, a plurality of connector terminals (connector terminals) being insulated from each other and provided on the front side and the rear side of the insulation substrate along the first side, a plurality of memory ICs (20) provided on the insulation substrate and notches (12a, 12b) for mechanical key-in for preventing the wrong insertion, which is provided almost at the center of the first side of the insulation substrate. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to an IC mounting technology and a technology particularly effective when applied to a semiconductor mounting insulating substrate having a plug terminal row. For example, the present invention is applied to a socket mounting type memory module in which a plurality of memory ICs are mounted at high density. And effective technology.

  In recent years, memory modules in which a plurality of memory ICs are densely mounted on an insulating substrate having a plug terminal row on one side have been developed for small electronic devices such as notebook personal computers. The plug terminal rows in the conventional memory module are formed by plating copper on the front and back of the mounting insulating substrate 10 and then etching the plug terminals 11a, 11b having the same shape along one side of the substrate as shown in FIG. , And 11a ', 11b',... Are formed on the front and back of the board, respectively, and drilled to penetrate the base end of each plug-in terminal 11 and the board to form through holes 15; By applying copper plating from the surface of the plug terminal 11 to the inner surface of the through hole 15, the corresponding plug terminal 11 on the front and back of the substrate is electrically connected.

However, the inventors have clarified that the above-described technique has the following problems.
That is, in the conventional socket mounting type memory module, the pitch of the plug terminals provided on the mounting insulating substrate is standardized to be 2.54 mm or 1.27 mm, so that the plug can be provided on a board of a certain size. There were restrictions on the number of terminals. In other words, there is a problem that the outer dimensions of the board are limited by the number of plug terminals when trying to secure the required number of plug terminals.

SUMMARY OF THE INVENTION An object of the present invention is to provide a module using a substrate having a structure capable of providing twice as many plug terminals without changing the pitch on an insulating substrate having the same size as the conventional one. Alternatively, it is another object of the present invention to provide a substrate structure capable of reducing the size of an insulating substrate to about half if the number of plug terminals is the same, and a module using a substrate having such a structure.
The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

The outline of a representative invention among the inventions disclosed in the present application will be described as follows.
That is, the plug terminals provided on the front and back of the insulating substrate are formed so as to be separate plug terminals electrically insulated from each other.
Specifically, a rectangular insulating substrate having first and third sides facing each other, and second and fourth sides facing each other, and a surface of the insulating substrate along the first side Plural semiconductors including a plurality of plug terminals electrically insulated from each other on a side and a back side, and a plurality of memories provided on the insulating substrate and including a plurality of memories and a driver for transmitting a common signal to the plurality of memories. According to another aspect of the present invention, there is provided a semiconductor mounting device including: a device; and a wiring provided on the insulating substrate and electrically connecting the semiconductor device and the plug terminal.

  According to the above-described means, it is possible to provide twice the number of plug terminals without changing the pitch on an insulating substrate of the same size as the conventional one, or if the number of plug terminals is the same, the number of plug terminals can be reduced. The size can be reduced by about half.

  Further, in the insulating substrate, it is preferable that a notch for preventing erroneous insertion is provided on the first side, and a notch for retaining is provided on each of the second and fourth sides. With this, it is possible to prevent erroneous insertion when the insulating substrate is mounted on the socket, and to prevent the substrate from coming off after mounting the substrate.

  A rectangular insulating substrate; a plurality of plug terminals provided on both surfaces of the insulating substrate along one long side of the insulating substrate so as to be electrically insulated from each other; and a plurality of plug terminals provided on the insulating substrate. And a wiring provided on the insulating substrate and electrically connecting the semiconductor device and the plug terminal, wherein the plug terminal may be a semiconductor mounting device including a terminal for board identification. Good. As a result, it is possible to standardize a substrate for a plurality of types of modules having different specifications, thereby reducing the total cost.

  Further, in the case of the insulating substrate as well, a notch for preventing erroneous insertion may be provided on a long side of the insulating substrate, and a notch for preventing slippage may be provided on each of two short sides of the insulating substrate. This can prevent erroneous insertion when the insulating substrate is mounted in the socket, and can prevent the substrate from coming off after the substrate is mounted.

The following is a brief description of an effect obtained by a representative one of the inventions disclosed in the present application.
That is, twice the number of plug terminals can be provided on the insulating substrate on which the IC is mounted without changing the pitch, or if the number of plug terminals is the same, the size of the insulating substrate can be reduced. Can be halved.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  1 to 3 show one embodiment of a memory module to which the present invention is applied. In the memory module of this embodiment, eight memory ICs 20 and one driver IC 30 are mounted on the front and back surfaces of the insulating substrate 10, respectively, and the same shape is formed on one side of the insulating substrate 10 along one side of the substrate. Are formed at equal pitches P. The plug terminals 11a, 11b, 11c,. The plug terminals 11a, 11b, 11c on the front side of the insulating substrate 10 and the plug terminals 11a ', 11b', 11c 'on the rear side are electrically insulated from each other. Moreover, in this embodiment, although not particularly limited, the front connection terminals 11a, 11b, 11c... And the rear connection terminals 11a ′, 11b ′, 11c ′. As shown in FIG. 2, the positions are shifted from each other by a half pitch P / 2.

  The insulating substrate 10 has a multilayer structure in which a plurality of (for example, six) insulating substrates each having a wiring pattern formed of a conductive layer formed on the surface thereof are stacked. In this embodiment, a high TG material (glass having a high softening temperature) having a thermal expansion coefficient of about 10 ppm called FR-5 is used as a material of the insulating substrate 10. Thus, the memory IC 20 having a TSOP (thin small outline package) structure can be mounted.

  That is, in the case of a substrate made of glass epoxy or the like called FR-4 which has been generally used in the past, since the coefficient of thermal expansion is about 16 ppm, the TSOP (solder joint) has a coefficient of thermal expansion of about 5 ppm. When a memory IC having a thin small outline package) structure is used, a solder joint may be peeled off due to a thermal cycle or the like. Therefore, a memory IC having an SOJ structure in which the thermal expansion coefficient of the solder joint is about 10 ppm is mounted. I had to do it.

  However, in this embodiment, since a high TG material having a thermal expansion coefficient of about 10 ppm is used as the material of the substrate 10, the TSOP (the thermal expansion coefficient of which is bent so that the lead terminals are spread outward) of about 5 ppm is used. A memory IC having a thin small outline package) structure can be used. As a result, the height of the IC mounted on the substrate is reduced, and the module can be reduced in size.

  Further, in this embodiment, memory ICs 20 whose lead terminals are bent in opposite directions are soldered to predetermined positions of the insulating substrate 10. That is, as shown in FIG. 3, the memory IC 20 mounted on the front side of the insulating substrate 10 has the lead terminals 21 bent toward the antinode of the IC, and the memory IC 20 mounted on the back side of the insulating substrate 10. In ', the lead terminal 21 ′ is bent toward the back of the IC. As a result, the signal terminals of the IC on the front surface and the signal terminals of the IC on the back surface come to the same position, so that the wiring pattern to be formed on the front surface of the substrate 10 can be shared, and the shortest distance wiring can be easily formed. Become. Therefore, the design of the wiring pattern is facilitated, the number of intersections between the wirings can be reduced, the wiring is simplified, and the characteristics and quality of the module are improved.

  As shown in FIG. 1, notches 12a, 12b and 13a, 13b are formed on the side of the insulating substrate 10 on which the plug terminal 11 is formed and on two sides orthogonal thereto. Of these, notches 12a and 12b on the side where the plug terminal is formed are mechanical key-in notches (recesses) for preventing erroneous insertion, and 13a and 13b are notches for retaining.

  That is, the insulating substrate 10 of this embodiment has a structure suitable for being mounted on the socket 40 as shown in FIG.

Next, an embodiment of the socket 40 will be described.
The socket 40 on which the insulating substrate 10 is mounted has terminals corresponding to the number of the plugging terminals 11a, 11b, 11c,... And 11a, 11b, 11c,. .. Have pins 41a, 41b, 41c... On the outside, and have projections 42a, 42b on the inside corresponding to the notches 12a, 12b, respectively, which can be engaged with the notches.

  As shown in FIG. 5, the terminal pins 41a, 41b, 41c... Are integrally formed with reeds 43 made of elastic pieces that can come into contact with the plug terminals 11, respectively. Are held in the socket housing 44 at a pitch P / 2, which is half the pitch P of the plug-in terminals. The leads 43 are spaced apart from each other, and the leads 43 alternate between a slightly downward lead as shown by a solid line A and a slightly upward lead as shown by a two-dot chain line B in FIG. , An engaging portion facing each other with a slightly smaller interval than the thickness of the substrate 10 is formed. The insulating substrate 10 is mounted by inserting the plug terminal portion into the engaging portion formed by the lead 43 in the direction of arrow C and rotating in the direction of arrow D.

  As shown in FIG. 4, a pair of holding arms 45a and 45b having protrusions 47a and 47b at the ends thereof are rotatably attached to both ends of the socket 40 with pins 46a and 46b as fulcrums. After the insulating substrate 10 is mounted on the substrate 10, the holding arms 45a and 45b are rotated inward, and the protrusions 47a and 47b are engaged with the notches 13a and 13b on the side surfaces of the substrate 10, thereby preventing the substrate from coming off. It has become so.

  Further, the holding arms 45a, 45b are formed with operating pieces 48a, 48b inward, and when the pins 46a, 46b are pivoted outward with the pins 46a, 46b as fulcrums, the operating pieces 48a, 48b are mounted. The substrate 10 is configured to be pushed out and separated. As a result, the connection between the substrate 10 and the socket 40, which has become difficult to remove due to an increase in terminal density, can be easily removed by leverage principle by operating the holding arms 45a and 45b.

  Furthermore, the insulating substrate 10 of this embodiment has PD terminals 17a, 17b, 17c, 17d for board identification, jumper chip connection terminals 18a, 18b, 18c, 18d, and ground terminals (or Vcc terminals) 19a, 19b. , 19c, 19d on the surface of the substrate, and the wiring pattern 50 for connecting the PD terminals 17a, 17b, 17c, 17d to the jumper chip connection terminals 18a, 18b, 18c, 18d, as shown by broken lines in FIG. A conductor (0Ω resistance) is provided between the PD terminals 17a, 17b, 17c, 17d and the ground terminals (or Vcc terminals) 19a, 19b, 19c, 19d. ) Having jumper chips 50a, 50c... Are selectively connected. The jumper chips 50a, 50c... Are used to generate codes for identifying modules having different specifications.

  That is, as shown in FIG. 6, the PD terminals 17a and 17c to which the jumper chips 50a and 50c are connected are fixed to the ground potential (or Vcc potential), and the PD terminals 17b and 17d to which no jumper chips are connected are NC terminals (NO). Connection terminal), the microprocessor reads the state of these PD terminals 17a to 17d to determine the specification of the module, that is, the storage capacity and electrical characteristics of the module, for example, in a table held by itself. It can be known by referring to (memory). If there are four PD terminals, 16 types of modules can be identified, and if there are n PD terminals, 2 n types of modules can be identified.

  FIG. 7 shows an example of a block configuration of the memory module. The module of this embodiment includes 16 dynamic RAMs D0 to D15 (memory IC 20) and drivers B0 to B26. The drivers B0 to B26 are each formed on a single semiconductor chip in half, are formed into ICs, and are mounted on the substrate 10 (IC30 in FIG. 1). The drivers B0 to B26 are used to transmit signals (OE, WE, CAS, etc.) common to a plurality of dynamic RAMs to each chip.

  As described above, since the driver is provided on the module side, the driver on the CPU side for driving the module becomes unnecessary, and the user does not need to design a driver for each type of module. That is, if there is no driver on the module side, if the module to be used changes, the driving force required to drive the module also changes, so it is necessary to redesign the optimum driver each time. Since it is provided on the module side, a driver on the CPU side is unnecessary.

  As described above, in the above embodiment, the plug terminals provided on the front and back sides of the insulating substrate are formed so as to be separate plug terminals electrically insulated from each other, so that the same size as the conventional one is used. Twice the number of plug terminals can be provided on the insulating substrate without changing the pitch. Alternatively, if the number of plug terminals is the same, the size of the insulating substrate can be reduced to approximately half.

  Furthermore, since a material having a low coefficient of thermal expansion is used as the material of the insulating substrate, and it is mounted as an IC having a TSOP (thin small outline package) structure, it is mounted on an insulating substrate as compared with an IC having a SOJ structure. There is an effect that the height of the IC in the state is reduced and the module is downsized.

  In addition, since the plug terminal row on the front side and the plug terminal row on the back side of the insulating substrate are formed so as to be shifted from each other by a half pitch, a lead (connector) contacting each plug terminal row is formed. This has the effect of making it easier to make a socket that has

  Further, a notch is provided on the end surface of the insulating substrate on the side of the connector terminal row, and a protrusion engageable with the notch is provided at a corresponding position of the socket, so that the system can be inserted into an incorrect substrate (module). Can be prevented from malfunctioning and the IC in the module can be prevented from being damaged.

  A plurality of board identification terminals (PD terminals) are provided in a part of the connector terminal row of the insulating board, and a jumper chip for selectively short-circuiting these terminals and the power supply terminal can be mounted. Since the terminals are provided, it is possible to standardize the substrate for a plurality of types of modules having different specifications, thereby reducing the total cost.

  Although the invention made by the inventor has been specifically described based on the embodiments, the present invention is not limited to the above-described embodiments, and various changes can be made without departing from the spirit of the invention. Nor. For example, in the above embodiment, a plurality of memory ICs are mounted on the front surface and the back surface of the insulating substrate, respectively, but a plurality of ICs may be mounted on only one of the front surface and the back surface of the insulating substrate.

  In the above description, the case where the invention made by the present inventor is applied to a memory module, which is the field of application as the background, has been mainly described. However, the present invention is not limited to this case, and a memory card and other insulation It can be widely used for a semiconductor mounting substrate in which a plurality of ICs are mounted on a substrate.

FIG. 3 is a plan view showing one embodiment of a memory module to which the present invention is applied. FIG. 2 is an enlarged explanatory view of a plug terminal part of the memory module of FIG. 1. FIG. 2 is an enlarged explanatory diagram illustrating an IC mounted state of the memory module in FIG. 1. FIG. 2 is a side view showing one embodiment of a socket to which the memory module of FIG. 1 is mounted. FIG. 4 is an enlarged sectional view showing the structure of the socket of FIG. 3. FIG. 3 is an equalization circuit diagram illustrating a relationship between a PD terminal and a jumper chip. FIG. 2 is a block diagram illustrating a configuration example of a memory module in FIG. 1. It is an enlarged explanatory view of the plug terminal part of the conventional memory module.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 10 Insulating board 11a, 11b, 11c Plug terminal 12a, 12b Notch for mechanical key-in 13a, 13b Notch for retaining 17a-17d PD terminal 20 Memory IC
30 Driver IC
40 socket 50a, 50c jumper chip

Claims (2)

A rectangular insulating substrate having first and third sides facing each other and second and fourth sides facing each other;
A plurality of plug terminals provided electrically insulated from each other on the front side and the back side of the insulating substrate along the first side;
A plurality of memory ICs provided on the insulating substrate;
A memory module comprising: a mechanical key-in notch for preventing erroneous insertion, provided at a substantially center of the first side of the insulating substrate.   The insulating substrate includes a notch for preventing erroneous insertion provided on the first side, and a notch for retaining provided on each of the second and fourth sides. The memory module according to claim 1, wherein:

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