JPS63237144A - Semiconductor device with imitation preventing function - Google Patents

Abstract

PURPOSE:To make imitation impossible by making the contents of a RAM and a circuit destroyed when a sub-substrate covering a semiconductor element is detached or a part of the sub-substrate is destroyed. CONSTITUTION:A main substrate 10 is equipped with the semiconductor element and the main substrate is covered with the sub-substrate 12. A battery 14 for backup is put on the sub-substrate 12 and an external lead 16 is connected to the main substrate 10. If the sub-substrate 12 is detached from the main substrate 10 in order to decode the supply line and line of a voltage from the battery for backup 14 are destroyed, so that the decoding is impossible.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a semiconductor device with an imitation prevention function in which built-in programs, data, etc. cannot be read out.

[Conventional technology] Developing software such as new games requires enormous costs.
It requires labor and time, and in terms of cost, it occupies a considerable proportion of the overall product. However, if you go through the trouble of developing software and selling a new product,
The current situation is that a counterfeit product with exactly the same functions will appear one to two months later. Therefore, manufacturers are taking various measures to prevent imitations.

For example, remove all programs that run the CPU from the ROM.
A part of the program is stored in the RA inside the semiconductor device.
There is something to be stored in M. Even if the person trying to imitate the program copies the external ROM, they will not be able to know the program unless they know the contents of the internal RAM.

In addition, program data from an external ROM is transferred to the internal gate array or PLA (Programsable
There are some that convert using logic elements such as Logic Array and manually input to the CPU. Since the external ROM contains the data before conversion, counterfeiters cannot decipher it and know the program.

[Problems to be Solved by Invention C] Even if the program is made unreadable by various means as described above, it is impossible to disassemble the semiconductor device, expose the CPU molded inside, and probe the terminals of the CPU. If this were done correctly, the input and output signals of the CPU during operation could be known, and the contents of the program could be completely deciphered.

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a semiconductor device with an imitation prevention function that can prevent software such as programs from being decoded.

[Means for Solving the Problems] In order to achieve the above object, a semiconductor device with an anti-counterfeiting function according to the present invention includes a backup battery, a volatile memory semiconductor element backed up by the backup battery, and a volatile memory semiconductor device. A first substrate on which a semiconductor element is mounted and a first connection part connected to a power supply wiring to the volatile memory semiconductor element is formed, and a part of the power supply wiring from a backup battery to the volatile memory semiconductor element. and a second substrate formed with a second connection portion connected to a part of the power supply wiring, the second substrate covering the volatile memory semiconductor element on the first substrate. , and the second connection part is assembled so as to be in contact with the first connection part, and the volatile memory semiconductor element is backed up by a backup battery via the power supply wiring, the second connection part, and the first connection part. It is characterized by

Further, the semiconductor device with anti-counterfeiting function according to the present invention includes a semiconductor element and a first
a first substrate on which a wiring portion is formed, a first connection portion connected to the first wiring portion, and a second substrate for a semiconductor element.
and a second substrate formed with a wiring portion and a second connection portion connected to the second wiring portion, the second substrate covering a semiconductor element on the first substrate. , and the second connection part is assembled so as to be in contact with the first connection part, and the first wiring part and the second wiring part are connected to each other for the semiconductor element via the first connection part and the second connection part. It is characterized by being connected as wiring.

[Function] In the semiconductor device with anti-counterfeiting function according to the present invention, when an attempt is made to remove the first substrate covering the volatile memory semiconductor element for decoding, the first connecting portion and the second connecting portion are disconnected. The voltage from the backup power supply will no longer be supplied if the battery is separated.

Further, in the semiconductor device with anti-counterfeiting function according to the present invention, when the first substrate is destroyed in order to expose the terminals of the semiconductor element for decoding, the wiring is also destroyed.

[Embodiment] A semiconductor device with a counterfeit prevention function according to an embodiment of the present invention is shown in FIGS. 1 to 4. The anti-counterfeiting 11-function semiconductor device according to this embodiment is comprised of a main board 10 on which a semiconductor element is mounted, and a sub-board 12 that covers this main board 10, as shown in FIG. A backup battery 14 is mounted on the sub-board 12. External leads 16 are connected to the main board 10.

FIG. 2 shows the state before the main board 10 and sub-board 12 of the semiconductor device with counterfeit prevention function according to this embodiment are assembled. The upper surface of the main board 10 has three recesses 18 for mounting semiconductor elements.
20.22 is formed. A plurality of layers of wiring are embedded in the main substrate 10, and these wirings connect the connecting portions with the external leads 16 and the semiconductor element terminals in the recesses 18, 20, and 22. Recess 18.20.22
Inside, semiconductor elements 24, 26, and 28 are mounted, respectively. In this embodiment, the semiconductor element 24 is PLA
(Prograviable Logic Arra
y), the semiconductor element 26 is a CPU, and the semiconductor element 28 is a RAM that requires backup by the backup battery 14. These semiconductor elements 24.26
．． The bonding pads 28 are connected to semiconductor element terminals exposed on the recesses 18, 20, and 22 by bonding wires.

The sub-board 12 includes semiconductor elements 24 mounted on the main board 10.
It is intended to cover 26.28. Wiring is formed on this sub-board 12, which includes a ground wiring layer that is grounded, a power wiring layer to which a power supply voltage is applied, and an insulating layer disposed between these ground wiring layers and the power wiring layer. There is. Although this wiring may be formed on the sub-substrate 12 in this way, it may also be embedded within the sub-substrate 12. Moreover, this wiring may be a single layer or, conversely, may have more layers. Furthermore, the wiring is not limited to power supply wiring, and may be general wiring.

The electrical connection between the main board 10 and the sub board 12 is made on the main board 1
This is done by contacts 30.34 formed on the top surface of the sub-board 12 and contacts 32.36 formed on the bottom surface of the sub-board 12. That is, as shown in FIG. 2, the contacts 30 of the main board 10 and the contacts 32 of the sub-board 12 are formed at positions that match during assembly, and the contacts 34 of the main board 10 and the contacts 36 of the sub-board 12 are and are formed in positions that match during assembly.

For example, if solder bumps are formed on the contacts 30 and 34 of the main board 10, the connection between the contacts will be ensured during assembly.

Note that the contact may have a double shape so that the power supply wiring and the ground wiring are connected with one contact.

FIG. 3 shows a specific example of the power supply wiring of the semiconductor device with anti-counterfeiting function according to this embodiment. In this specific example, the power supply wiring from the backup power supply 14 to the semiconductor element 28, which is a RAM, is formed on the main substrate 10 and the sub-substrate 12.
The power supply wiring formed on the main board 10 and the sub-board 12 are electrically connected by contacts 30, 32, 34, 36. That is, the terminal of the backup power supply 14 is connected to the main board 10 through the lead wire 38. The power supply wiring 40 is connected to the power supply wiring 40 inside the sub-board 12 via the contact 34 on the main board 10 and the contact 36 on the sub-board 12.
2, and this power supply wiring 42 is connected to a power supply wiring 44 via a contact 32 on the sub-board 12 and a contact 34 on the main board 10.

This power supply wiring 44 is connected to a semiconductor element 28 which is a RAM. In this way, in this embodiment, the voltage from the backup power supply 14 is not directly applied to the semiconductor element 28;
The power is applied to the semiconductor element 28 via the power wiring 40.44 in the main substrate 10, the power wiring 42 in the sub-board 12, and the contacts 30.32.32.34.

Semiconductor elements 24, 26, 28 are mounted on the main substrate 10,
When the main substrate 10 and the sub-board 12 are assembled, the entire semiconductor device including the backup power supply 14 is molded with resin to complete the semiconductor device. Instead of molding the entire body with resin, as shown in FIG. The and sub-board 12 may be molded with resin 48, and the backup power source 14 may be covered with a cover 50.

A counterfeiter who attempts to decode the program of the semiconductor device with anti-counterfeiting function according to this embodiment would first melt the molding resin to expose the main substrate 10 and the sub-substrate 12. Thereafter, the sub-board 12 covering the semiconductor devices 24, 26, and 28 will be removed in order to apply probes to the terminals of the semiconductor device 26, which is the CPU, on the main substrate 10. However, when the sub-board 12 is removed, the electrical contact between the contacts 30 and 32 is also broken, and the power supply to the semiconductor element 42, which is a RAM, is cut off. Then, the contents of RAM are instantly destroyed. Even if the sub-board 12 is returned to its original state, the contacts 30 and 32 are brought into contact again, and power is supplied again, the contents of the RAM once destroyed will not be restored. Therefore, it becomes impossible to read the built-in program. In this way, according to this embodiment, it is possible to prevent a counterfeiter from decoding the program.

In the first embodiment, when the sub-board 12 is removed, the backup battery is automatically turned off. Therefore, there is a possibility that an imitator may try to achieve his goal by destroying only the necessary parts without removing the sub-board 12. FIG. 5 shows a sub-board of another embodiment of the present invention for preventing such imitation.

FIG. 5 shows the internal wiring of each layer of the sub-board 12. FIG. 5A shows the power supply wiring 52. As shown in FIG. This power wiring 5
2 connects the contact 32 from one of the contacts 36, and is characterized in that the contact 36 and the contact 32 are routed within the sub-board 12 without taking the shortest distance. In particular, the power supply wiring 52 is formed above the semiconductor elements 24, 26, and 28. Figure (b) shows general wiring 5 such as address lines, data lines, control lines, etc.
4 is shown. This film wiring 54 connects one contact among the contacts 36 to another, and is characterized in that the wiring 54 is routed over the entire surface of the sub-board 12.

According to this embodiment, since the wiring inside the sub-board 12 is formed on the entire surface, if a part of the sub-board 12 is destroyed without removing the sub-board 12 for imitation, the power supply wiring or wiring is also destroyed, and the semiconductor device with anti-counterfeiting function of this embodiment is no longer able to operate normally. That is, if the power supply wiring is destroyed, the contents of the RAM will be destroyed, and if the - membrane wiring is destroyed, the circuit operation will become impossible.

Note that since the sub-board 12 of this embodiment is a multilayer wiring, there is an advantage that when it is cut with a laser, the wiring layers are short-circuited at the cut surface, and the wiring is likely to be destroyed.

Further, the wiring example shown in FIG. 5 is simplified for illustration purposes, and may be more complicated. For example, wiring may be run vertically and horizontally using a plurality of wiring layers. Further, circuit elements such as resistors may be included in the wiring.

A sub-board 12 according to another embodiment of the present invention is shown in FIG. The sub-board 12 of this embodiment has four blocks 12a, 12b, 1
2c, 12d, these four blocks 12
a, 12b, 12c.

Contacts 32, 36 and power wiring 52 on the lower surface of 12d.
is formed. This sub-board 12 is manufactured as follows. First, four blocks 12a, 12b, 12c
, 12d (FIG. 6(a)), these blocks 12a, 12b.

12C and 12d are combined to form one sub-board 12 and bonded to each other with adhesive, for example (FIG. 6(b)).
. Thereafter, contacts 32, 36 and power supply wiring 52 are formed on the lower surface of this sub-board 12 across each block 12a to 12d.

The sub-board 12 of this embodiment is composed of a plurality of blocks, but since they are firmly fixed with adhesive or the like without any gaps, the contacts 32 and 36 and the power supply wiring 5
2 can be formed across each block 12a-12d.

According to this embodiment, imitation can be effectively prevented. That is,
If an imitator attempts to remove the sub-board 12 of this embodiment for imitation and destroys the space between the blocks, the power supply wiring 52 formed on the surface will also be destroyed. Therefore, even if a counterfeiter recombines the blocks to repair the damage to the power supply wiring 52, the power supply wiring 52 once destroyed will not return to its original state.

FIG. 7 shows a semiconductor device with anti-counterfeiting function according to another embodiment of the present invention. The semiconductor device with anti-counterfeiting function according to this embodiment is composed of a main board 10 on which a semiconductor element is mounted, and a sub-board 12 that covers this main board 10, as in FIG. A backup battery 14 is mounted on the sub-board 12. In the semiconductor device with anti-counterfeiting function according to this embodiment, the direction in which the external leads 56 are formed is the first direction.
This is different from the semiconductor device with counterfeit prevention function shown in the figure. That is, in this embodiment, external leads 56 are formed on the side surface of the main substrate 10. Wiring to the external leads 56 on the lower side of the main board 10 is formed inside the main board 10.

According to this embodiment, a semiconductor device with an anti-counterfeiting function can be installed in a narrow installation space.

The present invention is not limited to the above-mentioned embodiments, and various modifications are possible.

For example, it is not necessary to form general wiring on the sub-board. Furthermore, in the case of a semiconductor device that does not include a RAM backed up by a battery, only general wiring may be formed in the sub-substrate. In that case, it is desirable to increase the amount of wiring on the sub-board compared to the amount of wiring on the main board. Further, the number of RAM or semiconductor elements may be one or more. Furthermore, there may be a plurality of backup batteries, and there may be a plurality of types of power supply voltages.

Alternatively, the main substrate may not have a concave portion, the semiconductor element may be mounted on a flat main substrate, the sub-substrate may be provided with a concave portion corresponding to the semiconductor element, and the sub-substrate may be placed over the main substrate.

Alternatively, a semiconductor element may be mounted on the lower side of the main board, and a sub-board may be attached to the main board from below to cover the semiconductor element.

Furthermore, the function preventing function according to the above-described embodiments may be achieved by completely inverting the semiconductor device upside down.

[Effects of the Invention] As described above, according to the present invention, if the sub-board covering the semiconductor element is removed or even a part of it is destroyed for decoding, the contents of the RAM or the circuit will be destroyed. imitation becomes impossible.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the main parts of a semiconductor device with anti-counterfeiting function according to an embodiment of the present invention, FIG. 2 is a perspective view showing the semiconductor device with anti-counterfeiting function before assembly, and FIG. FIG. 4 is a longitudinal cross-sectional view of the semiconductor device with anti-counterfeiting function; FIG. 4 is a cross-sectional view showing the final assembled state of the semiconductor device with anti-counterfeiting function;
6 is a plan view of a sub-substrate of a semiconductor device with anti-counterfeiting function according to another embodiment of the present invention, FIG. FIG. 7 is a perspective view showing a main part of a semiconductor device with anti-counterfeiting function according to another embodiment of the present invention. DESCRIPTION OF SYMBOLS 10... Main board, 12... Sub board, 14... Backup battery, 16... External lead, 18.20.
22... recess, 24.26.28... semiconductor element,
30.32.34.36...Contact, 38...Lead, 40.42.44...Power supply wiring, 46...Plastic member, 48...Mold resin, 50...Cover, 52 ...Power supply wiring, 54...General wiring, 56.
・External lead. Applicant's agent Sato - Yuuki 2 Figure P) 3 Gate card 4 Prisoner 5 Prisoner also 6- P) 7 z

Claims (1)

[Claims] 1. A backup battery, a volatile memory semiconductor element backed up by the backup battery, and a device on which the volatile memory semiconductor element is mounted and connected to a power supply wiring to the volatile memory semiconductor element. a first substrate on which a first connection portion is formed; a part of a power supply wiring from the backup battery to the volatile memory semiconductor element; and a second board connected to a part of the power supply wiring. a second substrate formed with a connecting portion, the second substrate covering the volatile memory semiconductor element on the first substrate, and the second connecting portion forming the first connecting portion. The imitation prevention function is characterized in that the volatile memory semiconductor element is assembled so as to be connected to the power supply wiring, the second connection part, and the first connection part and is backed up by the backup battery. Semiconductor equipment with. 2. a semiconductor element, a first substrate on which the semiconductor element is mounted, a first wiring part for the semiconductor element, and a first connection part connected to the first wiring part; a second wiring portion for the semiconductor element; and a second wiring portion connected to the second wiring portion.
a second substrate formed with a connecting portion, the second substrate covers a semiconductor element on the first substrate, and the second connecting portion is connected to the first connecting portion. The device is assembled so as to be connected, and the first wiring portion and the second wiring portion are coupled as wiring for the semiconductor element via the first connection portion and the second connection portion. A semiconductor device with anti-counterfeiting function.